만나서 반가워요 2008년 8월 21일 맹 완 영, 한국원자력연구원

자연세계는 무섭고도 아름답다 우리나라의 설경 하와이 칼리우에 화산폭발 무섭고도 아름다운 것에 대한 경외감 대둔산; 아름다움에 감탄하여 모두 웃통 벗고 사진 찍다 과학은 탐험이다. 미지의 것을 향해 떠나는 여행이고 모험이다….신기하고 새로운 것을 찾아 떠나는 여행이다. 하와이 칼리우에 화산폭발

자연세계는 무엇으로 되어있을까? 원자의 세계: 보이지 않는 것의 큰 세계 자연세계는 무엇으로 되어있을까? 원자의 세계: 보이지 않는 것의 큰 세계 책 소개돌턴과 함께하는 13일간의 신비로운 원자 세계 여행 세상은 무엇으로 이루어져 있을까? 물질 세계의 신비를 밝히는 원자의 모든 것이 13일 만에 해결된다. <돌턴이 들려주는 원자 이야기> 돌턴에서 시작된 원자 세상은 무엇으로 되어있을까? 정말 오래 전부터 많은 사림들이 가장 궁금하게 여기던 문제이다. ‘더 이상 쪼갤 수 없는 것’이라는 뜻으로 ‘atom’(원자)라는 말을 처음 생각해낸 것은 고대 그리스 철학자들이었지만, 충분한 과학적 근거를 찾지 못했기 때문에 널리 사용되지는 못했다. 18세기 말 영국의 존 돌턴은 원자의 개념을 이용하면 여러 가지 화학반응의 특성을 체계적으로 설명할 수 있다는 사실을 발견했다. 그 후 원자 개념은 화학, 물리학, 생명과학을 포함한 현대 과학의 가장 중요한 개념이 되었다. 물질 세계의 비밀이 많이 밝혀진 오늘날에는 물질이 원자로 이루어져 있다는 사실을 누구나 알고 있다. 그러나 막상 ‘원자란 무엇인가’는 물음에 대해 명확하게 답할 수 있는 사람은 그리 많지 않을 것이다. 이 책에서는 원자 세계의 발견 과정을 아주 쉽게, 그리고 친숙하게 느낄 수 있도록 이야기처럼 풀어내고 있다. 친절한 안내자와 함께 하는 원자 세계 여행 낯선 곳을 여행하려면 안내가 필요하다. 이 책을 읽으면 20여 년 동안 화학을 가르치고, 본격적으로 화학교육학을 전공한 저자와 함께 아름답고 신비로운 원자들의 나노 세계로 여행을 떠날 수 있다. 달콤한 사탕에서 출발해서, 전자들이 펼쳐내는 마술을 구경하고, 너무나도 게을러 빠져서 친구조차 사귀지 못하는 아르곤 역에 도착하면 여러분의 마음 속에 상상도 하지 못했던 멋진 새 세상이 자리잡고 있다는 사실을 깨닫게 될 것이다. 중학생에서 고등학생에 이르기까지 폭넓은 독자층 화학이 뭔가요? 꽤 많은 학생들이 던지는 질문이다. 이 질문에 ‘화학이란 물질 세계를 설명하는 학문’이라고 답한다면 좀 지루한 답변이 될 것이다. 이 책에서는 물질 세계를 만들어내는 원자, 그리고 원자의 신비한 성질들이 모두 원자핵과 전자에서 비롯된다는 것을 재미있는 이야기로 풀어내고 있다. 크기가 나노미터(10억분의 1미터) 정도로 작아서 우리 눈으로 직접 볼 수 없는 원자 세계. 블록을 이어 붙여 온갖 모양의 구조를 만들어내듯이, 여러 종류의 원자들이 화학결합으로 이어지면 수없이 많은 종류의 분자들이 만들어진다. 그런 결합은 원자를 구성하는 전자들에 의해서 이루어진다. 그래서 원자들의 결합으로 만들어지는 분자들의 온갖 성질도 원자핵과 전자의 성질과 깊은 관계가 있다. 분자에서 전자가 떨어져 나오면 ‘이온’이 만들어지고, 그런 전자들이 전깃줄을 따라 흘러가면 전등을 밝혀주거나, 컴퓨터를 움직이게 해주는 전기가 된다. 너무 작은 세상의 이야기이기 때문에 어렵다고 생각할 수도 있지만, ‘아는 만큼 보이고, 알면 사랑한다’는 말처럼 원자의 세상을 공부하고 나면 주변에 있는 모든 것들이 새로운 모습으로 보일 것이다. 알고 보면 NT(나노기술)과 BT(바이오기술)도 모두 원자 세계로부터 시작되니까 말이다. 흥미로운 원자 세계를 소개하는 이 책은 과학이나 화학을 배우는 중, 고생들의 학습에도 많은 도움이 될 것이다. 물질 세계에 관심이 많은 학생들을 위한 책 우리 눈에 보이는 세상은 110종류의 원자들로 이루어져 있다. 원자핵과 전자들로 구성된 원자는 그 크기가 너무 작아 우리가 쉽게 볼 수 없는 나노미터의 세상에 살고 있으며, 작고 작은 원자의 세계는 아름답고 신비스럽기까지 하다. 아무나 함부로 엿볼 수 없는 세상이라서 더욱 흥미로운 원자 세계! 이 세계의 아름다움을 즐기려면 끝없는 상상력과 튼튼한 과학 지식이 필요하지만, 그렇다고 천재들만 볼 수 있는 곳도 아니다. 원자 세계는 물질에 관심을 가지고 힘껏 노력하는 사람이라면 누구나 마음껏 즐길 수 있는 곳이며, 창의적인 사람이라면 다른 사람이 생각하지 못하는 새로운 아름다움을 만들어낼 수도 있는 곳이기도 하다.

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옛날 철학자들은 세계가 무엇으로 되어있는지 생각하고 또 생각했다 단맛도 짠맛도 파랑색도 노란색도 생각에 불과하고 실재는 원자다 A Greek philosopher, born at Abdera, in Thrace, Democritus was a pupil of Leucippus, whose system of philosophy he developed and promulgated. His name is associated with the first exposition of the atomic theory of matter, according to which all matter is composed of similar indivisible elementary particles called “atoms” (Greek for “un-cuttable”). This theory was a departure from the views of the earlier Ionian philosophers, who held that matter is composed of particles differing qualitatively from each other. Democritus lived to a very advanced age and was a prolific writer — the titles of more than fifty of his works have come down to us, ranging in subject matter from mathematics to physics, astronomy, navigation, geography, anatomy, physiology, psychology, psychotherapy, medicine, philosophy, music, and art. The later philosophers Epicurus and Lucretius were his disciples. It is said that, upon the death of his wealthy and influential father, Democritus inherited a hundred talents (perhaps worth over a million of today’s dollars), most of which he spent in travel. Unconfirmed stories send him as far as Egypt, Ethiopia, Babylonia, Persia, and India. “Among my contemporaries,” he said, “I have traveled over the largest portion of the Earth in search of things the most remote, and have seen the most climates and countries, and heard the largest number of thinkers.” At Thebes in Boeotia he sojourned long enough to drink in the Pythagorean atomism of Philolaus. Having spent his money he became a philosopher, lived simply, devoted himself to study and contemplation, and said, “I would rather discover a single geometric theorem than win the throne of Persia.” He was a modest man, for he shunned argument, founded no school, and sojourned in Athens without making himself known to any of the philosophers there (perhaps he felt that it was best for a philosopher not to draw too much attention to himself, in the wake of the trials of Anaxagoras and Socrates.) Thrasyllus called him the pentathlete of philosophy, and some of his contemporaries gave him the very name of Wisdom (sophia). His range of knowledge was as wide as Aristotle’s, and his style was as highly praised as Plato’s. Although Democritus may not have added greatly to the basic ideas which hatched in the mind of Leucippus, still he developed these fragmentary ideas into a systematic and comprehensive theory of the nature and order of things in which it was difficult even for the ancients to distinguish clearly between the work of Leucippus and that of his successor. Because Leucippus’ works have not come down to us and he is known to us almost entirely through the works of Democritus, and because even his historical existence has come into question, it seems best to regard the ideas of Leucippus and Democritus together under the philosophy of Democritus, the prolific savant who we know existed. The momentous atomistic theory of Leucippus and Democritus was conceived in order to surmount a conceptual impasse which had threatened to strangle Natural Philosophy (Science) while it was still in its infancy. This impasse was created when Parmenides, the father of Metaphysical Philosophy, argued quite persuasively that, by its very definition, non-existence (or nothingness) cannot exist; and since space is nothing, space cannot exist either; and if space does not exist, then “all is one,” since the existence of multiple separate things requires the existence of a space or gap between them; and if space does not exist then motion cannot exist either, for an object cannot move unless it has an unoccupied space to move into, but such a space cannot exist; our senses assure us that motion and multiplicity do exist in the world, but our senses are fallible and untrustworthy, so if experience derived from sense perceptions comes into conflict with Reason, the testimony of the senses must be discounted, for the violation of logic itself is a far more serious matter. The effect of this line of reasoning was to invalidate the very basis of Natural Philosophy (Science), for, why should anyone bother with observing Nature or dissecting animals in the effort to understand their workings if such observations were untrustworthy, or even illusory? To Parmenides, the only way to discover Truth was by Reason alone, with one’s eyes and ears closed to the world. For a while the scientific progress of the world halted as the greatest philosophers wrestled with this formidable problem. None were able to resolve this problem and remove this obstacle until Democritus developed and unleashed upon the world the atomistic theory of Leucippus. Leucippus met Parmenides’ line of reasoning by denying the premise upon which the arguments against motion and plurality rests, namely, the premise that being is identical with fullness. As Leucippus pointed out, this assertion contains an ambiguity. If it means that there is no part of what is that is not, then it is clearly true, for to deny this assertion would be self-contradictory. But if it is taken to mean that there is no part of what is that is empty, then the truth of this assertion is no longer so obvious. After all, there is no contradiction in asserting that some part of what is is empty. There would be a contradiction in asserting this only if we identified body or mass with being; and it is evident that this is precisely what Parmenides had done. By showing that Parmenides’ premise was flawed by ambiguity, and his conclusion therefore did not necessarily follow, Leucippus broke the strangle-hold of Parmenidean logic and took the wind out of the sails of the metaphysical Eleatics, and Democritus jumped in and went to work weaving his own sails with which Natural Philosophy might embark upon the future, to one day become modern science. Leucippus had already put a considerable dent in Parmenides’ argument by drawing a distinction between “being” and “having body” — for, “to exist” does not mean the same thing as “to take up space.” Now Leucippus and Democritus further defused Parmenides’ line of reasoning, by suggesting that all matter exists in the form of indivisible atoms. Zeno of Elea had bolstered Parmenides’ argument by claiming that if space existed, then matter would in principle be divisible, and divisible again and again, into an infinite number of ever-smaller particles, each having some size. But if there are an infinite number of particles, each having some size, this means that every material object must be infinitely large, which is absurd. By Democritus’ introduction of the concept of atoms, Zeno’s reductio ad absurdum was neutralized: “Those who assert the existence of atoms say that the cutting [of any material object] does not proceed without limit, but stops at bodies having no parts.” Aetius According to the atomic theory of Democritus, space does have real existence — it is what separates the one into the many, and what allows motion to occur — and matter exists in the form of eternal, invisibly small, indivisible particles called atoms (meaning “un-cuttables”). In a return to Pythagoreanism (in which the space between pebbles was as important as the pebbles themselves in determining their number) Democritus declared that everything in existence was made up of atoms and the void, with the void (or empty space) being every bit as real as the atoms themselves. These atoms were taken to be indestructible, incompressible, and homogeneous, differing from one another not in substance, but in shape and size — with these elementary particles (made of the same stuff) producing substances of different qualities when they conglomerate together in different numbers and arrangements. In other words, the constituent atoms of a substance differed quantitatively, not qualitatively — bone was not made of “bone atoms” and stone of “stone atoms,” but the elementary particles making up these disparate substances were the same in kind, differing only in number and arrangement. The differing qualities which we distinguish in things are thus produced by the movement or rearrangement of these atoms. The atoms themselves exist forever. Only compounds of these atoms “come into being” and “pass away,” and these are formed and dissolved by the coming together and the separation of atoms in the void. Just as atoms are eternal and uncaused, so also is motion, which, of necessity, derives its impetus from a preceding motion, so that motion, too, is perpetual in the cosmos. As everything is made up of these unchangeable and eternal atoms in perpetual motion, it follows that coming into being and passing away are only apparent, a mere rearrangement of atoms. A human being, for instance, is but a temporary aggregation of atoms that will soon separate once more to enter into the substance of other beings or things. And yet, in an infinitude of time, perhaps the atoms may come together in just the same way again, and we may be re-formed anew, and in this way history may repeat itself endlessly. Although some of these profound ruminations may seem strikingly modern, it should be kept in mind that the atoms of Democritus were not the product of experimental investigation, but were purely theoretical constructs, devised in order to surmount the obstacle to Natural Philosophy (Science) — and to common sense — offered by Parmenides’ metaphysical arguments against motion and plurality, and Zeno’s paradoxical fortifications of them. According to Democritus, all of the senses are ultimately forms of touch, and these senses give us only opinion; clear and genuine knowledge comes only by investigation and thought. “We know nothing for certain,” he said, “but only the changes produced in our body by the forces that impinge on it.” In Democritus’ view, there was no nous, or cosmic intelligence, to guide the atoms, no Empedoclean forces of attraction or repulsion to govern their interactions, rather, necessity rules over them — that is to say, the atoms simply behave according to their inherent nature. Democritus also maintained that there is no such thing as chance — chance is a mere fiction to disguise our ignorance. In Democritus’ cosmos, the quantity of matter always remains the same; none is ever created, none is ever destroyed; only the combinations and permutations of atoms change. Forms, however, are innumerable, and even of worlds there is probably an infinite number, coming into being and passing away in an endless pageant. According to Theophrastus, Democritus was able to use his atomic theory in order to account for the various characteristics of different types of matter. In dense substances, like lead, there was said to be little void between the atoms, whereas in light substances, such as pumice, there was much more space between its atoms. Hardness he ascribed to the orderliness of the arrangement of the atoms, so that iron, which is less dense than lead, is nevertheless harder because its atoms are arranged in a more orderly fashion, even though it has more space between the atoms than does the denser metal. To account for more subjective characteristics, such as sweetness or sourness, Democritus rather fancifully attributed these characteristics to the shapes and sizes of the atoms in the substances exhibiting those qualities. Sweet substances, for example, he claimed consist of atoms that are “round and of a good size,” while that which is sour consists of atoms that are “bulky, jagged, and many-angled, without curves.” It is not clear how Democritus arrived at these descriptions of things that no one had ever seen. Atomism was an a priori theory, not an empirical one. To the modern reader, the assumptions that Democritus made regarding the size and shape of (invisible) atoms which produce different tastes may sound goofy. One must always bear in mind, though, that no man has ever been right about everything, and the fact that none of us is infallible in no way invalidates those few rare and precious truths that we may chance to find. It is up to future generations to question all claims, to test them, and to decide for themselves what is truth and what is nonsense. This mode of skeptical free-thinking is the only way that the mind of man is able to advance. Before dismissing Democritus’ views on the atomic causes of qualities such as sweetness it would be well to remember, though, that the core theory of the atomists still persists today in modern chemistry — albeit in modified form. Even today, chemical reactions, especially in the realm of biochemistry, are explained on the basis of the shape of a given molecule fitting together with the shape of other molecules that it can react with, or bond with. As for qualities like color, the atomists held that these are not qualities of the atoms themselves, but rather are synergistically produced by different combinations and arrangements of atoms, in much the way that the same alphabetical letters can be arranged in one way to produce a tragedy, and in another way to produce a comedy — the letters, or even the words, are the same in these types of plays; it is their arrangement which gives them the power to move us in different ways, a power which, if the words or letters are taken separately, they lack. The atomists were careful to distinguish between the real properties of material bodies and the properties which only appear to belong to them: “Sweet exists by convention, bitter by convention, color by convention; but in reality atoms and the void alone exist.” — Democritus, as cited by Sextus Empiricus This 25-centuries-old view is strikingly modern. In order to bring this statement up to date, it would only be necessary to rephrase it as follows: “In reality primary particles and the void (i.e., space) alone exist; energy is the interaction of primary particles, and energy has time built into it.” It is in this way that matter, energy, space, and time appear to be interrelated. It would be difficult to overestimate the importance of the atomic theory of Leucippus and Democritus for the history of human thought, and this theory’s epistemological consequences were great, as well: It is, after all, sense perception which tells us that the world is full of odors, sounds, and colors. If, as atomic theory suggests, these are not real, but exist only subjectively, then sense perception clearly does not give us knowledge of what is. It is in this sense that man is “cut off from the real.” But it is only with regard to sensation that “it is impossible to know what each thing is;” through Reason the real can be known. In this view, the truth which is revealed through Reason has a greater reality than the appearances revealed through the senses. A classic clash between the theoretical “realities” of geometry and what common sense tells us about real objects occurred when Protagoras, the sophist, took issue with a fundamental assertion of geometry: “... [Protagoras] used to maintain, in his refutation of the geometers, that a hoop touches a straight edge not at one point [but at more than one].” — Aristotle, Metaphysics In other words, Protagoras concluded that the geometers were mistaken in thinking that a circle can touch a straight line at only one point. Protagoras was speaking of hoops and straight-edges, though, not of circles and lines, and of these it is perfectly true to say that they cannot touch at one point, for, in order to exist in our world of three spatial dimensions, a hoop must have thickness, and its area of contact with a flat surface is then a line-segment as long as this thickness, and not a point. But the geometer is not talking about 3-dimensional hoops and straight-edges. He is talking about 2-dimensional circles and straight lines (which, like all 2-dimensional figures, can have no material existence in our 3-dimensional world, for if a material object were to have no thickness it could not exist as a physical object) and these 2-dimensional figures can (at least in theory) touch at one point. Two-dimensional figures such as circles and lines can be perceived only in the mind, and they can touch at only one point, albeit this tangency is only a theoretical one, for it is as invisible as are the circle and line themselves. Of course, this does not mean that the senses have no place whatever in the acquisition of knowledge. Democritus suggested that the senses might reply to the Reason in the following way: “Wretched mind, would you overthrow us, from whom you have received your evidence? Our overthrow would be the end of you!” — Democritus, as cited by Galen From this statement we may conclude that sense perception gives us evidence to apply Reason to, but it takes us just so far; where it fails, (because of the smallness of atoms, which renders them invisible) only Reason can penetrate. For Democritus, this means that Reason alone can reach the truth, for the atoms and the void are the truth. This is a major concession to Parmenides. It represents the rationalism which has entered into the framework of modern science, but even more than this, Democritus’ philosophy addresses the epistemological problem of the Relativity of Truth as revealed by sense perception: “They say that to many living creatures the same things appear opposite to the way in which they appear to us, and that even to the same person the same thing will not always appear the same. Which of these appearances is true and which is false is not obvious, for neither is more true than the other, but both are alike. Hence, Democritus at least, says that nothing is true — or that truth is not evident to us at any rate.” Democritus’ idea of the Relativity of Truth is the very cornerstone of the humanistic philosophy of humility and tolerance, for it is only those who arrogantly claim to have a monopoly on Truth that become murderously intolerant of those not sharing their views. Ortwin Luposchainsky of Germany (by way of Transylvania) offers perhaps the clearest illustration of the Relativity of Truth: Two men look at the same house from two different vantage points. Question: Which one sees the “truth”? Answer: Both views are equally valid. Each is “true” from that particular point of view. All truth is like that — we can see only that part of it which presents itself to our particular vantage point, and the other points of view will provide differing, though equally valid glimpses of the Truth. To get the best possible picture of the truth, it is necessary to take into consideration the views from all of the possible vantage points, and then use the power Reason to synthesize these disparate views into one coherent, all-inclusive mental image. This is in essence what we do all the time with regard to visual perception. Each of our retinas offer us only a two-dimensional image of what we see, but by factoring the two slightly-different viewpoints of the two eyes together, our brains are able to inferentially perceive depth. Similarly, if we want to assess the design of a house that we are thinking of buying, we don’t look at it from only the back yard, and then stubbornly refuse to look at it from any other vantage point; rather, we look at it from every possible perspective — even from inside it — and only in this way are we able to use our limited senses (such as our two-dimensional vision) in order to develop a more comprehensive (three-dimensional) mental image of what the house is really like. Why can we not learn to use this same approach — that of carefully considering all points of view before rushing to judgment — in all of our thinking? Luposchainsky’s Illustration of the Relativity of Truth is rather more subtle, and rather grander, than Democritus’ own illustration of this principle, but perhaps this is simply because men have had twenty-five centuries to build on the ancient sage’s ideas. Be that as it may, Democritus’ own illustration of the Relativity of Truth involves something that Democritus was personally very fond of: the taste of honey. He proposes, as a thought experiment, that a sick man and a healthy man be given honey to taste. What are we to conclude if to the sick man the honey tastes bitter, and to the healthy man it tastes sweet? In this case we are faced with two alternatives: either the honey is both sweet and bitter, or it is neither sweet nor bitter. But the first of these alternatives is ruled out for us by the Law of Contradiction, for it is logically impossible that the same thing should be both sweet and not sweet at one and the same time. Democritus therefore assumed that the second alternative must then be true: “From the fact that honey appears bitter to some and sweet to others Democritus concluded that it was neither sweet nor bitter in itself, whereas Heraclitus said it was both.” — Sextus Empiricus It appears that the Law of Contradiction held no terrors for Heraclitus; but it is the pivot upon which the argument of Democritus turns. Sweetness and bitterness exist only for the perceiver; in reality there are only atoms and the void. The senses offer only subjective perceptions, which often contradict each other; the Truth can only be perceived by the mind after a careful consideration of all of the conflicting subjective perceptions. Democritus subscribed to the cosmological vortex theory of his predecessors and held that the world-order arose as the result of the centrifugal sorting-effects of the cosmic whirlpool. The proposition that the cosmos was a whirlpool seemed indisputable to the ancients, for anyone that looked into the heavens could not deny that the sun, moon, stars, and planets all whirled about at different rates, each in an apparently circular motion. Leucippus and Democritus only put a slightly different spin on this vortex theory, by proclaiming that it is the primary bodies known as atoms which move perpetually in the infinite void. Aristotle later questioned why the atoms should move in this way, but this question, had it occurred to Leucippus at all, would probably have been answered with a shrug and a statement to the effect that it is in the nature of atoms to move in this way. Anaxagoras had answered this question by asserting that the nous, or cosmic intelligence, had caused and continued to control the rotation, but Democritus would have none of this. To Democritus, such an explanation was as unacceptable as saying that the world turns because somewhere there is a god turning a crank. To Democritus such an anthropomorphic explanation was not only childish, but unnecessary, for the operation of the cosmos was explainable by the action of purely mechanical forces: “There are some who explain this heaven and all the world-orders by chance; for the vortex and the motion that separated and ordered the whole in its present arrangement arises by chance.” — Aristotle, Physics (referring here to Democritus) From this passage it is evident that, according to Democritus, the atoms move at random in the void, their movements interacting in an infinite number of possible ways, until at last, in the course of infinite time, they fall by chance into a vortex motion. In this clever application of the theory of natural selection to the field of mechanics, (instead of to biology) all possible modes of motion come to be, at random, until a stable mode — such as vortex motion — is hit upon by accident, after which this self-perpetuating mode persists on its own! All that is required is enough time, and Democritus meets this requirement by making time infinite: “Democritus is so convinced that time is everlasting, that when he wants to prove that not everything has come into being he employs as self-evident that time has not [finished coming] into being.” — Simplicius, Physics According to Democritus, then, the atoms must sooner or later fall into a vortex motion. The process is not guided, though, by a god or a “cosmic intelligence,” but is the result of the same process as that by which a chimpanzee locked in a room with a typewriter for a sufficient length of time would eventually produce a duplicate of the Bible simply by pounding the keys at random. The odds of this happening are quite small — so small, in fact, that it would be unlikely to happen in the life-time of a single chimp — but in an eternity (and given an infinite number of simian typists) there is enough time to make this unlikelihood certain to occur, sooner or later. Democritus’ follower, Lucretius, puts it very clearly: “Certainly the atoms did not arrange themselves in order by design or intelligence, nor did they propound what movements each should make. But rather myriad atoms, swept along through infinite time or myriad paths by blows and their own weight, have come together in every possible way and tried every combination that they could possibly create. So it happens that, after roaming the world for aeons of time in making trial of every combination and movement, at length they come together — those atoms whose sudden coincidence often becomes the origin of mighty things: of earth and sea and sky and the species of living things.” — Lucretius, De Rerum Natura In other words, the Universe does not require for its creation and operation the existence of a man-like being who makes it all happen. Democritus’ subtle variation of the theory of natural selection makes it seem entirely reasonable that order can emerge out of chaos by itself, as the result of random interactions of matter operating under the laws of Nature. Once the cosmos has fallen, by chance, into a vortical motion, the rotation perpetuates itself, other atoms are drawn into it, and that sorting-process begins which leads eventually to the formation of a world-order. Leucippus maintained that the atoms separate “like to like;” “the light bodies go off into the outer void like chaff.” Democritus, too, compared the action of the vortex to that of a sieve: “For living things consort with their own kind: doves with doves, cranes with cranes, and similarly with other irrational creatures. So it is with inanimate things also, as one can observe in the sifting of seeds and in pebbles on the beach. For in the one case, by the rotation of the sieve beans are arranged separately with beans, barley with barley, and wheat with wheat; in the other, by the motion of the waves the oval pebbles are driven to the same place as the oval , and the round to the round — as if the similarity among them exercised some kind of attractive force.” — Democritus, cited by Sextus Empiricus This passage offers an insightful ancient explanation of why, for instance, gold has the fortunate tendency to congregate in veins, and is not evenly distributed throughout the earth. Democritus believed that the force of attraction between “likes” is simply the result of the fact that random forces act upon similar things in similar ways; this tends to make similar things wind up in the same place, or wind up in similar circumstances, thus bringing “likes” together by random chance. As a young girl, my sister arrived at this same principle without having ever heard of the ancient sage who thought of it first: whenever I lost a marble, she would ask me for its “sibling;” she would then toss this second marble into the air, telling it to find the lost one, and would watch where it would roll. In my youth it seemed like magic when the trick worked, but today it seems only natural to me that both marbles would tend to roll to the same place (i.e., the lowest place), and in this way random forces act upon similar things in similar ways, just as Democritus claimed. We have devoted so much attention here to the vortex because its importance for early Greek thought was very great. Its usefulness lay originally in its explanatory power. From the very beginning it provided an explanation of the large-scale features of the physical world as it appeared to the Ionians. It even proved capable of explaining small-scale phenomena (including dizziness) as well. But the vortex came to serve an even more important function for the philosophers of the Ionian tradition. It symbolized for them the operation of impersonal Natural Law: “All things come into being by necessity, the cause of the coming into being of all things being the vortex, which Democritus calls ‘necessity’.” — Diogenes Laertius And what Democritus means by “necessity” is quite clear: “He means by it the resistance, motion, and impact of matter.” — Aetius The vortex, therefore, exemplifies the working of the laws of motion and impact in the world-order. To these Natural Laws, there are no exceptions. Although we have repeatedly referred, here, to the action of random forces at work in the cosmos, Democritus did not believe that anything ever really occurs at random, “but everything occurs for a reason and by necessity.” In his view, when we ascribe an occurrence to chance we signify not that it has no cause, but that we do not know what the cause is: “Some people question whether chance really exists. For nothing, they say, happens by chance, but there is a definite cause, other than chance, for everything which we say happens ‘spontaneously’.” — Aristotle, Physics Democritus’ employment of randomness in his cosmological model, followed by his rejection of the notion that randomness exists in the world may at first sight seem contradictory, but this contradiction is resolved when we recall that randomness is regarded by him as only apparent. Every event really follows deterministically from the inexorable Natural Laws of motion and impact, and there is no exception to these laws. But there are so many atoms colliding with each other that we cannot possibly know the exact details of all their histories and trajectories, and so the outcomes of their innumerable interactions are unpredictable to us (even though we know the laws that govern their fates) and in the end their interactions seem random to us only because of our ignorance of the innumerable details which would make it possible for us to precisely predict the outcome. These insights into the question of randomness seem profound, almost modern, but Democritus does not stop there. He goes on to assert that there is not just one world-order, but that they are infinite in number. Whether Democritus meant by this that there is more than one star-system in the Universe is not known, but in any event, vortex theory would have been given a considerable boost if the ancient Greeks would have been able to see that the cosmos is in fact filled with galaxies — including our own — which spin eternally in the void, like vortices or hurricanes. The earlier Ionians, too, had spoken of a plurality of world-orders; but they had thought of them, apparently, as succeeding one another in time. The atomists enlarged upon this idea, and though we do not know what prompted them to do so, the reasoning may be guessed at from an argument attributed to Democritus’ pupil, Metrodorus of Chios: “Metrodorus says that it would be as absurd to suppose that there was only one world-order in the infinite as it would be to suppose that a single cornstalk would grow in a vast plain.” In other words, if the whole is infinite in extent, and the atoms are everywhere in motion in it, there is no reason to expect that the chance combinations which lead to the formation of the vortex should not be repeated over and over again. On the other hand, there is no reason to assume that the process of world-formation will follow exactly the same course in every instance. Anaxagoras had maintained that in any world-order there would be men like ourselves, living in cities like our own and practicing the same arts. Democritus evidently thought this picture overdrawn. He agreed that the general structure of each world-order will be the same, as each would be made of the same atoms obeying natural laws which are always and everywhere the same, but the details in any given world-order are strictly a matter of chance. For example, the presence of men in any given world-order is not necessary. Man has no special claim to being. His existence is contingent upon the blind operation of mechanical forces, and the Universe is as indifferent to his birth as to his death. Indeed, in Democritus’ view, the world-order (i.e., the cosmos) itself has no greater claim to being: “As the world-order has its coming into being, so also it has its waxing, its waning, and its destruction ...” In this rather bleak and fearful vision of the fate of all that exists, Democritus assures us that at a certain moment the atoms, released from the hold of the vortex, must return into the disorderly motion which belongs to them by nature, and the world-order must perish, swallowed up in the eternal night of the infinite as though it had never been. This gloomy cosmology caused pious men of later times to shudder, and to cross themselves, but when all things are considered, the vortex was of incalculable importance in the history of human thought, for it was the very symbol of the action of impersonal Natural Law in the cosmos. It was the guarantor of the natural order, playing in the “new age” of Greek thought the rôle formerly played by fate and the gods. Democritus’ thoughts on the rise of civilization were that the lives of the first men were solitary, poor, brutish, and short, for they were the prey of animals swifter and stronger than themselves. It was the fear of these that eventually brought men together. Once having banded together, success taught them the value of cooperation. The need for cooperation between human beings was also the cause of language: at first men made sounds at random; but as they came to realize the usefulness of such sounds in communicating with one another, the meanings of words came to be fixed by agreement in each locality, and in this way the diversity of languages to be found among different peoples of the earth arose. Even after the development of language, men led a nomadic existence, wandering from place to place, living off the land, and were at the mercy of cold and famine. Only gradually did they learn to seek refuge in caves in winter, and then to construct their own shelters. Eventually they learned to use fire and to supplement their slender resources with means of their own contrivance. They learned, for example, that they were less likely to starve if they stayed in one place, planting, tending, and harvesting crops, and storing food for times of famine, instead of relying on luck to find food every day while on the move. This great invention called “agriculture” was the very basis of civilization. The domestication of animals, too, was a great boon, for it enabled man to exploit other life-forms for his own benefit. The mule, for example, was bred by men to plow the land: “For the mule is not a product of nature, but this craftily invented device is a figment of man’s thought — a daring deed of adultery, as it were. It seems to me, Democritus says, that an ass forcibly impregnated a mare by chance, and when men found out about the offspring of this rape they made a practice of breeding such offspring.” — Aelian Democritus felt that animals existed not only to be exploited by man, though, but they were also among man’s greatest teachers: “In the most important things we are the pupils of the animals: of the spiders in spinning and mending, of the swallows in building houses, of the swan and the nightingale in singing, through imitation.” — Democritus, cited by Plutarch In Democritus’ view, man must rely upon what is given to him by Nature, and in the intelligence with which Nature has endowed him, he possesses an instrument which enables him to impose upon his environment an order of his own making. The order which he creates does not infringe upon the order of Nature, though — it supplements it, for man is himself part of Nature, and his capacity to create order is but a manifestation of hers. At the same time, the exercise of this capacity brings about changes in man himself, for as he learns, his capacity for thought increases: “Nature and teaching are very similar; for teaching transforms a man, and in transforming him makes his nature.” — Democritus, cited by Clement Democritus held that this transformation is not figurative but literal. Each discovery that man makes changes his mode of life; but every change in his mode of life brings about a corresponding change in the configuration of the atoms of which he is constructed. A continuously moving hunter/gatherer would, for instance, be more likely to be slender and swift than would a sedentary field-plowing farmer. Such changes also affect the way men see things, as well as the way that they think about the things they see. Thus, through the use of his capacity to impose order upon his environment, man in effect makes himself. The gap between man and the other animals, at first nonexistent, widens with every discovery he makes. The ascent of man is a slow one, though. It takes place little by little. For a long time men were wholly preoccupied with the problem of survival. The securing of the necessities of life — food, shelter, protection against wild beasts — left him no time for the pursuit of leisure. Only when these basic wants were satisfied did music — the first of the arts — come into existence, issuing from abundance. Abundance brought with it something else, too: a new conception of human existence. This new view of life placed the goal of human existence not in mere subsistence, but in the achievement of something to which survival is only a means: human happiness. Democritus’ views on happiness and on “the good life” are perhaps the most edifying part of his philosophy to the modern reader. A long lifetime of contemplation led him to conclude that the wise man will cultivate thought, will free himself from passion, superstition, and fear, and will seek in contemplation and understanding the modest happiness available to human life: “It is best for man to spend his life with as much equanimity and as little distress as possible. This would happen if a man did not base his pleasures on mortal things.” — Democritus, cited by Strobaeus Happiness does not come from external goods either, the formerly-rich philosopher assures us, rather, a man “must become accustomed to finding within himself the sources of his enjoyment.” “Culture is better than riches ...” he added, “No power and no treasure can outweigh the extension of our knowledge.” And why is happiness not to be found in material possessions? Democritus gives the following answer: “The desire for material possessions, if it is not limited by repletion, is far more unpleasant than extreme poverty. For the greater the desires, the greater the needs they create.” Or, as Socrates put it, “He who is not contented with what he has, would not be contented with what he would like to have.” This is axiomatic because if a man is not generally contented with what he has, then this will still be the case once what he wants has become what he has. “The needy animal knows how much it needs;” said Democritus, “but the needy man does not.” Man does not know when to stop but always wants more, and so makes contentment unreachable. To make matters worse, surfeit actually injures our ability to enjoy: “If one oversteps due measure, the most pleasant things become the most unpleasant.” On the other hand: “Moderation increases enjoyment, and makes pleasure greater.” The injunction to observe moderation in all things is a familiar one. Inscribed at the temple of Apollo at Delphi, it is the very “prime directive” of the ancient Greeks, rooted in the traditional view of man’s relation to the gods. To “lust after more” is to forget one’s mortality, and to bring down upon oneself the wrath of the gods. Democritus enjoins moderation and the avoidance of excess for quite a different reason. It is not from fear of the gods that the wise man chooses moderation, but from fear of pain. In order to choose one’s course of action wisely it is necessary to consider the pleasureableness or painfulness of the consequences: “The landmark of what is beneficial and what is not beneficial is pleasure or displeasure.” A course of action is beneficial, then, it if produces pleasure. This principle lies at the foundation of the philosophy of hedonism, but Democritus suggests that not every pleasure is beneficial: “Accept no pleasure unless it be beneficial to you.” — Democritus On the one hand, Democritus has told us that the surest way to recognize whether a course of action is beneficial or not is by whether it results in pleasure or pain. On the other hand he has suggested that not every pleasure is beneficial. On first sight, these assertions may seem contradictory, but the inconsistency is resolved when we recall that, for Democritus, happiness lies in the maintenance of a certain condition of the soul — namely, equanimity. Whatever leads to the maintenance of this condition is beneficial. Pleasure is a sign to us that this condition exists in the soul. On the other hand, some actions which we suppose to be pleasurable may in fact not be ultimately so, for they may not promote that condition of the soul which we experience as pleasure. To maximize one’s pleasure in life, and to minimize one’s suffering (which is the goal of hedonism), it is necessary to strive always for that stable condition of the soul which is the source of happiness. The wise man, then, will choose his pleasures with care; for equanimity comes to men through moderation in life: “Therefore one ought to pay attention to those things which are attainable, and be satisfied with what one has, paying little heed to objects of envy and wonder, and not letting one’s thoughts dwell on them. One should consider rather the lives of those who suffer hardship, being mindful of what they suffer, in order that what one has may seem great and enviable, and the soul may not suffer some misfortune through over-covetousness.” The best way to be contented with what one has, then, is by considering those who have much less. There is always someone who has it much worse in life, so you ought to be compassionate and be glad that you have it as good as you do. But what of equanimity? Just what is this source of the imperturbable mental balance which Democritus equates with happiness? The ancient sage put it this way: “Equanimity comes to men through proportionate pleasure and moderation in life. Excesses and defects are apt to change and cause great disturbances in the soul. Those souls which are moved over great distances have neither stability nor equanimity.” To be happy, then, is to possess a soul unshaken by passion; for all violent emotions throw the soul into as state of turmoil in which equanimity is shattered. The origins of this conception lie in Greek medicine, for according to Hippocrates himself, health depends upon a balance of contending forces; and “... pleasures, joys, laughter and amusements, as well as pains, griefs, anxieties and tears arise from the brain and from nowhere else ... It is by means of the brain that we think, see, hear, and tell the difference between what is ugly and what is beautiful, what is evil and what is good, and what is pleasant and what is unpleasant.” Imperturbable mental equipoise was thus the key to happiness. Just as distress in a household results from conflict between its members, so distress in a man results from the same kind of conflict in himself. Such distress can only be treated by philosophical contemplation, which deals with the soul as medicine deals with the body: “Medicine cures diseases of the body; wisdom, on the other hand, relieves the soul of its sufferings.” Democritus goes on to assure us that happiness which has its source in external things is but transitory, and “sensual pleasure affords only a brief satisfaction.” One finds a more lasting contentment by acquiring peace and serenity of soul (ataraxia), good cheer (euthumia), moderation (metriotes), and a certain order, symmetry, or balance of life (biou symmetria). This ancient variant of the philosophy of hedonism, is quite different from the modern idea of hedonism (whose slogan is, “If it feels good, do it!”) Indeed, Democritus viewed sexuality with all the philosophical detachment of an old man for whom the subject has become merely theoretical: “The brave man is he who overcomes not only his enemies but his pleasures. There are some men who are masters of cities but slaves to women.” Democritus, cited by Strobaeus “To be ruled by a woman is the ultimate disgrace for a man.” Men, it seems, were given peckers and testicles for women to control them with. This is how women have controlled their men from time immemorial. Democritus was quite right in pointing out that sexual passion disturbs the soul and makes equanimity impossible, and that men become the slaves of their passions and of the women who inflame those passions. But this is how Nature has decreed that things should be, for if men did not occasionally think with their Willies and surrender to passion, the human race would have died out long ago. And if women did not have such immense sexual power over men — the power to addict men to them — then men would be less likely to willingly enslave themselves to their women, and a man would be less likely to stick around to protect and support the woman when she is most in need of such protection and support (when she is pregnant, or raising an infant). Although passionate love and sex offer the greatest ecstasy that a human being can ever hope to experience, there is a heavy price to paid by both the man and the woman who are caught up in this enchantment. The euphoria of love and sex often brings in its wake the dysphoric discord of jealousy and possessiveness, as well as the loss of freedom for both the man and the woman, especially if children are the result of their union. Old philosophers who are unable to get sex anymore have always consoled themselves by telling the world how lucky they are, to have escaped from the enslaving madness engendered by the turbulent passions of love and sex, and Democritus was no exception to this. It is as in Aesop’s Fable of the Fox and the Grapes: The moral of the story is that it is consoling to despise what you cannot get. Democritus’ views on children suggest that he was never a parent, for there is a certain pragmatic coldness to them: “I do not think that one ought to have children. For I can see that in having children there are many great dangers on the one hand, and many griefs, while on the other hand the advantages are few, and these are slight and weak.” Indeed, Democritus suggests that the adoption of children is far preferable to the begetting of them. Again, the argument is entirely pragmatic: “A man who wants children would, I think, do better to get one from friends. The child will be of the sort he wants, for he can choose as he wishes. And the one that seems suitable will be most likely to realize his natural endowment. The great difference is that in this way it is possible to choose according to one’s mind from many, whereas, if one begets one’s own children, there are many dangers involved; for he must live with whomever he gets.” The assumption here is that there are many parents that will happily give away their children to whomever may ask for them. This assumption seems quite unreasonable today, but it should be recalled that, in the days before birth control, families often had a new member popping out every year or so, and children in those times were the slaves of the parents that owned them just as they are now — the difference was that in pre-Machine-Age times these slaves were put to use in plowing the fields, harvesting the crops, and performing chores around the house. Childbirth was thus the cheapest and most enjoyable way to acquire slaves — at least for the man. Democritus did not think highly of this practice of begetting litters of children for exploitation as a slave force: “Men think that they must have children because it is natural to do so, and because it is an institution of long standing. This is quite clear with the other animals, too; for all have offspring according to Nature, not because there is any profit in it. But once they are born they work hard and care for each of them as best they can, and fear for them while they are small; and if anything happens to them, they look after them. Such is the nature of everything that has a soul. But among men it has come to be felt that the parents should derive some benefit from their children.” Democritus was convinced that education has the power to transform a man, and to mold a child; that learning and reflection were the key to virtue and wisdom, and that virtue with wisdom were the key to happiness: “An imperturbable wisdom is worth everything.” “Neither skill nor wisdom is attainable unless one learns.” Democritus “More men become good by training than by nature.” “Men are not happy by virtue of their bodies or their possessions, but by virtue of right living and fullness of understanding.” Although the ancient Greeks were the inventors of body-building, as well as the originators of the concept of “a sound mind in a sound body,” and their tendency to equate beauty with goodness was legendary, Democritus apparently did not share this quintessentially Greek worship of the human body: “In cattle excellence is displayed in strength of body; but in man it lies in strength of character.” “Beauty of body is merely animal unless intelligence is present.” The morality of Democritus is essentially the old peasant morality of Hesiod, raised to a new level by its grounding in enlightened self-interest. Both the morality of Heraclitus and that of Democritus represent attempts to base a theory of the good life upon the nature of things, and so to provide it with an unshakable footing. In both, Reason plays the central rôle. For Heraclitus, Reason is embedded in the very nature of things; it is only reflected in man because man is himself part of Nature. But Democritus does not view Reason as being embedded in Nature; in his view, Reason is peculiar to man — a possession which at the same time sets him apart from Nature and enables him to use Nature for his own ends. Democritus equated equanimity with happiness, and it is only by arriving at an awareness of the nature of things, and acting in accordance with Nature, that happiness can be achieved. So long as a man bases his pleasures on “mortal things” equanimity is impossible: “Those who derive their pleasures from their bellies — overstepping due measure in eating or drinking or making love — find that they are brief and only last as long as they are eating and drinking, whereas the pains are many. They have a perpetual desire for the same things, and once men get what they desire the pleasure passes quickly, and there is nothing good in them but a brief enjoyment and then they want the same things again.” Now this is true whether the element of excess is present or not. The transience of such corporeal pleasures lies in their very nature. To base one’s life upon them is to build upon sand, for the pleasures of the body are but fleeting. The wise man, seeing this, will seek his happiness in the pleasures of the soul; and the purest, most unflagging of these pleasures of the soul are those of intellectual inquiry: “Reason accustoms itself to derive pleasure from itself.” Democritus, cited by Plutarch Kingdoms and empires perish, and the memory even of great deeds fades at last, but the laws of motion and impact remain, and to seek the truth about these things is to seek one’s pleasure not in mortal things, but in that which endures forever. The man who seeks his happiness in such things escapes the narrow confines of the here and now: “The whole world lies open to a wise man. For the native land of a good soul is the whole world-order.” We see in these sentiments a reflection of Pythagoreanism, and there are other similarities, as well, between the philosophies of Pythagoras and Democritus. For example, it is not difficult to see in the atoms of Democritus the mathematical units out of which the Pythagoreans attempted to construct the cosmos. And the body, regarded by Pythagoras as a “prison” for the soul, was considered by Democritus as a “tent,” a kind of temporary habitation for the soul, although he also likened the body to a tool which the soul uses for good or ill. In the Pythagorean view the soul was immortal though, transmigrating from one body to another at death, but here Democritus made a clean break from Pythagoreanism, for in the atomism of Democritus, the soul does not survive the body, and there is no life after death. Indeed, Democritus held the belief in a hereafter as one of the chief bugaboos which creates much anxiety and deprives men of happiness while they live: “Some men, not understanding the dissolution of mortal nature, but conscious of the sufferings of life, are troubled while they live by anxieties and fears, inventing false stories of a time after death.” But such a fear of the hereafter is absurd: “They are fools who hate life yet go on living through fear of the unknown.” Fears about what awaits us after death are groundless, for nothing awaits us after death, and the man who has grasped this ceases to be oppressed by such fears. As long as man lives with anxieties and fears, he cannot achieve that equanimity of soul in which happiness lies, and Reason alone is capable of exorcising these fears: “Cast out by Reason ungoverned grief from your benumbed soul!” The atomistic view of the nature of things teaches us that atoms and the void alone exist, that the body feels only as long as it is animated by the soul, and that the soul is utterly dissolved at death. To achieve this understanding is to be released from fears and anxieties, and to possess a soul untroubled by phantoms. As we have seen, Democritus’ view of happiness was “to spend one’s life with as much equanimity and as little distress as possible.” This is a suitable goal for the individual, but man is a social animal, an animal to whom it has become second nature to live with his own kind. Any theory of the good life which does not take cognizance of this fact would be unrealistic and incomplete. The framework within which men live together and pursue their happiness is provided by the city, and it is upon the well-being of the city that the well-being of all its inhabitants depends. It is in the city where men find their security, and when law and order breaks down in the city there is nowhere else to turn. There is nothing left but to revert to the anarchy in which the first men lived like animals. It was the consideration of these facts that caused Democritus to be concerned about the civil strife between the rich and the poor that increasingly threatened the security of the Greek city-states during the Fifth Century B.C.: “Civil strife is bad for both parties. For both the conquerors and the conquered alike the result is destruction.” “When the powerful have the courage to lend money to the have-nots, and assist them and do them favors, then compassion is present in their actions, and instead of being destitute they become their friends and help one another, and are in accord with their fellow citizens, and other good things happen which nobody could possibly catalogue.” Unless those in power are compassionate toward those who are less fortunate than they, the “have-nots” may support the revolutionary installment of a tyrant, hoping by this means to secure by force what the “haves” will not give willingly. This would be bad enough, but the collapse of the city would be worse still, for the alternative to it is savagery. Democritus felt that the city has the right to deal harshly with those who by their actions threaten the city’s security. To his mind, the city has a right to self-defense just as the individual has, and even execution was justifiable if it could be proven that this harsh measure was necessary to the survival and security of the city, or to civilization itself. He was, however, aware that the city’s right to kill directly contravenes the universal prohibition of the individual to take another’s life, so that, in effect, there is a double-standard in which it is perfectly acceptable for a group of people to do what it is forbidden for the individual to do. Harsh punitive measures could be avoided, though, if society were arranged so that it would never be necessary for anyone to break the law, and if men could be trained to reject the Law of the Jungle and embrace the Law of the Hive instead. Citizenship in a city requires a man to live, not as he sees fit, but in obedience to the laws: “The laws would not prevent each man from living according to his own inclination if men did not injure one another. For envy provides the starting point for civil strife.” The laws, then, are designed to provide an alternative to violence, as a means of resolving conflicts, and obedience of the law is necessary to happiness, for it is impossible for the covetous man to be happy. Even if a man succeeds temporarily in illegally taking what he desires, the possibility of being found out and punished by the magistrates hangs over his head like a sword: “The glory that results from justice is confidence of mind and imperturbability; but the fear that results from injustice is the starting-point of disaster.” “The equable man, who is prone to do what is just and lawful, rejoices by day and night and is strong and carefree; but the man who cares nothing for justice and does not do as he ought to do — to him all such things are displeasing ... and he lives in fear.” In other words, justice is a prerequisite to happiness, for the just man has nothing to fear, while the unjust man has everything to fear. Yet the fear of punishment alone is not sufficient to restrain the unjust man, for such a man is apt to discount the risk involved, in the hope that he will not be detected in wrong-doing. Some other way, then, must be found of dealing with such a man, and, in Democritus’ view, this other way was through the appeal to reason and to self-interest: “That man seems more effective in promoting virtue who employs exhortation and verbal persuasion than he who relies on Law and compulsion. For it is likely that a man who is prevented from injustice by law will do wrong secretly; but it is not likely that a man who is led by persuasion to do what he ought will do anything disastrous, either secretly or openly. Wherefore, one who acts rightly through intelligence and understanding becomes courageous and at the same time upright.” If a man can be brought to see that it is to his own advantage to obey the laws — since by doing so he preserves the city and thereby the conditions under which alone happiness can be sought — then he will obey the laws freely, of his own will. Such men alone are virtuous, for the good man fears not so much the condemnation of his fellow men as the judgment of his own conscience: “One ought not to respect other men more than oneself, nor to harm them more than oneself, whether no one will know about it or everyone will. But one ought especially to respect oneself, and to set this up as a law in one’s soul so as to do nothing which is unfitting,” To disobey this guiding principle of behavior is to invite a punishment more terrible than any that can be imposed by one’s fellow men. For it is always possible to regard the judgment of others unfair; but one’s judgment upon oneself is inescapable. For when a man does something wrong “this is bound to be on his conscience,” he will be ashamed of himself, and he will be more wretched than those he has wronged. Hypatia’s adoring pupil, Synesius of Cyrene made it clear why this is so when he wrote, “[It is] ... a greater evil to do injustice than to suffer injustice, for the one thing is one’s own, and the other another’s fault.” Earlier writers, too, stressed the importance of a sense of shame in preventing wrong-doing, but they meant by it that respect for the opinion of others which prevents a man from doing what will appear base in their eyes. Democritus felt that the shame which prevents wrong-doing was more properly the failure to warrant the respect that one owes to oneself. The sense of shame before others is less important than the sense of shame which a man feels at having done what he himself knows to be wrong, and he who has learned self-respect will possess the key to happiness. In this way Democritus appears to bridge the gap between the well-being of the individual and the well-being of the city. Far from finding that his happiness conflicts with the demands of justice (which requires him to live in accordance with the laws, contrary to his inclinations) he finds that happiness can only be found in the city. For the city equally restrains others from destroying him in the pursuit of their own well-being. There is, however, a certain ambiguity in Democritus’ system as regards conflicts of interest, and it is one of great significance for political theory. It concerns the nature of Law itself. To begin with, Democritus views all laws as man-made. Justice is not something which Zeus has given to men, as Hesiod teaches; it is something men have invented for themselves, and as such it is purely adventitious. When Democritus wishes to contrast those qualities of bodies which exist in nature with those qualities which exist subjectively, he does so by saying that the former are real whereas the latter exist only by convention. The distinction is clearly an individual one; it implies that Law is not grounded in the nature of things directly, but is made for a specific purpose, and it is therefore justified only insofar as it fulfills its purpose. The individual who obeys the law does so because he is persuaded that it is to his benefit to do so. He sees clearly that if he disobeys the laws and preys on others, then others will in turn prey upon him. The law that governs “fish, flesh, and fowl” (i.e., the Law of the Jungle) will then govern men, and the weak will be devoured by the stronger. How one looks at this situation, though, is affected by whether one is strong or weak. The strong might argue that it is only the weak who are benefited by the Law. For in protecting the weak the city deprives the strong of their natural prey; consequently, laws, far from benefiting the strong, hamper them at every turn. The strong man who realizes this has lost all reason for obeying the laws except fear of punishment, which, as we have seen, is inadequate. Indeed, such a man has a good reason for not obeying the laws, namely, the same reason which makes the weak obey them: self-interest. After all, every individual pursues what is advantageous to himself. Democritus acknowledged that in this regard the city is caught between two conflicting principles. On the one hand, there is the principle of self-interest, in accordance with which an enemy of the city (and all who break the laws are enemies of the city) must be punished, exiled, or put to death. On the other hand, there are sacred prohibitions against the taking of human life. Faced with this dilemma, what is the city to do? Democritus’ answer to this moral problem was that malefactors must be punished by those acting on the city’s behalf, for the city’s first duty is to itself. At the same time, the city must obey ancestral custom, not because this custom is ancient, but because the adherence to rules is the only way by which the city can preserve its own existence (although the rules themselves may vary form one place to another, and from one time to another.) Of course, the individual may at any time find himself to be confronted by the same dilemma. Self-interest may dictate a line of action directly contrary to what is permitted by law; and where this is the case it is difficult to see why, on Democritus’ principles, the bypassing of the law, if it could be done with impunity, could not be justified, although Democritus himself would have recoiled from this conclusion. Democritus contributed much to political theory and to the theory of Justice, but this was one of the problems which he was not able to resolve completely, though several of his contemporaries (namely, Protagoras, Antiphon, and Callicles) were willing to follow the argument wherever it led, without regard to consequences. Despite the fact that Democritus’ political theory and his theory of Justice were not brought to a state of perfection, his ethical philosophy — although founded not on the purported decrees of some judgmental god, but on rational materialism — was perhaps the loftiest ethic ever conceived by the mind of man, while it was simultaneously a down-to-earth expression of common sense: “Good actions should be done not out of compulsion but from conviction; not from hope of reward, but for their own sake ... A man should feel more shame in doing evil before himself than before all the world.” “It is only possible to produce great deeds ... through concord ...” “Good consists not in not doing wrong, but in not even wanting to do wrong.” “He who does wrong is more wretched than he who is wronged.” The last of these quotes contains the seed of what is perhaps the highest ethical principle ever devised by the mind of man. We see it taken to its logical conclusion in Jesus’ Sermon on the Mount, and in the maxims of Marcus Aurelius as well as the poetic aphorisms of Kahlil Gibran. The gist of the sentiment is just this: It is not within our power to stop all evil in the world — it is only within our power to resist evil by refusing to become evil ourselves. Violence and hatred cannot be combated by violent, hateful means because this only increases the amount of hatred and violence in the world, and almost invariably results in a feud-like self-perpetuating and escalating cycle of violence. “Love your enemies, do good to them which hate you .. and onto him that smiteth thee on one cheek offer also the other ... As ye would that men should do to you, do ye also to them likewise ... Judge not, and ye shall not be judged; condemn not and ye shall not be condemned; forgive, and ye shall be forgiven ...” These noble sentiments ascribed to Yeshua of Nazareth in the New Testament book of Luke (6:27-37) — and almost universally unheeded by Christians — have their basis in the realization that the cycle of violence, hatred, and misdeeds can only be broken if we refuse to return evil for evil — that it is far better to be the victim of evil, than it is to be another of its perpetrators, even if the evil we perpetrate is committed in retaliation for an evil that we have suffered. The precepts of Democritus’ hedonistic ethics seem to have served the so-called “laughing philosopher” well, for he seems to have achieved happiness through inner tranquillity, and his counsels were lent credibility by the fact that he lived to an extreme age. Although some say that he lived a mere 90 years, Hipparchus assures us that that he died at the age of 109. When asked the secret of his extreme longevity, he answered that he anointed his body with olive oil and ate honey daily. Finally, when he felt he had lived long enough, he reduced his food each day, determined to starve himself by easy degrees. It is said that he died without pain. His city gave him a great public funeral, and even history’s most famous misanthrope, Timon of Athens, praised him. Democritus founded no school, but he formulated for science its most famous hypothesis, and gave to the world a philosophy, a system which, though denounced by every other, has survived them all, reappearing in every generation. In the firmament of the guiding lights of history, Democritus was a star of the first magnitude. Leucippus (flourished around 475 B.C.) Leucippus was the Greek philosopher who was credited by Aristotle and by Theophrastus with having originated the theory of atomistic materialism (i.e., the philosophical precursor of atomic theory.) This important theory has, of course, had far-reaching influence in both ancient and modern times and today serves as the backbone of today’s science of chemistry, as well as constituting the foundation of philosophic materialism. Although we know very little about Leucippus, he is said to have been born in Miletus in Asia Minor, later moving to Elea to study under Zeno, and finally settling in Abdera, a flourishing Ionian colony in Thrace. Epicurus, however, denied his very existence and some modern scholars have reasserted this view. At any rate, if he existed at all, Leucippus was the pupil of Philolaus the Pythagorean, and the teacher of Democritus (a contemporary of Socrates,) and it is by his famous pupil (Democritus) that Leucippus’ ideas were developed, systematized, and promulgated. Leucippus’ theory appears to have been the result of an attempt to mediate between the monism of the Eleatics, which allowed neither plurality nor motion, and the qualitative pluralism of Empedocles and Anaxagoras. Leucippus held that matter was homogeneous, but existed ultimately in an infinity of small particles, which were indivisible. These particles he called atoms, meaning “uncuttables” or “indivisibles.” This atomistic theory arose in response to the arguments against the possibility of motion of the type advanced by Zeno of Elea. In the atomic theory of Leucippus and Democritus, motion was made possible by positing the existence of empty space which, Leucippus maintained, was every bit as real as material objects. In this ancient atomic theory, atoms were infinite in number and space was infinite in extent, and the differences between material objects were due to the number, arrangement and position of their constituent atoms, which were eternally in motion in all directions. This motion gave rise to collisions and entanglements and so to the formation of compound things. Within the compound things the atoms were in juxtaposition, and they continued even there to be in motion, albeit that motion was modified under those circumstances. According to Leucippus, a cosmos is formed by the collisions of atoms as they whirl together in the vortex, and in consequence similar atoms tend to get sorted together. Under this theory, our cosmos is not the only one, nor is it unique. The Universe, said Leucippus, contains atoms and space and nothing else. Atoms tumbling about in the cosmic vortex fall by necessity into the first forms of all things, like attaching itself to like, and in this way arose the planets and stars. According to Leucippus, all things, even the human soul, are composed of atoms. Leucippus’ greatest accomplishment was that he was the one that finally resolved the great monistic problem posed by Parmenides and perpetuated by the Eleatics, particularly by paradoxes of Zeno. According to Parmenides’ troublesome thesis of monism, (a term which derives from Xenophanes’ statement that “All is one”) empty space cannot exist, for this is nothing, and nothing cannot have any existence; and if there is no empty space, then there can be no movement, for a thing cannot move to where something else already is — a thing could only move into a place where nothing is, and there can be no such place, for nothing cannot exist or it would be something; moreover, if empty space cannot exist, then “All is one,” for the existence of separate objects (or separate entities) presupposes the existence of a space or gap between them, but again, such empty space cannot exist. If one accepts this line of reasoning, then one must conclude that neither motion nor plurality is real; and since the denial of these observable facts amounts to the denial of the world which is revealed to us through the testimony of the senses, sense perception is fatally undermined and Natural Philosophy (Science) becomes irrelevant, and metaphysical philosophy offers the only avenue in the search for truth. This Parmenidean conundrum had stumped the greatest philosophers and had thwarted the advance of Natural Philosophy (Science) until Leucippus came along and resolved it. Leucippus met Parmenides’ line of reasoning by denying the premise upon which the arguments against motion and plurality rests, namely, the premise that being is identical with fullness. As Leucippus pointed out, this assertion contains an ambiguity. If it means that there is no part of what is that is not, then it is clearly true, for to deny this assertion would be self-contradictory. But if it is taken to mean that there is no part of what is that is empty, then the truth of this assertion is no longer so obvious. After all, there is no contradiction in asserting that some part of what is is empty. There would be a contradiction in asserting this only if we identified body or mass with being; and it is evident that this is precisely what Parmenides had done. Again, the entire Eleatic school of philosophy is founded upon the premise that there is no such thing as nonexistence or void. To the Eleatics, this premise seemed self-evident, for to call it “void” or “nonexistence” is to admit that it does not exist. In other words, the Eleatics felt that the concept of nonexistence must be applied to itself: “Existence exists, but nonexistence does not exist.” This sounds like a tautology when phrased in this way, but if we rephrase the statement as “Existence is a possible state,” then it is not a logical inevitability that “Nonexistence is not a possible state.” When rephrased thus, the proposition that nonexistence is not a possible state now remains to be proven, but if we accept this as a self-evident fact, then all kinds of nonsensical conclusions follow quite logically — such as the conclusion that there can be no change or motion. This metaphysical philosophy is inimical to science and mathematics, for if all is one, eternal, and changeless, then natural science and mathematics are meaningless for they then merely describe illusory things which are based upon faulty sense perception. Although the arguments of the Eleatics could not easily be dismissed, it is fortunate for the history of science that Leucippus finally solved the Eleatic riddle, and Western civilization eventually came to embrace not the metaphysical world view of the Eleatics (which would have stymied inquiry and progress), but adopted instead the Natural Philosophy of the older Pythagorean world-view. This was Leucippus’ gift to mankind, and the profound and momentous philosophical advances of his pupil Democritus — advances which led ultimately to the modern age — were but further developments built upon the philosophical foundations which Leucippus had laid 데모크리투스 (460 ? - 362 ? B.C.)

달톤은 색맹이었지만 끈질긴 연구자였다 (1766-1844) - 물질을 쪼개고 쪼개면 더 이상 쪼갤 수 없는 입자가 되는데 이 것이 원자다. 쩐이 없어서 결혼도 못하고 혼자 살다가 78살에 죽음  12세에 학교의 교장, 그리고 켄달에서의 돌턴 돌턴은 컴벌랜드 주에 위치한 작은 마을 이글스필드에서 1766년 9월 6일 탄생하였다. 12세 때, 마을 초등학교의 교장이 되었다. 1781년 15세 때는 형 Jonathan과 함께 켄달(Kendal)이라는 곳으로 와서 퀘이커 교도의 학교를 경영하기도 했다. 맨체스트 뉴칼리지 대학에서의 강의1793년 돌턴은 자기 연구 수행에 많은 편의를 제공받았던 맨체스터의 New College로 옮겨 갔다. 1794년에는 1789년에 설립된 Manchester Literary and Philosophical Society에 회원으로 가입하고, 1800년에는 서기, 1808년에는 부회장직을 역임하고, 1817년에는 회장이 되어 1844년 그가 죽을 때까지 회장으로 활동하였다.  돌턴의 기상학 연구 돌턴은 기상을 전문적으로 연구하고 있었으나, 공기와 일반적 기체의 연구를 시작하고, 기체의 용해도에서부터 힌트를 얻어 원자설을 제안하고 뒤이어 배수비례의 법칙을 발견하게 된 것이다.  「영국학술협회」「에딘버그의 협회」에서 박사학위 수여 1832년에 옥스퍼드의 「영국학술협회」(The British Association for the Advancement of Science)로 부터 박사학위를 받았고, 1834년에는 에딘버그의 협회에서도 박사학위를 받아, 돌턴의 학식은 널리 인식되었다. 돌턴이 78세때 변함없이 그날의 기상 기록을 하려고 하였을 때 이상하게도 손이 떨리는 것을 자각한 돌턴은 곧 침실에 누었으나 다음날 인사불성에 빠지고, 의사의 치료도 아무 효과 없이 그대로 이 세상을 떠났다. 경제적 이유로 결혼하지 않았던 그는 78살에 가족도 없이 외로운 죽음을 맞이했던 것이다. Dalton, John /1766-1844 18세기 후반 라부아지에가 원소의 개념을 정립하고 산소이론을 발표하면서, 화학은 과거의 연금술과 결별했다. 그러나 여전히 화학적 현상을 일으키는 원소의 물리적 실체는 밝혀지지 않고 있었다. 1803년 돌턴이 원소는 "딱딱하고 단단하여 궤뚫을 수 없으며 움직일 수 있는 입자들"인 '원자'로 구성되어 있다고 주장하면서 화학의 역사는 새로운 국면으로 접어들었다. 비록 19세기와 20세기에 들어와 원자도 그보다 더 작은 입자로 이루어져 있을 뿐 아니라 깨어질 수도 있다는 사실이 밝혀지면서 빛이 바래기는 했으나, 돌턴의 원자설은 근대적인 의미에서 '원자'의 실체를 제시한 과학사 상의 쾌거였다. 영국 컴벌랜드 지방에서 태어난 돌턴은 1793년 이후 산업혁명의 중심지가 되면서 급속히 팽창하고 있던 도시 맨체스터에 정착하여, 유명한 '맨체스터 문학·철학협회'에서 활동했는데, 1817년에는 이 협회의 회장이 되었고, 1822년에는 왕립학회의 회원으로 선출되기도 했다. 여기서 그는 자신이 색맹환자였던 탓에 색맹에 대해 연구하기도 했다. 1803년의 한 강연에서 돌턴은 자신의 '원자론'을 소개했다. 그는 원소들이 결합하여 여러 기체를 구성하며 그 원소들은 무게가 일정하고 더 이상 쪼갤 수 없는 작은 입자들로 구성되어 있다는 의견을 내놓았다. 이러한 '원자론'은 1808년에 출간된 <화학철학의 새로운 체계>에서 집대성되었다. 이 책에서 그는 과거의 원자설에서 한 걸음 더 나아가, 화합물은 원자가 모여 이루어져 있으며, 동일한 화합물을 이루는 성분 원소의 원자 수는 항상 일정하다는 화합물 구성의 원리를 제시했다. 1794년 돌턴이 색맹에 대해 연구한 것은 스스로가 색맹이었기 때문이다. 그는 빨간색, 주홍색, 황색, 녹색을 구별하지 못하고 모두 회색 또는 칙칙한 엷은 갈색으로 인식하는 적록색맹이었다. 오늘날 적록색맹을 영어에서는 그의 이름을 빌어 ‘돌터니즘’(Daltonism)이라고 한다. 돌턴이 예순 여섯 살이 되었을 때, 그를 추종하던 사람들은 그에게 월리엄 4세를 알현할 수 있는 기회를 주선하려 하였다. 그러나 돌턴은 궁정의 예복을 입기 싫다는 이유로 그 제의를 받아들이려 하지 않았다. 사람들은 돌턴은 옥스퍼드 대학에서 박사 학위를 받았기 때문에 옥스퍼드 대학의 예복과 같은 색인 붉은색 예복은 입을 수 있으리라 생각했으나, 퀘이커 교도들은 붉은색 옷을 입지 않았다. 돌턴은 색맹이었기 때문에 붉은색이 회색으로 보였다. 그래서 그는 결국 자기 눈에는 회색으로 보이는 붉은색 예복을 입고 궁정에 나가게 되었다. 1808 Dalton's Atomic Theory : A new system of Chemical Philosophy • All matter is made of atom. • In a chemical reaction atoms are neither created or destroyed but only arranged differently. • Atoms of the same element are identical. • Atoms of different elements are not the same. • Compounds are formed from two or more atoms. A given compound always has same relative number and type of atoms.

톰슨은 전자를 발견했다. 그것이 텔레비젼이다. 전자가 날아가는 길 텔레비전 화면 자석 전기를 띤 금속 판 고압 전기

러더포드는 원자의 중심에는 뭔가 단단한 것이 있다 는 것을 발견했다-> 원자핵 러더포드는 원자의 중심에는 뭔가 단단한 것이 있다 는 것을 발견했다-> 원자핵

원자 구조를 알아내기 위해 많은 사람들이 연구한 결과 이만큼 알게 되었다

원자를 볼 수 있을까? 뮐러 교수, 펜실바니아 주립 대학 Individual atoms of the element silicon can be seen in this image obtained through the use of a scanning transmission electron microscope. The atoms in each pair are less than a ten-millionth of a millimeter (less than a hundred-millionth of an inch) apart. U.S. Department of Energy, Oak Ridge National Laboratory Appears in these articles: Chemistry; Atom; Chemistry, Inorganic* Looking back on the history of science, a number of important and great discoveries that have contributed to human civilization were made by chance, including the discovery in this book. I hope the contributions in this book will help humanity to improve scientific knowledge in the future. The underground resources, such as oil and coal, are limited in their quantity, while scientific knowledge is endless. Scientific knowledge will grow and develop constantly with human history. From the beginning there have been two worlds in the universe. One of them is already well known to us. It is composed of every visible material, including this book that you are reading now. On the other hand, the other one which consists of the elementary particles inside this material is little known to us. It can be seen only through a penetrator scope that shows the inner world and structure of materials.  It is the latter that I intend to deal with in this book. This book will show the atomic world within materials, by following the direction of the atomic world, hidden within the visible world of materials. Scientists know that there exists a world of elementary particles in atoms, but they have failed to get the evidence of it. Over the years several theories of atoms have been discovered.  The first hypothesis on atoms was made by the Greek philosophers of Democritus' school around 460 BC. Then, John Dolton inducted their hypothesis into his study and completed the atomic theory called "the origin of an atomic theory". Modern scientists such as Bohr, Rutherford and Tomson advocated their own atomic models.  Afterwards, it became apparent that the radius of an atom is 10-8  centimeters. Out of many scientists who studied atom, only Bohr won the Nobel prize for his atomic model. If you visit the council room of I.A.E.A. you will find an enlarged picture of his theory diagram hung on the wall as the association's symbol. As the practical methods to explore the structure of a material with x-rays and electron microscopes have advanced remarkably, scientists have tried to improve the experiments and theories of atoms as earnestly as they could. Nevertheless, they failed to reveal the true substance of an atom.  It seemed impossible for men to see the real one. I think if scientists got a chance to directly observe it, they might have done every effort to make it come true. This study shows how to discover the real atomic world that has been in fog until now. I am sure that this book will make a lasting contribution in the science history. Through this study you will see a bare atom with its nucleus and bands. This book was originally titled as "A revealed atom: how to see an atom." The atomic world has been the object of interest and worship not only to physicists and chemists but also to the scholars engaged in other adjacent academic field involving atoms. If scientists examine and understand this book thoroughly, it will greatly help in advancing their studies. This book, showing a real atom, introduces a penetrator scope searching for the structure of a material, in a very simple and easy way by making a visible ray penetrate objects. As the invention of x-rays surprised the world with its simplicity, so will this method.  It works as incredibly simple as x-rays, and is not so expensive as electron microscopes.  I believe it will be diffused to all the scientists throughout the world in a short time. This book deals with the physical description of the symmetry of a material as well as important physical discoveries including the penetrator scope searching for the structure of a material. As you will probably know after reading this book, most of the physicochemical teaching materials presently used in many colleges are insufficient and incorrect to understand the immense atomic world which has existed since time immemorial. Chapter 2 discusses the description and the theory connected with the invention of the penetrator scope, the new physical instrument searching for the structure of a material. Chapter 1 enumerates, without any theoretical interpretation, the phenomena which I have already observed through various experiments. Conduct the tests by yourself and you will find the phenomena so beautiful you would like to call them "the gems of science". Many scientists are expecting atomic power to solve the energy problem of the future world but a great part of the atomic world still remains unknown to us. This study will clearly unveil the atomic world which has been obscure for 24 centuries since the first atomic theory was established (about 460 BC).  Now, I present this book to the world and I am sure that this book will influence future generations directly or indirectly.  The physical reviewer,           Sang-ho Kim            BIOGRAPHICAL MEMOIRSNational Academy of Sciences Erwin W. Müller June 13, 1911–May 17, 1977 By Allan J. Melmed THE FORTY-SEVENTH INTERNATIONAL FIELD Emission Symposium, which took place July 29 to August 6, 2001, was held in Berlin to commemorate the fiftieth anniversary of Erwin Müller's first publication on the invention of the field ion microscope there in the summer of 1951. The opening session of the meeting was devoted to historical accounts of the development of field electron microscopy (FEM), field ion microscopy (FIM), and atom probe mass spectroscopy (APMS, also known as APFIM for atom probe field ion microscopy)--all fields of scientific and technical endeavor originated by the late Erwin W. Müller. The achievements of these fields of study and their influence on other scientific fields stand as a tribute to the remarkable creativity and ingenuity of Professor Müller. Those of us who knew him remember with admiration his great ability as a scientist, an experimentalist, and a teacher. The history of the creation and development of FEM, FIM, and APMS is in large part the biography of Erwin Müller. Erwin Wilhelm Müller was born in Berlin on June 13, 1911, the year the Kaiser-Wilhelm-Institute for Physical Chemistry and Electrochemistry (now the Fritz-Haber-Institute of the Max Planck Society) was founded. He died on May 17, 1977. A short time later his wife kindly reminisced with me about her husband, providing some insight into his early life. He was the only child of Wilhelm M. and Käthe Müller (nee Käthe M. Teipelke), a family of modest means. His father was a construction worker specializing in plastering ceilings in houses. Erwin Müller worked as a part-time research assistant at the Osram company in Berlin from 1932 to 1935; from 1935 to 1937 he was a research physicist at the Siemens company, also in Berlin, where he invented the FEM while continuing his education. He married Klara Thüssing in 1939, and their daughter Jutta, their only child, was born in 1940. He obtained his university education at the Technische Hochschule Berlin-Charlottenburg (now Technische Univerität Berlin), receiving an engineering diploma in 1935 and a doctor of engineering (physics emphasis) in 1936, working under the direction of the Nobel Prize-winning physicist Gustav Hertz. Those were stressful times for the young family because Erwin was not a National Socialist Party member and therefore had great difficulty trying to rise to a university post. Consequently, it was only after the war, in 1950, that he achieved his Habilitation from the Technical University Berlin (successor to the Technische Hochschule). After Siemens he worked for the Stabilovolt company in Berlin, where he was director of research and development from 1937 to 1946, a critical time in German history. Of possible consequence to science, it is interesting that according to Klara Müller, he was protected from the party by his good research efforts. Michael Drechsler, a former coworker of Müller's has written1 that the Stabilovolt laboratory in Berlin was destroyed by bombs in 1944 and that Müller attempted to rebuild it in Altenburg and in Dresden. He notes Müller's good fortune in managing to survive the firebombing of Dresden. Müller retained considerable resentment against the Allies for this late event in the Second World War, which was made clear in a 1951 conversation with Ralph Klein in Berlin. Klara, and earlier Erwin Müller, told me that immediately after the war they survived by picking up scraps from recently harvested fields and by learning to prepare baking powder for making bread from scraps of marble in the cemetery, maintaining a diet of about 900 calories a day. At this time, from 1946 to 1947, Müller was lecturer of physical chemistry at the Technical Institute in Altenburg, several miles from his home, to and from which he walked every day. While Müller was working in Altenburg, I. N. Stranski invited him to come to the Kaiser-Wilhelm Institute in Berlin, where Müller went next and where he worked from 1947 to 1951. He began as an assistant to Stranski and later became a group leader and then a department head. Here he invented the field ion microscope. (Considering the extensive war damage in Germany, one can imagine that conditions for research and development at the German institutes were as bad as the food situation, and it required unusual inventiveness and experimental skill for Müller to obtain his excellent results.) With his Habilitation in 1950 he also became a teacher at the Technical University Berlin, and in 1951 he became a professor at the Free University Berlin. Then he moved to the United States and started a new laboratory at Pennsylvania State University. At the same time he maintained close contacts with the Fritz-Haber-Institute by way of a lively correspondence with his former students and coworkers as well as with I. N. Stranski and M. von Laue, and mutual visits. The Max Planck Society officially recognized these good relations by making him an external scientific member of the Fritz-Haber Institute, Berlin, in 1957, which he accepted as much as an obligation as an honor. At Penn State he began as professor of physics. In 1955 he became a research professor of physics, and was appointed to the prestigious Evan Pugh Professor of Physics post in 1968. Finally, he was named professor emeritus in 1976. Erwin Müller's first publication was in Zeitschrift für Physik in 1935: "A Method for Photometric Measurement of the Intensity of Spectral Lines." His dissertation research, "The Dependence of Field Electron Emission on Work Function," was published in Zeitschrift für Physik in 1936. Overall, four papers and most importantly the invention of the field electron microscope resulted from his work with Gustav Hertz at Siemens. He went on to publish some 211 scientific papers over an active research career of 41 years. The political circumstances in Germany during the 1930s strongly influenced Erwin Müller's scientific career, and it is remarkable that he was able to develop FEM at that time. Drechsler has written about some of the prevailing circumstances.1 The cast of great scientists then working and lecturing in Berlin was certainly impressive: Einstein, Planck, Schrödinger, Debye, Nernst, Hertz, Haber, von Laue, Grotrian, Volmer, and Schottky. This made for an inspirational setting for Erwin Müller to begin his scientific career. The political climate, however, was far from nurturing with respect to the scientific community. Many of the internationally well-known scientists reacted to the growing political persecution by leaving their university posts, either because they were directly persecuted or in protest of the treatment of their colleagues. Müller's research professor, Gustav Hertz, felt compelled to leave his university chair in protest, and he moved to the Siemens company, where he became director of a new laboratory set up especially for him. Fortunately for Müller, Hertz brought him along to Siemens, where he was able to continue his research into field electron emission. Müller has described2 the situation when he began his dissertation research. In 1936 A. Wehnelt and W. Schilling had used a magnetic electron microscope to image the electron field emission from the edge of a sharp knife to find that the emission was coming from discrete and non-stable small points along the knife edge. In addition, in 1936 R. P. Johnson and W. Shockley published their description of a cylindrical field emission microscope.3 Their images viewed on a phosphor screen also showed that the electrons were being emitted by tiny protrusions on the wire cathode surface. Müller decided to view the electron emission distribution, or pattern, from the point cathodes he was studying, so he made the point equivalent of the Johnson-Shockley microscope. Next, he constructed a vacuum tube in which an ingenious electrically heatable tungsten tip was positioned a few centimeters away from a thin phosphor screen on the front inside surface of the tube. This tube allowed him to visualize directly the electron emission from the tip, prior to and following tip heating. He observed the patchy emission from as-etched tips, similar to what had been seen in the emission from edges and wires. Very easily, however, he was able to thermally smooth the protrusions and remove contamination from the W tip and to view the electron emission pattern of the clean surface on the screen. This tube was the first point projection field emission microscope.4 He was then able to measure the electron emission characteristics of the clean W surface and to verify the high field necessary for field emission predicted by the Fowler-Nordheim equation. Later, after Müller had left the Siemens laboratory, R. Haefer5 quantitatively confirmed the F-N equation in 1940. FEM became a powerful microscopy, however, far beyond the attempt to visualize the surface condition of a point field electron emitter. The simplicity of design of Erwin Müller's FEM instrument is evident when compared to other microscopes. Consider that a 105-106 enlarged image of a metal surface, with resolution of 2.5 nm (and 1 nm in special cases) can be gotten with a small laboratory-built FEM. However, in the years before the advent of commercially available metal vacuum components considerable experimental expertise was needed to actually make a working FEM. Müller devised a host of experimental "tricks," that is, special techniques, to enable most students to construct his microscope. Pankow related to me that later, from 1951 to 1961, he and P. Wolf and later Ralf Vanselow were assigned by Müller the task of making FEM microscopes for commercialization by the Leybold company. These were various sealed tubes including a barium evaporation source, sold primarily as demonstration equipment for schools. As director of research and development at the Stabilovolt company Müller managed to continue some studies of field emission even though the Second World War had begun. Drechsler has noted1 that Stabilovolt manufactured glow discharge tubes that used Ba-activated cathodes, and this provided the opportunity for Müller to investigate surface diffusion of Ba on W using his FEM. Müller's study of Ba adsorption and perhaps more importantly his discovery of field desorption of Ba from W was published in 1941.6 His pioneering measurements of the velocity distribution of field emitted electrons7 and his study of the resolution of the FEM8 were published in 1943. Due to the war Müller published no further scientific research until 1949. By this time, as described above, Müller was at the Kaiser-Wilhelm-Institute. He continued to do FEM research, publishing papers on W surface self-diffusion,9 the imaging of phthalocyanine molecules,10 the visibility of atoms and molecules,11 and (with M. Drechsler) the polarizability of atoms and molecules,12 and other seminal experiments. His interpretation of the images of adsorbed barium and phthalocyanine molecules as atoms and molecules, respectively, met with considerable skepticism. However, these pioneering FEM experiments, especially the surface self-diffusion work, led to considerably more work by many researchers. As important as his FEM results were, Müller's greatest contribution to microscopy and in fact to the scientific world was his invention of FIM. Let us consider the context in which this achievement took place. The electron microscope (TEM) had achieved Ruska's original aim of exceeding the resolution of traditional optical microscopy and had reached a resolution of about 2 nm. Müller's FEM had a resolution of about 2.3 nm in general and 1 nm in special cases. Ruska and Müller, both at the Kaiser-Wilhelm-Institute, were in friendly competition with each other, according to Gustav Klipping (private communication), to get the best results. Erwin Müller, however, aimed to make a great leap forward to achieve his dream of atomic resolution. After all, scientists had no direct proof that matter consisted of discrete atoms--only indirect evidence from X-ray diffraction and chemical experiments. No one had seen atoms to prove their existence. Erwin Müller reached 40 years of age in the summer of 1951. Ten years earlier he had reported that atoms adsorbed on a W surface could be torn off, or desorbed, by the application of a large positive electric field,7 and since then he had pondered a way to use the desorption phenomenon to image the tip surface. It was clear to him that simply desorbing a monolayer of Ba, for example, and accelerating the resulting positive ions to the screen would not provide sufficient image intensity. He recognized the need for a continuous supply of ions but did not immediately realize how to accomplish this. Finally in 1951 the solution occurred to him. His assistant at that time, Gerrit Pankow, recently related to me (private communication) the circumstances surrounding the first FIM experiments. One morning in the summer of 1951 when Pankow came into the laboratory, Müller was preparing to do an experiment. Pankow noticed that something was wrong, so he told Professor Müller that the tip voltage polarity was set to be positive instead of negative! Müller looked at him and simply said, "From now on, we work with positive tip voltage." The first FIM microscope was an FEM operated with positive tip voltage plus the addition of a palladium tube that when heated with a hydrogen flame, allowed the introduction of hydrogen into the microscope. (A small anode ring was added to minimize any field emission from the inside wall of the microscope but was later found to be unnecessary.) This microscope, primitive by our present scientific criteria, operating at room temperature enabled Erwin Müller to see that the surface did not have a continuous structure; rather he could clearly see rows of atoms. The invention of FIM by Erwin Müller was a remarkable achievement, especially considering the utter simplicity of such a lens-less microscope, which achieves magnification of 106 or more and atomic resolution by radial projection of ions from the specimen point. In contrast to the somewhat stepwise development of FEM, with contributions by several people, it is not obvious that anyone else could have or would have invented FIM. Even after Müller had the concept of imaging by field desorption of a continuously renewed source of ions, it required his great experimental ingenuity to make the microscope an actuality. His earlier experience with gaseous discharges and his lifelong interest in optics and activities as an amateur astronomer were important, especially considering that the room temperature FIM image was extremely dim, and image intensifiers did not yet exist. Müller proceeded with great efficiency to publish his historic first FIM paper,13 describing the significant improvement in contrast and resolution brought about by imaging with positive (hydrogen) ions compared to imaging by FEM and presenting the first evidence that atomic resolution was achieved. Müller's original manuscript was submitted on August 27, 1951. Interestingly, in terms of the friendly competition between Müller and Ruska, in a 1954 conference in Milan Ernst Ruska presented a published lecture in which he stated that the theoretical limit of TEM is such as to permit proving the existence of atoms. This is remarkable because Ruska knew first-hand about Müller's FIM results. One has to wonder how Müller reacted, especially because TEM had not come close to that objective, which he had reached in 1951. It is fascinating and somewhat ironic that knowledge gained through research using Müller's FEM was important in developing the present-day atomic resolution capability of the electron microscope. In a technical discussion tape-recorded at the first field emission symposium, in McMinnville, Oregon, in 1952 it was suggested that the use of a W point field electron emitter as the electron source in an electron microscope might lead to improved resolution. Then in 1959 the results of field-electron-emission energy distributions, mentioned above, revealed an unexpectedly narrow energy distribution, which is the basis of achieving atomic resolution with the electron microscope. The decision for Müller to leave Germany must have been difficult. He had lived and worked most of his life in Berlin and had begun to raise a family. In fact, his daughter was now 11 years old. However, after the Second World War the U.S. Joint Chiefs of Staff invited him to spend six months visiting universities in the United States, with the hope of enticing him and other good scientists to move to the United States. In September 1951, only a few weeks after submitting for publication his now celebrated first paper on FIM, he accepted the invitation and went to New York City, staying at the Alamac Hotel, visiting various universities, and probably not yet decided definitely to leave Germany. However, according to Müller, when he visited the Pennsylvania State University in central Pennsylvania he and Klara were immediately reminded of rural Germany. This and no doubt the miserable conditions of postwar Berlin convinced him to accept the suggestion of Dean Hall to move there, and he arrived in about February 1952. He became an U.S. citizen in 1962. At first he did only a minimum amount of classroom teaching, but he did an appreciable amount of informal teaching in the laboratory. This was perfectly suited to Müller's preferred working mode, which was devoting as much time and effort as possible toward his dream of achieving what he considered the ultimate accomplishment of microscopy: the full resolution of the surface atomic lattice of a metal. Thus far his FIM operating at room temperature with hydrogen as the imaging gas could only resolve atoms along multiple step-height ledges formed, for example, by heating the W tip after carbon adsorption--a very special case. By late spring or early summer of 1952 Müller had begun to attract students and to set up his new Penn State field emission laboratory, in the sub-basement of Osmond Hall, which housed the Physics Department. Two years later he moved his laboratory to more spacious and more pleasant quarters on the second floor of the building. Here he worked for the remainder of his scientific career. In the early years at Penn State the majority of students in his laboratory did research on issues related to field electron emission and FEM, and only one student worked, with Müller, on FIM matters. Müller's first few publications in this period were either papers written in collaboration with M. Drechsler, his former assistant at the Fritz-Haber-Institute laboratory or review articles, most notably Müller's 1953 review of FEM.2 However, events significant to the development of FIM were taking place. I have written about the relevant historical details,14 from the personal perspective of my years, 1954-58, as a student of Professor Müller. I will summarize here the key points and suggestions related to his thinking that may be of biographical interest. Müller's first paper, in 1951, introducing FIM was remarkable. Of course, it provided the world's first view of the atomic nature of solid matter and began an entirely new field of study. It also presented Müller's ideas for several further developments of FIM, such as cooling the microscope, the use of helium for imaging, and the phenomenon of field-induced surface dissolution, later termed field evaporation. This phenomenon ultimately made the FIM and the APFIM (atom probe field ion microscope) uniquely powerful analytic instruments. He clearly believed that his success in achieving improved image contrast and resolution, compared to FEM, validated his hypothesis that operating the FIM with a low-pressure hydrogen-ambient-enabled image formation by positive ions desorbed from a layer of continuously replenished adsorbed gas atoms. He also believed that the factor limiting resolution of the FIM was diffraction. Although he later showed that these mechanisms were not strictly correct, his belief in them somewhat retarded the complete fruition of the FIM. Another remarkable aspect of Müller's first FIM publication was the relatively short time between the conception of the experiment and the actual publication. This undoubtedly resulted from his genius for conceiving eloquently simple experiments, one of the defining characteristics of his scientific career. During the period 1954-58, while studying under Müller, I observed what I came to recognize as his awesome experimental talent, evident to all of his students and coworkers. The time span between an idea and setup of a new experiment was typically only a few days. This was true also for his later introduction of various low-temperature FIM microscope designs, and T. T. Tsong has related (private communication) that it was the case also for his invention of the atom probe. During 1952-55 attempts were being made toward improving the resolution of the FIM both in Germany by Müller's former students and coworkers at the Fritz-Haber-Institute and in the United States at Penn State. Müller was striving to achieve what he considered the ultimate objective of microscopy, that is, the ability to see the atomic surface structure of a metal. However, before 1954 both theory and experiment seemed to agree that the FIM was not likely to succeed in improving beyond the 1951 room temperature image quality. In 1952 R. Gomer published a paper in which he theorized that no improvement in resolution of the hydrogen FIM would be expected by cooling the emitter, and at about that time Pankow reported to Müller that he had found no improvement in image quality by immersing the FIM in liquid air. Then in 1954 M. G. Inghram and R. Gomer found that most of the ions contributing to the FIM image intensity originated slightly away from the surface, which was contrary to Müller's original concept of image formation. In 1954 Müller and Bahadur tried imaging at liquid nitrogen temperature and again found that cooling the FIM specimen, even using helium as imaging gas, did not improve the resolution. This added to Müller's pessimism about achieving his goal. A fascinating breakthrough occurred in October 1955, and I have described and analyzed this event and its background in detail.14 Müller, assisted by his student Kanwar Bahadur, once again cooled the FIM specimen with liquid nitrogen. This time, due to a fortuitously well-prepared specimen, they unintentionally discovered the phenomenon of surface smoothing by low-temperature field evaporation while imaging with helium. This immediately gave them the world's first view of the atomic surface structure of a metal--Erwin Müller's long sought goal. The FIM had evolved somewhat from Müller's original design, now using helium for imaging, cooling the specimen by liquid nitrogen or liquid hydrogen and smoothing the tip by field evaporation, but it still was by all criteria a marvelously simple instrument, something that Müller never tired of reminding audiences. He had wonderful showmanship and frequently exaggerated this instrumental simplicity, to the delight of audiences. During the period 1956-66 Müller increasingly emphasized further development of FIM techniques and conducted exploratory research into many areas of FIM applications, although he continued to make significant contributions to the applications of FEM. In 1960 he published a major review paper15 that gave practical information so that others could more easily get started doing FIM, and this helped to spread the technique around the world. In addition, in this period his work with R. D. Young, a student of his, refining the method of measuring electron energy distribution16 led to a new theoretical analysis17 and experimental verification of field emission energy distributions, and revealed an unexpectedly narrow energy distribution. Müller published a paper in 195718 that motivated the later extensive FIM research by others, notably G. Ehrlich, T. T. Tsong, and D. W. Bassett, on the diffusion of single atoms on surfaces. Müller's final research papers in FEM were published in 1962, with Young on the electron work function of (011)-oriented W, and with W. T. Pimbley on their unsuccessful search for polarized field electrons. Müller reviewed the progress in his microscopies in his 1969 book with T. T. Tsong.19 Müller's final major contribution to science was his invention of the instrument he called the atom probe, in 1967.20 It later also became known as the atom probe field ion microscope, recognizing that it incorporates an FIM capability to give an atomic map of the specimen surface, by means of which the user selects atoms for chemical identification by time-of-flight mass spectrometry. This uniquely powerful analytical instrument has made and continues to make important contributions to materials science. The introduction of the atom probe by Müller burst like a supernova, at least on the international field emission community. After all, he was already 56 years old, had created two microscopies, and had given the world its first view of atoms. It would still be some 13 years until any other microscopy could claim the capability of seeing atoms in a solid. In retrospect it is fascinating that at least in principle other scientists came very close to inventing the atom probe. Inghram and Gomer, H. D. Beckey, W. A. Schmidt, and J. H. Block all designed, built, and worked with mass spectroscopic instruments using field ion sources that could have been adapted to analyze the composition of the tip itself, perhaps leading them to invent the atom probe FIM. They were dedicated, however, to using the instrumentation to analyze only the composition of field ionization or adsorbed species, while Erwin Müller was focused on trying to determine the composition of individual surface atoms. Students of Müller who were present during the time of the invention of the atom probe have described some of the relevant events to me, and J. A. Panitz has recently published21 his description of the historical development. Müller had been trying for a few years to find a way to chemically identify atoms for which the FIM image contrast was not understood. The immediate motivation for this effort was the uncertainty in interpretation of FIM contrast in some binary alloys, where one element imaged with bright contrast and the other with dark contrast (his student, T. T. Tsong was studying Co-Pt, for example). Müller was well aware of the techniques of field ion mass spectroscopy and had students working with them. In addition, his students, M. P. R. Thomsen and D. F. Barofsky, had shown that field-evaporated metallic species could be mass analyzed. However, Müller realized that there were two existing shortcomings for his purposes. The detectors did not possess single-ion sensitivity and there was no way to pre-select and localize the region of analysis to do single-atom identification. He conceived the idea of using a probe hole to limit the field of view, or field of analysis, to a pre-selected atom or atoms, and believed that improved detectors could be built to detect single ions. He asked Barofsky to assess the feasibility of doing single-ion mass spectroscopy using a magnetic sector instrument with a continuous dynode detector. A short while later Barofsky learned about the time-of-flight technique from a course he was taking and suggested its use to Müller, who directed him to determine the instrument parameters suitable for an atom probe using the contemporary timing electronics. His technicians, Gerry Fowler and Brooks McLane, were assigned to put together the hardware to make such an instrument and then his student J. A. Panitz was given the project for his Ph.D. research. The atom probe came to fruition in mid-1967, a matter of only several months from its conception by Müller. Müller's steadfast, focused effort to improve the microscopy he had invented was the defining characteristic of his scientific career. He strove to be first in all aspects of FEM and FIM, so much so that the phrase "for the first time" became his mantra. In point of fact, until about 1960 Müller had personally discovered most of the aspects of the microscopies, and it was not uncommon for him to remind the author following a presentation, or as a manuscript reviewer, that he had done it first, usually years ago. This zeal sometimes caused resentment and certainly masked his warm personality. In private Erwin Müller was friendly, kind, and charming. But his public persona was something else--more like a lion defending his lair. Müller retired from active research in 1976 and was named professor emeritus. He was suffering from the after-effects of treatment for cancer of the throat, which caused him difficulty in lecturing, but his condition seemed to be improving. Then, on May 17, 1977, at the age of 65 he died from a stroke while attending the annual meeting of the National Academy of Sciences in Washington, D.C. Erwin Müller received a number of awards and honors during his lifetime. These were as follows: 1936 Bronze Medal for outstanding work, the Technische Hochschule Berlin-Charlottenburg 1952 C. F. Gauss Medal (laudatio by Max von Laue) 1957 External scientific member, Fritz-Haber-Institute of the Max Planck Society, Berlin 1960 Achievement Award, Instrument Society of America 1961 Fellow, American Physical Society 1964 H. N. Potts Gold Medal, Franklin Institute, Philadelphia 1968 Elected member, Deutsche Akad. d. Naturforscher, Leopoldina, Halle Dr. rer. nat. honoris causa, Free University, Berlin 1969 Honorary fellow, Royal Microscopical Society, Oxford Centenary Lectureship Silver Medal, Chemical Society, London 1970 M. W. Welch Gold Medal, American Vacuum Society John Scott Medal, City of Philadelphia (oldest Am________ Sci_______ Award) 1972 Davisson-Germer Prize, American Physical Society 1975 Dr. honoris causa, Claude-Bernard University of Lyon Honorary member, Indian Vacuum Society Elected member, National Academy of Engineering Elected member, National Academy of Sciences In addition, he was to have received the very prestigious National Medal of Science in 1976, but the award ceremony was postponed. It was awarded instead posthumously to Müller's daughter by President Jimmy Carter on November 22, 1977, at the White House. Erwin Müller's career had an immeasurably large impact on science and technology. His invention and development of FEM clarified the physics of field electron emission from metals and led to important contributions to the progress of surface science. In recent years knowledge gained from FEM research has become important in product development for flat-panel image displays and vacuum electronics applications. His development of ultra-high vacuum techniques, from the pioneering use of barium and other metal vacuum getters to his early achievement of vacuum levels down to below 10&12 torr quietly advanced both surface science and vacuum technology. His invention of the FIM dispelled the intellectual myth that atoms were too small to be seen and began the age of atomic resolution metallurgy and materials research. With it Müller brought to surface science the ability to study surface phenomena, such as single-atom and cluster surface mobility on the atomic scale. Müller's atom probe (APFIM) transformed the FIM to a major analytical instrument. A few years after his death, as instrumental innovations extended APFIM capabilities even beyond Müller's concepts, the instrument began to have and continues to have wide impact on materials research. I AM DEEPLY GRATEFUL for useful information and manuscript comments from many people, especially Mrs. Klara Müller, Mrs. Jutta Moser (nee Müller), Kanwar Bahadur, Doug Barofsky, Paul Cutler, Norbert Ernst, Jerry Fowler, Gary Kellogg, Ralph Klein, Gustav and Ingrid Klipping, John Panitz, Gerrit Pankow, Walt Pimbley, Werner Schmidt, Tien T. Tsong, Ralf Vanselow, Nelia Wanderka, Russ Young, the Archives of the Max Planck Society, Berlin, and the Penn State Physics Department. NOTES 1 M. Drechsler. _______________________. Surf. Sci. 70(1978):1. 2 E. W. Müller. ___________________________. Ergebn. der Exakten Naturwiss. 27(1953):290. 3 R. P. Johnson and W. Shockley. Report to New England Section, American Physics Society, 1935; ______________________. Phys. Rev. 49(1936):436. 4 E. W. Müller. _______________________. Z. Phys. 106(1937):541. 5 R. Haefer. _______________________. Z. Phys. 116(1940):604. 6 E. W. Müller. _______________________. Naturwiss. 29(1941):533. 7 E. W. Müller. ________________________, Z. Phys. 120(1943):624. 8 E. W. Müller. ______________________. Z. Phys. 120(1943):270. 9 E. W. Müller. _______________________. Z. Phys. 126(1949):642. 10 E. W. Müller. _________________________. Naturwiss. 37(1950):333. 11 E. W. Müller. ____________________. Z. Naturforsch. 5a(1950):473. 12 M. Drechsler and E. W. Müller. _______________________. Z. Phys. 132(1952):195. 13 E. W. Müller. ________________________. Z. Phys. 131(1951):136. 14 A. J. Melmed. ________________________. Appl. Surf. Sci. 94/95(1996):17. 15 E. W. Müller. __________________________. In Advances in Electronics and Electron Physics, vol. 13, ed. _____________, p. 83. ____________________: Academic Press, 1960. 16 R. D. Young and E. W. Müller. ________________________. Phys. Rev. 113(1959):115. 17 R. D. Young. ___________________________. Phys. Rev. 113(1959):110. 18 E. W. Müller. _________________________. Z. Elektrochem. 61(1957):43. 19 E. W. Müller and T. T. Tsong. Field Ion Microscopy Principles and Applications. New York: Elsevier, 1969. 20 E. W. Müller, J. A. Panitz, and S. B. McLane. _______________________. Rev. Sci. Instrum. 39(1968):83. 21 J. A. Panitz. ____________________. Mater. Charact. 44 3-10 (2000). SELECTED BIBLIOGRAPHY Die Abhängigkeit der Feldelektronenemission von der Austrittsarbeit. Z. Phys. 102:734-61. 1937 Beobachtungen über die Fieldemission und die Kathodenzerstäubung an thoriertem Wolfram. Z. Phys. 106:132-40. 1938 Weiterer Beobachtungen mit dem Feldelektronenmikroskop. Z. Phys. 108:668-80. 1943 Zur Geschwindigkeitsverteilung der Elektronen bei der Feldemission. Z. Phys. 120:261-69. 1950 Atome und Moleküle werden sichtbar. Umschau 50:761-64. 1953 Image formation of individual atoms and molecules in the FEM. J. Appl. Phys. 24:1414. 1955 Work function of tungsten single crystal planes measured by the FEM. J. Appl. Phys. 26:732-37. 1956 With R. H. Good, Jr. Field emission. In Handbuch der Physik, vol. 21, ed. ________________, pp. __-__. ________________________: _____________________. Field desorption. Phys. Rev. 102:618. Study of atomic structure of metal surfaces in the FIM. J. Appl. Phys. 28:1-6. _________________________________________. In Advances in Electronics and Electron Physics. ed., _____________________. New York: Academic Press. 13:83-179. With R. D. Young. Determination of field strength for field evaporation and ionization in the field ion microscope. J. Appl. Phys. 32:2425-28. 1962 Field ion microscopy. Industrial Research 4:32-36. 1963 Field emission microscopy of clean surfaces with electrons and positive ions. Ann. N. Y. Acad. Sci. 101:585-98. The effect of polarization, field stress and gas impact on the topography of field evaporated surfaces. Surf. Sci. 2:484-94. 1965 With S. Nakamura, O. Nishikawa, and S. B. McLane. Gas-surface interactions and field ion microscopy of nonrefractory metals. J. Appl. Phys. 36:2496-2503. 1966 Increased image brightness by immersion of a FIM. J. Appl. Phys. 37:5001-5002. 1967 Hydrogen promotion of field ionization and rearrangement of surface charge. Surf. Sci. 8:463-73. Field ion microscopy of point defects. In Vacancies and Interstitials in Metals, ed. ______________, pp. 557-73. Amsterdam: North-Holland. With S. V. Krishnaswami and S. B. McLane. Atom-probe FIM analysis of the interaction of the imaging gas with the surface. Surf. Sci. 23:112-29. The imaging process in field ion microscopy. J. Less Comm. Met. 28:37-50. 1973 Atom probes. Lab. Pract. 22:408-13. U.S. Patents 3,504,175 and 3,602,710. With S. V. Krishnaswami. Energy spectrum of field ionization at a single atomic site. Surf. Sci. 36:29-47. 1974 With T. Sakurai. A magnetic sector atom-probe FIM. J. Vac. Sci. Technol. 11:899. With S. V. Krishnaswami. Aiming performance of the atom probe. Rev. Sci. Instrum. 46:1237-40. Biographical MemoirsNational Academy of Sciences Atom Prove Field Ion Microscope Prof. E. W. Müller The Atom Probe was invented by Professor Erwin Wilhelm Müller who was a professor at Pennsylvania State University in the United states. Of couse, he invented not only the Atom Probe but also Fileld Ion Microscope (FIM) and Field Emission Microscope (FEM). When he was at the Kaiser-Wilhelm-Institute (today:Max Plank Institute) from 1947 to 1951, he invented the FIM in the Second World War. Surprisingly, Ruska, who invented Transimmsion Electron Microscope (TEM) (It was published in 1932) and recieved the Novel Prize in 1986, and Müller were in friendly competition at the Kaiser-Wilhelm-Institute. Müller's dream was to achive atomic resolution using his microscope. In 1951, he published his first FIM paper. Actually, he had found the desorption phenomenon of a monolayer of Ba (barium) from a W (tungsten) tip surface by the application of a large positive electric field in 1943. Thus, when he apply positive tip voltage and introduce hydrogen into the FEM (In case of FEM, it is applied negative voltage to the tip, i.e. the polarization of the tip is opposit), he could see rows of atoms in the "FIM". This is known as the first microscope to visualize in atomic resolution. Just after the publication of the first FIM paper, he moved in Pennsylvania state and studied at Penn State University. His work on this FIM is extremely varied and he and Professor T. T. Tsong were reviewed their progress in his microscopies as a text book in 1969. The first publication associated with the Atom Prove was in 1967; besides he improved it as the Atom Prove Field Ion Microscope so that FIM has a capability to give an atomic map of the specimen surface. This microscope was adopted a time-of-flight mass spectrometry. His contributions to science are enormous as you can comprehend to read these historical backgrounds. Nevertheless he was first person to identify individual atoms using FIM, unfortunately he passed away from cancer on May, 1977, at the age of 65. It won갽t be surprised if he might receive the Novel Prize. He is sorely missed the shortest-lived.

원자 속에 감춰져 있던 에너지를 발견하다! 아인슈타인은 언제나 행복했을까? Person of the Century: Albert Einstein He was the pre-eminent scientist in a century dominated by science. The touchstones of the era — the Bomb, the Big Bang, quantum physics and electronics — all bear his imprint By FREDERIC GOLDEN Stephen Hawking: A Brief History of Relativity J. Madeleine Nash: Einstein's Unfinished Symphony Roger Rosenblatt: The Age of Einstein TIME's Choice: Who Mattered — and Why Runner-Up: Franklin Delano Roosevelt Runner-Up: Mohandas Gandhi The Necessary Evil? Why Hitler Is Not Person of the Century Monday, Jan. 3, 2000 He was the embodiment of pure intellect, the bumbling professor with the German accent, a comic cliché in a thousand films. Instantly recognizable, like Charlie Chaplin's Little Tramp, Albert Einstein's shaggy-haired visage was as familiar to ordinary people as to the matrons who fluttered about him in salons from Berlin to Hollywood. Yet he was unfathomably profound — the genius among geniuses who discovered, merely by thinking about it, that the universe was not as it seemed. Even now scientists marvel at the daring of general relativity ("I still can't see how he thought of it," said the late Richard Feynman, no slouch himself). But the great physicist was also engagingly simple, trading ties and socks for mothy sweaters and sweatshirts. He tossed off pithy aphorisms ("Science is a wonderful thing if one does not have to earn one's living at it") and playful doggerel as easily as equations. Viewing the hoopla over him with humorous detachment, he variously referred to himself as the Jewish saint or artist's model. He was a cartoonist's dream come true. Much to his surprise, his ideas, like Darwin's, reverberated beyond science, influencing modern culture from painting to poetry. At first even many scientists didn't really grasp relativity, prompting Arthur Eddington's celebrated wisecrack (asked if it was true that only three people understood relativity, the witty British astrophysicist paused, then said, "I am trying to think who the third person is"). To the world at large, relativity seemed to pull the rug out from under perceived reality. And for many advanced thinkers of the 1920s, from Dadaists to Cubists to Freudians, that was a fitting credo, reflecting what science historian David Cassidy calls "the incomprehensiveness of the contemporary scene — the fall of monarchies, the upheaval of the social order, indeed, all the turbulence of the 20th century." Einstein's galvanizing effect on the popular imagination continued throughout his life, and after it. Fearful his grave would become a magnet for curiosity seekers, Einstein's executors secretly scattered his ashes. But they were defeated at least in part by a pathologist who carried off his brain in hopes of learning the secrets of his genius. Only recently Canadian researchers, probing those pickled remains, found that he had an unusually large inferior parietal lobe — a center of mathematical thought and spatial imagery — and shorter connections between the frontal and temporal lobes. More definitive insights, though, are emerging from old Einstein letters and papers. These are finally coming to light after years of resistance by executors eager to shield the great relativist's image. Unlike the avuncular caricature of his later years who left his hair unshorn, helped little girls with their math homework and was a soft touch for almost any worthy cause, Einstein is emerging from these documents as a man whose unsettled private life contrasts sharply with his serene contemplation of the universe. He could be alternately warmhearted and cold; a doting father, yet aloof; an understanding, if difficult, mate, but also an egregious flirt. "Deeply and passionately [concerned] with the fate of every stranger," wrote his friend and biographer Philipp Frank, he "immediately withdrew into his shell" when relations became intimate. Einstein himself resisted all efforts to explore his psyche, rejecting, for example, a Freudian analyst's offer to put him on the couch. But curiosity about him continues, as evidenced by the unrelenting tide of Einstein books (Amazon.com lists some 100 in print). The pudgy first child of a bourgeois Jewish couple from southern Germany, he was strongly influenced by his domineering, musically inclined mother, who encouraged his passion for the violin and such classical composers as Bach, Mozart and Schubert. In his preteens he had a brief, intense religious experience, going so far as to chide his assimilated family for eating pork. But this fervor burned itself out, replaced, after he began exploring introductory science texts and his "holy" little geometry book, by a lifelong suspicion of all authority. His easygoing engineer father, an unsuccessful entrepreneur in the emerging electrochemical industry, had less influence, though it was he who gave Einstein the celebrated toy compass that inspired his first "thought experiment": what, the five-year-old wondered, made the needle always point north? At age 15, Einstein staged his first great rebellion. Left behind in Munich when his family relocated to northern Italy after another of his father's business failures, he quit his prep school because of its militaristic bent, renounced his German citizenship and eventually entered the famed Zurich Polytechnic, Switzerland's M.I.T. There he fell in love with a classmate, a Serbian physics student named Mileva Maric. Afflicted with a limp and three years his senior, she was nonetheless a soul mate. He rhapsodized about physics and music with her, called her his Dolly and fathered her illegitimate child — a sickly girl who may have died in infancy or been given up for adoption. They married despite his mother's objections, but the union would not last. A handsome, irrepressible romantic in those years, he once had to apologize to the husband of an old flame after Mileva discovered Einstein's renewed correspondence with her. He later complained that Mileva's pathological jealousy was typical of women of such "uncommon ugliness." Perhaps remorseful about the lost child and distanced by his absorption with his work — his only real passion — and his growing fame, Mileva became increasingly unhappy. On the eve of World War I, she reluctantly accompanied Einstein to Berlin, the citadel of European physics, but found the atmosphere insufferable and soon returned to Zurich with their two sons. By 1919, after three years of long-distance wrangling, they divorced. He agreed to give her the money from the Nobel Prize he felt sure he would win. Still, they continued to have contact, mostly having to do with their sons. The elder, Hans Albert, would become a distinguished professor of hydraulics at the University of California, Berkeley (and, like his father, a passionate sailor). The younger, Eduard, gifted in music and literature, would die in a Swiss psychiatric hospital. Mileva helped support herself by tutoring in mathematics and physics. Despite speculation about her possible unacknowledged contributions to special relativity, she herself never made such claims. Einstein, meanwhile, had taken up with a divorced cousin, Elsa, who jovially cooked and cared for him during the emotionally draining months when he made the intellectual leaps that finally resulted in general relativity. Unlike Mileva, she gave him personal space, and not just for science. As he became more widely known, ladies swarmed around him like moonlets circling a planet. These dalliances irritated Elsa, who eventually became his wife, but as she told a friend, a genius of her husband's kind could never be irreproachable in every respect. Cavalier as he may have been about his wives, he had a deep moral sense. At the height of World War I, he risked the Kaiser's wrath by signing an antiwar petition, one of only four scientists in Germany to do so. Yet, paradoxically, he helped develop a gyrocompass for U-boats. During the troubled 1920s, when Jews were being singled out by Hitler's rising Nazi Party as the cause of Germany's defeat and economic woes, Einstein and his "Jewish physics" were a favorite target. Nazis, however, weren't his only foes. For Stalinists, relativity represented rampant capitalist individualism; for some churchmen, it meant ungodly atheism, even though Einstein, who had an impersonal Spinozan view of God, often spoke about trying to understand how the Lord (der Alte, or the Old Man) shaped the universe. In response to Germany's growing anti-Semitism, he became a passionate Zionist, yet he also expressed concern about the rights of Arabs in any Jewish state. Forced to quit Germany when the Nazis came to power, Einstein accepted an appointment at the new Institute for Advanced Study in Princeton, N.J., a scholarly retreat largely created around him. (Asked what he thought he should be paid, Einstein, a financial innocent, suggested $3,000 a year. The hardheaded Elsa got that upped to $16,000.) Though occupied with his lonely struggle to unify gravity and electromagnetism in a single mathematical framework, he watched Germany's saber rattling with alarm. Despite his earlier pacifism, he spoke in favor of military action against Hitler. Without fanfare, he helped scores of Jewish refugees get into an unwelcoming U.S., including a young photographer named Philippe Halsman, who would take the most famous picture of him (reproduced on the cover of this issue). Alerted by the émigré Hungarian scientist Leo Szilard to the possibility that the Germans might build an atom bomb, he wrote F.D.R. of the danger, even though he knew little about recent developments in nuclear physics. When Szilard told Einstein about chain reactions, he was astonished: "I never thought about that at all," he said. Later, when he learned of the destruction of Hiroshima and Nagasaki, he uttered a pained sigh. Following World War II, Einstein became even more outspoken. Besides campaigning for a ban on nuclear weaponry, he denounced McCarthyism and pleaded for an end to bigotry and racism. Coming as they did at the height of the cold war, the haloed professor's pronouncements seemed well meaning if naive; Life magazine listed Einstein as one of this country's 50 prominent "dupes and fellow travelers." Says Cassidy: "He had a straight moral sense that others could not always see, even other moral people." Harvard physicist and historian Gerald Holton adds, "If Einstein's ideas are really naive, the world is really in pretty bad shape." Rather it seems to him that Einstein's humane and democratic instincts are "an ideal political model for the 21st century," embodying the very best of this century as well as our highest hopes for the next. What more could we ask of a man to personify the past 100 years? 아인슈타인은 언제나 행복했을까?

원자핵 속의 에너지가 어떻게 나오는가? 중성자 이것은 원자력발전소다 이것은 태양이다 핵분열 핵융합 Vocabulary 원자핵 속의 에너지가 어떻게 나오는가? 핵분열 중성자 이것은 원자력발전소다 Vocabulary Critical Mass: The exact amount of fissionable material needed maintain a fission chain reaction. Fission: A nuclear reaction in which an atomic nucleus splits into fragments, usually two fragments of comparable mass.                                                                                      Fissionable Material: Material, such as the uranium isotope 235, that can go through the process of fission. Fusion: A nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy.                                                                                        Fission chain reaction: A chain reaction refers to a process in which neutrons are released in fission to produce an additional fission in at least one further nucleus. In other words, the neutrons/protons released in fission (or fusion) collide with other nuclei causing them to split and release more neutrons/protons and repeat the process, the domino effect.                                                                                               Implode: When explosives are detonated on the outer surface of an object, instead of the inner surface, causing the shock wave to move inward, which crushes the object. This is the exact opposite of explode. Subcritical: When there is too little fissionable material to maintain a fission chain reaction. Supercritical: A term used to describe the state of a given fission system when the quantity of fissionable material is greater than the critical mass under existing conditions. Meaning that the amount of energy produced by nuclear fission is increasing rapidly, because there is more than enough fissionable mass, which usually leads to an explosion. Uranium-235: A rare, and unstable, isotope of uranium that is capable of undergoing a nuclear fission chain reaction. 핵융합 이것은 태양이다

조약돌로 남산을 깰 수 있을까?  오토한과 마이트너 중성자로 핵을 두 쪽으로 나누었다 조약돌로 남산을 깰 수 있을까?  오토한과 마이트너 중성자로 핵을 두 쪽으로 나누었다 Years of Preliminary Research Years of scientific effort and study lay behind this demonstration of the first self-sustaining nuclear chain reaction. The story goes back at least to the fall of 1938 when two German scientists, Otto Hahn and Fritz Strassmann, working at the Kaiser Wilhelm Institute in Berlin, found barium in the residue material from an experiment in which they had bombarded uranium with neutrons from a radium-beryllium source. This discovery caused tremendous excitement in the laboratory because of the difference in atomic mass between the barium and the uranium. Previously, in residue material from similar experiments, elements other than uranium had been found, but they differed from the uranium by only one or two units of mass. The barium differed by approximately 98 units of mass. The question was, where did this element come from? 1t appeared that the uranium atom when bombarded by a neutron had split into two different elements, each of approximately half the mass of the uranium. Lise Meitner and Otto Hahn in their laboratory in the 1930s. Before publishing their work in the German scientific journal Die Naturwissenschaften; Hahn and Strassmann communicated with Lise Meitner who, having fled the Nazi-controlled Reich, was working with Niels Bohr in Copenhagen, Denmark. Miss Meitner was very much interested in this phenomenon and immediately attempted to analyze mathematically the results of the experiment. She reasoned that the barium and the other residual elements were the result of a fission, or breaking, of the uranium atom. But when she added the atomic masses of the residual elements; she found this total was less than the atomic mass of uranium. There was but one explanation: The uranium fissioned or split, forming two elements each of approximately half of its original mass, but not exactly half. Some of the mass of the uranium had disappeared. Miss Meitner and her nephew O. R. Frisch suggested that the mass which disappeared was converted into energy. According to the theory advanced in 1905 by Albert Einstein in which the relationship of mass to energy was stated by the equation E = mc2 (energy is equal to mass times the square of the speed of light), this energy release would be of the order of 200,000,000 electron volts for each atom fissioned. Otto Hahn and Lise Meitner

페르미와 실라드는 나치가 두려웠다 Fermi and Szilard Enrico Fermi Leo Szilard(1898-1964) Science Death of a Navigator ALSO IN THIS ISSUE Dec. 6, 1954 Table of Contents » Science Moon Markings The Erudite Faker The New Chemistry TheFall-OutandC 14 Dec. 6, 1954 Historians differ about which battles were really decisive and about which great men of history were really great. Few will differ about Italian-born Physicist Enrico Fermi, a great man of science who achieved the first nuclear chain reaction and thereby initiated the Atomic Age. This week in Chicago, Enrico Fermi, 53, died of cancer. If he had lived a few years longer, medical techniques growing out of his own discoveries might have rid him of his fatal disease. Squash-Court Drama. The high point of Fermi's career is one of those rare events that will be described again and again as long as men are interested in the history of their species. It happened on Dec. 2, 1942, in a squash court under the stands of the University of Chicago's football stadium. An international group of physicists watched with some apprehension a massive, dead-black structure of graphite bricks with uranium spotted through it. Fermi was in charge. His discoveries in Italy about neutron behavior (which won him the Nobel Prize in 1938) had laid the "pile's" scientific foundations. His development work in the U.S. had built it out of theory. Now the pile was ready to go. The watchers knew that on its performance hung the success of the plutonium bomb and perhaps the outcome of World War II. Calmly and cautiously, Fermi gave the necessary orders. Inch by inch, a neutron-absorbing control rod was drawn out of the reactor. The instruments watching its behavior began to click louder. Fermi would not be rushed. At 11:35 a.m. he casually remarked, "Let's go to lunch," and the reactor was shut down. Back from a long, unhurried lunch, Fermi reassembled his crew. The control rods were drawn out. The instruments clamored louder; the curve of the reaction climbed toward the critical level. At 3:25 p.m. the pile "went critical," i.e., a self-sustained chain reaction started. Its mass was still silent and motionless, but the physicists knew that a new kind of fire was burning inside it. Later Physicist Arthur Compton telephoned President James Conant of Harvard, who was chairman of the National Defense Research Committee, and gave lim a prearranged code message. Said Compton: "The Italian navigator has reached the New World." Faint Beginnings. Fermi fled from Mussolini's tyranny and reached the U.S. n time to become a key man in the atom-bomb project. Many honors came to Fermi, but they did not make him less be-oved by his colleagues and students. His ife after the squash-court event was omething of an anticlimax (it could not lave been otherwise), but it was happy and productive. He had a zest for life (skiing, swimming, mountain climbing) as ell as for knowledge. Like most physicists, Fermi regretted that atomic energy, so far, has been used largely for military purposes. He died just as the world was on the verge of seeing the faint beginnings of the peacetime good that it can bring. Fermi. APEnrico Fermi in 1946 at the University of Chicago Enrico Fermi He was the last of the double-threat physicists: a genius at creating both esoteric theories and elegant experiments By RICHARD RHODES 21st Century: What's Next? Test-Based Society: The IQ Meritocracy They Were Onto Something: A Century of Science Fiction Monday, March 29, 1999 If the 19th century was the century of chemistry, the 20th was the century of physics. The burgeoning science supported such transforming applications as medical imaging, nuclear reactors, atom and hydrogen bombs, radio and television, transistors, computers and lasers. Physical knowledge increased so rapidly after 1900 that theory and experiment soon divided into separate specialties. Enrico Fermi, a supremely self-assured Italian American born in Rome in 1901, was the last great physicist to bridge the gap. His theory of beta decay introduced the last of the four basic forces known in nature (gravity, electromagnetism and, operating within the nucleus of the atom, the strong force and Fermi's "weak force"). He also co-invented and designed the first man-made nuclear reactor, starting it up in a historic secret experiment at the University of Chicago on Dec. 2, 1942. In the famous code that an administrator used to report the success of the experiment by open phone to Washington, Fermi was "the Italian navigator" who had "landed in the new world." Leo Baekeland Tim Berners-Lee Rachel Carson Francis Crick & James Watson Albert Einstein Philo Farnsworth Enrico Fermi Alexander Fleming Sigmund Freud Robert Goddard Kurt Gödel Edwin Hubble John Maynard Keynes Louis, Mary & Richard Leakey Jean Piaget Jonas Salk William Shockley Alan Turing Ludwig Wittgenstein Wilbur & Orville Wright He had personally landed in the new world four years earlier, with a newly minted Nobel Prize gold medal in his pocket, pre-eminent among a distillation of outstanding scientists who immigrated to the U.S. in the 1930s to escape anti-Semitic persecution in Hitler's Germany and Mussolini's Italy — in Fermi's case, of his Jewish wife Laura. A dark, compact man with mischievous gray-blue eyes, Fermi was the son of a civil servant, an administrator with the Italian national railroad. He discovered physics at 14, when he was left bereft by the death of his cherished older brother Giulio during minor throat surgery. Einstein characterized his own commitment to science as a flight from the I and the we to the it. Physics may have offered Enrico more consolatory certitudes than religion. Browsing through the bookstalls in Rome's Campo dei Fiori, the grieving boy found two antique volumes of elementary physics, carried them home and read them through, sometimes correcting the mathematics. Later, he told his older sister Maria that he had not even noticed they were written in Latin. He progressed so quickly, guided by an engineer who was a family friend, that his competition essay for university admission was judged worthy of a doctoral examination. By 1920 he was teaching his teachers at the University of Pisa; he worked out his first theory of permanent value to physics while still an undergraduate. His only setback was a period of postdoctoral study in Germany in 1923 among such talents as Wolfgang Pauli and Werner Heisenberg, when his gifts went unrecognized. He disliked pretension, preferring simplicity and concreteness, and the philosophic German style may have repelled him. "Not a philosopher," the American theorist J. Robert Oppenheimer later sketched him. "Passion for clarity. He was simply unable to let things be foggy. Since they always are, this kept him pretty active." He won appointment as professor of theoretical physics at the University of Rome at 25 and quickly assembled a small group of first-class young talents for his self-appointed task of reviving Italian physics. Judging him infallible, they nicknamed him "the Pope." The Pope and his team almost found nuclear fission in 1934 in the course of experiments in which, looking for radioactive transformations, they systematically bombarded one element after another with the newly discovered neutron. They missed by the thickness of the sheet of foil in which they wrapped their uranium sample; the foil blocked the fission fragments that their instruments would otherwise have recorded. It was a blessing in disguise. If fission had come to light in the mid-1930s, while the democracies still slept, Nazi Germany would have won a long lead toward building an atom bomb. In compensation, Fermi made the most important discovery of his life, that slowing neutrons by passing them through a light-element "moderator" such as paraffin increased their effectiveness, a finding that would allow releasing nuclear energy in a reactor. If Hitler had not hounded Jewish scientists out of Europe, the Anglo-American atom bomb program sparked by the discovery of fission late in 1938 would have found itself shorthanded. Most Allied physicists had already been put to work developing radar and the proximity fuse, inventions of more immediate value. Fermi and his fellow emigres--Hungarians Leo Szilard, Eugene Wigner, John von Neumann and Edward Teller, German Hans Bethe--formed the heart of the bomb squad. In 1939, still officially enemy aliens, Fermi and Szilard co-invented the nuclear reactor at Columbia University, sketching out a three-dimensional lattice of uranium slugs dropped into holes in black, greasy blocks of graphite moderator, with sliding neutron-absorbing cadmium control rods to regulate the chain reaction. Fermi, still mastering English, dubbed this elegantly simple machine a "pile." The work moved to the University of Chicago when the Manhattan Project consolidated its operations there, culminating in the assembly of the first full-scale pile, CP-1, on a doubles squash court under the stands of the university football field in late 1942. Built up in layers inside wooden framing, it took the shape of a doorknob the size of a two-car garage — a flattened graphite ellipsoid 25 ft. wide and 20 ft. high, weighing nearly 100 tons. Dec. 2 dawned to below-zero cold. That morning the State Department announced that 2 million Jews had perished in Europe and 5 million more were in danger; American boys and Japanese were dying at Guadalcanal. It was cold inside the squash court, and the crowd of scientists who assembled on the balcony kept on their overcoats. Fermi proceeded imperturbably through the experiment, confident of the estimates he had charted with his pocket slide rule. At 11:30 a.m., as was his custom, he stopped for lunch. The pile went critical in midafternoon with the full withdrawal of the control rods, and Fermi allowed himself a grin. He had proved the science of a chain reaction in uranium; from then on, building a bomb was mere engineering. He shut the pile down after 28 minutes of operation. Wigner had thought to buy a celebratory fiasco of Chianti, which supplied a toast. "For some time we had known that we were about to unlock a giant," Wigner would write. "Still, we could not escape an eerie feeling when we knew we had actually done it." From that first small pile grew production reactors that bred plutonium for the first atom bombs. Moving to Los Alamos in 1944, Fermi was on hand in the New Mexican desert for the first test of the brutal new weapon in July 1945. He estimated its explosive yield with a characteristically simple experiment, dropping scraps of paper in the predawn stillness and again when the blast wind arrived and comparing their displacement. Fermi died prematurely of stomach cancer in Chicago in 1954. He had argued against U.S. development of the hydrogen bomb when that project was debated in 1949, calling it "a weapon which in practical effect is almost one of genocide." His counsel went unheeded, and the U.S.-Soviet arms race that ensued put the world at mortal risk. But the discovery of how to release nuclear energy, in which he played so crucial a part, had long-term beneficial results: the development of an essentially unlimited new source of energy and the forestalling, perhaps permanently, of world-scale war. Richard Rhodes is the Pulitzer-prize winning author of The Making of the Atomic Bomb

아인쉬타인은 루스벨트대통령에게 편지를 보냈다 아인쉬타인은 루스벨트대통령에게 편지를 보냈다

연쇄반응이 일어나야 불이 계속 탄다 International The Winter Book ALSO IN THIS ISSUE Nov. 12, 1945 Science By-Products of the Bomb ALSO IN THIS ISSUE Oct. 1, 1945 Table of Contents » Science Lily Electronic Piper Oct. 1, 1945 The atomic bomb may save more lives than it ended. At the University of Chicago, where man's first nuclear chain reaction simmered underneath a grandstand, the Institute of Radiobiology and Biophysics last week began work. Professor Raymond E. Zirkle and assistants began applying the new atomic techniques to the study of living organisms and their ills. During the frantic race to build the atomic bomb, many incidental discoveries were made and put on ice. Among the most important: the radioactive by-products of the uranium-graphite pile. Almost any substance, stuck in the pile's atomic furnace, comes out brimming with radioactivity. Where radiobiology formerly had only one strongly active element—radium—to work with, it now has dozens. All will be far cheaper and more useful than radium. What radium and X rays now do for cancer, the synthetic radioactive substances will presumably do better. The chances are that no more radium will be refined, though the uranium mined with it has a new, spectacular market. Another important by-product of the bomb is the "tagging" of vitamins, hormones and food compounds. Normal atoms in their molecules can be replaced, in part, by radioactive ones. As these move through a living organism, they can be followed by instruments sensitive to their radiation. Industrially, too, the atomic bomb may save more money than it cost ($2,000,-000,000). A. L. Baker of the Kellex Corp. of Oak Ridge (code name: Dogpatch), Tenn. last week issued an impressive list of non-atomic advances made while the bomb was in production. Among them: ¶ Improved defenses against industrial poisons. ¶ For the petroleum industry, better heatexchangers, new methods of separating gasoline fractions, better mass-spectrograph analysis. ¶ High-vacuum techniques, which will benefit many industries. ¶ More efficient gas pumps, some of which shoot out a stream of gas at a speed above that of sound (about 1,100 ft. per second). The collateral discoveries of the Manhattan Project, said Baker, totted up to around 5,000 new products, procedures and devices. The improvements in pumps alone, over the next 20 years, might be worth the cost of the bomb. Table of Contents » World "Do Not Forget" Paradox A String for UNRRA TWELVE POINTS Nov. 12, 1945 Just before the atomic bomb was first tested in New Mexico, a distinguished scientist offered an uncollectible bet: ten-to-one that the bomb would set off a chain reaction in the atmosphere. His colleagues were pretty sure that the planet would not go up in that particular explosion. But many scientists think that some future bomb, or series of bombs, may well have the power to end the world.

페르미에 의해 시카코 대학 풋볼 경기장 지하에서 최초로 원자에서 에너지가 끌어내졌다. - 연쇄반응을 실현 시켰다! Q31. Draw diagram of a nuclear reactor. What is the role of moderators in it? How are nuclear reactors used to generate electricity? Ans31. Nuclear reactors were discovered by Enrico Fermi. The nuclear reactor in which heavy water is used as moderator, is known as swimming pole atomic reactor. While the nuclear reactor in which graphite is used as moderator is known as atomic pile. Role of moderator is to slow down the fast moving secondary neutrons produced during the fission. They prevent the rate of chain reaction to be uncontrollably fast. Suitable materials to be used as moderator are heavy water,graphite, cadmium, or boron.

원자력 발전으로 전기를 얻는다 전구를 쓴다 [사설] 다시 주목받는 원자력발전 관련기사 9개국 공동 차세대 원자로 개발…과기부 "참여 포기" 한국, 차세대 원자로 개발 포기 파문 세계 원전 건설 시장의 절반을 거머쥔 웨스팅하우스가 일본 도시바에 넘어가게 됐다. 매각 대금은 예상의 두 배 이상인 자그마치 54억 달러에 이른다. 향후 원전 건설 붐을 미리 반영한 것으로 보인다. 최근 흐름만 봐도 분명하다. 러시아.이란.베네수엘라가 자원 민족주의를 노골화하면서 화석연료 가격은 폭등세다. 에너지 수입국인 미국.중국은 그 대안으로 원전에 눈을 돌리고 있다. 원전 건설 러시는 피할 수 없게 돼 있다. 왜 다시 원자력인가. 국제에너지기구에 따르면 2030년 화석연료 사용량은 지금보다 50% 이상 늘어날 것이라고 한다. 1년 전 발효된 교토기후협약으로 더 이상 무분별하게 화석연료에 의존할 수도 없는 상황이다. 어디선가 새로운 에너지가 나와야 한다. 최선책이자 가장 깨끗한 해법은 에너지 절약이다. 그러나 한계가 있다. 대체 에너지인 바이오 연료와 풍력.태양광 발전은 아직 갈 길이 멀고 값도 비싸다. 현실적으로 원전을 빼고는 대안을 찾기 힘들다. 미국 에너지부는 32년 만에 원전 건설 재개와 함께 핵연료 재처리 방침까지 내놓았다. 고유가에 맞선 초강수다. 러시아의 천연가스 공급 중단으로 몸살을 앓은 유럽도 마찬가지다. 독일과 이탈리아는 원전 건설로 방향을 틀고 있다. 중국도 원전 30기를 짓기로 했다. 지금 원전은 생존 수단이자 새로운 국가전략으로 재평가받고 있다. 우리나라는 울진 6호기 준공으로 현재 20기의 원전을 가동하고 있다. 전체 전력 중 원자력이 차지하는 비율은 38%로 비교적 높은 수준이다. 지난해에는 마침내 장기간 표류하던 방사성 폐기물 처리장 부지도 선정했다. 그러나 원전을 향한 세계의 새로운 조류를 강 건너 불 보듯 해선 안 된다. 우리의 에너지 자급률은 고작 3%에 불과하다. 중동지역 석유에 목을 매는 한 우리 경제는 늘 불안 요소를 떨칠 수 없다. 무엇보다 환경단체들의 원전에 대한 인식부터 고쳐야 한다. 경제성이나 에너지 안보 따위의 거창한 구호를 내세울 생각은 없다. 그러나 환경 유토피아로 꼽히는 스칸디나비아, 그중에서 환경론자 천국이라는 핀란드가 요즘 원전 건설에 열을 올리는 이유는 뭘까. 지금 지구촌은 고결한 비판론을 접고 불편하지만 현실을 직시하는 게 대세다. 지구 온난화 문제로 온실가스 배출량이 적은 원자력 발전을 새롭게 인식하고 있다. 우리 환경단체들도 환경 일방주의에서 벗어날 필요가 있다. 우리가 소모적인 논쟁에 휩싸여 있는 동안 세계 곳곳에서 원자력 발전이 다시 주목받고 있다.

원자력 이용 분야 – 건강 만들기

원자력 이용 분야 – 우주 정복 태양 Galileo Voyager Cassini 과학뉴스] 토성 고리서 `달 부스러기`나온 이유는 ? 혜성간 충돌에 의한 고리발생설 뒷받침 토성은 지구를 제외한 태양계 행성 중 가장 대중적 인지도가 높은 행성이다. 이 같은 유명세는 오로지 이 행성을 둘러싼 둥글고 거대한 고리 덕분이다. 목성 천왕성 해왕성에서도 고리가 관찰되지만 토성만큼 크고 아름답지는 않다. 지구에서 보면 고형 관처럼 보이는 이 고리는 수없이 많은 크고 작은 입자가 토성 둘레를 공전하고 있는 것이다. 이 고리는 어떻게 해서 토성을 둘러싸게 된 것일까. 토성 고리의 형성과 관련해선 대략 두 가지 학설이 존재한다. 하나는 토성 주위를 돌던 위성들이 충돌로 부서져 생긴 파편들이 시간이 지나면서 점점 더 잘게 부서졌다는 것이고, 또 하나는 토성을 구성하고 남은 물질들이 토성 탄생과 동시에 고리를 이뤘다는 것이다. 최근 미국ㆍ이탈리아 합동 토성 탐사선인 카시니호가 보내온 자료들은 토성 고리가 혜성 간 충돌에 의해 형성됐을 것이라는 첫 번째 가설을 뒷받침하고 있다. 미국 콜로라도주립대 연구진은 카시니호가 토성의 최외곽 A고리를 지나가면서 지름이 각각 60~140ｍ쯤 되는 8개 `달 부스러기`를 발견했다고 네이처지 최신호에 발표했다. 연구진에 따르면 이런 달의 잔해들은 밀도 높은 물질 사이를 유영하면서 마치 배가 물살을 가를 때처럼 앞뒤에 작은 바위 파편을 뿌려 놓는다. 이런 파편들의 중력은 다른 고리를 구성하는 물질에도 상호 영향을 미친다. 연구진은 "밀도 높은 물질들이 작은 프로펠러 모양으로 휘저어진 이런 현상은 토성에서 약 13만㎞ 거리에 있는 A고리의 3000㎞ 구간에 집중돼 있다"면서 "8개 파편을 모두 합쳐 볼 때 이들은 약 3000만년 전 혜성이나 운석 충돌로 부서진 지름 32㎞ 정도 위성에서 나온 것으로 보인다"고 말했다. 달 부스러기가 발견된 것은 토성의 여러 고리를 통틀어 이번이 처음이다. 연구진은 이들 파편이 생성된 시점이 토성에 이미 고리가 생긴 이후 시점일 것으로 추론하고 있다. 토성 고리의 최초 생성 시점은 최소 수억 년, 길게는 수십억 년 전까지 거슬러 올라간다. 연구진은 "달 부스러기들이 토성 고리들을 만들어 낸 태초 하나의 거대한 사건에서 남은 것으로 보기는 어렵다"면서 "이는 오랜 세월에 걸쳐 위성들이 충돌로 부서져 파편들이 만들어지는 과정이 거듭돼 고리가 생겼음을 시사하는 것"이라고 설명했다. 즉, 토성 고리는 한두 차례 일과성 사건의 결과물이 아니라 수억 년을 두고 누적된 혜성 간 충돌의 총체적 결과물이라는 얘기다. 지금까지 혜성 간 충돌에 의한 토성 고리 발생설은 다양한 크기의 파편이 발견되지 않아 근거가 다소 불충분했다. 혜성들이 충돌할 때는 지름 1㎞에서 몇 ㎝에 이르는 크고 작은 파편들이 생기게 마련이기 때문이다. 그런데 지난해 코넬대 연구진에 의해 큰 파편 4개가 발견된 데 이어 이번에 중간 크기 파편이 발견됨으로써 이 가설은 한층 힘을 얻게 됐다. [노원명 기자] [ⓒ 매일경제 & mk.co.kr, 무단전재 및 재배포 금지] 토성에서 나는 소리가 인기였다. 서울신문이 ‘토성에선 나는 소리는? NASA 첫 공개’ 기사에 삽입한 영상은 미국항공우주국(NASA)이 수집한 소리를 담은 것으로 21만회 이상의 플레이수를 기록했다. 카시니-호이겐스는 지난 1997년에 발사돼 토성과 그 주변 위성을 탐사한지 올해로 10주년을 맞이하는 우주탐사선이다. 미국항공우주국(NASA)은 우주탐사선 ‘카시나-호이겐스(Cassini-Huygens)가 수집한 토성과 그 주변 위성의 소리를 홈페이지에 공개해 관심을 모았다. 무인우주선 보이저호가 가는곳은? lushqt 2007.11.09 12:59 답변 3| 조회 264 질문자인 저는 일단 나이가 좀있습니다. 20대후반. 초딩같은 답변들은 삼가해주시고 정확한 답변만 부탁드립니다.   제가 초등학교때인가? 그때 미국에서 발사한 무인우주선 보이저호가, 목성인지 토성인지를 지났다고 들은 기억이있습니다. 그리고 몇주전에 보이저호가 명왕성을지나서 수명을 다할것으로 예상했지만 아직도 항해하고있으며, 지금 이순간에도 사진을 찍어서 전송하고 있다고 하더군요. 보이저호의 속도는 초속 31키로입니다. 우리 은하계의 그림을 보니, 태양계는 은하계의 왼쪽부분 즉 중심에서 3만광년정도 떨어진곳에 위치하더군요. 그리고 은하계는 가로로 10만광년입니다. 태양에서 명왕성까지의 거리는, 빛의속도로 6시간인데, 보이저호는 20년이상을 날아서 명왕성을 겨우 통과했을 뿐이므로, 저의 몇백대 후손까지 내려간다하더라도, 그나마 가까운 거리인, 은하계 왼쪽끝쪽으로 날아간다하더라도, 3만광년이 소모돼서 은하계를 벗어날수는 없을거라 생각합니다. 질문들어갑니다. 제 기억으로는, 보이저호가 출발하면서, 화성, 목성등등 태양계에 알려진 거의 모든 행성들을 촬영하면서 지나간걸로 알고있는데, 태양은 우리 은하계의 중심을 돌고있으며, 그이전에, 태양계안의 모든행성들도 태양을 돌고있습니다.  모든 별들이 일열로 멈춰있을경우는, 보이저호가 그사이를 통과하면서 사진촬영이 가능하지만, 화성을 촬영할당시, 목성은 정 반대방향을 돌고있을수도 있었을겁니다.  그리고, 명왕성의 경우, 지구보다 태양의 공전 반경이 훨씬 넓기때문에 보이저호의 항해로 반대쪽에있으면 아예 보이지 않았을수도 있겠죠.  Nasa측에서 이것을 예측하고, 보이저호의 항해속도를 가만해서 몇년도 몇월몇일에 발사하면 다 촬영할수있겠구나 하고 예상해서 쏘아 올린건가요? 두번째 질문 들어갑니다.  보이저호는 현재 어느방향으로 날아가고 있는건가요? 1.태.중....10   이것을 은하계로 가정했을경우, 1은 은하계 한쪽끝, 태는 태양계, 10은 은하계 반대쪽 끝으로 가정했을때, 보이저호는, 1을 향해 날아가고 있나요? 아니면 은하계 중심쪽을 향해 날아가고있나요? 그것도 아니라면, 그림상 위쪽인가요? 아니면 밑쪽인가요? 명왕성을 지났다고 하더라도 동서남북 어느방향으로든 날아갈수 있기때문에, 과학자들도 모르는 상황인가요? 초,중,고딩들은 답변 삼가해주시고, 천체학혹은, 물리학 전공자님들의 답변 기다리겠습니다. 추가된 질문 2007.11.10 04:36 추가 태양의 진행방향이라는 뜻이 뭔지 자세히 알려주시기 바랍니다. 태양쪽을 향해간다는것은 이론상 맞지않는데요. 왜냐하면, 명황성을 지났고, 태양계의 끝지점이라고 예상하는 헬리오시스에 위치해있다는 뜻은, 태양과 점점 멀어진다는 뜻인데, 태양의 진행뱡향이라는게 무슨 소리인지요? 신고 의견 2 이 질문에 답변 시 내공 2점(채택 시 +10)을 얻게 됩니다. 현재 답변들 3 등록순 | 최신순 re: 무인우주선 보이저호가 가는곳은? 96kyungyun 답변채택률 42.3% 2007.11.09 13:14 초딩임에도 내공이 탐나서 답변들어 갑니다... 네 맞습니다, 그러니까 그 많은 행성들을 다 봤죠.....하지만 그 계산을 위해 슈퍼컴이 동원되었다고합니다. 그만큼 계산이 어렵고 힘든거죠... 과학자들은 그것까지는 계산하지 않았죠. 필요가 없기 때문에,, 그래서 외계인을 만나면 우리 문명을 알려주기 위해 구리판에다가 금도금을한 레코드 판을 실었습니다. 여기에는 지구에서나는 자연의 소리와 50가지 말이 있습니다. 그리고 어느쪽으로 날아가는거는 태양계 내까지(말단 충격파)까지는 예측 가능하다고 하는군요. 이상 초딩의 허렵한 답변이었습니다. 채택부탁!!! ㅠㅠ 의견 쓰기 zxe14 답변채택률 66.7% 2007.11.09 15:55         무인우주선 보이저호가 가는곳이란       먼 외계로 가서 우리 인간들의 목소리를 그쪽에 녹음하여       우리의 존재를 외계인에게 알려 주는것입니다.       그러면 우리 지구도 있다는걸 알수있지요. 8ackspace 답변채택률 50.0% 2007.11.11 10:22 다른답변에 약간 불필요한 부분이 있어서 올림니다. 지금 말하시는 것은 보이저 1호 같은데요 보이저 1호는 지금 까지 인간이 만들어 낸 것 중에 가장 멀리간 물체 입니다. 1.네 그렇습니다. 예측하고 지나 간 것이지요. 약 175년 쯤에 한번 정도로 행성탐사하기 좋은 배열(?)이 된다고 합니다. 거기에 맞춰서 보이저 2호가 발사되고, 그다음 보이저 1호가 발사된 것입니다. 2. 이부분 수정헤씁니다. 보이저 1호는요 궤도 위쪽으로 갔구요 보이저 2호는요 궤도 아래쪽을 갔어요 정확한 뱡향은 잘 모르겠네요. .. 오늘의뉴스 | 뉴스속보 | 종합 | 정책 | 정보통신 | u미디어 | 비즈테크 | 콘텐츠 | 글로벌 | 경제과학 | 디지털산업 | 퍼스널 | 열린마당 | 영상뉴스 | 보도자료 광고안내 | 구독신청    [20 면 경제과학] •주요 서비스 •번역 의뢰 •센터 소개 Export of Semiconductor, Wireless Communications and Display Will Thrive Next year, the export of semiconductor, wireless communications and display is predicted to increase includin… Home > 경제과학 [우주강국에 도전한다](1)중장기 개발 계획 이기사 번역의뢰하기 SoP, SiP 설계 및 기술ㆍ시장동향과 사례 세미나 IT리더 남충우 사장님, ALEX 특허로~ 새출발 하셨군요! 　지난달 제1차 우주개발진흥기본계획이 확정됐다. 오는 9월에는 우리나라 첫 우주인이 탄생한다. 또 내년에는 전남 고흥의 ‘나로 우주센터(가칭)’가 완공돼 국내에서 제작된 과학기술위성 2호가 우리 발사체에 실려 지구 궤도에 쏘아 올려 질 전망이다. 우리나라에서도 이제 우주 시대가 열리고 있는 것이다. 이에 전자신문은 항공 우주 연구개발(R&D)의 본산인 한국항공우주연구원과 공동 기획으로 우주 강국에 도전하고 있는 우리나라의 우주 개발 기술과 정책·계획을 점검하고 향후 나아갈 방향을 제시한다. 　 　2030년 12월 나로 우주센터. 거대한 발사체가 굉음을 내며 2톤이 넘는 우주선을 싣고 힘차게 솟아오른다. 우리나라 처음으로 식민지 건설을 위한 달 탐사 길이다. 이 우주선 발사에는 15년 전 만들어진 ‘한국항공우주국’이 중심이 돼 R&D를 주도했다. 이 탐사가 성공한다면 달의 일부분은 향후 우리나라에 자원을 제공하는 식민지가 될 것이다. 이와 함께 한국항공우주국은 2040년께 화성 탐사 계획도 내놓았다. 　우리나라 우주 개척에 관한 가상 시나리오다. 물론 나로 우주센터에서는 로켓 발사각이 안 나와 위와 같은 대형 발사체를 쏘아 올릴 수 있는 상황은 아니지만 우리나라가 자체 선발한 우주인을 태운 달 탐사가 불가능한 것만은 아니다. 　과학기술부와 한국항공우주연구원이 항공 우주 관련 전문가의 지원을 받아 지난달 제1차 우주개발진흥기본계획을 완성했다. 이 계획안에 따르면 2030년께에 이르러 우리나라는 우주 기술에 관한 선진국 수준의 안정화 단계에 진입할 전망이다. 　◇갈 길 먼 우주 개발=2015년까지 항공 우주 과학기술계가 풀어야 할 과제는 모두 16개다. 가장 중요한 제1 과제는 위성체 기술 개발의 자립화다. 차세대용 고속 기동 위성 본체 기술 및 대구경 광학 카메라 기술·레이더영상탑재체(SAR)·위성체 플랫폼 제작 능력 등을 확보하는 것이 급선무다. 　항우연 측은 2010년까지 SAR가 탑재된 다목적 실용위성 5호를 개발할 계획으로 기술 개발을 추진 중이다. 이와함께 발사체 기술 개발의 자립화와 저가 소형 위성의 수출 등도 현안이다. 항우연은 현재 위성 영상의 수출과 우주 전자부품의 산업화를 위한 연구소 기업 설립을 추진 중이다. 　과기부와 항우연은 중장기적인 관점이긴 하지만 우주 탐사 프로그램도 염두에 두고 있다. 미국이나 유럽·일본 등 우주 선진국의 국제 우주 탐사 프로그램에 참여해 기초기술을 습득하는 방안을 검토 중이다. 궁극적으로는 우주 식민지를 둘러싼 경쟁 대열에 나설 수밖에 없을 것으로 보고 있다. 　이외에 정밀 대형위성시험동 확장 및 로켓 엔진 조립·연소시험동 구축 등 인프라 보강, 우주 관련 고급 인력의 양성 사업, 법·제도적인 우주 개발 체계 확립 등이 중장기적으로 진행된다. 과기부는 이를 위해 오는 2016년까지 총 3조5719억원의 예산이 투입돼야 할 것으로 예상하고 있다. 　◇그동안 뭐했나=우주 기술 개발에는 크게 위성체와 발사체 등 2개 부문으로 나눌 수 있다 위성체 부문에서 우리나라는 현재 총 6기의 위성을 개발 중이다. 　다목적 실용위성 3호와 3A호·5호 등은 지상 관측 및 적외선 지구 관측, 전천후 지상 관측 용으로 각각 2009년, 2013년, 2009년 완성된다. 또 소형 위성인 과학기술위성 2·3호가 우주 환경 측정 및 선행 기술 시험 우주 관학 연구용으로 현재 개발 중이다. 이외에 내년에 정지궤도 위성인 통신해양기상위성이 공공통신망 구축과 기상해양 관측용으로 현재 개발되고 있다. 　다목적 실용위성 1·2호는 현재 운영 중이며 우리별 위성 1·2·3호와 과학기술위성 1호는 임무를 모두 종료한 상태다. 발사체 부문에서는 지난 93년과 98년 고체 추진 방식의 과학로켓 KSR-Ⅰ, 98년 단분리형 과학로켓 KSR-Ⅱ이 발사에 성공했다. 2003년에는 액체추진 방식인 KSR-Ⅲ이 충남 안흥 ADD 시험장에서 성공적으로 시험됐다. 　현재는 내년 나로 우주센터에서 100㎏급 위성을 쏘아 올릴 KSLV-Ⅰ을 개발 중이다. 이 발사체는 33m크기에 1단은 액체, 2단은 고체 연료를 사용한다. 　◇지금 해외에선=지난 68년 아폴로 11호로 인간으로는 처음 달에 발을 내디딘 미국은 오는 2010년 국제 우주정거장 건설, 2012년 유인 탐사선 개발, 2018년 유인 달 탐사 계획을 내놓았다. 　러시아는 최근 우주산업 재건 계획을 발표하고 총 24기 위성으로 구성되는 독자 위성항법시스템 구축을 오는 2011년 완공을 목표로 추진하고 있다. 　이 위성항법시스템은 유럽에서도 갈릴레오프로젝트로 이름 붙여 오는 2012년 상용 서비스에 착수한다. 유럽은 지난 2001년부터 태양계를 탐험하는 오로라 프로그램을 진행하고 있다. 　일본의 경우는 위성항법시스템 개발해 달 유인 과학기지 건설·태양계 탐사·은하계 관측 기술 개발을 지속 추진하고 있으며, 중국은 유인 우주선 선조우 5·6호의 성공적인 발사에 힘입어 2017년 유인 달 탐사를 진행 중이다. 　김창우 과학기술부 우주기술심의관은 “오는 20일 우주 개발 계획에 대한 공청회 외에도 3∼4차례 전문가가 참여하는 토론회 등을 열어 구체적인 실행 계획을 마련할 것”이라며 “국가 간 기술 통제가 심한만큼 기술 자립화를 통한 경쟁력 확보가 관건”이라고 말했다. 　 ◆인터뷰-백홍열 항우연 원장 　“지난달 만들어진 우주개발진흥기본계획은 급변하는 국내외 우주 기술의 발전과 정책 및 환경 변화에 대응하기 위한 새로운 국가 우주 개발 육성 전략이라고 보면 됩니다. 기존의 사업 중심에서 핵심 기술 확보로 패러다임이 달라진 것도 눈여겨 볼 만 합니다.” 　백홍열 한국항공우주연구원장은 우리나라 우주개발진흥기본계획에 대해 나름대로 의미를 부여하며 “항공 우주 분야야말로 고부가가치 미래 산업”이라고 말했다. 　“미래전은 우주 항공전이기에 국가 안보 차원에서도 중요하지만 우주 개발을 통해 초정밀 가공·조립 기술의 확보나 극한 우주 환경을 이용한 신소재, 신의약품 개발이 가능해 집니다. 또 기상·환경·재난 감시, GPS, 위성통신 등 대국민 공공 서비스도 모두 우주 기술 개발을 통해 이루어질 것입니다. 우주 기술이야말로 신산업 창출의 돌파구가 되는 셈입니다.” 　백 원장은 항공 우주 기술 개발의 중요성을 재차 강조하며 우리나라 기술 수준에 대해 “현재 고해상도 1m 급 영상을 획득할 수 있는 위성 개발 능력과 액체추진 과학로켓 개발에 이은 100㎏급 소형 위성 발사체 제조, 위성 관제 시스템 등의 기술을 보유하고 있다”고 설명했다. 　이와함께 백 원장은 “한국형 발사체 개발 및 전천후 영상 획득 위성 개발을 완료하는 시점에 이르면 우주 탐사에 대한 계획이 실행될 것”이라며 “이 때가 되면 과학적인 연구 및 실생활에 기여할 수 있는 우주 연구로 이어질 것”이라고 덧붙였다. 　“그동안 우리나라의 우주 개발은 인공위성, 우주발사체 등 하드웨어적인 연구 개발에 집중해 왔던 것이 사실입니다. 이는 우주 분야의 자립을 위해서는 인공위성 등 우주 인프라의 구축이 무엇보다 필요했기 때문입니다. 앞으로는 우주 자산의 확보와 더불어 우주 활용과 임무 중심의 소프트웨어적인 우주 개발도 함께 이루어질 것으로 봅니다.” 　대전= 박희범기자@전자신문, hbpark@etnews.co.kr 최신 센서/센서네트워크 기술 분석 교육 과정 (12월13일~14일) - 물리센서(가전/로봇/자동차)를 중심으로 - ○ 신문게재일자 : 2007/07/18      ASUS G1S 게임 전용 노트북 인체공학기술, 모바일 게임, 초슬림,혁신적그래픽, 인텔® 센트리노® 듀오 www.asus.com Prober 엠에스텍 Probe Station 직접개발, 생산Total 전문업체 DC, RF, TFT. www.probestation.or.kr 복사 제본 출력 모두카피 A415원, 제본 500원,칼라150제안서, 파워포인트 출력, 와이어제본 www.moducopy.co.kr • 탄소나노튜브, 단일벽 시대 진입 • 알뜰 소비는 `신용카드`로 • 내리막길 증시, 커지는 한숨소리 • [인터뷰]김준하 GIST 담수화연구센터… • 증시, 대선모드로 전환 경제과학 전체보기 종합  |  정책  |  정보통신  |  u미디어  |  비즈테크  |  콘텐츠  |   글로벌  |  경제과학  |  디지털산업  |  퍼스널  |  열린마당 200자평(0) 필명비밀번호 내용 관련기사 •[우주강국에 도전한다]결산 좌담회08/21 15:10:00 •[우주강국에 도전한다](4)항공우주 산업기반 조성 “기지개”08/07 11:20:01 •[우주강국에 도전한다](3)발사체07/31 11:25:00 •[우주강국에 도전한다](2)인공위성07/24 10:25:00 (6부) 미국 로봇현장을 가다 ③하와이대 수중로봇 연구실 (6부)미국 로봇현장을 가다 ②하와이 미래학 연구소(HRCFS) (6부)미국 로봇현장을 가다①어번 챌린지(Urban Challenge) (5부)로봇강국으로 가는길⑪지방 로봇클러스터 (5부)로봇강국으로 가는길⑩수술로봇 (5부)로봇강국으로 가는길⑨무인자동차 美 PMP 구매때 고려 사항 유럽 멀티태스커 온라인 활용 美 SNS 이용 현황 美 고소득계층 인터넷 활용 실태 美 건강 관련 UCC 활용 실태 美 게임 종류별 선호도 조사 전자신문사 : 회사소개 | 독자서비스 | 지면광고안내 | 행사문의   전자신문인터넷 : 회사소개 | 이용약관 | 개인정보취급방침 | 온라인광고안내 Copyrightⓒ 2000-2007 ELECTRONIC TIMES INTERNET CO., LTD. All Rights Reserved NASA 우주선 갈릴레오, 내주 목성 충돌 후 소멸 케블라(사진) 섬유는 철보다 인장강도가 5배가 강하고, 가벼우며, 뛰어난 내열성과 낮은 절단율을 특징으로 하는 파라계(系) 아라미드(Aramid) 강화 섬유다. 높은 강도와 경량화가 요구되는 산업분야에서 다양하게 적용돼 항공기 내장재· 로프·광케이블·산업보호복·방탄복 등에 사용된다. 듀폰의 케블라는 목성탐사용 로켓 갈릴레오의 낙하산과 국제우주정거장의 피복소재로 활용된 바 있다.손병문 기자 moon@ebn.co.kr [EBN화학정보]이 기사에 대한 소유권 및 저작권은 (주)이비뉴스에 있으며 무단전재 미국 항공우주국(NASA)의 목성탐사 우주선 갈릴레오호가 다음주 목성에 충돌함으로써 14년 간의 임무를 마치고 우주에서 사라진다. 갈릴레오호는 애초 계획의 약 3배인 35번째로 목성 궤도를 돈 후 오는 21일 오후 3시49분께(미 동부시간) 시속 10만8천마일(시속 약 17만3천700㎞)의 속도로 목성 대기권으로 뛰어들게 된다. 갈릴레오호는 대기권에 진입하면서 발생하는 엄청난 열로 인해 공중 분해될 예정이다. 이는 갈릴레오호가 목성의 위성인 유로파의 얼음 표면에 충돌해 지난 89년 발사 이후 갈릴레오호에 기생하고 있는 미생물이 유로파를 오염시키는 것을 방지하기 위한 조치다. 1개 행성만한 크기의 위성인 유로파는 태양계에서 외계의 생명체가 존재할 가능성이 가장 큰 것으로 평가돼왔다. 만일 지구의 미생물이 유로파에 전파될 경우 향후 유로파의 토착 생명체에 대한 조사를 어렵게 만들 수 있다. NASA는 대개 태양계 내 다른 행성이 오염되는 것을 막기 위해 우주선 내 미생물을 모두 제거하지만, 갈릴레오호는 애초 목성 주위의 궤도에 남겨둘 예정이었기 때문에 이같은 조치를 받지 않았다. (패서디나<美 캘리포니아州> =연합뉴스) 태양

원자력은 두 얼굴을 가지고 있다. 좋은 점을 활용해야 하고 나쁜 점은 잘 관리해야 한다. 원자력은 두 얼굴을 가지고 있다. 좋은 점을 활용해야 하고 나쁜 점은 잘 관리해야 한다. 선한 얼굴 원자력 에너지 원자력의 평화적 이용: 의학, 공학, 산업 악한 얼굴 원자력 위험성: 핵 폭탄, 핵폐기물

과학을 하면 인생이 재미 있다. 관찰력을 기르자 상상을 하자 끈질기게 탐구하자 끈질기게 기록을 하자 한번 더 보자 한번 더 생각하자 그림을 그리자 상상을 하자 겉으로 드러나지 않는 것을 상상하는 힘을 기르자 끈질기게 탐구하자 마리퀴리의 창고, 에디슨의 전구, 석주명의 나비 책을 읽자: 파브르의 과학이야기, “얘들아 정말 과학자가 되고 싶니?”김성화, 권수진 끈질기게 기록을 하자

여러분 사랑해요. 감사합니다. 한국원자력연구원 맹 완 영