2015 세계 빛의 해

What are sources of light? 빛의 원천? 태양 불 번개 별

What is a source of light? 빛의 원천?

Luminous vs. non-luminous 광원 vs. 비-광원  Light bounces into our eyes 빛을 반사 시킨다 Luminous 광원 (光源)  create light 빛을 생성

How does light travel? 빛은 어떻게 이동할까? Light travels in straight lines 빛은 오로지 직진만 합니다

Can light travel through everything? 빛은 물체를 통과할 수 있을까? Light cannot bend (빛은 휘어질 수 없어요) Shadows are made because light cannot travel through some objects (그림자는 빛이 통과하지 못하는 곳에 만들어져요) Things that light cannot travel through are opaque (불투명한 물체에서는 빛이 잘 통과하지 못해요) Light can travel through transparent objects. (빛은 투명한 물체를 잘 통과해요) Translucent objects let a bit of light through. (반투명한 물체는 빛을 조금만 통과시켜요)

Where does light come from? 빛은 어디서 오나? Nucleus surrounded by orbiting electrons 전자는 핵을 감싸고 있어요 Heat atom up 원자를 달구면 Electron jumps into bigger orbit 전자가 더 큰 전자 궤도(위치)로 뛰어요 Cool atom down 원자를 식히면 Electron jumps back Electron emits light energy 전자가 제자리로 돌아오고, 빛을 내보내요

What colour is the light? 빛의 색깔은? Depends on how big the jump between orbits was 궤도간의 이동이 얼마나 큰가에 따라서 The bigger the jump, the higher the energy 더 멀리 뛸수록 더 많은 힘(에너지)을 내보내요 The energy determines the colour 그 힘에 따라 빛의 색깔이 달라져요

파동은 에너지를 한 지점에서 다른 지점으로 전달할 수 있어요 Light is a wave. Can waves transfer energy? 빛은 파동(波動). 파동은 에너지를 전달 할 수 있을까? A wave is a way to transfer energy and information from one point to another without sending any material 파동은 에너지를 한 지점에서 다른 지점으로 전달할 수 있어요

Wavelength and Frequency 파장(波長), 주파수(周波數) The wavelength of a wave is the distance between a point on one wave and the same point on the next wave. 파장이란, 한번의 주기가 가지는 길이, 이 길이에 따라 빛의 색깔이 달라져요 The colour of the light depends on the wavelength The frequency of a wave is the number of waves produced by a source each second. 주파수란, 단위 시간동안 반복되는 파장의 횟수

How fast do light waves travel? 빛의 속도는? All kinds of light travel at one speed 모든 빛은 속도가 같아요 Faster than sound Really fast! 소리가 이동하는 속도보다 빨라요! See lightning before we hear thunder 천둥소리는 번개가 치고 나중에 들려요 See fireworks before we hear the BANG 불꽃놀이에서 폭죽이 터지면 소리는 나중에 들려요 300,000 km / s = 300,000,000 m / s Earth is 149,600,000 km from sun 지구는 태양으로부터 149,600,000 km 떨어져 있어요! Light travels as waves. These are transverse waves, like the ripples in a tank of water. The direction of vibration in the waves is at 90° to the direction that the light travels. Light travels in straight lines, so if you have to represent a ray of light in a drawing, always use a ruler. Unlike sound waves, light waves can travel through a vacuum (empty space). They do not need a substance to travel through, but they can travel through transparent and translucent substances. The table summarises some similarities and differences between light waves and sound waves: 𝑆𝑝𝑒𝑒𝑑= 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑇𝑖𝑚𝑒 𝑇𝑖𝑚𝑒= 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑆𝑝𝑒𝑒𝑑 = 149,600,000 300,000 =498.67 𝑠=8.32 𝑚𝑖𝑛𝑢𝑡𝑒𝑠

Light waves? wavelength Light is made of tiny photons which carry electromagnetic energy 빛은 전자기파(電磁氣波) 에너지를 전달하는 아주 작은 입자(광자, 光子)로 이루어져 있어요 The intensity of light depends on the amount number of photons in the light 빛의 세기는 광자의 갯수에 따라 달라져요

굴절 느린 Can we separate the different energies? 빠른 빠른 빛을 여러가지 색깔(에너지)로 분리할 수 있을까요? 굴절 빠른 빠른 느린 Light travels as waves. These are transverse waves, like the ripples in a tank of water. The direction of vibration in the waves is at 90° to the direction that the light travels. Light travels in straight lines, so if you have to represent a ray of light in a drawing, always use a ruler. Unlike sound waves, light waves can travel through a vacuum (empty space). They do not need a substance to travel through, but they can travel through transparent and translucent substances. The table summarises some similarities and differences between light waves and sound waves: When light passes through some objects, it slows down 빛이 어떤 물체를 통과할때, 이동 속도가 느려져요 White light contains all colours 백색광은 모든 색깔을 가지고 있어요

Invisible Balls 투명한 공과 빛의 속도 When light passes through some objects, it slows down 빛이 어떤 물체를 통과할때, 이동 속도가 느려져요 Light travels as waves. These are transverse waves, like the ripples in a tank of water. The direction of vibration in the waves is at 90° to the direction that the light travels. Light travels in straight lines, so if you have to represent a ray of light in a drawing, always use a ruler. Unlike sound waves, light waves can travel through a vacuum (empty space). They do not need a substance to travel through, but they can travel through transparent and translucent substances. The table summarises some similarities and differences between light waves and sound waves:

Other examples of waves 파동의 다른 예 wavelength Light travels as waves. These are transverse waves, like the ripples in a tank of water. The direction of vibration in the waves is at 90° to the direction that the light travels. Light travels in straight lines, so if you have to represent a ray of light in a drawing, always use a ruler. Unlike sound waves, light waves can travel through a vacuum (empty space). They do not need a substance to travel through, but they can travel through transparent and translucent substances. The table summarises some similarities and differences between light waves and sound waves: Sound waves in a gas!