1
00:00:00,000 --> 00:00:07,500
Hello everyone, this is Kori and today we are going to continue talking about heat and light.

2
00:00:07,500 --> 00:00:18,679
We will be focusing on the basic laws of light. Remember, light is radiation we can see with our

3
00:00:18,679 --> 00:00:33,899
eyes. We need light to see objects and determine their shape, size, and color. Reflection is

4
00:00:33,899 --> 00:00:43,000
one of the basic laws of light. Reflection occurs when light energy

5
00:00:43,000 --> 00:00:53,119
bounces off a surface and changes direction. Let's discuss how a mirror

6
00:00:53,119 --> 00:01:06,530
reflects light. So light travels in a straight line from the object to the

7
00:01:06,530 --> 00:01:21,299
mirror. The mirror reflects the light causing it to change direction. Now the

8
00:01:21,299 --> 00:01:32,340
boy can see the reflection of the object in the mirror. So light energy hits a

9
00:01:32,340 --> 00:01:39,099
mirror. The light energy is reflected and the boy sees a reflection in the mirror.

10
00:01:39,099 --> 00:01:49,280
Reflection can be specular or diffuse.

11
00:01:50,879 --> 00:01:58,219
Specular reflection is when light rays are reflected off a surface in one direction.

12
00:02:01,849 --> 00:02:04,310
Mirrors produce specular reflection.

13
00:02:06,719 --> 00:02:14,840
Diffuse reflection occurs when a surface reflects light rays in lots of directions.

14
00:02:14,840 --> 00:02:28,979
This happens when a surface is rough. This causes the light to reflect at different angles. A surface

15
00:02:28,979 --> 00:02:38,479
may look smooth to us, but actually be rough at a microscopic level. So you may need a microscope

16
00:02:38,479 --> 00:02:54,580
to see that the surface is rough. Refraction. Refraction occurs when light

17
00:02:54,580 --> 00:03:03,800
passes through some transparent substances and the light energy changes

18
00:03:03,800 --> 00:03:13,280
direction slightly. Remember, transparent substances are substances that allow all

19
00:03:13,280 --> 00:03:27,610
all light to pass through. Let's look at how water causes refraction. The water in this cup

20
00:03:29,610 --> 00:03:39,710
changes the direction of the light energy that passes through it. If we look closely

21
00:03:39,710 --> 00:03:48,270
at the straw, you can see that the straw appears to be bent. This is because water is

22
00:03:48,270 --> 00:04:08,280
refracting the light. White light. White light is made up of all the colors combined together.

23
00:04:08,280 --> 00:04:23,500
red, orange, yellow, green, blue, violet. We can divide white light into colors by refraction

24
00:04:23,500 --> 00:04:34,379
because each colored light travels at a specific wavelength. So white light is made up of all of

25
00:04:34,379 --> 00:04:43,420
colors, but we can divide these colors because the light travels at different speeds. They

26
00:04:43,420 --> 00:04:52,939
travel at different wavelengths. Red has the longest wavelength and violet has the shortest

27
00:04:52,939 --> 00:04:58,459
wavelength. The wavelengths are different for each color, so we can separate them.

28
00:04:58,459 --> 00:05:09,339
Okay, that's all for now. I hope you can continue to look on the bright side. Goodbye!