unit 10

Today in class we had reviewed for our unit 9 test for about an hour then took our test which ended at about 10. The rest of class was used for learning about Unit 10 which is about light. Light cannot be seen unless it gets to your eyes. For example you have a sandwich, as you pick up the sandwich you lose sight of some of the sandwich due to the light of the sandwich not being able to reach your eyes because your hand is blocking it. There are many different types of lights used for many different types of situations. For example the military uses infrared to see through walls and detect enemy presence without the enemy knowing. They can do this because our eyes cannot see infrared light which makes it good for when you're being a secret spy agent like 007. So far it is predicted that the speed of light is the fastest thing EVER and nothing will be able to go faster than it. But this hasn't been tested yet so we'll never know until then. Light travels at 299,792,458 meters per second. Many people think that "light years" is a unit, it is not it simply is the distance travelled going at the speed of light you can figure this out by using D = VT. Time would be one year and velocity would be 3x10^8. 

This is a computer screen, usually you can see all of it. But because my hand is blocking some of the light from the computer screen I can't see it, instead i can see the light coming off my hand which is why i can see my hand.