You're reading this to learn a little about light. Well, you're going to learn a lot. Right now scientists are still trying to figure out the connection betIen light and matter. Scientists began studying light a long time ago. A big breakthrough happened when Newton started to break light up with prisms in the late 1600s. Only recently have scientists begun to understand how light works and its connection to everything in the Universe.
How "Fast" is the Speed of Light?
Light travels at a constant, finite speed of 186,000 mi/sec. A traveler, moving at the speed of light, would circum-navigate the equator approximately 7.5 times in one second. By comparison, a traveler in a jet aircraft, moving at a ground speed of 500 mph, would cross the continental U.S. once in 4 hours
Let's take a moment to talk about visible light. As you can tell by the name, visible light is the light I can see as humans.
More specifically, you see the light that is not absorbed by objects. For example... Green plants are green because they absorb all of the colours of the visible spectrum except the green colour (you could also say the green wavelengths). A red wall is red to your eyes because it is not absorbing light from the red wavelengths. Mirrors reflect all of the colours of visible light.
We describe the world the way we see it as humans. Other living things on Earth see the world in different ways. Dogs only see things in black, white and gray. Some insects see colours that none of us can see. When you are learning about visible light you should remember I mean visible to humans. And then of course I should mention that not all humans can see all the colours. There...