Entry 20

There are little things about light which everyone knows about but don't really consider. Light reflects off all surfaces to varying degrees. We all know more light reflects off white walls than off black but when was the last time you really compared the two. The walls of my room are a simple shade of white and because of that I almost never have to turn on the lights. There is only one window light can enter from and yet even with the blinds close there is more than enough light for me to work in. What's more, all the surfaces in the room are more or less equally lit from floor to ceiling. How does a light coming in from above reach the ceiling of my room? What are the mathematics behind it? When writing lighting programs how did early developers program virtual light to do this? What does the spread of a light representing the sun say about the environment's conditions.