|MadSci Network: Astronomy|
I had a prof. who was trying to make the point that the most obvious answer is not always the correct answer. The obvious answer is the earth is casting a shadow , so there is no sunlight in the atmosphere. He says that because the sun is behind us, the sunlight is travelling away from us so the light is red shifted; so, in fact, there is plenty of light but it is not in our visual spectrum because it is infrared. I say that light cannot be red shifted unless the source of the light itself ( the sun ) is travelling away from the observer at a very fast rate; and that there is just as much infrared duting the day as there is at night. Space is black unless there is something to illuminate it such as atmosphere or surface. So, the fact that there is no sunlight in the atmosphere makes the sky dark. Am I right? or is he? neither? He also says you can see starlight without an atmosphere or a surface. I say your eye is the surface. Also even if the light was red shifted, you would be able to look 90 degrees beyond the horizon into space where the light would not be travelling away from you, hence the horizons would never go dark. Barry
Re: Why is the sky dark at night?
Try the links in the MadSci Library for more information on Astronomy. MadSci Home