Okay, some questions about the speed of light:
If I'm not mistaken, the speed of light slows down when passing through water. That's the explanation I've been given as to why straws look bent in a water glass.
First question: Is that correct?
Second question: If the first question is correct, what is the speed of light through water?
Third question: Does light decrease speed in our atmosphere compared to space's vacuum?
Fourth question: If a photon is skimming through space at the speed of light, then slows down as it passes through, say, Earth's atmosphere, does it speed up after exiting the atmosphere back into space? If so, what speeds it back up?