[LeGrande]

If the sun is orbiting, then the light will actually follow a curved path -- and could go through a curved tube -- on its way to the earth. If the sun is not orbiting, on the other hand, then the light is going straight and will only go through a straight tube.

Ahh I think I see your misconception. light always travels in a straight line (shortest path through space-time in a vacuum, but lets not quibble). It is only your perception that it curves, and the perception is the same on both ends but the perception is wrong.

[mrjesse]

Ahh I think I see your misconception. light always travels in a straight line (shortest path through space-time in a vacuum, but lets not quibble). It is only your perception that it curves, and the perception is the same on both ends but the perception is wrong.

Well, I'm pretty certain that if I stand out in the yard, spraying the garden hose in a solid jet, swaying right to left that the water at any instant forms an arc shape at peak angular rate. Each drop is traveling in a straight line, but the overall swath of water isn't straight. But you're right in that the drops themselves travel in a straight line. (and that light travels in a straight line.) I would like to retract my claim that light could go through a bent tube.

Thanks,

-Jesse