[grey_whiskers]

Sorry, dudes, I've had insomnia and not slept all night. Let me take a brain-fog stab at it. The problem is not that the light diverges from its path, it is that the rotation of the earth means that the observer is no longer seeing each ray of light from the same angle as he would have, absent the earth's rotation. And so I think LeGrande is suggesting that, just like a mirror, you get an optical illusion (so to speak). the human eye traces light back to its *apparent* source.

Two possibly complicating factors here: one is the problem at sunrise and and sunset, when the motion of the earth is parallel or antiparallel to the direction of the light, this divergence is minimized. Also, the earth is not a sphere, it is an oblate ellipsoid (i.e. a beachball with an elephant sitting on it, not a football).

Also, you have the issue of what the ancients called "lack of stellar parallax" -- the distance between the stars and the earth is so great, one can travel anywhere one likes on Earth without affecting the apparent relative positions of the stars. I'm just a little too tired to decide if something analagous would kick in here.

Cheers!

[LeGrande]

And so I think LeGrande is suggesting that, just like a mirror, you get an optical illusion (so to speak). the human eye traces light back to its *apparent* source.

True. Add in the fact that you are seeing back in time (8.3 minutes in the case of the Sun) and you have got it.

Two possibly complicating factors here: one is the problem at sunrise and and sunset, when the motion of the earth is parallel or antiparallel to the direction of the light, this divergence is minimized. Also, the earth is not a sphere, it is an oblate ellipsoid (i.e. a beachball with an elephant sitting on it, not a football).

Correct again.

Also, you have the issue of what the ancients called "lack of stellar parallax" -- the distance between the stars and the earth is so great, one can travel anywhere one likes on Earth without affecting the apparent relative positions of the stars. I'm just a little too tired to decide if something analagous would kick in here.

Correct again. The distances are so far that Triangulation doesn't work. Remember that we are also looking into the past and that in some instances (Hubble) we are looking billions and billions of years into the past, at objects that no longer exist.