[Ethan Clive Osgoode]

I just want to be clear, when you look up into the night sky and aim a telescope at Saturn, do you really believe that Saturn is exactly where you are pointing the telescope?

According to you, the actual position of Saturn is 10AU * 2.1 degrees/AU = 21 degrees from its observed position in the sky. People who are on some serious drugs might believe that. Do you believe it?

[LeGrande]

According to you, the actual position of Saturn is 10AU * 2.1 degrees/AU = 21 degrees from its observed position in the sky. People who are on some serious drugs might believe that. Do you believe it?

Do you really believe that if someone on Saturn had a special light that was instantaneous that they would appear in the same exact position that you would see them with our normal light? LOL

Let me clue you in on a little secret. The speed of light is 299,792,458 metres per second and once the photons are sent on their way they are independent of the body that sent them. At night when you point your stick at Saturn or a distant star you are merely pointing your stick in the direction that the light at the time is hitting your eyeballs. It has nothing to do with where those objects actually are.

[mrjesse]

Said LeGrande: I just want to be clear, when you look up into the night sky and aim a telescope at Saturn, do you really believe that Saturn is exactly where you are pointing the telescope?

According to you, the actual position of Saturn is 10AU * 2.1 degrees/AU = 21 degrees from its observed position in the sky. People who are on some serious drugs might believe that. Do you believe it?

That's a great point. Now Saturn does orbit the sun at the rate of 29.5 years per full orbit, or .0000232021 degrees per minute. Saturn, at 9AU, would be about 75 light minutes away. So the angle changed in Saturn during the time it takes its light to reach us would be .0000232021 degrees. That's light time correction.

But as you say, in LeGrande's world, 75 light-minutes times the earth's rotation would be 18.75 whole degrees!

Or what about Jupiter, which is 30AU out? That's roughly 60 degrees lagged. Are you saying that if I were to look up at night with a super powerful telescope and see Jupiter, it would be actually 60 degrees off?

What if there were a reasonably stationary star 86.5722414651AU away (that's 12 light hours) - if we looked up and saw it at night, would it really be on the other side of the world? (Hey - it might have moved a little - but it aint gonna have moved 180 degrees in 12 hours!)

Thanks,

-Jesse