we were discussing this in sportslife &reck. one girl said that you could not becuz the earths atomic number or something. there was another girl in the class she is so smart and bewtiful. do you guys think i should ask her out?
For all intents and purposes yes, slight changes due to objects in the way such as dust, and gravitational lensing will all slightly alter the velocity of the light
If for example you had some instantenous communication (telepathy say) with a twin 2000 light years away. If you asked him what he saw through a telescope, then yes, he should see the Earth 2000 years ago. But there would be no way for you to get there to see it.
Well to keep the wormhole's open and to stop it collapsing into a blackhole when a human walks through, it requires the equivalent in negative energy of what you would get of normal energy if you liberated all the mass of Jupiter into energy. Practically near impossible.
But you can in theory. A human will most likely never see themselves, but an atom might.
Also there would be a point inside a blackhole where the light would bend itself around and you could see yourself. Of course that would involve crushing you into a insey pulp.