So, seeing events that happened a thousand years ago by looking at galaxies a thousand light years away may aswell be happening right now because "light years" literally means a distance in time AND space?
If you are in the correct observational frame, which would be the (limiting) frame travelling at lightspeed from the distant galaxy to this one. However, in that frame, which only a massless particle could exist in, the separation between the event and observer would be zero. Standing at rest upon the earth, the event is still a thousand years past. Light years distance only refers to a measurement from one particular frame. If you travel at a different velocity relative to one of the endpoints, the distance of separation changes.
It might help you to be aware of an experiment conducted in 1971 with two atomic clocks, which as you probably know are incredibly accurate timepieces which measure up to very small increments; i.e. billionths of a second. Both were set to the same exact time, and then one of them was placed on board a US military aircraft and flown around the world at an average speed of 600mph. When the clocks were reunited, the clock that had been flown at high speed had slowed down and was now reading a slightly earlier time than the one which had remained stationary. It was by a miniscule amount, but it nevertheless proved the part of the theory that time slows down the faster you go. This is not an excuse for setting off late for work and driving very fast! Al
I've often wondered about that. Although in the Time Traveler's case he never moved from that one spot on Earth, suggested the machine was still held in place by gravity or some such...
Actually, that test included gravitational time dilation adjustments to the predicted time differential based on Fitzgerald-Lorentz contraction equations. Turns out, time dilation effects are produced by both differentials in velocity/acceleration/viewer frame of reference and proximity to gravity fields. The actual test results using those atomic clocks not only confirmed the F-L time dilation predictions based on velocity/acceleration, but the mathematical adjustments for the gravitational time dilation effects also proved accurate. Pretty exciting stuff! .....NaCl ps "acceleration" and "deceleration"...only one "l"
One of the short stories I read recently the MC traveled at close to the speed of light to fight a war, by the time he got back, which was only a few years for him, on earth everyone he knew was long dead. He had a hard time coping with that, so he back to fight. Another story a guy traveled close to the speed of light to get a brainchip installed, but they said he couldn't, and he would have to go back home. He was counting on them letting him install this brain chip for he could travel the universe. He knew by the time he got back home everyone he knew would be dead, even though from his point of view he was only gone for a few years. It makes for some interesting story telling.