Originally Posted by
Vampyre
Time travel may not be possible, but it actually is plausible to look back into the past.
To explain how, consider this: it takes 8 minutes for light to travel from the Sun to Earth. That means, when you look at the Sun, you aren't seeing it in present time, you see how the Sun was 8 minutes ago.
Therefore, if someone was at the Sun (or equivalent distance) and had a way to look down at Earth, they'd see it, 8 minutes previous.
So theoretically, we could build a space station with an extremely powerful scope on it. Placing it 12 951 034 185 km away from earth (the distance light will travel in 12 hours) and have it relay what it observes back to earth at the speed of light.
Then, operators on Earth could use it to look at anything that happened the day before. Because it takes so long for the light and information to travel, they could watch exactly what happened 24 hours previous to the current time on Earth.
If you're interested, I'd recommend watching Brian Cox's video: "What Time Is It?" You can find it in parts on Youtube.