help me unkill mind

You would probably see nothing for a few years or months or days depending on how far it is. After the light is finally reflected and hits the viewer's eye then yes, you could see what happened minutes, days, months or years ago from the moment the light first reached the mirror onwards.

 

Yes

 

Technically you always are seeing the past.

 

Ye, your brain takes 45~ milliseconds to process information. Therefore you live 45~ milliseconds in the past.

 

Let's say that theoretically conditions were perfect and the light was reflected in the mirror and was easily view visible telescope. Then yes you would see everything happening with a delay of a few years. The length of the delay would be dependent on the amount of light years that the mirror was from the earth. It is like when there is a delay in the signal for any kind of phone or VoIP, you aren't hearing things in real time, but everything occurs at normal speed and is perceived as if it you were hearing it as it was said.

 

Alright! Here goes!

First off, assuming it is impossible to travel faster than light, you would not be able to see into the past, as in, before the rocket with the mirror was launched. The time it takes to get the mirror there in the first place would be greater than the length of time into the past you could see. So, no, we could not watch Washington cross the Delaware River, or see if Jesus really rose from the dead or whatever.

Now, if the mirror was already there, sure you could. If it were 1 light year away, you would see two years into the past, because it would take one year for a photon bouncing off the surface of the Earth to reach the mirror, and one year for that photon to be perfectly reflected back to your telescope.

EDIT: Also, I love questions like this. They're so much fun to think about.

 

You could only see events that occured after the mirror was built, but if you looked at the mirror many years after it had been built, you would definitely see the past.