Looking into the past

Post Reply New Topic

Theoretically, we can take a look back into the world's history if we are on a planet many light years away and observe our planet through a phenomenally powerful telescope (one that has yet to be developed). If you are on a planet 100 light years away, you can take a look at the world in 1908 (although without sound). Of course, the probability of either is next to nil but it's nice to dream isn't it?

Yeah, it is!

Ah, I read about that not too long ago. It is such an exciting idea! 1908...I could see a newborn Jimmy Stewart (one of my obsessions)! !!

I once imagined a similar concept a long time ago, and was surprised when I learned that I wasn't the only one having weird sci-fi daydreams. But it never clicked with me that there would be no sound until you mentioned it.

However, to put the telescope there, it would have to travel at the speed of light for a hundred years to go a hundred lightyears away, letting it see the present on earth the entire time. And for it to send a message back at the speed of light would take another hundred years for it to get here. Sorry to ruin the idea, it's not physically possible, but it's still fun to imagine.

And this is why (although i do think about it from time to time) I don't think about these things too often. They're often quite mind-boggling

Ah, but it isn't necessarily impossible. All that is certain is we don't know how yet. The trick is to find a shorter distance than a "straight line".

Or potentially to find a phenomenon that has bent the light so much out of a "straight line" that it is relatively easy finding a straight 3D line to where you can place the telescope to get out "ahead" of the light and intercept it. Like a big mirror mounted tangental to us 50 LY away, we wouldn't have to go anywhere ... just build the amazingly precise telescope pointed at the mirror.

P.S. Assuming extremely high accuracy of measurement you could infer and recreate sound from measurement of physical movement. Sort of like those laser microphones that read vibrations off of windows in front of people talking. Only it would have to be a passive system rather than active like the laser microphone, making it tricker yet.