StametsOct 28

Space is beautiful

https://lemmy.dbzer0.com/post/56465024

Show threadNatanoxOct 28
But only after 10 years. You couldn’t see anything that wasn’t visible from the viewpoint of the mirror beforehand, as from earth’s point of view the mirror isn’t there yet. And if you’re there anyway… you can just look at Earth with the craft that’s on the position of the mirror already.
Show threadBeaconOct 28
That's why we need to find a natural mirror somewhere already out there, so we can see into our past. Something like a planet made of pure mercury, or an arrangement of blackholes doing gravitational lensing that bends our light back to us, or whatever
Show threadkernelle
I’m assuming the inverse square law would hinder us from seeing anything useful. But now I’m imagining scientists being ecstatic about discovering a foreign signal, only to realise its us from the past
Oct 28 at 6:16pmWeb
Show threadMotoAshOct 28

That’s highly unlikely basically because of the inverse square law. Even tightly focused beams dissipate quite effectively over light-hours, let alone light years. We’d be lucky to catch a single photon from our past selves over any significant distance.

For reference, look up how weak the signal is even just coming back from the moon when people try to hit the retroreflectors with lasers. Or how crazy weak the signals are when they reach Voyager.