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You would need a gravitational lens so powerful it not only bent light, but made the light perform a complete slingshot around it so that it would be aimed back at Earth. The nearest such object is the Milky Way's black hole, and there's no way we'd be able to resolve Earth in an image coming from a) that far away and b) that close to the galactic core where so much other stuff is in the way.

But could a photon make such a journey? Yes. But you'd never be able to recognize it against everything else.




To correct myself, because I didn't actually bother to check first, there are actually black holes or probable black holes closer than the center of the galaxy. Like, a lot closer. [1] And we've seen a lensing effect from at least one of them. And moreover that one happens to be isolated from other material. [2]

[1] https://en.m.wikipedia.org/wiki/List_of_nearest_known_black_...

[2] https://en.m.wikipedia.org/wiki/OGLE-2011-BLG-0462


Fermi problem: How many photons do? Have you or I ever seen one?


wait until we launch the next telescope... er graviscope




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