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Two galaxies aligned in a way where their gravity acts as a compound lens

(phys.org)
268 points wglb | 1 comments | 16 Nov 24 16:48 UTC | HN request time: 0.001s | source
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waltbosz ◴[16 Nov 24 19:38 UTC] No.42158640[source]▶
One fun thing think about is that these two galaxies are only aligned from our perspective in the universe. Viewed from a different location, and they're just two normal galaxies.

Also, imagine having the technology to send signals through the lens and get the attention of intelligent life on the other side.

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snakeyjake ◴[16 Nov 24 20:57 UTC] No.42159262[source]▶
In order to use them as a signaling platform (how?) the signal would have needed to have been sent several billion years ago.

At 10 billion light years away from the most distant lens it is 100% certain that they are no longer in a gravitational lensing configuration.

For a frame of reference, the Milky Way will be in the middle of its epic merger with Andromeda in about 5 billion years.

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0xDEAFBEAD ◴[17 Nov 24 08:05 UTC] No.42162722[source]▶
>In order to use them as a signaling platform (how?) the signal would have needed to have been sent several billion years ago.

Conceivably, a civilization could predict in advance that two galaxies would form a lens configuration, and send a signal that arrived just as the lens formed, correct?

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consp ◴[17 Nov 24 10:49 UTC] No.42163345{3}[source]▶
Isn't the universe (near) chaotic on those timescales and you can only predict the general flow? Or is this me mixing things up?
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1. 0xDEAFBEAD ◴[17 Nov 24 14:33 UTC] No.42164376{4}[source]▶
Take a Monte Carlo approach. Run a bunch of simulations to generate a probabilistic point cloud in spacetime of where the lenses end up. Fire a signal through every point in the cloud.