Radius of the observable universe is 46 billion light years. Say you have two civilizations 26 billion light years apart. Could they send maps of their observable universe to the other civilization so in 26 billion years they know what was beyond the edge of their observable universe?
In: Physics
Short answer: yes.
Long answer: Also yes, but with a lot of caveats.
The issue: a signal 26 billion lightyears away will take far longer than 26 billion lightyears to arrive. The universe is expanding, so the distance increases while the signal is travelling resulting in farther to travel.
There is something called the particle horizon. This is the distance where the expansion of the universe exceeds the ability of a light speed signal from ever crossing the distance. No action from a particle (even the generation of light) will ever interact with another particle that distance away or farther.
Watch PBS Spacetime. Lots of videos covering this sort of thing. Very well done.
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