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by lukastr0 1859 days ago
What do you mean? Why can't we receive signals from more than "100 hundred light year" away?
3 comments

Well, signals sent from Earth (radio, TV, etc...) are indistinguishable from noise at about that distance.
Because of the very large amounts of energy to transmit information in all directions from such a large distance. Also because it's such a stupid waste of energy. Why send radio waves out in all directions in order to communicate with a neighbor? Use a light beam instead.

So the lack of huge radio transmitters that we can detect really just means aliens aren't investing huge amounts of money into letting us know they exist. Why would they? Especially if they already know of other civilisations.

I mean, we definitely can. We see stars that are thousands of lightyears away! However, maybe OP means "receive" as "response to a message we sent". This is indeed something we are able to do since ~100 years, so our communication bubble is currently ~100 lightyears.