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The Universe Within 12.5 Light Years

(www.atlasoftheuniverse.com)
266 points algorithmista | 1 comments | 05 Sep 25 22:20 UTC | HN request time: 0.2s | source
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stephc_int13 ◴[06 Sep 25 01:21 UTC] No.45145686[source]▶
When the Fermi Paradox was first posited, scientists and engineers seemed to believe that interstellar travel was soon to be technologically achievable, a few decades, maybe centuries for the less optimistic. Progress around space propulsion has kind of stalled since then and we should maybe question the possibility of interstellar travel as this would give an easy but unpleasant answer to the famous paradox.
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shireboy ◴[06 Sep 25 01:36 UTC] No.45145776[source]▶
Right- “where are all the aliens?” is answered by either “they don’t exist” or “they do but physics of the universe prevent them from moving between solar systems.”
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1. cryptonector ◴[06 Sep 25 15:01 UTC] No.45149864[source]▶
Or by "none exist right now nearby". If there are technological aliens 3 bly away and 3 bya, we won't likely discover their signals. If there are technological aliens 10 ly and 10 ya then we're extremely likely to pick up their signals (if they emit any), but they're not likely to come here -- not anymore than we are to go there. The Fermi paradox is most easily understood as "the probability of two concurrent technological species in different but nearby star systems is vanishingly small".

For all we know there have been thousands of technological species in our galaxy, but never two at roughly the same time and roughly close together, and never will be.