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Note that our very best IR telescopes have a resolution great enough to detect an IR signature of a Dyson swarm at a distance of about 0.2 kiloparsecs, or ~600

Note that our very best IR telescopes have a resolution great enough to detect an IR signature of a Dyson swarm at a distance of about 0.2 kiloparsecs, or ~600 light years. That is a very, very small area of the universe. If there was a Dyson swarm out there, we would only know it if it was extraordinarily close to us.

cletus 6y ago
So you raise a good point. I went looking for more facts about this. As best as I can tell, current surveys for individual Dyson swarms rely on IRAS and as best as I can tell the range is about what you say. So there are two points worth making here: 1. This is, as far as I can tell, pretty similar to the range SETI is looking at. The power required for signals beyond that range to be detectable by us starts to get to a significant portion of stellar output, at which point you either have to assume such a civilization is is capable of the kind of astro-engineering we could otherwise detect and why are they outputting something with that much power? 2. On the Kardashev scale, you have K1 civilizations who use the power output of an entire planet (10^16 Watts in the Carl Sagan scale), K2 is an entire star (10^26 Watts) and K3 is an entire galaxy (notionally, 10^36 Watts). A K3 civilization is envisioned as Dyson Swarms through an entire galaxy (although, "civilization" is a loose concept when there's light lag of 100,000 light years from one end to the other). I found a link to a study of 100,000 of the nearest galaxies looking for that kind of IR signature on a galactic rather than solar level. No evidence has yet been found. The gap between a K2 and.a K3 civilization is actually not that large.
- CRUDite 6y ago
  'No evidence has yet been found' has an empasis on 'yet' and suggests this may change. K3 civs in these galaxies are ruled out are they not? The result you mention is sobering and fairly suggestive we are alone.

cletus 6y ago

So you raise a good point. I went looking for more facts about this. As best as I can tell, current surveys for individual Dyson swarms rely on IRAS and as best as I can tell the range is about what you say. So there are two points worth making here: 1. This is, as far as I can tell, pretty similar to the range SETI is looking at. The power required for signals beyond that range to be detectable by us starts to get to a significant portion of stellar output, at which point you either have to assume such a civilization is is capable of the kind of astro-engineering we could otherwise detect and why are they outputting something with that much power? 2. On the Kardashev scale, you have K1 civilizations who use the power output of an entire planet (10^16 Watts in the Carl Sagan scale), K2 is an entire star (10^26 Watts) and K3 is an entire galaxy (notionally, 10^36 Watts). A K3 civilization is envisioned as Dyson Swarms through an entire galaxy (although, "civilization" is a loose concept when there's light lag of 100,000 light years from one end to the other). I found a link to a study of 100,000 of the nearest galaxies looking for that kind of IR signature on a galactic rather than solar level. No evidence has yet been found. The gap between a K2 and.a K3 civilization is actually not that large.

CRUDite 6y ago
'No evidence has yet been found' has an empasis on 'yet' and suggests this may change. K3 civs in these galaxies are ruled out are they not? The result you mention is sobering and fairly suggestive we are alone.