07-29-2014, 12:08 AM
I don't think that a dyson sphere could be cooled to the CMBR temperature by refrigeration, however advanced; the energy would have to go somewhere. If the radiating surface were big enough then this would work, but then you have a very large object emitting large amounts of diffuse radiation.
On the other hand a very advanced civilisation could disguise itself in a number of other ways, or simply extend itself into an arbitrary number of baby universes, making them very tricky to spot. If the civilisation only used comm-gauge wormholes this could be a good disguise, although the process of making wormholes and baby universes is probably one that emits a significant amount of radiation.
On the other hand a very advanced civilisation could disguise itself in a number of other ways, or simply extend itself into an arbitrary number of baby universes, making them very tricky to spot. If the civilisation only used comm-gauge wormholes this could be a good disguise, although the process of making wormholes and baby universes is probably one that emits a significant amount of radiation.