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Voids aren’t empty they just have less stuff in them. There’s galaxies and things in there.
Sometimes I wonder about the percentage of HN commenters who actually read the article. Literally a few paragraphs in: “The lack of radio sources means that there are no galaxies or clusters in that volume.”
Earlier quoted context omitted.
It might not be as empty as it looks. Maybe it’s just got a really big dark sheet over it. Astronomers don’t consider the possibility of ginormous dark sheets in space.
A dyson sphere? I believe that possibility has been raised.
Posted it because it reminds me of an hypothesis I once saw, that we might be able to detect alien civilizations based on blank spots in the sky where they've managed to divert all the energy from their environment.
I've heard this idea in the context of Dyson spheres/swarms. The issue is that, while they'd be invisible or dim to the eye, the areas would be very bright in infrared.
Voids aren’t empty they just have less stuff in them. There’s galaxies and things in there.
Sometimes I wonder about the percentage of HN commenters who actually read the article. Literally a few paragraphs in: “The lack of radio sources means that there are no galaxies or clusters in that volume.”
Voids aren’t empty they just have less stuff in them. There’s galaxies and things in there.
Sometimes I wonder about the percentage of HN commenters who actually read the article. Literally a few paragraphs in: “The lack of radio sources means that there are no galaxies or clusters in that volume.”
Tracing out how the very earliest structures in the CMB compare with much more recent galaxy filaments (and the voids between the dense filaments) is an interesting area of research, and there will be open questions for many years to come as galaxy surveys at different redshifts produce observational data.
(All the galaxies will be at a lower redshift than the CMB cold spot, and it is a good guess that the CMB cold spot reflects an arrangement of matter much closer to the hot big bang or cosmic inflation than that. Perhaps one day our descendants will be able to examine the cosmic neutrino background to see if it too has a comparable cold spot, and the same with primordial gravitational radiation; alternatively perhaps they will discover that later-time physics distorted the CMB very slightly. The latter hypotheses are in practice much easier to test with observational data, and of course one can exploit the many unknowns in the dark matter and dark energy sectors without colliding with constraints from known physics.)
Earlier quoted context omitted.
I've heard this idea in the context of Dyson spheres/swarms. The issue is that, while they'd be invisible or dim to the eye, the areas would be very bright in infrared.
Depends on how large the swarm is. Using our sun as the example a 1AU swarm would be very warm, but at 100 AU it would be extremely cold and much harder to detect. Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible.
Posted it because it reminds me of an hypothesis I once saw, that we might be able to detect alien civilizations based on blank spots in the sky where they've managed to divert all the energy from their environment.
I've heard this idea in the context of Dyson spheres/swarms. The issue is that, while they'd be invisible or dim to the eye, the areas would be very bright in infrared.
Any space-faring culture will have mastered controlled fusion long ago, and have entirely left behind any material dependence on stars. The best places to live, then, are out in the Kuiper belts and beyond, where unlimited room and cold are available for free, and valuable gases are lying about, frozen. Inner planets are for extreme primitives. If aliens got here, they would find Triton much more interesting than Earth, except maybe as a curiosity.
Expanding menace civilizations will run up against overwhelmingly more advanced stable cultures before long and be contained or destroyed, so odds are none could get here before that happens.
Imagine being a civilization on the edge of a galaxy on the edge of the void. One direction, nothing whatsoever. The other direction, billions upon billions of galaxies. Would be neat!
Imagine being a civilization on the edge of a galaxy on the edge of the void. One direction, nothing whatsoever. The other direction, billions upon billions of galaxies. Would be neat!
Imagine being a civilization on the edge of a galaxy on the edge of the void. One direction, nothing whatsoever. The other direction, billions upon billions of galaxies. Would be neat!
Imagine being a civilization alone in the void, and not even a generation ship could make contact with anyone else, even if they knew which direction to send it.