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Astronomers Search For Dyson Spheres of Alien Civilizations
Hugh Pickens writes "An article by Ross Andersen makes note of Freeman Dyson's prediction in 1960 that every civilization in the Universe eventually runs out of energy on its home planet, a major hurdle in a civilization's evolution. Dyson argued that all those who leap over it do so in precisely the same way: they build a massive collector of starlight, a shell of solar panels to surround their home star. Last month astronomers began a two-year search for Dyson Spheres, a search that will span the Milky Way, along with millions of other galaxies. The search is funded by a sizable grant from the Templeton Foundation, a philanthropic organization that funds research on the 'big questions' that face humanity, questions relating to 'human purpose and ultimate reality.' Compared with SETI, a search for Dyson Spheres assumes that the larger the civilization, the more energy it uses and the more heat it re-radiates. If Dyson Spheres exist, they promise to give off a very particular kind of heat signature, a signature that we should be able to see through our infrared telescopes. 'A Dyson Sphere would appear very bright in the mid-infrared,' says project leader Jason Wright. 'Just like your body, which is invisible in the dark, but shines brightly in mid-infrared goggles.' A civilization that built a Dyson Sphere would have to go to great lengths to avoid detection, building massive radiators that give off heat so cool it would be undetectable, a solution that would involve building a sphere that was a hundred times larger than necessary. 'If a civilization wants to hide, it's certainly possible to hide,' says Wright, 'but it requires massive amounts of deliberate engineering across an entire civilization.'"
Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth, much like humanity.
I don't believe this. I think the most advanced aliens have probably realized that there isn't much point of growth after a certain threshold.
But where is that threshold? Is it before or after they build a Dyson sphere?
There's the /civilization's/ recognition of the limit, vs. the individual's desire to procreate, in the battle of need vs. freedom/rights.
I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.
Also, as for remaining hidden, a race may decide instead of building a Dyson sphere which radiates over it's whole surface, to instead radiate over a smaller portion of the surface, and at a narrower angle. While you could be detected from the right angle, if you point it the right way, the closest thing that could bother you, probably wouldn't be close enough to care about.
Then again, the amount of mass needed for a Dyson sphere would be insane, if you have that level of tech, to acquire that mass, you probably have other solutions to the problem (direct matter->energy conversion perhaps?)
Self proclaimed typo king, and inventor of the bear destroying coffee table (patent not pending).
Basic laws of reality? Isn't science about increasing our understanding of reality? Many theories and ideas have come and gone and been replaced by more refined ones. We would be extremely naive to think our current understanding is even remotely close to all there is to know and completely correct. There is much to learn my friend.
We'll make great pets
Probably, but the issue is whether it's worth looking. If there was a detectable civilization in our range, and it later was discovered that we could have detected it much earlier via a relatively small expenditure, we'd be kicking ourselves in the ass.
Plus, it may lead to the discovery of a new unexpected natural phenomenon.
- Sara N. Dipity.
Table-ized A.I.
Well, the second law is more of a statistical observational law than one deduced from higher principles. Its really good at predicting things and seems really reliable and is tied into all kinds of other areas of physics. I would be shocked to near death if we found a repetable, observable violation.
But the science fiction lover in me would prefer to think of it a just a setting in the universe that could be switched off when convineint. Its also linked to time, so if we can just step out of the stream of time then we're good and possibly gods.
Well.. maybe. Or Maybe not. But Definitely not sort of.
I can't recall who said it but someone (more famous than myself) put the idea out there that if you had the resources to build a Dyson sphere you wouldn't need to build one. Makes sense to me but I'm not an engineer.
we have *always* relied on sunlight
Past performance is not an indicator of future performance. Humans always used horses... until they invented a car. Humans were using only land transport.. until they invented an airplane. Humans were always planet-bound, until they flew into space.
A Dyson sphere is not a scientific fact, it's only a possibility, and not trivial one at that. The approach has many problems.
First, the Dyson Sphere, even if it is ideally constructed, will only supply energy to your sites near the star. However it is logical to expect that an advanced civilization will need spaceships for all kinds of purposes, from research to migration. This cannot be done without movable sources of energy (thermonuclear at the least.) Once you have them, the effort of building the Dyson sphere appears to be too high.
Then the Dyson sphere needs to be constructed. There isn't much material in an average planetary system to do that, unless you can transmute your common silicon and carbon into scrith and make a thin foil out of it. You also need to deliver that material to where it is needed, and join it. A Ringworld is a much easier possibility at this point.
Once you build the sphere you need to equip it with collectors of solar energy. Where would they come from? If we build a sphere at 1AU from the Sun, do you think we can line it with solar panels? We'd have not one atom left in this Solar system after we built the sphere. Besides, the sheer volume of the effort would be impossible.
The sphere would need to be thermally balanced. (This is how they intend to find it.) If you collect all the energy and keep it inside it will heat up to the temperature of the star - and that is perhaps not what you want. So you need to cool it. Earth is rotating, radiating heat every night and collecting it every day. Planets like Mercury show what happens when a planet is thermally overloaded. The Dyson sphere would have to have radiators of energy somewhere on the external side, and there would have to be conduits. This is a lot of work.
Then the question would arise of atmosphere. Is your Dyson sphere is at 1AU then you need to live on that sphere - and that means that you must have means of holding the atmosphere in place. If you leave Earth (for example) in place and instead build the sphere on a farther orbit then the surface of your sphere grows and you need even more material. Also the problem of transportation of collected energy arises.
Considering these and other technological and conceptual difficulties, it may be easier to just use local sources of energy, like thermonuclear reactors or better. Astronomers, of course, want something to look at, and you can't look for reactors that far away. I don't think they will find Dyson spheres, though. A civilization that is advanced enough to build such a sphere probably does not need it.