Astronomers Search For Dyson Spheres of Alien Civilizations 686
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.'"
So why can't we do it? (Score:2, Interesting)
I suspect at this point humanity, as a collective whole, is still too small-minded to consider such an endeavor. Our politicians are narcissistic/sociopathic, and private industry would want it to be profitable.
*sigh*
If they have the tech to build it, do they need to (Score:3, Interesting)
Re:Flawed assumptions. (Score:5, Interesting)
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?
Re:Flawed assumptions. (Score:5, Interesting)
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?)
Earth alone has a perpetual energy supply. (Score:2, Interesting)
moreover, the earth is a collector of solar and lunar energy. We call it wind and sunshine and tides, there's even solar "wind" if one goes a bit outside the atmosphere. Together these have more than enough energy to power all of the earths needs. Harvesting these may not be simple, but it would be a lot simpler than a dyson sphere. ergo, no dyson spheres will ever be built unless the planet is too far from the sun to collect enough solar energy on its crossection.
What the earth lacks is a perpertual supply of transportation fuels or a means to adequately replace them. But replacing them is forseable and we don't absolutely need them--we just over exploit them now because we can.
Re:what about nuclear fusion? (Score:4, Interesting)
A star is a fusion reactor. In fact, if you need the kind of power that's given out by a Dyson sphere, then a Dyson sphere is by and large the most efficient method for generating it, especially for long periods of time.
The question should be whether any civilization would require so much power in such a static and concentrated way (as opposed to dispersed across hundreds of planets across thousands of lightyears), and where they'd find the materials required to build it (we're speaking about transforming entire planets from crust to core, or harvesting dozens more in a less destructive fashion).
Re:First space-faring race = a bunch of nutjobs (Score:5, Interesting)
That's only given all civilizations started at roughly the same time. However, this isn't Civilization V. A space-faring race could have formed a contigous civilization several hundred thousands or millions of years ago, not a couple thousand years like ours. It might be the natural evolution of things at that point.
Re:Flawed assumptions. (Score:5, Interesting)
Re:Let me predict.... (Score:5, Interesting)
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.
Silly waste of time. (Score:4, Interesting)
First off a dyson sphere does not take into account the MASSIVE amount of praticle energy that is coming off the star. the Stellar wind on that scale would be immense. Secondly, Orbits are not magical. a dyson sphere is unstable and will either wobble and start to collapse into the star, or rip apart due to the uneven gravity well. Just the technology to even be able to have the ability to think of building a Ringworld, something far, far, FAR easier than a Dyson sphere is so mind bogglingly compex that it collapses in upon it's self.
Sorry but it's a waste of time we might as well look for civilizations that are harvesting black holes to power their space ships.
Re:Flawed assumptions. (Score:5, Interesting)
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.
Re:Flawed assumptions. (Score:5, Interesting)
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.
Re:If they have the tech to build it, do they need (Score:3, Interesting)
Small black holes are basically 100% efficient at turning mass into energy via Hawking Radiation, which is nearly two orders of magnitude more efficient than Stars powered by fusion.
There are some serious suggestions as to how to go about making them (ultra powerful converging gamma ray lasers, as photons aren't subject to Pauli Exclusion Principle). While it probably requires a moon-sized machine to do it, it is probably feasible for a civilisation capable of building a Dyson sphere, and once you have that technology you don't need stars or the gravitational hassles that they create anymore.
Re:First space-faring race = a bunch of nutjobs (Score:4, Interesting)
Assuming current predictors of life-supporting planets are at least within ballpark, each space-faring civilization existed, prospered and dyed off before running into any other civilization.
What more reasonable assumption is that WE are product of such advanced civilization, that is some form of life-seeding DNA-based life that originated on some planet elsewhere produced advanced civilization and they realized that due to scale of our universe they will never get to explore most of it and just seeded universe with life.
Re:what about nuclear fusion? (Score:4, Interesting)
Re:what about nuclear fusion? (Score:5, Interesting)
Matter-antimatter reactions may have extremely high power density, but there's a big problem: where do you get the antimatter from? It's unlikely there's large naturally-occurring deposits of it available anywhere, since it annihilates itself when it contacts matter. M-A energy sources really only make sense as a way of storing energy, not producing it. Even Star Trek takes this position: the starships use antimatter for propulsion, but only because of the energy/power density it offers, and it's produced artificially specifically for this purpose, probably using solar energy production.
Energy is a primary need of any civilization. Every civilization has to get it somewhere. Back in the early days, we got our energy from the sun solely: we used it to grow crops (for food) and feed our animals (for transportation), and to power our ships (for water-based transportation; we used the sun to produce wind to power these ships; luckily, we didn't have to produce the wind ourselves, as natural processes had already done this for us, but we took advantage of it). These days, we largely get our energy from hydrocarbons created millions of years ago by solar-fueled processes, though we're getting some power from nuclear fission (where we break apart large atoms that were created in stars long ago). In short, we get energy where we can find it naturally-occurring. A more advanced civilization will probably be no different: though it may convert energy from one form to another, it'll have to mine that energy from somewhere, and the most obvious source is a nearby star which is giving off lots of energy for free already. Of course, if they figure out how to get energy directly from quantum fluctuations, or by mining antimatter from a parallel universe or something, then they might not need stars any more, but that sounds even more advanced than a Kardashev Class II civilization which we're talking about here.
Re:You ain't seen me, right? (Score:4, Interesting)
Makes me wonder if some civilisations are hiding, and what they're hiding from.
Re:Flawed assumptions. (Score:5, Interesting)
I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.
It may not diminish your desire, but hopefully it alters your actions. At the very least I would hope you would choose have 1 or 2 and not 3 or more. If all couples had just 1 child the population would drop by 50% each generation (obviously with a time delay since people live much longer than one generation). 2 is steady state.
You'd be surprised how many people simply don't ever procreate. Your point is still valid, but if everyone who wanted/could have kids did have just 2 that lived to maturity (another factor) the population would still decline. Three kids (during your child bearing years) per willing/able couple is more practical for holding a steady population. A guilt trip for having 3 kids is completely unwarranted.
Re:Flawed assumptions. (Score:5, Interesting)
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.
Re:Flawed assumptions. (Score:4, Interesting)
I dunno, let's give it a try...
Love; the evolutionary behavior surrounding mating and parenting designed to ensure members of your gene pool proliferate.
Spirituality, the embrionic cognitive appreciate of a finite being and its relationship to a virtually infinite universe.
Science doesn't explain psychics, the Amazing Randy explains psychics.
Auras look up "Phosphenes."
Hhhhmmm, After life there is what? Decomposition? Tea and crumpets with St. Peter?
The power of prayer? Seeing as the Amygdala is the part of the brain doing the heavy lifting during a prayer, let's say the power of a prayer is 15-45 microwatts depending on how hard you pray and whether you are concentrating.
I know I'm being sarcastic, but you just said it yourself, Science doesn't dabble in unreality. That would be the realm of mystics and metaphysicists. I'm not even saying none of these thing may exist. I'm saying that until you can separate the magical thinking from some describable real world phenomenon, there's nothing for science to do, but nod its head and thank you for sharing.
Re:Flawed assumptions. (Score:2, Interesting)
There are basically 2 kinds of "Dyson Spheres" the kind from the Star Trek episode (Relics), and the kind that Dyson actually theorized about.
The former (a single-structure hollow sphere that encapsulates a star) are impractical because of the amount of material they require and the mind boggling stresses that would be exerted on the structure during construction. The later on the other hand (a cloud of small satellites in orbits that result in a dense "shell" around the star) doesn't take any more technology that we have now (except maybe incremental improvident in wireless power transmission efficacy). It mostly just requires a big enough energy need to justify the scale of the project.
Re:Flawed assumptions. (Score:5, Interesting)
Bees, ants, wasps, and nearly all other social insects are also adapted to living with a gender-bending endo-parasite.
Namely, the wolbachia parasite. It is a protozoan that inhabits cellular cytoplasm of the cells of those species of insects, and procreates through forcing males to develop as females, because it can only perptuate itself through the larger ova of those species, and not through the smaller sperm of those species.
As such, the centralized reproductive practice of those organisms is directly tied to the limitations imposed upon them by the highly aggressive wolbachia parasite.
Removal of the parasite through aggressive use of antibiotics has shown radical changes in cytoplasmic composition and embryonic development, which results in sexual infertility and even outright death in many infected species.
http://www.tandfonline.com/doi/abs/10.1080/0958315031000110355 [tandfonline.com]
Literally, these lifeforms have become very efficient host vehicles for their parasites, and their reproductive strategies more closely favor proliferation of the parasite than their own.
Essentially, the parasites have forces their hosts to evolve in such a way that the host's behavior has been altered significantly.
The effects of wolbachia infection on the behavior of insect model species has been well researched. Take for instance, a study of wolbachia on mosquitos.
http://m.sciencemag.org/content/323/5910/141.short [sciencemag.org]
What I a getting at here is that the existence of communal reproduction centric organisms like bees and wasps does not negate the validity of the prior poster's statement, because the bees and wasps did not develop this strategy so much as have it impose upon them by a more aggressive species that does conserve the poster's conjecture.
Re:Flawed assumptions. (Score:5, Interesting)
Reltive velocity time dilation only theoretically solves the time aspect of the problem, and only if you neglect the fact that at least the delivered presents have to STOP in my frame of reference..
I don't care how damn amazing a Wii U is supposed to be, when 1.5 kg of mass rips to a halt under my Christmas tree from, let's be generous here, 0.9c, the resulting vaporization of my house (k.e. ~ 0.5mv^2, or 1.09*10^17 joules, or 26.06 Mt of TNT) is going to result in a very unhappy Christmas.