Dyson sphere hunt using Kepler data
October 12, 2012
A Dyson sphere under construction (credit: Steve Bowers)
Geoff Marcy has received a grant from the UK’s Templeton Foundation to look for Dyson spheres, Paul Gilster writes on Centauri Dreams, the news forum of the Tau Zero Foundation.
Freeman Dyson hypothesized the vast structures over fifty years ago that could ring or completely enclose their parent star. Such structures, the work of a Kardashev Type II civilization — one capable of drawing on the entire energy output of its star — would power the most power-hungry society and offer up reserves of energy that would support its continuing expansion into the cosmos, if it so chose.
Marcy’s plan is to look at a thousand Kepler systems for telltale evidence of such structures by examining changes in light levels around the parent star.
Interestingly, the grant of $200,000 goes beyond the Dyson sphere search to look into possible laser traffic among extraterrestrial civilizations. Says Marcy:
Technological civilizations may communicate with their space probes located throughout the galaxy by using laser beams, either in visible light or infrared light. Laser light is detectable from other civilizations because the power is concentrated into a narrow beam and the light is all at one specific color or frequency. The lasers outshine the host star at the color of the laser.
The topic of Dyson spheres calls Richard Carrigan to mind. The retired Fermilab physicist has studied data from the Infrared Astronomical Satellite (IRAS) to identify objects that radiate waste heat in ways that imply a star completely enclosed by a Dyson sphere. This is unconventional SETI in that it presumes no beacons deliberately announcing themselves to the cosmos, but instead looks for signs of civilization that are the natural consequences of physics.
Carrigan has estimated that a star like the Sun, if enclosed with a shell at the radius of the Earth, would re-radiate its energies at approximately 300 Kelvin. Marcy will turn some of the thinking behind what Carrigan calls ‘cosmic archaeology’ toward stellar systems we now know to have planets, thanks to the work of Kepler. Ultimately, Carrigan’s ‘archaeology’ could extend to planetary atmospheres possibly marked by industrial activity, or perhaps forms of large-scale engineering other than Dyson spheres that may be acquired through astronomical surveys and remain waiting in our data to be discovered. All this reminds us once again how the model for SETI is changing.
For more, see two Richard Carrigan papers: “IRAS-based Whole-Sky Upper Limit on Dyson Spheres,” Journal of Astrophysics 698 (2009), pp. 2075-2086 (preprint), and “Starry Messages: Searching for Signatures of Interstellar Archaeology,” JBIS 63 (2010), p. 90 (preprint). Also see James Annis, “Placing a limit on star-fed Kardashev type III civilisations,” JBIS 52, pp.33-36 (1999).
A recent Centauri Dreams story on all this is Interstellar Archaeology on the Galactic Scale but see also Searching for Dyson Spheres and Toward an Interstellar Archaeology.
References:
- Richard Carrigan, IRAS-based Whole-Sky Upper Limit on Dyson Spheres, Journal of Astrophysics 698 (2009), pp. 2075-2086
- Richard Carrigan, IRAS-based Whole-Sky Upper Limit on Dyson Spheres, arxiv.org/abs/0811.2376
- Richard Carrigan, Starry Messages: Searching for Signatures of Interstellar Archaeology, JBIS 63 (2010), p. 90
- Richard Carrigan, Starry Messages: Searching for Signatures of Interstellar Archaeology, arxiv.org/abs/1001.5455
- James Annis, Placing a limit on star-fed Kardashev type III civilisations, JBIS 52, pp.33-36 (1999)
Comments (48)
by Queeny
“Or as I mentioned above, another distinct possibility is that they’d be manipulating vibrations along superstrings.”
+1 ! Quite difficult, but seams possible !
by Chuck Ivie
We always envision the future in terms of our understanding of the present and we are almost always wrong. Consider that we have had communications by means of electromagnetic radiation (radio) for just a bit over 100 years yet we assume that an advanced civilization will still be using that technology even if they are thousands (or millions) of years in advance of us. I realize that we must play the game with the cards we have in our hand but but we should also accept the fact that we may be playing without a full deck. We take for granted technologies that would have been unthinkable 100 years ago. The computer in my iphone is vastly more powerful than that which flew on Apollo almost 50 years ago. Will we even recognize an advanced civilization if we see it? I remember an old adage from my days as a radio astronomer “one man’s noise is another man’s data”. We could be seeing evidence of an advanced civilization even now and not recognize it for what it is.
by Jim Mooney
I’m not a New Age type of guy – I was a jet mechanic and programmer. But when I used to lay on my back at night in fhe fifties (when the sky was still clear, unlike now) I could see very faint lines connecting certain stars. These were not the constellations and I’ve never had a visual imagination strong enough to create a hallucination. I can’t say what they were – just throwing it out there.
by Vin
Could this be a form of synaesthesia?
by Klaatu
Dyson is how old now? He never got that Phd. and played
with the Hall of Famers. He is now a AGW denier playing
for the Corp. Science farm team. Did he ever meet another
giant, Keynes? Different field, I know.
by LKWIII
I find myself thinking about Durabys’ statement, and then taking it to its logical conclusion:
She/He wrote, “Near-godlike aliens use device X’ where device X is something even we could built. I have a only single thing to say to such breed of thinkers: A century ago we didn’t even know LASER existed.”
Isn’t a Dyson Sphere just a ‘Device X’. This is just taking a device from our current technological level (solar collector/satellite/space station) and magnifying it so it encapsulates a star (Type II Civ.) or all the stars in a galaxy (Type III Civ.).
This is comparable to a primitive man thinking that he could hypothesize & categorize more advanced cultures by how much wood they would collect and burn: Type I – all the wood on the island; Type II – all the wood on the continent; Type III – all the wood in the world.
Within just a few thousand years we have moved from wood, to coal, oil, solar, nuclear (fission) and stand on the edge of fusion. What unknown energy sources will we discover in another hundred years? A thousand? A million?
Should it be assumed the most efficient collection of energy by an advanced civilization would be to huddle around the ‘bonfire’ of its local star, or even all the stars in its galaxy? The visible universe, detectable by our current civilization, represents only approximately 5% of what is out there (the rest: 70% dark energy, 25% dark matter). Might the remaining 95% of our universe prove a more lucrative source of energy and matter to a civilization even a thousand (2, 3, 4. . . .) years more advanced than our own.
How long does it take before a civilization matures enough to walk away from the warm nest that a star represents? I suspect it is far shorter than we think, and long before it would take a civilization to engulf a detectible percentage of its galaxy’s stars. Or even one star – its own.
by Jim Mooney
Maybe it would just be a preference. Why not use the energy that is already there instead of making more? Rather like the way we recycle things.
by Jim Conant
Excellent points. Love the wood analogy.
by Bennie Beavere
This reads like a pretty good comment especially when we consider Ray Kurzweil’s singularity by 2045.
Otherwise, I might be looking among the stars for civilizations close to ours. If the Kurzweil singularity comes true, anywhere close to as soon as 2045 as predicted, one could imagine civilizations beyond our level being simply far beyond discovery. I would be looking for a Dyson Sphere around a single planet designed for solar energy and protection from global warming.
by LWIII
I remember a related scifi book I read a few years ago.
In it a group of individuals (pre-singularity augmented humans and some digital human-equivalents) travel at relatavistic speed to a a near by star to investigate an alien signal. At home, humanity continues to evolve into completely digital beings; because of their increasing need for processors and bandwidth for their expanding minds (programs), they start the dismantling and reassembly of the Sol System into a Dyson Sphere.
At their destination, the travelers find another Dyson-like structure. It is empty but for a few senscient sub-programs. The parent species had long ago left the structure behind and evolving away from its use.
The idea explored was that a god-like intelligence that is too strongly tied to the power and material density of a solar system would be inclined to stay put and not enplore. Because, to do so they would have to decrease their massive minds/intelligences to a size that could be maintained aboard a starship. It would be like agreeing to a lobotomy so your brain could fit inside the ship. Once a species solved this problem, they moved on and left their sphere behind.
by A4i
Dyson Sphere is not practical. A super powerful Barbarian type of civilization will build collapse the inner core of it’s own star into a black hole, suspending stars other layers in a spherical confined space engulfing the newly formed black hole. Then Barbarians will build Dyson Sphere around the black hole and start sending jets of plasma to the event horizon. That will give millions of time greater energy output.
by {i}Pan~
I don’t think we’ll find one.
They likely transcend to the multiverse around the time the reach Kardashev Lv 1.
First Contact is unlikely to occur pre-Singularity.
We need to connect to their internet – not muck around looking for industrial age artifacts.
by Sean Brazell
transcend to the multiverse? Where did you get that? Transcendence is pseudo-scientific word soup.
by Jim Mooney
All of our science could be pseudo-scientific word soup to a civilization that has gone beyond Aristotelian logic. Even now we have fuzzy logic, quantum logic, and the logic of General Semantics.
by GAUSS
Their “Internet” could consist of anything – vibrations along superstrings, projection of quantum effects, god knows what.
by Mark A.
Will they find Scotty there?
by Carl Brooks
that was good episode of star trek
by Mats Svensson
But how will we know what we found isn’t a Dyson cylinder?
by Lord Penguin
If you took the measurements carefully enough from enough points around the star, you can fairly well tell the shape of the object, but either way, it’s the same idea.
by Gorden Russell
Let me tell you true Mats, I wouldn’t want to live in a cylinder. I’d be creeped out by looking up into the sky only to be looking down into somebody else’s backyard.
by Ron Fontes
Are you freaking kidding? This is sci-fi crap.
by Gorden Russell
Not at all, Ron. Given world enough and time, we will start turning all the asteroids in this system into habitats orbiting the sun. In time everything in the main asteroid belt will have been moved into the Goldilocks orbit. Then the Kuiper Belt objects will be mined. After they are used up we will have to take all the heavy bits out of all those dirty snowballs in the Oort Cloud. Long before all these are gone we will be mining the Alpha Centauri System, then, on and on out to other systems. This is not sci-fi crap, this is reasoned projection.
by Weithel
Said someone like Ron about every piece of technology and knowledge we have today.
by Editor
You may be right. I once interviewed Freeman Dyson and he dismissed the Dyson sphere as “science fiction.”
by Justin
I agree. Why should this one idea be the best way to generate power?
Seems boring and wasteful.
by GAUSS
Then how does somebody get a $200K grant for this? Something’s fishy…
by Vin
Easy if the funding agency has more money than sense. Its the way of the world :D. Methinks Templeton hopes to find something and say, see, we told you heaven exists (or reincarnation target, hell, etc exists).. then they will say, hey everybody invest in religion (preferably one that makes Templeton richer).
by Nick Radonic
Sorry, a Dyson sphere implies that the poles are static, supported strictly by internal material stress, not counterbalanced by rotational forces (centripetal acceleration). I suspect this would collapse any known material. However a rotating ring world might be neutrally balanced. I’ve heard that rings are dynamically unstable, collapsing gravitationally towards the star due to minor perturbations in forces building up on one side. Big engineering will need big design solutions.
by Gorden Russell
It doesn’t have to be a sphere, Nick. Just a vast number of separate habitats in carefully maintained orbits. There will certainly be enough computer power by then for all these spinning wheels to keep on station by using ion drives that will avoid them running into each other.
I’m old-fashioned and still like the idea of spinning wheels with solar arrays jutting out from their hubs. Of course, all the surface of a wheel will be coated with a photovoltaic coating, but that won’t be enough to supply the thousands of people in the habitat with their power needs.
There is uranium in some asteroids, so habitats in orbits farther out won’t need the sun as much. These will still soak up the sunlight that leaks pasts the habitats in the Goldilocks orbit. Of course, in time, we hope to have fusion power…I just don’t count on it, having been disappointed in its prospects for so long. But we will need it for trips to the stars, so we can’t stop researching.
by Mority
I think its not a bad idea to look for that. An advanced civilisation with nanotec could probably build a dyson sphere easily. I allways think about dark matter being highly advanced and intelligent replicators that absorb light and matter. But thats just one of many possibilities. Maybe there are no “advanced” civilisations at all.
by GatorALLin
Why is it exactly emitting a 300 Kelvin signature…? if 350 can she still see/find them easily?
by S Borg
I’d bet on a Ringworld first :)
by Rick Bryant
Wait…why can they not channel all waste heat to just a few outlet channels and aimed at specific dead regions of space….better to hide…sheeeesh!!!!
by Gorden Russell
Three cheers for the Templeton Foundation! This is a worthy quest for Geoff Marcy. Can you all imagine what this will do to the world if he finds a darkened star emitting that 300 Kelvin signature? Of course the science deniers (like those two on the House Science Committee (especially the one who calls evolution a “damnable lie” and believes that the world is 9,000 years old)), won’t want to believe it…even though Jesus said “my father’s house has many mansions.”
by Jim Mooney
The supporters of the current paradigm will Always find skeptical reasons why-not, to keep their jobs as department heads of old science. When the first Mars Rover found evidence of life they found a dozen reasons why it Had to Be something else. My question is, if the experiment was that bad, why didn’t they advance all those quibbles Before the launch ;’)
by Durabys
*coughcough*
It always makes a small smile on my face when I hear a honourable scientist say that ‘Near-Godlike Aliens use device X’ where device X is something even we could built. I have a only single thing to say to such breed of thinkers: A century ago we didn’t even know LASER was existed. Now, extrapolate from that please.
by Gorden Russell
That does raise the question, just how can we detect a laser if we are not directly along the path of the beam? Certainly these aliens are too smart to try to shine a laser through a nebula.
by Gorden Russell
Wait a minute, while out in a chill rain walking the dogs, something dawned on me. An advanced civilization capable of star travel won’t be using lasers or radio waves. They’ll be using entanglement communicators, tapping out coded messages by altering the spin of one particle “here” and watching the spin change on another particle somewhere over “there”.
by DeBee Corley
Finally, an “advanced” idea.
by Sno
Except that you can’t transmit data using only entanglement.
It’s a common error of bad sci-fi to assume that you can. Here’s how entanglement works; say you have 2 entangled particles. Measure one, and you’ll break quantum coherence for both particles. This means that with the information from your measurement, you now have information about the 2nd particle as well as the first. However, if you now change this information, like the spin, the 2nd particle won’t mirror it !
Because quantum coherence is now lost.
It’s basically a one-use only mechanism that can be used to determine the result of a quantum dice roll. Some people, misunderstanding it, think that it can be used to transmit data instantly, but in reality you’d need to send information about your measure on the first particle to the person holding the second one, so that he could know if his particle state means 1 or 0. And remember, it’s one use only, and you have no influence on the result of the quantum dice roll, so you can’t have any sort of transmission convention that can circumvent that.
The only ways i can think of that would let you transmit data faster than light, is either using tachyons, or micro-wormholes. Or if you can use higher dimensions (hyperspace) maybe.
by Dan Robinson
So is there any significance at all to the idea of entanglement?
by Allanx
Yes. It can be used to make unbreakable cryptographic keys. Think of a set of entangled particles as a sort of one-time use pad (to put it in very simplistic terms), and you quickly get the picture.
by Jim Mooney
If it’s one use only per particle, what about using multiple particles to form a pattern? Or am I missing something?
by Sno
Even if you have unlimited particles, you still need to send data about the distant measures, because the results are random and can’t be forced.
Let’s use an image here. Say you have one nut and two cups. “Entangling” the two cups means that the nut is under one of the cups, and you can’t know which one, but if you look under one cup, you’ll immediately know if there is a nut under the other “entangled” cup, no matter how far it is from you now.
Looking under a cup means “measuring”. As long as you don’t look, quantum physics says that the nut is under both of the cups and none at the same time, a state highly unintuitive, but proven to be real.
So imagine you send hundreds of tiny cups to a distant place, each labeled to associate it with it’s counterpart. No matter what you do, you can’t send information with that, and quantum physics won’t change that.
by Sno
To clarify, when i say that quantum states (like superposition) are proven to be real, i’m not referring to the image with the nuts and cups, i’m talking about particles at extremely small scales.
At those small scales, things behave according to probabilities, but their collective behavior creates the macroscopic reality and laws that we are familiar with.
I hope that makes sense.
by Bruce Wright
This kind of thing, of course, is why it’s treacherous to predict what kind of technology an advanced civilization will be using. As Arthur C. Clarke put it, “Any sufficiently advanced technology is indistinguishable from magic.” It’s probably more likely that you can predict some of what an advanced civilization WON’T be able to do than what they will (eg, from everything we know about physics, it’s extremely unlikely that they’ll be able to create new matter or energy from nothing with no net expenditure of either).
by GAUSS
Or as I mentioned above, another distinct possibility is that they’d be manipulating vibrations along superstrings.
by Bruce Wright
If the location or probe with which they’re exchanging messages is on the other side of a nebula that wasn’t too dense to absorb too much of the light, why shouldn’t they shine the laser through the nebula? Any other solution using lasers would require a relay station in the proper geometry, which they may or may have in place and which in any event would entail significant delays. It’s not as if they have to hide their activity from us (if they even know about us) ….. there’s not a whole lot we’d be able to do about it in any event.