Seeking Silent Aliens - How to Search for Advanced Alien Civilizations - Space.com article

There is a good article up at Space.com about using data from the Wide-field Infrared Survey Explorer aka the WISE space telescope, to hunt for large scale astro-engineering like Dyson Spheres, of an advanced alien civilization.

Here's an excerpt:

Look at a picture of the Earth at night, and the world appears to be, quite literally, glowing. Now, scientists are starting to look for signs of advanced alien civilizations by the glow given off by technology used to harvest the energy from a star or even an entire galaxy.

Theoretical physicist and mathematician Freeman Dyson first proposed the idea that advanced alien civilizations might develop technology to encircle a star and harvest most of its power, a structure now known as a Dyson sphere. If these objects do exist, astronomers might be able to detect the waste heat they produce using telescopes that peer into space using infrared light.

"The main point," Dyson told LiveScience, "is looking for aliens who don't want to communicate. My question was, 'How do you look for silent aliens?' They have to radiate away their waste heat. The only way to do that is to radiate lots of infrared radiation."

Now, astronomers at Pennsylvania State University are starting to narrow the search for Dyson spheres. But the search has only just begun, and may take hundreds of years, Dyson said. Finding Dyson spheres isn't inevitable, but "it's certainly possible," he said.

Great balls of fire

Much of the search for extraterrestrial intelligence (SETI) effort has focused on listening for radio signals sent by an intelligent civilization, as depicted in the movie "Contact." But this approach assumes the aliens want to communicate with humans. Dyson spheres get around this problem, because even a civilization that wasn't actively trying to communicate with others would give off waste heat.

Russian astrophysicist Nikolai Kardashev classified long-lived civilizations as one of three types: those that control the resources of a planet (Type I), of a star (Type II), or of a galaxy (Type III). A Dyson sphere represents a Type II civilization.

An episode of "Star Trek: The Next Generation" depicts the starship Enterprise responding to a distress call from a transport ship that has crashed into the outer hull of a Dyson sphere. But Dyson himself never envisioned the structure as a solid sphere.

"It doesn't have to be a sphere at all," Dyson said, "just any place where aliens happen to be generating a lot of energy." He described his structure as an "artificial biosphere," which could be a cloud of objects orbiting a star closely enough to absorb all the starlight. A solid sphere would be too weak to support its weight against the gravity of a star.

Dyson estimated that an alien civilization with a surface temperature around 80 degrees Fahrenheit (27 degrees Celsius) would emit infrared radiation at a wavelength of around 10 microns. Earth's atmosphere emits a lot of radiation in this region, so a telescope located in space would work best. But the necessary technology wasn't available when Dyson proposed the idea.

Now it is....

See more at: www.space.com...

I came across a video which talks about the search through data from both the Kepler and Wide field Infrared Survey Explorer telescopes for evidence of "astro engineering" by more advanced civilizations and thought you might be interested in it:




In case you were wondering what a Type II or Type II civilization is, Michio Kaku gives you a primer here:



Also on the Kardashev Scale (the scale of Type I, Type II, and Type III civilizations which Michio Kaku referred to) we have been estimated to be a Type 0.7 by Carl Sagan in the 1980s and a Type 0.8 now. The original 3 Kardashev civilization types have had a few additions.

A Type IV would have access to all the energy in the known universe.

A Type V would have access to energy beyond the known universe or across the multiverse in M-Theory.

To rank some familiar civilizations from Sci-FI:

The Government of Elysium = Type I

The Federation and The Borg from Star Trek = Type II

The Empire from Star Wars or The Engineers from Prometheus = Type III

Q from Star Trek The Next Generation or The Ancients from Stargate: Atlantis = Type IV

The Infinite Consortium from Magic: the Gathering = Type V

The most common civilization in our galaxy is likely a Type I or II. It is likely that if we were in a galaxy with a Type III we'd know it because as Jim Oberg said the signs would be all around us and easily observable. If a Type IV civilization existed in our galaxy it would likely be almost impossible to detect if it didn't want to be found. And for all purposes a late Type IV or Type V would be referred to by most people on Earth as "God".

While the search through the WISE telescope data looked for Type II and above civilizations there are people who are proposing to build a huge 70 meter telescope on Earth to look for the heat given off by a Type I civilization on plants around other stars.

Here was a Google hangout about the Colossus telescope project




If that whet your appetite for more including technical details here is a more in depth presentation about it:

reply to post by JadeStar


Wonderful post. S+F!

I like the idea of this approach, but, have some reservations in hanging any hope on us finding anything on the scales proposed in any order of magnitude approaching the size, organization, ambition, and management something like a Dyson Sphere would require.

In consideration of speculations involving some current models where intelligence has a greater likelihood of development from a predatory line of evolution, I think the population densities that would require the energy of such massive engineering projects, even if primarily enacted by a cloud of robots would be off-set by a demand for a diversity of other resources, like "elbow" room.

I think the likelihood for a civilization developing artificial suitcase stars, or portable suns prepackaged and bottled in smaller scale, more manageable Dyson Spheres, just as we ourselves are attempting in our quest for sustainable fusion to be of higher probability.
Beyond that, I feel we're looking at spookier energy solutions of the likes we find in the pages of Science Fiction, but, all still relatively compact and "portable".

Psychologically, one of the problems we ourselves have is territoriality over energy, and other resources.
Development of portability would be the more rational and reasoned approach to an energy solution because territory, whatever, and wherever that territory might be can be taken where your loss then becomes any aggressor's gain.

Once you've established mobility of all your major concerns, if the neighborhood goes to pot, one then simply weighs anchor and shoves off to sunnier shores.

That's a little difficult to do in investing material resources on stellar or even just planetary scales.

Then again, that's just one perspective.
In a Universe of possibilities, there are quite certainly many possibilities on wide variety by any potential number X of sundry civilizations of diverse psychology and technological development.
Should we sight positive results, it could be we've found some home-bodies that don't share the same interest we have in looking outward in scanning the horizon.

AliceBleachWhite
reply to post by JadeStar

 

Wonderful post. S+F!

I like the idea of this approach, but, have some reservations in hanging any hope on us finding anything on the scales proposed in any order of magnitude approaching the size, organization, ambition, and management something like a Dyson Sphere would require.

I understand. The reason for these searches is less on hope and more along the lines of other parts of astronomy which use observations to place limits on the mass of a star, planet, etc of a certain type.

In other words if we search for these types of large scale civilizations and do not find any well that just places an upper constraint on the known capabilities of intelligent alien species.

If we do the experiment we either find advanced aliens (WOO HOO!) or we have some idea what is and isn't likely so the next search can be more directed at what is likely (Woo HOO!).

Example of that is this paper: IRAS-based Whole-Sky Upper Limit on Dyson Spheres - Richard A. Carrigan, Jr., Fermi National Accelerator Laboratory - retrieved from ArXiv

In consideration of speculations involving some current models where intelligence has a greater likelihood of development from a predatory line of evolution, I think the population densities that would require the energy of such massive engineering projects, even if primarily enacted by a cloud of robots would be off-set by a demand for a diversity of other resources, like "elbow" room.

Fair point but I would not place a lot of stock in the idea of intelligence developing -only- as a result of a predatory line of evolution. Sure that's possibly how it played out on Earth. But as we've seen with other solar systems, nature is not obligated to have things develop the same way if things developing a different way does not violate a physical law.

Prior to the first exoplanet discoveries we thought all single star systems would look like our solar system. Mother nature had a much bigger imagination! So we were treated to a variety of worlds which are not like any which exist in our solar system (Hot Jupiters, Super Earths, Gas Terrans, Water Worlds, etc)

In other words, intelligence may very well evolve from predatory evolution but it might be way too soon to conclude that it -only- evolves from predatory evolution.

And as for elbow space, there would be plenty of it for a species with access to Type II energy levels.

I think the likelihood for a civilization developing artificial suitcase stars, or portable suns prepackaged and bottled in smaller scale, more manageable Dyson Spheres, just as we ourselves are attempting in our quest for sustainable fusion to be of higher probability.

Another excellent point Alice. However there is the problem that if you're scaling up fusion to a solar system wide level you have to transmit that energy from multiple small 'stars' or reactors (which then makes the civilization detectable either by laser, microwave or some other type of electromagnetic radiation) -or- a single source would end up having the same mass as a small red dwarf star (which would defeat the purpose of artificially creating one).

Beyond that, I feel we're looking at spookier energy solutions of the likes we find in the pages of Science Fiction, but, all still relatively compact and "portable".

Even with something spooky the amount of energy from a star would not be trivial. The means to harness it are likely many orders of magnitude easier than harnessing something like say, dark energy or 'zero point energy'.

Psychologically, one of the problems we ourselves have is territoriality over energy, and other resources.
Development of portability would be the more rational and reasoned approach to an energy solution because territory, whatever, and wherever that territory might be can be taken where your loss then becomes any aggressor's gain.

I'd be careful about anthropomorphizing an older, perhaps more stable and certainly more intelligent alien species which may very well be post-biological.

Once you've established mobility of all your major concerns, if the neighborhood goes to pot, one then simply weighs anchor and shoves off to sunnier shores.

True and so that makes me wonder how we'd detect that? Slow moving IR point sources the scale of say a gas giant planet maybe? But then that would be classed as a brown dwarf unless it had a very interesting spectrum

That's a little difficult to do in investing material resources on stellar or even just planetary scales.

Then again, that's just one perspective.
In a Universe of possibilities, there are quite certainly many possibilities on wide variety by any potential number X of sundry civilizations of diverse psychology and technological development.
Should we sight positive results, it could be we've found some home-bodies that don't share the same interest we have in looking outward in scanning the horizon.

So true. And thanks for the thought provoking response. I always enjoy your posts Alice.

I guess it's the old adage, if we don't seek, we will never find so seek we must

reply to post by JadeStar


Excellent thread, JadeStar ... this would tie in with more recent theories about ET civilizations probably being able to remain invisible and essentially undetected regarding our current methodology in trying to find traces of them.

Would it perhaps even be possible to shield that infrared radiation coming from potential Dyson spheres (if they existed) depending on the civilization type in question? From our perspective, it's certainly difficult to say just what solutions they'd be able to come up with to really keep us from detecting them.

As a rationale for them not wanting to expose themselves or having any contact with inferior civilizations, I could imagine a variety of good reasons incl. ethical ones. But looking into that more in detail would certainly be worthy of an own thread. Just my 2 cents, as usual ... !

"The main point," Dyson told LiveScience, "is looking for aliens who DON'Twant to communicate.

Then why are we trying to find them ??????

Easy. So Easy! move in ANY direction to the farthest reaches of the universe AWAY from trhe kardashians, the farther you go the more likely you are to find intelligence racing AWAY from the kardashians as fast a you are. (Note: the kardashians alluded to here are the ones from the "E" channel "reality" show, and not the kardasians from the Sci-fi epic "Last star fighter" with the doofy guy, the hot chick, and the guy that looks lke a potato that was left out in the sun to long, and then run over by a freight train, before being included in a tasty breakfast omlette that gets eaten by your do and later barfed up on your brand new Oingo-Boingo CD !

Sakrateri

"The main point," Dyson told LiveScience, "is looking for aliens who DON'Twant to communicate.

Then why are we trying to find them ??????

Because we want to know that we are not alone!

Sakrateri

"The main point," Dyson told LiveScience, "is looking for aliens who DON'Twant to communicate.

Then why are we trying to find them ??????

Because one can learn a lot about the universe, our place in it and perhaps our future just by verifying their existence. That's what the search for intelligent extraterrestrials is all about.

Communication would just be a bonus.

Do you really believe that if we ever found the existence of another civilization we would just leave them be in peace? Please look at our history it is not one of peace and prosperity.

We (as in the powers that be) would do everything possible to get to them and exploit everything that is of value on their planet then we would fight over who gets what parts of it.

If you do not believe that this is how it would be then you know nothing of the power mad thugs that have run this planet for thousands of years.

I would rather think we are alone in the universe then find some poor unsuspecting civilization and leave them at our " leaders " hands.

Sakrateri
Do you really believe that if we ever found the existence of another civilization we would just leave them be in peace? Please look at our history it is not one of peace and prosperity.

We (as in the powers that be) would do everything possible to get to them and exploit everything that is of value on their planet then we would fight over who gets what parts of it.

Good thing most of the aliens will be older and more advanced than us then isn't it?

We're most likely the kids. Our solar system is young compared to most of the star systems we look at out there.

It's highly unlikely that we're the top intelligent species in this part of the galaxy much less the entire galaxy or grander universe.

reply to post by JadeStar


What if there's no single massive power generating unit but they're spread out? For example, what if there're just a lot of small scale fusion power plants?

Does this require a gigantic power plant or what?

Could another species in our galaxy detect the waste heat around earth? If not now, when? Do we have to encircle our star to be measurable?

JadeStar

Sakrateri
Do you really believe that if we ever found the existence of another civilization we would just leave them be in peace? Please look at our history it is not one of peace and prosperity.

We (as in the powers that be) would do everything possible to get to them and exploit everything that is of value on their planet then we would fight over who gets what parts of it.

Good thing most of the aliens will be older and more advanced than us then isn't it?

We're most likely the kids. Our solar system is young compared to most of the star systems we look at out there.

It's highly unlikely that we're the top intelligent species in this part of the galaxy much less the entire galaxy or grander universe.

edit on 15-1-2014 by JadeStar because: (no reason given)

I want to agree, but where's the evidence? Even the most primitive people on earth can see airplanes and/or satellites cross the sky. They can also receive visitors from developed nations. You'd think peoples on earth would receive some visitations from superiors elsewhere or could observe their artificial objects traversing nearby. For there to be a case where we're the children of the galaxy the adults of our galaxy must either be (as I'm thinking now):
1 only slightly more advanced (and thus not yet visible)
2 greatly advanced yet their existence is covered up by our leadership.
3 greatly advanced yet they're still crossing over to soon be exposed to us

I just don't think advanced civilizations would work so hard to be invisible. I see present day earth as giving us the best example of this. Humans don't try to hide from moles or spiders or whales or other creatures, do they? Certainly, we try to respect the living space of other creatures and put distance between us and them, but we don't work feverishly to remain hidden from them. So we do on occasion bump into them. And I'd expect the same to happen with advanced civilizations periodically bumping into us and thus exposing their (far superior) presence.

To say another civilization in our galaxy is greatly superior you must say they can breach virtually every boundary which confines us here. This means they should be visible. As I said earlier, the only way I can imagine them not being visible is if they exist within similar boundaries and thus have not crossed over or they're in the process of crossing over. In the former case, it'd be a situation akin to the time before humans could easily cross the oceans to exchange goods and services. It's the time before Columbus sailed to the new world and perhaps before the Romans sailed to far away lands. If they're still crossing over, perhaps they're extinct and waiting to be found or maybe the physical or temporal constraints are mighty enough to make even the greatest civilizations not so great after all.

Being visible and covered up is a different matter. What're the odds the superior civilization can be covered up by our leadership effectively? This smells more of irrational conspiratorial paranoia. What're the benefits of conspiring to hide the presence of superiors nearby? Are there any precedents in history of cultures attempting to hide the existence of outsiders? Even if it were the case, it cannot probably last, as it would seem the costs and effectiveness would be dismal.

My feeling is if we don't discover something soon either the superiors you speak of are extinct, are not present, will be exposed in a gradual or more rapid disclosure or are not nearly as impressive as you think they should be.

jonnywhite
reply to post by JadeStar

 

What if there's no single massive power generating unit but they're spread out? For example, what if there're just a lot of small scale fusion power plants?

Good question. One I kinda talked about in my response to Alice.

There would still be ways to detect a large advanced civilization which did this.

It just would differ from trying to detect a Dyson Sphere.

The use of energy of all types generates some sort of detectable output. Heat is the most common. And something like the Colossus telescope would be able to detect that

But lets suppose they set up lots of portable small fusion plants as you say. How do they transmit that power to the rest of their civilization?

Copper wire would seem old and obsolete to really advanced ETs, mainly because it is inefficient. It turns a lot of the energy put through it into heat (which then becomes detectable), suppose they have high temperature superconductors, then at the end point the work that the energy does might be detectable in the visual (lights), IR (heat) or radio (microwaves).

Another way to transmit power which we know how to do with our present day technology is beaming it via microwaves or lasets from one point to another. We could do this in space from one point to another or even on a planet.

Large scale beaming of power would be detectable at interstellar distances.

Does this require a gigantic power plant or what?

It does. It's the star the civilization lives around. The reasoning is that because solar energy is so easy to harness that it would be logical to take advantage of all the energy output of a star.

Even large fusion generators would have to number in the billions to match the output of our Sun.

Could another species in our galaxy detect the waste heat around earth?

Yes. If a civilization had a very advanced series of telescopes all synced together in a way which we call an "interferometer" we'd be detectable through it if there were enough telescopes in the network. Basically an interferometer uses a bunch of little telescopes to make one gigantic telescope.

And we've been detectable this way since the Steam Era.

We know how to do this now. We just haven't built such a thing because of the costs.

NASA's cancelled Terrestrial Planet Finder was a very small version of one of these. So was the ESA's Darwin.

If not now, when?

Well if you wonder how long it will be before we would be detectable by a civilization with no large space interferometer, then something like the earth based Colossus 70 meter telescope on another planet out to about 600 light years could likely detect the waste heat we'll be generating in about 200 years (if our energy use continues on the projected curve its on).

Do we have to encircle our star to be measurable?

Nope. And like I said, to a species with a large enough interferometer we could have theoretically been detected since the mid 1800s and certainly since 1900.

I'll get to your second response tomorrow. It's a great examination of what's called the Fermi Paradox and its a puzzle even the smartest people on the planet have wrestled with since it was first proposed.

I have my own speculation as to why we might be surrounded (relatively speaking) by advanced extraterrestrial civilizations and not really see any signs. None of it involves active hiding by them either. More or less it just involves us just learning how to look for them.

As for interstellar travel. Your example brings the question of how we'd detect such travel. Would we know it to see it if it didn't involve our solar system? I've got some ideas on that as well. Speculation of course but some food for thought.

Just look at large gamma-ray bursts. That's no stellar phenomenon. It's an industrial accident.

Anyway, Dyson spheres are unstable, require gravity generation to retain atmosphere, and vent to space in the event of a puncture. Very dangerous.

Bedlam
Just look at large gamma-ray bursts. That's no stellar phenomenon. It's an industrial accident.

Well if we saw a bunch of small bursts in a continuous line, doppler shifted indicating motion, well that would be........interesting.

Anyway, Dyson spheres are unstable, require gravity generation to retain atmosphere, and vent to space in the event of a puncture. Very dangerous.

Dyson never imagined them as solid (that's why i used the picture i did in the OP).

An episode of "Star Trek: The Next Generation" depicts the starship Enterprise responding to a distress call from a transport ship that has crashed into the outer hull of a Dyson sphere. But Dyson himself never envisioned the structure as a solid sphere.

"It doesn't have to be a sphere at all," Dyson said, "just any place where aliens happen to be generating a lot of energy." He described his structure as an "artificial biosphere," which could be a cloud of objects orbiting a star closely enough to absorb all the starlight. A solid sphere would be too weak to support its weight against the gravity of a star.

Perhaps this is a better picture of what we envision when talking about Dyson Spheres/Dyson Shells:

JadeStar
Well if we saw a bunch of small bursts in a continuous line, doppler shifted indicating motion, well that would be........interesting.

I always thought of it as something like:

"Today, we will launch a new day for Gixgax! From this moment on, our power will come from space itself! Vacuum energy is safe, efficient, clean. The future is now!" EEpthork 8 paused dramatically, then pulled the toggle with a fore-tentacle. Below, in the Energy Pit, a cool blue glow began to swell and


As far as seeing GRBs nearby, did you ever read Bear's "Eon"? It starts off that way, sort of.

Perhaps this is a better picture of what we envision when talking about Dyson Spheres/Dyson Shells:

Nice. That's probably the first article where the author understands a sphere is unstable orbiting a central mass. Which is also why "Hollow Earth" guys are wrong.

One other thing...

Is it possible Dyson Spheres or something like them is the reason the measurable gravitational "output" of galaxies so much more than the visible matter? I've read the stars on the outside edges of galaxies should revolve slower and the galaxies should break apart because there's not enough visible matter to account for what's observed. The idea is dark matter holds all of it together. Not sure about dark energy. I know all this probably is stupid, but I wanted to say something.

How do you hide a galaxy without being able to hide its gravitational influence? I'm not saying hiding the galaxy is intentional, maybe it's just a byproduct.

YOu'd think whatever they do it'd have enormous heat leakage, but it'd be cool if dark matter or dark energy was just other alien civilizations.

JadeStar

Sakrateri

"The main point," Dyson told LiveScience, "is looking for aliens who DON'Twant to communicate.

Then why are we trying to find them ??????

Because one can learn a lot about the universe, our place in it and perhaps our future just by verifying their existence. That's what the search for intelligent extraterrestrials is all about.
Communication would just be a bonus.

We also might someday need them as a food source.

What? We're predators, dammit!

jonnywhite
One other thing...

Is it possible Dyson Spheres or something like them is the reason the measurable gravitational "output" of galaxies so much more than the visible matter?

I've got a SF book at home, The Wanderer by Fritz Leiber, the central theme is that pretty much the stars you see are all "old" light, and nothing's that way anymore - it's all Dyson spheres or the like now, and Earth is in a sort of wildlife preserve. The discrepancy you see now would be because from our viewpoint, the transformation's already well underway, and the "dark matter" is Dyson spheres already going up like condos on a beachfront.

Bedlam

jonnywhite
One other thing...

Is it possible Dyson Spheres or something like them is the reason the measurable gravitational "output" of galaxies so much more than the visible matter?

I've got a SF book at home, The Wanderer by Fritz Leiber, the central theme is that pretty much the stars you see are all "old" light, and nothing's that way anymore - it's all Dyson spheres or the like now, and Earth is in a sort of wildlife preserve. The discrepancy you see now would be because from our viewpoint, the transformation's already well underway, and the "dark matter" is Dyson spheres already going up like condos on a beachfront.

I would think the distribution of "unseen matter" would have to be just right so that the predicted rotation curves would fit observations and also solve other riddles dark matter handily takes care of (lensing observations). There's a remarkable consistency between the speed of stars near the center and the stars further away. More mass at the center wouldn't explain it because even that would still show a curve where the stars on the outside are moving slower than the ones on the inside. The distribution of "unseen mass" has to allow for the observed consistency, wherein stars on the outside are moving at an almost equal pace as the ones on the inside and indeed some are moving even faster. I think they usually create a sort of dark matter halo to be the distribution. So if the "unseen matter" were something like dyson spheres then it would resemble these dark matter halos in terms of its size and shape and density at all levels.

And what about the heat leakage we should be able to observe if they're dyson spheres? It may be these dyson spheres or whatever they may be must also exhibit all of the traits we've associated with dark matter. There're others I've not mentioned here that I'm reading about nwo. It's beyond me to understand all of it. One of the listed traits is most dark matter is not made of baryons and doesn't interact much with normal matter. Baryonic matter (like neutrons and protons) constitutes most of the visible matter in the unviverse.

Maybe it's possible, but it probably involves many things we don't yet understand. We'll probably have ot be wrong about things for dark matter to become aliens.