NASA Is Quietly Funding A Hunt For Alien Megastructures

maximus otter

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In the last decade, we have devised amazing instruments to glare unflinchingly at the stars and discovered that other planets are common around them. These exoplanet discoveries have thrown gasoline on the fire of the astrobiology field, where scientists seek to explore whether life might exist beyond Earth. But they have also fueled SETI, or the search for extraterrestrial intelligence. If life does evolve on other worlds, then we may very well find more than just biosignatures like oxygen.

fractal_dyson_sphere_by_eburacum45-d2yum16.jpeg


File depiction of theoretical Dyson Sphere.

We might find technosignatures, too. These are things like radio signals, or even megastructures; that is, artificial objects on a gigantic scale such as hypothesized star-sized supercomputers. Now, Supercluster reported in an article this week, NASA has quietly begun to fund the search for such alien megastructures for the first time in the agency's history.

Since the end of 2019, NASA has awarded four grants to fund searching for technosignatures. In November 2020, NASA awarded a grant to Ann Marie Cody of the NASA Ames Research Center and Croft to survey the whole sky for anomalous objects that transit across stars. It is possible, however uncertain, that they and their collaborators will find artificial alien megastructures.

Cody studies natural causes of dimming, which make stars vary in brightness. These can range from objects in orbit, like exoplanets or exocomets, to sources inherent to the star, like sun spots. In general, dimming is a key investigative tool for discovering new exoplanets or other objects that "transit," or pass in front of, stars. But dimming should also provide a way to identify the presence of alien megastructures, which might block out starlight in transit. With their collaborators, the pair will create the first large scale survey for transiting technosignatures. It is work that is pioneering on both a technical and organizational level.

Recent SETI efforts have been aided by the fact that they dovetail neatly with mainstream astronomy. The Kepler and TESS space telescopes, which were launched to find exoplanets, also make ideal instruments for looking for transiting technosignatures. In particular, Cody and Croft's new project will analyze the TESS dataset.

TESS was launched in 2018 to collect the patterns of light variation from across 85 percent of the sky. It measures the “light curves” of stars, which indicate the way their light dims, for example when an exoplanet passes in front of them.

Light curves have already revealed mysteries besides exoplanets. In 2015, astronomers and citizen scientists found that a star now known as Tabby’s star, or Boyajian’s star, exhibited unusual dimming, losing as much as 22 percent of total brightness. Since then, astronomers have come up with several natural explanations, including possibilities like the collision of exoplanets, which would create planet-sized shrouds of debris.

The strategy for the team's survey is to “search for the weird.”

https://www.vice.com/en/article/pkbq7z/nasa-is-quietly-funding-a-hunt-for-alien-megastructures

maximus otter
 

kamalktk

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Not sure why this is in the "damned science" section? It seems like "normal science".
 

eburacum

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The concept of Dyson Spheres is highly speculative, and therefore a bit fringe. The fact that we haven't seen any yet is more interesting, and invites even more speculation, some of it extremely fringe.

Dyson Spheres emerged as a concept from the extrapolation of known science. What could be the largest amount of energy that could be produced by a single civilisation without resorting to magical technology? One of the first people to take this to a logical extreme was the philosopher and science fiction author Olaf Stapledon, who imagined that stars could be surrounded by 'necklaces' of artificial worlds collecting energy. Nikolai Kardashev pondered how much energy could be collected by a civilisation which gathered all the energy from a local star; and Freeman Dyson extended the concept further to imagine a spherical swarm of orbiting power collectors.

If a civilisation wants to maximise its power throughput, a Dyson swarm would be a stage in that process (further down this route, the star could be disassembled and used more efficiently). Bur we don't see them, either nearby in our galaxy, or in nearby galaxies. Do advanced civilisations not exist? Or do they find some other strategy for maximising their happiness?

Speculation follows speculation, but we should keep looking, since we haven't looked everywhere yet by a long chalk.
 

ramonmercado

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Perhaps the Dyson Spheres utilise Black Holes for energy.

In the long-running TV show Doctor Who, aliens known as time lords derived their power from the captured heart of a black hole, which provided energy for their planet and time travel technology.

The idea has merit, according to a new study. Researchers have shown that highly advanced alien civilizations could theoretically build megastructures called Dyson spheres around black holes to harness their energy, which can be 100,000 times that of our Sun. The work could even give us a way to detect the existence of these extraterrestrial societies.

“I like these speculations about what advanced civilizations might do,” says Tomáš Opatrný, a physicist at Palacký University Olomouc, who was not involved with the work but agrees that a Dyson sphere around a black hole would provide its builders with lots of power.

If humanity’s energy demands continue to grow, a point will come when our power consumption approaches, or even exceeds, the total energy available to our planet. So argued physicist Freeman Dyson way back in 1960. Borrowing from British sci-fi author Olaf Stapledon, Dyson proposed that any sufficiently advanced civilization that wanted to survive would need to build massive structures around stars that could harness their energy. ...

https://www.sciencemag.org/news/202...nergy-harvesting-structures-could-power-alien
 

Tunn11

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Not sure whether this belongs here or the Saturn thread or elsewhere.

Has anyone considered that Saturn’s rings may be an artefact? Hoagland wrote a lot about Iapetus and it is seriously weird, but it also provides a view of the rings.

I can’t see a reason to construct them other than aesthetics but that would be an encouraging sign.

Most large planets have some sort of ring system but nothing as spectacular as Saturn’s (Although Uranus because of its axial tilt would be the most interesting from the Sun’s orbital plane)

Jupiter’s gravity attracts a lot of debris which may disrupt any similar system built there.

And one for the ancient aliens theorists. Why did no one tell any of the ancient civilisations about Saturn’s rings or Uranus, which can be seen with the naked eye if you know where to look? Peoples like the Sumerians would have been able to track it.
 

Erinaceus

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Would the Sumerians and others have been able to see Saturn's rings with the naked eye? When they are at their most open, tilted towards earth, Saturn appears oval so maybe if the ancient civilisations noticed it there may be depictions of an oval star somewhere.
 

eburacum

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The flat rings of Saturn are not really very useful if considered as megastructures. As Cassini realized, they can only exist if they are made up of innumerable small orbital particles, and those particles are probably little more than fluffy snowballs that continually collide with each other. It would be difficult to inhabit such objects comfortably, or convert them into giant data processing nodes, or extract power from the environment without de-orbiting.

A better use of rings might be the supramundane ring concept devised by Paul Birch; this consists of a broad, dynamically-supported ring with a habitable surface on the outside - a bit like an inverted ringworld or Halo. Here's my picture of such a structure.

med_suprajupiter.png
 

eburacum

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Saturn is too distant to be seen as an oval by the naked eye. The rings are not discernible.

But Uranus is (just) a naked eye object, so might have been seen on occasion - the problem is it just looks like a dim 6th magnitude star, like so many others. In order to realise that it was a planet the Sumerians would have needed to map all the 6th magnitude stars in the Zodiac accurately, something that was not done till the 18th century or later.
 

Tunn11

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Apparently there are people who can see Ganymede one of the Galilean moons of Jupiter, usually by blocking Jupiter and the phases of Venus with the naked eye, although I don't know of any ancient accounts of these unless some of the legends around Venus are attributable to its shape as perceived by others.

Saturn's rings are right out, even with small binoculars. Galileo noticed that the planet was unusual but not that it had a ring. He also mapped Neptune nearly 250 years before its actual discovery but didn't realise what it was.
 

kamalktk

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The flat rings of Saturn are not really very useful if considered as megastructures. As Cassini realized, they can only exist if they are made up of innumerable small orbital particles, and those particles are probably little more than fluffy snowballs that continually collide with each other. It would be difficult to inhabit such objects comfortably, or convert them into giant data processing nodes, or extract power from the environment without de-orbiting.

A better use of rings might be the supramundane ring concept devised by Paul Birch; this consists of a broad, dynamically-supported ring with a habitable surface on the outside - a bit like an inverted ringworld or Halo. Here's my picture of such a structure.

med_suprajupiter.png
Wouldnt residents of such a structure have problems with the massive magnetic fields of a Jupiter type planet?
 

Tunn11

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I was actually theorising that the ring may have no function other than alien art, a sort of effort by an interstellar Banksy. :) I hadn't heard of the supramundane ring, it's an interesting concept but wouldn't it be too far out for Earth type life at Saturn's distance? On Uranus it wouldn't get much sunlight at all, especially if it was in the orbital plane because of the axial tilt. How would it cope with tidal forces? Would the concept work better with a series of sections rather than a continuous ring as in the refined ringworld concept?
 

eburacum

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A supramundane ring wouldn't have any issues with tidal forces from the planet, since it is a flexible, actively supported structure, but it could suffer some minor disruption from any moons that may be present. In most cases the ring would be constructed from the moons themselves, so they would no longer be there to cause problems.

The amount of sunlight collected by the ring can be increased by increasing the ratio of light collecting area to habitable space - or by choosing an extrasolar planet with more incident sunlight. Because of the way we currently detect planets, most extrasolar worlds found to date receive more sunlight than Earth.
 

Tunn11

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While I’m on insane musings about alien tech can I throw out a few more thoughts?

When we are looking for signs of these structures are we considering advances in energy use? For example the heat signature of a Victorian house compared to a modern one would be quite high; inefficient fuel burning, no insulation, etc. Wouldn’t a civilisation able to utilise all the power from its sun (Kardashav type 2) have developed more efficient energy usage and be more difficult to detect?

We don’t know nearly enough about the origins of life, could it have evolved at a very slow chemical rate. Equivalent of the Edgeworth/Kuiper belt or Oort cloud and “speeded up” life like ours have arisen from a spread from these regions. Given this may the time span of some civilisations be far longer than we currently believe?

Thinking of why von Neumann probes haven’t colonised the Galaxy could viruses be von Nuemann probes? Designed to produce a “life form” that somehow transmitted information back to their originators but which “evolved” in the wrong way giving rise to a variety of life forms here and maybe elsewhere?

I’ve speculated above that Saturn’s rings may be an alien art installation, but what about some of the seemingly structural forms seen in planetary nebulae. They could arise naturally but could they have been “helped” just because they look good? After all to a Kardashav type 3 civilisation (Able to use the power output of a galaxy) would it be any more trouble than spray painting a wall?

This is all idle speculation if anyone feels it worth discussing. I’m not fixated on any of this so feel free to point out any and all flaws or just roll about laughing I won’t be offended.:bthumbup:
 

eburacum

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Wouldn’t a civilisation able to utilise all the power from its sun (Kardashav type 2) have developed more efficient energy usage and be more difficult to detect?
A good point. I suspect that most people who anticipate the construction of large power-collecting megastructures already expect the civilization concerned to utilize energy at high efficiency. If a civilization uses such large amounts of energy they will presumably have very demanding uses for this energy; perhaps they are simulating entire universes in there, or processing data for some other purpose we can barely imagine. Another highly demanding use for power and energy would be the propulsion of interstellar spacecraft from star to star, or the support of biospheres in deep space far from the star.

I would note that whenever a civilization uses power, it will always need to radiate the same amount of energy as waste heat; if this energy is not re-radiated, the temperature of the infrastructure will increase. There are two ways to reduce this waste heat signature to undetectability; first, you can increase the radiating surface area until it is large enough to radiate at a low, undetectable temperature. If you had the entire luminosity of a star to eliminate, this would require a radiating surface many AU in radius.

Secondly, you could dump all the waste heat into a cool black hole- if the black hole is large enough, it will be colder than the rest of the universe and could act as a heat sink. All these options have been discussed by Isaac Arthur on his YouTube channel, by the way.

So if a civilisation is undetectable, it must be too small to notice, or use very large and very demanding heat sink technology. Or (most probably) be too far away to see with current telescopes.
 

Tunn11

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I would note that whenever a civilization uses power, it will always need to radiate the same amount of energy as waste heat; if this energy is not re-radiated, the temperature of the infrastructure will increase. There are two ways to reduce this waste heat signature to undetectability; first, you can increase the radiating surface area until it is large enough to radiate at a low, undetectable temperature. If you had the entire luminosity of a star to eliminate, this would require a radiating surface many AU in radius.

Secondly, you could dump all the waste heat into a cool black hole- if the black hole is large enough, it will be colder than the rest of the universe and could act as a heat sink. All these options have been discussed by Isaac Arthur on his YouTube channel, by the way.

So if a civilisation is undetectable, it must be too small to notice, or use very large and very demanding heat sink technology. Or (most probably) be too far away to see with current telescopes.
But isn't waste heat still energy and therefore capable of being re-used and then re used again? Assuming very advanced tech, e.g. frictionless surfaces and possibly moving the energy to other environments via for instance focused lasers to collectors in a nearby star system, etc.! Could that energy be stored in a sort of mega battery and taken elsewhere? As you say biosphheres in other systems or ones built in interstellar space - a sort of power source for an O'Neill habitat but in deep space where we would see it, if at all as a small star.

Could an advanced technology convert energy to mass? Dunno why they'd want to but who knows. What would that process look like?

Are alien civilisations actually building stars or black holes

Could FRBs be a method of dumping energy? A bloody dangerous one I imagine but then our record of dumping waste isn't great.

When we look at the landscape in most places on Earth we tend to think that if there is no obvious sign of human inntervention that we are looking at a natural landscape whereas in many cases we are not. Past de forestation, over grazing, etc. all contribute to what we see as natural. How much of the observable Universe that we see are we sure is natural and not the result of the past efforts of a galaxy cluster wide civilisation?

Sorry for all the extra questions - I'm beginning to sound like the "ancient aliens" programme, but I've always found the subject fascinating.

Thanks @eburacum for the Isaac Arthur tip btw. :)
 

eburacum

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But isn't waste heat still energy and therefore capable of being re-used and then re used again?
Yes. You can re-use the energy as many times as you like, but at the end of the day it must be radiated or dumped, otherwise the infrastructure will get hotter and hotter. It is like putting a heat source inside a perfect insulator - unless you dump the heat, everything inside the insulator will get hotter and hotter until it vapourises.
 

eburacum

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Could an advanced technology convert energy to mass? Dunno why they'd want to but who knows. What would that process look like?
This is another good question. Energy and mass are interchangeable, so you could convert waste heat into mass. Unfortunately all the methods we know about which convert energy into mass are very inefficient*- so you'd end up creating far more waste heat than you dispose of.

*except one - that is dumping energy into a black hole, which converts energy directly into undifferentiated 'mass-energy', which usefully increases the effective mass of the black hole, and paradoxically makes it colder.
 
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