by Paul Gilster | May 18, 2024 | Astrobiology and SETI | 39 comments
I’m enjoying the conversation about Project Hephaistos engendered by the article on Dyson spheres. In particular, Al Jackson and Alex Tolley have been kicking around the notion of Dyson sphere alternatives, ways of preserving a civilization that are, in Alex’s words, less ‘grabby’ and more accepting of their resource limitations. Or as Al puts it:
One would think that a civilization that can build a ‘Dyson Swarm’ for energy and natural resources would have a very advanced technology. Why then does that civilization not deploy an instrumentality more sly? Solving its energy needs in very subtle ways…
As pointed out in the article, a number of Dyson sphere searches have been mounted, but we are only now coming around to serious candidates, and at that only seven out of a vast search field. Two of these are shown in the figure below. We’re a long way from knowing what these infrared signatures actually represent, but let’s dig into the Project Hephaistos work from its latest paper in 2024 and also ponder what astronomers can do as they try to learn more.
Image: This is Figure 7 from the paper. Caption: SEDs [spectral energy distributions] of two Dyson spheres candidates and their photometric images. The SED panels include the model and data, with the dashed blue lines indicating the model without considering the emission in the infrared from the Dyson sphere and the solid black line indicating the model that includes the infrared flux from the Dyson sphere. Photometric images encompass one arcmin. All images are centered in the position of the candidates, according to Gaia DR3. All sources are clear mid-infrared emitters with no clear contaminators or signatures that indicate an obvious mid-infrared origin. The red circle marks the location of the star according to Gaia DR3. Credit: Suazo et al.
We need to consider just how much we can deduce from photometry. Measuring light from astronomical sources across different wavelengths is what photometry is about, allowing us to derive values of distance, temperature and composition. We’re also measuring the object’s luminosity, and this gets complicated in Dyson sphere terms. Just how does the photometry of a particular star change when a Dyson sphere either partially or completely encloses it? We saw previously that the latest paper from this ongoing search for evidence of astroengineering has developed its own models for this.
The model draws on earlier work from some of the co-authors of the paper we’re studying now. It relies on two approaches to the effect of a Dyson sphere on a star’s photometry. First, we need to model the obscuration of the star by the sphere itself. Beyond this, it’s essential to account for the re-emission of absorbed radiation at much longer wavelengths, as the megastructure – if we can call it that – gives off heat.
“[W]e model the stellar component as an obscured version of its original spectrum and the DS component as a blackbody whose brightness depends on the amount of radiation it collects,” write the authors of the 2022 paper I discussed in the last post. The modeling process is worth a post of its own, but instead I’ll send those interested to an even earlier work, a key 2014 paper from Jason Wright and colleagues, “The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. II. Framework, Strategy, and First Result.” The citation is at the end of the text.
The recently released 2024 paper from Hephaistos examined later data from Gaia (Data Release 3) while also incorporating the 2MASS and WISE photometry of some 5 million sources to create a list of stars that could potentially host a Dyson sphere. In the new paper, the authors home in on partial Dyson spheres, which will partially obscure the star’s light and would show varying effects depending on the level of completion. The waste heat generated in the mid-infrared would depend upon the degree to which the structure (or more likely, ‘swarm’) was completed as well as its effective temperature.
So we have a primary Dyson sphere signature in the form of excess heat, thermal emission that shows up at mid-infrared wavelengths, and that means we’re in an area of research that also involves other sources of such radiation. The dust in a circ*mstellar disk is one, heated by the light of the star and re-emitted at longer wavelengths. As we saw yesterday, all kinds of contamination are thus possible, but the data pipeline used by Project Hephaistos aims at screening out the great bulk of these.
Seven candidates for Dyson spheres survive the filter. All seven appear to be actual infrared sources that are free of contamination from dust or other sources. The researchers subjected the data to over 6 million models that took in 391 Dyson sphere effective temperatures. They modeled Dyson spheres in temperature ranges from 100 to 700 K, with covering factors (i.e., the extent of completion of the sphere) from 0.1 to 0.9. Among many factors considered here, they’re also wary of Hα (hydrogen alpha) emissions, which could flag the early stage of star growth and might be implicated in observations of infrared radiation.
Image: IC 2118, a giant cloud of gas and dust also known as the Witch Head Nebula. H-alpha emissions, which are observed over most of the Orion constellation, are shown in red. This H-alpha image was taken by the MDW Survey, a high-resolution astronomical survey of the entire night sky not affiliated with Project Hephaistos. I’m showing it to illustrate how pervasive and misleading Hα can be in a Dyson sphere search. Credit: Columbia University.
I want to be precise about what the authors are saying in this paper: “…we identified seven sources displaying mid-infrared flux excess of uncertain origin.” They are not, contra some sensational reports, saying they found Dyson spheres. These are candidates. But let’s dig in a bit, because the case is intriguing. From the paper:
Various processes involving circ*mstellar material surrounding a star, such as binary interactions, pre-main sequence stars, and warm debris disks, can contribute to the observed mid-infrared excess (e.g. Cotten & Song 2016). Kennedy & Wyatt (2013) estimates the occurrence rate of warm, bright dust. The occurrence rate is 1 over 100 for very young sources, whereas it becomes 1 over 10,000 for old systems (> 1 Gyr). However, the results of our variability check suggest that our sources are not young stars.
Are the candidate objects surrounded by warm debris disks? What’s interesting here is that all seven of these are M-class stars, and as the authors note, M-dwarf debris disks are quite rare, with only a few confirmed. Why this should be so is the object of continuing study, but both the temperature and luminosity of the candidate objects differs from typical debris disks. The questions deepen and multiply:
Extreme Debris Disks (EDD) (Balog et al. 2009), are examples of mid-infrared sources with high fractional luminosities (f > 0.01) that have higher temperatures compared to that of standard debris disks (Moór et al. 2021). Nevertheless, these sources have never been observed in connection with M dwarfs. Are our candidates’ strange young stars whose flux does not vary with time? Are these stars M-dwarf debris disks with an extreme fractional luminosity? Or something completely different?
The authors probe the possibilities. They consider chance alignments with distant infrared sources, and offsets in the astrometry when incorporating the WISE data. There is plenty to investigate here, and the paper suggests optical spectroscopy as a way of refuting false debris disks around M-dwarfs, which could help sort between the seven objects here identified. Stellar rotation, age and magnetic activity may also be factors that will need to be probed. But when all is said and done, we wind up with this:
…analyzing the spectral region around Hα can help us ultimately discard or verify the presence of young disks by analyzing the potential Hα emission. Spectroscopy in the MIR [mid-infrared] region would be very valuable when determining whether the emission corresponds to a single blackbody, as we assumed in our models. Additionally, spectroscopy can help us determine the real spectral type of our candidates and ultimately reject the presence of confounders.
So the hunt for Dyson spheres proceeds. Various pieces need to fall into place to make the case still more compelling, and we should remember that “The MIR data quality for these objects is typically quite low, and additional data is required to determine their nature.” This layman’s guess – and I am not qualified to do anything more than guess – is that rather than Dyson spheres we are glimpsing interesting astrophysics regarding M-dwarfs that this investigation will advance. In any case, do keep in mind that among some five million sources, only seven show compatibility with the Dyson sphere model.
If Dyson spheres are out there, they’re vanishingly rare. But finding just one would change everything.
The paper on Dyson sphere modeling is Wright et al., “The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. II. Framework, Strategy, and First Result,” The Astrophysical Journal Vol. 792, Issue 1 (September, 2014), id 27 (abstract). The 2022 paper from Project Hephaistos is Suazo et al., “Project Hephaistos – I. Upper limits on partial Dyson spheres in the Milky Way,” Vol. 512, Issue 2 (May 2022), 2988-3000 (abstract / preprint). The 2024 paper is Suazo et al., “Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS, and WISE,” MNRAS (6 May 2024), stae1186 (abstract / preprint).
Ben Walmisleyon May 18, 2024 at 5:11
A sufficiently advanced technology is indistinguishable from natural phenomena when enough stars are examined!
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Edmund K.on May 18, 2024 at 12:41
My sense with these searches is that we are still looking for twentieth-century fantasies of what ET might look like rather than dealing with what is actually out there. The Dyson Sphere seems like a conceptual “scaling-up” of mid-century industrial society—very much a 1950s understanding of what an alien society might do (based on 1950s understandings of energy needs and how they might be satisfied). The failure so far of SETI—the fact that the universe doesn’t appear to resemble 20th-century sci-fi fantasies of an inhabited realm full of humanity analogues—surely calls for some recalibration of our expectations?
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henry cordovaon May 18, 2024 at 19:23
Please forgive me for reprising this comment to a previous thread, but I believe your own remarks are apt, and I wish to reinforce them further.
I don’t really expect any of these infrared anomalies will ever be found to be an artifact of an extremely powerful civilization, one operating on a scale involving entire planets, stars and planetary systems. Even if one can conceive of a civilization lasting long enough to develop such near-godlike powers, its difficult to come up with a reason why they would want to.
Our desire to speculate about such colossal powers is that we simply haven’t been able to explain away the embarrassing fact that much easier means of interstellar communication have so far failed to turn up. Instead, we fantasize about brooding, almost supernatural, intelligences hammering away at the forges of heaven creating…what? SETI enthusiasts are fascinated by technology, seduced by our own pathetic dabbling in those arts, and think of this sort of aggressive hyper-industrialism MUST be the sign of true intelligence, genuine civilization.
I suppose its not impossible, the universe is old enough and big enough to make almost anything possible, somewhere, sometime. But I suspect a truly wise and advanced culture would find less spectacular and disruptive hobbies, such as securing eternal life, security from cosmic catastrophe, true scientific understanding, or even deliberately searching for other species. Making bonfires of planets and harnessing the power of entire suns seems like an awful lot of sturm und drang. It makes sense to us mostly because we’re desperate for some sort justification of our own fantasies. We like to think of ourselves as an aggressive tribe of explorers, entrepreneurs and conquerors, and we can’t imagine anyone worthwhile not being the same. We listened for microwave signals and we didn’t find any (after listening for a whole half century!) So now we fantasize about Marioshka Brains, Dyson megastructures and Kardashev Kultures. Surely, they must have left some imprint on the cosmos.
I suspect intelligent civilizations are out there, but they are few and far between for the reasons I have spelled out previously. They are highly separated in space and time, and there is little incentive for any of them to expand indefinitely until they are capable of leaving a footprint that can be detected at galactic distances. Once they have reached a certain level of comfort and security they simply will have no need to continue expanding. and “progressing”. The few crazy enough to follow that psychotic path will eventually kill themselves off or stew in their own poisons.
Still, I welcome this interest in sifting through old astronomical catalogs and databases. Something of interest is bound to turn up, even if it isn’t evidence of technological overreach, but just some interesting little astrophysical process we haven’t stumbled onto yet.
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Fredon May 20, 2024 at 9:52
@Henri
“SETI enthusiasts are fascinated by technology”.
When we read this kind of paper, we quickly see that it is almost an advertisem*nt to buy Tesla; very in the mind of the man-god, transhuman, master of the earth and the universe. It’s just if it’s not written down: subscribe here:) Technocentric vision of our societies…
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Andrew Pon May 21, 2024 at 8:20
A Dyson Swarm does not necessarily have to be built by technological aliens. If there are creatures that can live and breed in space, and feed upon dust and sunlight, it is conceivable that some, somewhere have filled the space around a star to the maximum extent possible, and if this is the case, one would expect that such life would be able to spread to other nearby suitable stars.
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Destination Centaurion May 22, 2024 at 1:48
I could be misunderstanding your comment but…
Are you saying it’s “psychotic” to want to explore and expand, and spread life and technology to places where there is none?
If so I guess that makes me a psychpath!
Also I dont think we can be so certain that ALL civilizations–every single one of them–will be content to stay at home…
And that not a single one of them will share some of our expansionist and explatory and large project goals and pyschological traits?
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Robin Dattaon May 19, 2024 at 3:57
Sophistication in handling matter, energy, time and space will manifest itself in such minimized disruption of these that no disruptions may be detected. Or maybe dark matter and dark energy are their waste products, as suggested here many moons ago by Alex Tolley.
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Montieon May 18, 2024 at 8:46
According to the Bradbury M-Brain page using our own star as an example, a cloud of material could cover a star all the way out to the orbit if Neptune. That much material between star and cloud edge would make it no more visible than background radiation.
See AlsoAdvanced Civilizations Could be Using Dyson Spheres to Collect Unimaginable Energy From Black HolesScientists have found 'evidence' of advanced alien civilisationsAlien 'Dyson sphere' megastructures could surround at least 7 stars in our galaxy, new studies suggestAstronomers Are on the Hunt for Dyson SpheresWas he wrong? Would IR still get through? Can not heat be directed away so as to not point at other stars?
–sincerely, Not A Real Scientist.
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Roberton May 18, 2024 at 11:37
It seems unreasonable to me that a truly advanced civilization would be interest in tapping the last joule of solar energy of it’s star over more exotic but convenient forms of energy such as fusion. Do what stars do but on your own terms. More likely it would be far in advance of fusion to some source we can’t even imagine yet. Yet, Sir Arthur C. Clarke did imagine something exotic in his books with monoliths exponentially multiplying over Jupiter blocking out its light and engineering its properties. Like a local Dyson Sphere but for another purpose. Perhaps as Sir Arthur suggested, it would appear like magic to us.
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Wojciech Jon May 19, 2024 at 7:50
There is no reason to assume such constructs would serve to only gather energy, besides other functions.
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Roberton May 19, 2024 at 16:38
I was originally going to make the point that attempts to hide a civilization from others would be futile if even humans with current technology can devise ways to detect them as demonstrated by the above paper.
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Ron S.on May 18, 2024 at 12:36
“5 million sources”
“1 over 10,000 for old systems”
“Seven candidates”
These number popped out at me. Despite my having eliminated much of the nuances of this data related to those quotes, the rough statistics seem underwhelming to me. If there are Dyson swarms/spheres, they must be very rare.
Robert: “It seems unreasonable to me that a truly advanced civilization would be interest in tapping the last joule of solar energy of it’s star over more exotic but convenient forms of energy such as fusion. ”
I agree. A civilization isn’t advanced if it must huddle around a campfire.
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Michaelon May 19, 2024 at 4:04
Ron, that’s is one huge camp fire ! There would be enough energy concentrated to throw huge vessels out into space at great velocities. But thinking about wether they are Dyson swarms or natural phenomenon I would tend towards the latter. The reason being is that if an advanced race were to build one around their host star surely they would build another one around the next nearest star. The candidates appear to be randomly about the sky with huge distances between them.
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Ron S.on May 19, 2024 at 16:43
Have you ever tried to transport a large electric generating station on a truck? A generator that can’t be moved is of very limited utility. I repeat: a civilization that can’t produce the power it needs where it’s needed is not advanced.
Yes, a star is big and powerful, but it’s still a campfire in this respect. Stay close if you need to stay warm! We aspired higher and found ways to generate power and cut the tether.
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Michaelon May 20, 2024 at 14:13
Ron, solar power is a lot easier to do than nuclear fusion and can be converted into laser and particle beams to be exported around the solar system.
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nemoon May 21, 2024 at 19:05
There have been several proposals for building stellar engines.
A dyson swarm could do this as well.https://www.youtube.com/watch?v=v3y8AIEX_dU
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Mike Serfason May 19, 2024 at 19:34
The term “Dyson” has been overused, I think, to the point where it introduces more confusion than clarity. In this case, the authors are looking for an excess of mid-IR, but surrounding stars that we can still see in UV and visible wavelengths. If the source is artificial, it is not a hermetic sphere, nor even a dense cloud that blots out the star, but merely a lot of space traffic – enough that, combining all the surface area, it starts to rival the star if you look at the right wavelength. If we assume interstellar travel remains hard, and colonizing new systems is slow, and the attention of the spacefarers is divided among dozens or hundreds of nearby systems, then we can readily imagine that the traffic around any nearby star would be many orders of magnitude less than the homeworld, and therefore invisible to this sort of survey. (Development might also be paused by a Great Filter: wreckage of space habitats would continue to reflect infrared long after berserkers cleanse all systems in the area)
Spectroscopy could prove the presence of interesting materials, but there might be a problem there… One of the best and most readily available structural materials is graphene. It is also excellent for radiating heat because it is pretty much perfectly black, absorbing a fraction of radiation of any wavelength equal to pi times the fine structure constant per each layer of carbon atoms ( https://arxiv.org/abs/2303.14549 ). Graphene is also very common in ordinary cosmic dust… perhaps not for the same reason. Though I don’t really understand the details, deeper IR emissions from graphene oxide have been suggested to cause ‘extended red emission’ ( https://arxiv.org/pdf/1908.07787 ).
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LJKon May 20, 2024 at 12:02
Ron S. said on May 18, 2024 at 12:36:
“A civilization isn’t advanced if it must huddle around a campfire.”
If a massive fusion reactor that has been and will operate for billions of years or more and is freely available in the hundreds of billions per galaxy is not suitable enough for an advanced spacefaring civilization, then what is? i know black holes are one alternate candidate, but they too came from these natural fusion reactors.
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Ron S.on May 20, 2024 at 21:06
I’ll address this to both you and Michael since my reply is the same.
An advanced ETI has the technology to build a Dyson swarm/sphere but uses early 21st century technology for energy generation and transport? To put it mildly, I find this very doubtful (steampunk anyone?). I can’t usefully speculate (none of us really can) what it’ll be, but I’m pretty sure it won’t be that!
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LJKon May 21, 2024 at 9:04
As I wrote in the other essay on Dyson Shells, in addition to Matroishka Brains (or Jupiter Brains), there are two other reasons for their existence:
– As a method for pushing lots of light sail vessels to explore other star systems.
– As a formidable weapon. See here:
https://www.orionsarm.com/eg-article/48fe49fe47202
As I also said in the other post, just like rockets were first built and funded as weapons before they became instruments of scientific discovery, Dyson Shells might also be made first as weapons, especially if our galaxy is as hostile as we fear. Or maybe an ETI would do it just to preempt any hostile actions from other civilizations.
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Alex Tolleyon May 21, 2024 at 11:17
@Ljk
Dyson Shells as stellar Maginot Lines?Reply
LJKon May 21, 2024 at 15:06
If there is one thing life does here no matter the species, it is to make boundaries to protect themselves and their interests. It may be no different elsewhere.
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Markon May 18, 2024 at 12:57
Hi Paul
Great and informative article. I wondered what had happened to the search for Dyson artifacts, now I know.
Thanks…!
Regards
Mark
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Alex Tolleyon May 19, 2024 at 16:07
Mega engineering. I used to think it started with the Victorians – building bridges and large steel ships. However, it has a longer history. The Egyptian pyramids, the Biblical story of the Tower of Babel, The Roman roads connecting the empire (and Hadrian’s Wall), medieval castles, and cathedrals. In the 20th century, we were back to building the highest buildings, a throwback to Babel and the Florentine towers, with depictions of skyscraper cities in fact and fiction (Metropolis). Megaengineering seemed back in the exuberant 1960s with plans for a bridge spanning the Straits of Gibraltar, not to mention mega rockets (Saturn 5, N-1). With a brief “Small is Beautiful” (Schumacher) in the 1970s, we were back with exuberant mega engineering with the Burj Khalifa skyscraper in the UAE and now the planned mega city as a linear building in Saudi Arabia. I wonder if our Stone Age ancestors had similar ideas, as the later builders of Stonehenge and other megalithic structures.
Dyson’s “logical” ideas for maximal energy consumption seem more like the same. But as I have argued before, once complete, there is nowhere to go unless the same construction can be completed around neighboring stars. In which case they should be filling the galaxy as it doesn’t take more than a few millennia to complete to ensure energy growth matches economic growth (post-Malthusian, industrial [capitalist,] socio-political systems). Our current craze for cloud-based computing systems and now centralized AI are like the starting points for a planetary-scale need for huge energy-demanding computation systems, currently still small, but increasing energy demand in leaps and bounds and already causing problems in some areas with electrical and cooling water shortages. The problem with Dyson spheres is how to construct them as they need to be complete to fulfill their purpose. The swarms seem more sensible as they are useful from the first to the last independent component. Matrioshka brains seem even more fanciful as it seems that the civilization has to be hom*ogenous in its thinking to change a planetary system. I find that doubtful, just as we have difficulty in having hom*ogenous ideas on social and political systems. Such a civilization would have to be either like termite societies or permanent autocracies. Of course, my bias is showing in that I value Enlightenment ideas of individual freedom and democracy. We cannot assume that is the future for advanced civilizations.
We should not forget that the industrial period has been extant for a few hundred years, a mere eye-blink in time and that all of recorded human history is less than 15 millennia. This pales in time to our period as hom*o Sapiens, with increasing technological capabilities putting our civilization increasingly at risk from unforeseen catastrophes. Is spacefaring both a relief valve and a hedge for human civilization? Only after it has been achieved at scale. A Mars colony of even 1 million inhabitants would fail without the support of Earth. The path to civilizational longevity that allows [biological] ETIs to communicate may require keeping technology development controlled and economic growth restricted, a path that seems anathema to our species and current ideas.
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user-pat@orange.fron May 20, 2024 at 10:50
@Alex
>Je me demande si nos ancêtres de l’âge de pierre avaient des idées similaires, comme les constructeurs ultérieurs de Stonehenge et d’autres structures mégalithiques.
No. Above all, they had to ensure their biological survival in order to reproduce the species (it’s innate) => drink; eat; shelter, secure. It is only when primary needs are roughly met and a society is stable, that it can possibly dream a little. (Greek period and its scholars; cathedral of the Middle Ages because society was structured by the Church; and in some ways it is not surprising that the greatest authors of SF appeared in the 50s-60s in the USA, period of great prosperity that allowed Saturn V.
As for megalithic structures, they remain mysterious, although explanations such as astronomical calendars, linked to agriculture, have been found. Many of these prehistoric constructions refer more to spirutuel than to the idea of building a technology in other words to build something for a specific purpose.
Our distant ancestors could not imagine building a building or a rocket because they had not yet invented structures allowing for example the shoring of mines so the extraction of ore (iron) So his work, therefore the manufacture of tools etc. There is a kind of logical progression in the development of technology besides have spoken well of the stone age ; wood, iron, atom…
Thought is therefore correlated to the time. At best, some great brains are able to anticipate certain things but only on very short durations.This is also true for us today: except for some speculation based on universal constants and some statistics, in the “Big Bang” model (which is not 100% accepted) it is impossible for us to say what the world will be in 5 or 50 million years because our consciousness will have evolved according to the future environment in which our distant descendants will bathe.
A word on the paintings of prehistoric caves that we have in France: they remain a mystery: very generally it is admitted that the Men of that time had developed an embryo of cosmology and that the act of reproducing these drawings was a form of “communication” with a beyond (“behind the cave wall”) supposed but unattainable. But by a kind of mirror effect, this is what allowed devoloppé the conceptualization in the human brain. I allow myself a shortcut to say that in a way, it is thanks to the guy who drew Lascaux that Einstein could conceptualize relativity;) (Besides math is not a concept?)
I had visited a cave with prehistoric paintings that was 14,000 years old in the south of France: I assure you that you feel something incredible, like a kind of “bridge” between the present and these past millennia…a very strange feeling !
At these distant times, we were in the world of “magic” and can be more in the present moment. These beliefs are found in many peoples who are very linked to their natural environment but without great engineering. Note that the opposite is true: our material comfort is assured in our hypertechnological societies that have lost the link with Nature and therefore a certain faculty of conceiving the world : we are in a world of objects that we create profusely. but do we have as much mental creation? Not sure, if I reread what the Greeks were able to deduce from the shadow of a gnomon and some geometric figures;)
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Alex Tolleyon May 20, 2024 at 21:31
@user-pat@orange.fr
Let me offer a different viewpoint.
Above all, they had to ensure their biological survival in order to reproduce the species (it’s innate) => drink; eat; shelter, secure. It is only when primary needs are roughly met and a society is stable, that it can possibly dream a little.
You are assuming everyone in a Malthusian world was constrained to the lower levels of Maslow’s Hierarchy of Needs. However, most of all societies were in that Malthusian state until liberated by the Industrial Revolution. Yet in our ape-descended hierarchies, there are always those who enjoy more of the fruits of their population and can both dream up projects and get the population to devote time and effort to realize those projects.
Also, based on a study of Stone Age cultures, a hunter-gatherer had more leisure time than their agricultural descendants, not to mention they were better fed as shown by their relative body size.
Many of these prehistoric constructions refer more to spirituality than to the idea of building a technology in other words to build something for a specific purpose.
I don’t think the purpose matters. Religion has always played a role. From burial mounds to pyramids to cathedrals, and today mega-churches. Even technology has a spiritual/religious role. The technological wet dream of uploading minds has not for nothing been labeled the “Rapture of the Nerds”. Like many, I find my emotions well up with rocket launches, even though I have watched them on tv since the early 1960s. I am sure they would be even more stirring IRL. Were those Lascaux just shelters or did they have religious significance? Are the paintings the equivalent of prayer for the hunts? We are embedded in our time, unable to conceive of life in the future. We didn’t get our flying cars or moonbases, but I never conceived of the power of personal computers we have today, nor what we can use them for. Science fiction offers different visions of the future, but still embedded in their time.
Note that the opposite is true: our material comfort is assured in our hyper-technological societies that have lost the link with Nature and therefore a certain faculty of conceiving the world: we are in a world of objects that we create profusely. but do we have as much mental creation?
It depends on what you mean by “mental creation”. I would argue we are steeped in more art, maths, and science than ever before, certainly more compared to when I was born in the 1950s. I can hardly blink without coming across new ideas, some quite inventive, or new art. Yes, there is a lot of commercial dross in these fields, but the new ideas still burst into the light and dazzle. I think even the great minds of ancient Greece would be amazed at the exuberance of what we can achieve with our science and technology.
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Alex Tolleyon May 19, 2024 at 16:24
Crazy idea. Apropos to the idea that we cannot see the universe as artificial.
To manage the longevity of a star, “star lifting” – reducing its mass to reduce its luminosity – is one mega engineering solution. The lowest useful mass may be greater than a brown dwarf, e.g. a M dwarf. What if the large fraction of stars being M_dwarf stars is not a natural phenomenon, but the result of engineering? The consequences would seem rather dire for biospheres, but maybe the civilization is no longer biological?
Another thought. If the Parenago Effect is real (see How to Explain Unusual Stellar Acceleration):
https://www.centauri-dreams.org/2021/08/20/how-to-explain-unusual-stellar-acceleration/
could this be the use of the star lifted material to drive these lower mass stars at higher velocities through the surrounding stars to increase the number of encounters? This would allow these advanced ETIs to reach new stars with their populations to repeat the process. Each star would most likely continue in its general direction of movement, but faster, and be aligned with an intercept of another star with a greater probability than expected by randomness. This last might even be a testable hypothesis with the Gaia data.
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Andrew Palfreymanon May 19, 2024 at 17:53
It feels very analogous to Victorians searching for signs of steam power.
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LJKon May 21, 2024 at 8:08
Dyson Spheres? Two Studies Find Dozens of Stars with Bizarre Emissions
https://www.youtube.com/watch?v=GHLmAo_QuQs
Hello and welcome! My name is Anton and in this video, we will talk about intriguing studies that find some unusual stars with emissions that could be similar to what’s predicted about Dyson spheres or Dyson swarms
Links:
https://arxiv.org/abs/2405.02927
https://arxiv.org/abs/2403.18941
0:00 Dyson spheres
0:39 What is it though?
2:05 How we could detect these
2:40 Tabby’s star example
3:35 New studies and how they were done
4:15 What was discovered
5:30 Dyson spheres or what?
7:05 ConclusionsReply
Mike Serfason May 21, 2024 at 8:29
The paper is searching for signs of space habitats, which may or may not collect solar power. The main reason to look for an abundance of these close to stars, to quote an anonymous bank robber, is “that’s where the money is”. Our Solar system is 99.86% Sun, 0.14% gas giant, and a tiny bit of miscellaneous stuff. Jupiter’s atmosphere is nearly pure hydrogen and helium (0.3% methane and a little bit of other stuff); by contrast the Sun is 0.3% actual carbon. So unless a master safecracker intends to break apart the entire planet of Jupiter in search of the Earth-sized diamond rumored to be hidden at the center, the Sun is actually a better source of carbon, and far more of it, enough to outweigh all the total mass of all those gas giants twice over. The Sun is also a better source of nitrogen and especially oxygen; the “CHON” elements of core biochemistry are used because they come from the CNO cycle of the sort of star that gave rise to the Sun.
Mining the Sun for raw materials has another advantage – unlike Jupiter, the Sun sprays matter all over the Solar system in spectacular outbursts like we saw last week. ( https://earthsky.org/sun/sun-news-activity-solar-flare-cme-aurora-updates/ ) That’s enough natural space mining to view from a little space telescope near Earth. Imagine how much more material could be obtained if you could manipulate, or at least accurately predict, the Sun’s chaotic magnetic field.
Using space habitats for solar power seems like a no-brainer, no matter what other tech is available – but their real advantage is in anti-solar power. Even if you generate heat by nuclear fusion or nervously dropping particles into a ‘true’ vacuum state, any thermal energy is still useless (will do no physical work) without a cold sink to radiate energy into. That act of radiating energy is what the current paper searches for. (However, it will miss radiation of waste heat in neutrinos, which could be useful for stellar life forms)
If non-solar energy sources are used in these space habitat swarms, it should be possible to resolve lower-wavelength emissions at a sufficient distance from the star that we know, at least, the material is not being heated by ordinary stellar radiation.
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Andrew Pon May 21, 2024 at 8:33
I suspect astronomers may eventually detect extraterrestrial life. But it won’t be a civilization as we know it. Perhaps it will be something like space fungi that feed on dust, rock, and starlight and grow large structures in star systems with suitable raw materials, and issue spores that spread on the stellar wind to other suitable homes. If that is what was observed here, it may not be a coincidence that cooler M type stars are the ones with the IR emitting materials in orbit. Or life based on some chemistry that puts spectroscopically detectable substances into a planet’s atmosphere that clearly didn’t come from dead matter. Or plant/animal life on some planet that evolved the use of radio communications for some purpose. Just because Earth life never did that does not mean it couldn’t happen elsewhere.
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Steve Muiseon May 21, 2024 at 16:38
Given the tremendous power needs of even our entry-level existing AI systems, I can see a need for an advanced civilization to use a Dyson sphere to capture and use high levels of energy in a local system. That is, IF a civilization pursues a path toward high level Artificial Intelligence.
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Roberton May 22, 2024 at 12:41
Artificial Intelligence uses massive amount of power but that’s because we’re not using our heads which require very little power. Biology proves computation does not require a lot of power. Surely a truly advanced civilization would know how to simulate intelligence at such low power. Or maybe, as Frank Herbert implied, advanced civilizations really do just use their heads like the Mentats in Dune.
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Stadiston May 22, 2024 at 2:01
Scientists should provide some explanations, why and how should the extraterrestial civilizations need such amounts of energy?
This is just academic science fiction at this point.
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LJKon May 22, 2024 at 10:32
They have, going back to Freeman Dyson himself in 1960. Examples have been provided in this thread and related essays here.
What examples are you looking for?
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wdkon May 22, 2024 at 16:51
It was mentioned above, and I am inclined to agree: There is something about Dyson spheres that comes across like a page of Marxist science fiction, Grouch or Karl depending on your mood. In this case, the starlight blockage poses more questions than it answers. And conjectural answers could sound absurd.
Whether the builders are like us humans or something quite different, their “day” – which never ends – seems to be a glorified trip to the power plant. And if all this is photovoltaic, it leads one to think next about the switching circuit boards. And with all the soldering to build these devices and then put them to any constructive use… Like smashing any remaining planets to plug any spherical shell holes.
What clever ideas did the inhabitants come up with for smoke stacks and waste disposal?
One problem with a Dyson sphere might be that by the time construction really gets underway, someone or some collective just might come up with a better idea, such as putting the enterprise off. If there are Dyson spheres out there, they might be evidence simply of monomania in that particular star system. Or else a power station for someone living elsewhere.
Moreover, it would seem like a lot of sphere aspirations would be scaled back or pass through the “Dyson ring” phase. I suppose you could have concentric rings at varying planes and radii which from a distance might appear as spherical. But of the 3 cases, I think a ring would be least challenging and least subject to stress. I
Then suppose there was an actual stellar event of consequence? A storm?
A flare event like we had in recent week? Dyson spheres would have to be built to some environmental standards. And they could have an impact too.Curiously, the formation of systems like Trappist-1 with 6 or 7 synchronized planets appears to be associated with red dwarfs thus far too. A precursor?
I didn’t see mention so far of any doppler data on rotation rates. Say if we established one here in our solar system, the rotation rate of the structure would
be something to have a design session about. Should it be 30 km/sec locally, say,
so that a visitor could step off the Earth to go to work and then head home at the end of a day’s work…. Or what would a “day” or a work shift constitute on a Dyson sphere?There would still be the Earth’s axial rotation to contend with – unless the sphere gangway was a step off from the north or south pole.
So transition from Earth to the Dysonic future will still be a giant step in many respects.
But then the remaining question about Dyson spheres if we are looking from outside: Just what the blazes would they be working on within? And is their perspective on the question of “Are we alone?” the same as ours? And does it reflect, so to speak, on their pre-occupation with capturing all possible starlight?
Probably the biggest argument in behalf of Dyson spheres is the possibility that they can be detected as an artifact of civilization at relatively great distances.
What should the inhabitants be called other than perhaps monomaniacs?
And how should we react if they come bearing gifts such as a Dyson Sphere building handbook?
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Alex Tolleyon May 22, 2024 at 22:30
While Dyson did serious work, I often felt he made some of these speculation with a twinkle in his eye. A number of his speculations were about the ease of detection. The Dyson Sphere/Swarm hiding the star and emitting anomalous IR. The fish pushed into orbit by a plume on an icy moon for a probe to detect and find an unambiguous form of life. Light reflecting plants on icy bodies in the outer system beyond Pluto. All were backed with some form of logic of purpose and/or detection capabilities. There were silly ideas too, like mitigating global heating by engineering trees to produce diamond fruit to sequester carbon.
I wonder if the approach he took was not unlike his famous story of how to harden bomber aircraft in WWII. He looked at the aircraft that returned with holes in the airframe, and rather than beef up those areas, used the logic that it was the untouched areas that were the problem as these aircraft had not returned. So they protected those areas instead. It was this soft of thinking that I think led to some of his ideas that were in many ways fanciful. Just as Fermi’s Question has been puffed up in the community when it was possibly a light-hearted thought, I wonder if his speculation of trapping all the energy of a star is a thought experiment that perhaps should not be taken too seriously. A rigid sphere (or Niven-like ring) would be very hard to build, whilst the swarm is easier and may be more practical whose light capture is more a consequence of habitat building than the driver of maximum energy collection of a KII civilization.
We are already seeing the problems of energy use as we push towards being a KI civilization. Even if all that energy was “renewable”, it would still be an issue for biosphere impact. An intelligent species would not, IMO, attempt that, but rather moderate energy use to be compatible with maintaining a biosphere with only low to moderate changes. So far, our “paperclip maximizing” infinite growth approach to running our economies seems incapable of being controlled before disaster does it for us. Previous civilizations have collapsed, and this is our version of heading in the same direction. I see this as a “this time it is different” denial by the paperclip maximizers.
It would be nice to think that ETI has solved these issues and managed to become KII-level, but I fear this is just our manifestation of the religious hope that we can be saved by more powerful beings. I just don’t but it.
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Paul Gilsteron May 23, 2024 at 4:10
“While Dyson did serious work, I often felt he made some of these speculations with a twinkle in his eye.”
Exactly so.
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wdkon May 23, 2024 at 9:40
Considering the data from a different perspective than the one above:
In the paper, the Gaia source database appears to have about 250,000 entries.
And the selected candidates are shown to be at distances around 200+/- 50 parsecs. I haven’t found an indicator of where they are in the celestial sphere, but suspect that in that the locations are random. Were these actual artifacts of a civilization, it would seem more likely that the Dyson sphere candidates would be clustered in some region of the celestial sphere. If not, then perhaps the IR abundances are related to a considerable amount of debris surrounding the stars. Above, I did note that the Trappist-1 configuration ( though not common) is not unique. It is also based on a delicate dynamic balance. If one of the planets involved experienced a catastrophe, then perhaps a chain reaction could result among the other planets causing a debris disk late in the star system’s history.
Thus, perhaps this is another facet of the Trappist-1 synchronized planet phenomenon?Reply
