Signs of Life discovered on Venus and atmosphere
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This definitely could be the result of an unknown abiotic process. It also definitely could be evidence of life.
Some papers to check out:
- https://arxiv.org/abs/1910.05224
- https://www.liebertpub.com/doi/10.1089/ast.2017.1783
For 3 billion years, ending about 750 million years ago, Venus was likely hospitable, leaving the tantalizing possibility that we’ve detected the last vestiges of an ancient ecosystem.
Self-promotion: we'll cover this in-depth in Orbital Index (https://orbitalindex.com) this week.
According to the paper in your first link [0], PH3 gets destroyed by ultraviolet light-related chemistry, and so has a short lifetime in planetary atmospheres (section 2.3 on page 7, though that's specific to Earth's atmosphere). I assume this means if they've detected phosphine, there must be an ongoing process generating or replenishing it.
(Serious question, and I don't mean 'good' or 'bad'.)
Would that be a negative result, or positive? Or does the phrase have no meaning without reference to what you're looking at; so it'd be simultaneously a negative result for life on Venus, and a positive result for abiotic phosphine production processes?
If scientists don't attempt to explain a dramatic claim using other mundane explanations I'd be very suspicious of calling them scientists. Occam's razor is a useful tool. Be very suspicious if dramatic claims aren't tested. Otherwise I have a bridge for sale...
"I also expect some new Venus probes real soon now."
Maybe. You should also expect a lot more telescopes of all descriptions and varieties to be pointing at Venus. Multiple compute clusters are likely digging through old and new imaging data even as I write this.
I think this will be the critical thing to effectively communicate publicly. Given what we know about phosphine synthesis, a subject I presume most people aren't super familiar with, how confident are we that a new abiotic process is possible? Or is it so unlikely that life is a more plausible explanation?
Those aren't rhetorical questions. I wonder about the relative plausibility of one vs the other.
> This means either this is life, or it’s some sort of physical or chemical process that we do not expect to happen on rocky planets. We really went through all possible pathways that could produce phosphine on a rocky planet. If this is not life, then our understanding of rocky planets is severely lacking.
https://webcache.googleusercontent.com/search?q=cache:dUWrpm...
While I would love for this to be true, ignorance requires fewer assumptions than life at any level of complexity.
No one said it would be surprising (though it would to a great many people), the point is that it would require a LOT of assumptions about how life develops to get us to that point whereas human ignorance is the sole assumption we need to make to assume that these measurements are not life-related.
I think life is everywhere in the universe and that we will find that it descends along a great many entropic pathways in a great many frames of reference. But I also believe any given hint of life is more likely than not going to be related to human error, only because we have so many assumptions we need to make until we understand the underlying processes better.
https://www.nationalgeographic.com/news/2011/9/110923-neutri...
From the Quora article:
"The volume of Phosphine observed was stunning. They ruled out minerals blown into the atmosphere, volcanism, lightning and other known sources as there is simply no process that could maintain this abundance. So much Phosphine was observed we could conclude that the atmosphere of Venus is “teeming with life”."
I mean, I realize not all life necessarily engages in photosynthesis that emits highly reactive O2 into their atmosphere and radically and highly visibly transforms the entire atmosphere, but since the only energy source on the geological time frames those bacteria are going to be able to count on in the high atmosphere is going to be sunlight one would rather expect "teeming with life" to have very obvious spectra effects, i.e., "turning the planet funny colors" as life uses light energy in some sort of photosynthesis-like reaction, not merely creating an unexpected abundance of phosphine.
"Life scraping by" is a lot easier to believe than "teeming with life". "Teeming" life has no compelling evolutionary reason to also be well-hidden from us, and a lot of pathways to being very obvious as it exploits the energy available.
Energy it has in abundance, but where is it getting the atoms it's made out of? Carbon and oxygen are readily available, but you need more than that. Water is minimal in the atmosphere, and mere presence isn't enough, you need to be able to gather it against the strong osmotic pressures pulling it back out. (Earth life seems to have needed hundreds of millions of years just to grow on Earth land, a wildly more friendly environment than an atmosphere that still has puddles of nearly pure water to work with. Even a cloud is, by comparison, water-poor.) How do you get any nitrogen? Lightning may fixate it as it does on Earth, but then it immediately dissipates. It's very difficult to use N2 directly, although some Earth life manages. After that what's left in the atmosphere is some vicious acids and some noble gasses. So in the basic CHON equation, C & O are covered, N is exceedingly chemically difficult, and H is almost missing. Trace elements are also not available because they don't float, except sulphur (we use this ourselves, but it's not the most useful one), and while bacteria may get by without using as much of them as we do, I'm not sure you can make a life form out of nothing but CHON, let alone CO(Nish).
Of course it is possible. Everything is possible. But we have never seen such a process and we have seen life. So if life explains it but nothing else does except "possibly something" then life is the simplest explanation. The alternative really is no explanation, only speculation.
We could be living in a simulated universe, everything is possible, the simulation can include logically contradictory simulated laws of physics in other words "miracles". But such speculations don't really explain anything, they only say it is always possible that some other explanation may be found at a later time. Until an alternative equally good or better explanation is found it is best to use as working hypothesis the simplest explanation which explains all the observations, which seems to be "life" according to these scientists.
What I'm asking is some ballpark idea of the relative plausibility of (1) microbes, compared to (2) having discovered some new physical/chemical processes.
Is it a case where we feel like we've got our understanding of (2) locked down, and so "it would have to be a chemical process we've never seen" is a way of saying it's highly likely to be life? Or is it very plausible that we do have much more to learn about chemical processes, and it's just a face value statement? Are we talking 99% life, 1% likelihood of new process? 50/50? Something else?
http://www.sci-news.com/astronomy/phosphine-biosignature-gas...
> Astronomers will think of all the ways to justify Phosphine without life and I welcome that. Please do, because we are at the end of our possibilities to show abiotic processes that can make Phosphine
> there very well could be an abiotic source but that alone would be an amazing discovery. However we must deploy Occam’s Razor and suggest the simplest explanation and the evidence suggests the simple explanation is biological sources, life.
Wouldn't a better announcement be "Phosphine detected in Venus atmosphere". Maybe it's compelling evidence for life, but claiming "Signs of Life Detected" seems a bit premature, no?
And from the link on the author's Twitter bio:
> Over the long, winding arc of his career, Brian has built and run payments and tech businesses, worked in media, including the promotion of top musicians, and explored a variety of other subjects along the way.
Not exactly who I thought would be announcing the discovery of life beyond our planet.
I prefer my science news without a hype man but the author seems to take quite the initiative on Quora: "However we must deploy Occam's Razor and suggest the simplest explanation and the evidence suggests the simple explanation is biological sources, life."
https://www.quora.com/Was-life-discovered-in-the-clouds-of-V...
It's pretty sensationalized and coordinated like a PR campaign.
If you watch the video on his Twitter feed, the scientists themselves seem to focus on the science and don't claim to have "discovered life on Venus", so they do seem well intentioned. And their discovery certainly does sound interesting and potentially significant.
But strongly, strongly implies that. It's misleading marketing.
Considering his past Quora contributions, the most recent one above is a drastic theme change which I find quite weird
It's completely appropriate to center a headline around the likely meaning of the phosphine discovery rather than the discovery itself, because almost nobody is an astrobiologist. The scientists who study this stuff are just as compelled by the question of life on other planets as a layperson, because its discovery would be extremely meaningful to us as a species.
The question is not whether headlines should be represented as facts or their meaning, its whether the meaning that is presented is supported by the facts. In this case, it seems warranted.
This reads like a fifth grade science fair project.
Better announcement for whom? For the general public, which largely has no idea what phosphine is but has a decent chance of guessing it is a chemical, that title would not give them any indication that the article might be interesting to them.
For most people the only thing that makes phosphine on Venus interesting is that it might be a sign of life, so you want to have that somewhere in the title.
Article might be good but jeez, bad source.
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I wonder if lightning could produce phosphene? There if lightning on Venus in sulfuric acid clouds with a similar strength to Earth. https://www.nasa.gov/vision/universe/solarsystem/venus-20071...
On the off chance it is life, it might be a relative. Earth and Venus are close enough together for asteroid impacts to throw debris to each other. And bacteria is strangely resistant to the conditions of outer space. See the panspermia hypothesis.
Can you point me to a resource that describes phosphine occurring in nature from an abiotic process?
The Wikipedia article on Phosphine[1] describes an acid-based route to create Phosphine industrially, but notes that:
> The acid route requires purification and pressurizing.
While Venus would seemingly have the needed atmospheric pressure, what about the conditions for purification?
> The most likely source is reduction of phosphate in decaying organic matter, possibly via partial reductions and disproportionations, since environmental systems do not have known reducing agents of sufficient strength to directly convert phosphate to phosphine
You can make phosphine from entirely abiotic common elements and salts literally hundreds of ways. It's almost exactly like saying how many abiotic syntheses of water (OH2) are there (all combustions for starters...)
I have a PhD in chemistry from Berkeley and collaborated with nasa astrochemists. I'm not just reading wikipedia FYI ;P
The team that worked on this said they were thorough in going through the possible abiotic pathways that could cause this on a rocky planet like Venus. Now of course it's possible they missed something, like parent says: "There's about eleven bajillion abiotic routes to phosphine". I guess it was a sarcastic remark, but maybe parent really could have saved everyone a ton of time and $$. They're publishing as a starting point for the rest of the world to dig into this now, hopefully someone nails down what's happening one way or the other without waiting on a probe to be sent there!
It's a casual dismissal only because it's a comment on HN, rather than e.g. a review comment in a peer-reviewd journal. Otherwise, that's exactly the kind of reaction one learns to expect when one is doing research. Your work will be criticised. Ruthlessly.
It's not even a bad thing, long-term, quite the contrary. Only work that has survived the criticism of experts in a field can be expected to make a real impact.
And this is really just me being philosophical about it because of course criticism stings and rejection hurts. But you learn to live with it and I think most researchers who have taken a baptism of fire (submitted to a journal- or conference in CS) eventually come to terms with it: people will rubbish your work constantly. Until they are convinced it's good work.
From what I've read, the amount of phosphine plays a role, i.e. if there's lots of it it's a stronger sign of life. However, that's what I've read in the lay press that reports on the opinions of experts. Now, the thing about the opinions of experts is that there are always other experts that hold a completely different opinion and when you read an interview with one expert they very strongly support their own opinion, but don't really do justice to the opinions of others- because that's not their job. So it's often hard to know which expert's opinion is closest to the truth by reading what one team of experts tell the lay press. Science is a debate, after all- but not a debate carried out in news sites and internet forums (or at least not primarily there, I understand theoretical phycisists like their internet flame wars).
So, personally, before accepting anything as evidence of this and that, I'll just wait patiently until the dust has settled and the experts have agreed to disagree.
I wish more people did that when it came to my own area of expertise, btw. What I say above is what I've observed on reportage of my own field in the lay press.
I do have to note though that one of the researchers behind the announcement sounds very much like an expert on Phosphine, in particular. This is from the leaked article:
Clara Sousa-Silva at MIT, whose career specialty is studying phosphine, said in a statement:
It’s very hard to prove a negative. Now, astronomers will think of all the ways to justify phosphine without life, and I welcome that. Please do, because we are at the end of our possibilities to show abiotic processes that can make phosphine.
Finding phosphine on Venus was an unexpected bonus! The discovery raises many questions, such as how any organisms could survive. On Earth, some microbes can cope with up to about 5% of acid in their environment, but the clouds of Venus are almost entirely made of acid.
Sounds to me like there's going to be some er, lively debate around this. Or not, I'm not an expert in any of this, lucky me :)
People need to think less about people's university credentials when they assess credibility. Especially at places like MIT which burn through them like kindling.
Clara is a postdoc@MIT, and an expert in the _spectral lines_ of phosphine. The paper she refers to about known abiotic routes is really cursory and by no means exhaustively searches for routes to phosphine (https://sci-hub.tw/https://doi.org/10.1016/j.scitotenv.2018....). It considers a handful of reactions for a compound which has millions of chemical equilibria. The most obvious omission is hydrogen sulfide which is all over venus.
Honestly, I have no ability to judge this way or that in this thing. It's completely outside my expertise. Also, I have no idea of how common it is for people to make unsubstantiated claims in astronomy (or is it astrobiology in this case?). In my field, AI, it's common for people to use big words and say big things they can't really back up with anything concrete. I hope that's not the way it is in astronomy. I'm a little concerned by your turn of phrase "the pathological nature of the science community today". If this announcement turns out to be a dud it might make some damage, I guess.
> From what we're told the researchers have concluded that abiotic mechanisms (i.e. ones that do not involve life) that might produce phosphine cannot account for the large amount that they have detected. The phosphine has been detected in the region within the atmosphere of Venus that is considered by some to be potentially habitable. As to what spin the researchers put on this, we'll have to wait for reporters who have the press release or are allowed to participate in the Zoom press conference thing tomorrow at 15:00 GMT to let us know.
[1] http://astrobiology.com/2020/09/phosphine-detected-in-the-at...
The sensationalism is probably an excellent way to pick their skepticism, so get more people to find counter-arguments.
1. phosphine is found on earth in low-oxygen environments that harbor life (e.g., swamps)
2. abiological routes to phosphine, although known, require unusual reagents and/or elevated temperatures
This 2019 article gives some background:
https://news.mit.edu/2019/phosphine-aliens-stink-1218
Here's some evidence of phosphine production in a swamp:
https://www.sciencedirect.com/science/article/abs/pii/014663...
This leaves (2), which is a bear because it states a negative. The claim that the phosphine on Venus is biological in origin requires no feasible route to the substance given the known chemistry of the planet's atmosphere.
Given that Venus' atmosphere is a complex mixture held at very high temperature and pressure, the "sign" seems pretty weak here.
I think an unknown route to phosphine generation seems simpler and more likely than a biological explanation. YMMV.
Occam's razor would therefore imply that this is not life.
(And, by the way, the unknown process could also be biological!)
I also suspect 1 million is a massive underestimation.
Invoking Occam's razor to compare two unknowns makes about 0 sense.
e.g. http://www.sci-news.com/astronomy/phosphine-biosignature-gas...
>The scientists found that phosphine has no significant false positives, meaning any detection of phosphine is a sure sign of life.
The phosphine signal is coming from a portion of Venus' atmosphere that has pressure and temperatures similar to that of the the Earth's surface, according the the Earth and Sky article.
But again, this is just a string of tweets—hard to say anything without the paper!
"We should also not rule out far more complex life from the observations of Phosphine. It is quite possible we will observe life as large as a Whale on Earth quite happy suspended in the gravity waves of Venus." WTAF?
Also, how did the video in his tweet somehow become available a day early as well as the Earth&Sky article. Something doesn't smell right here. The explanation is that the Earth & Sky article was put up early by mistake and pulled.. and this guy happened to find it. Another explanation could be that an article was written to look like an Earth & Sky article and put on a google drive... and that he got a couple of friends to make the short video on the MIT campus. Otherwise how does that video somehow appear today, a day early as well as the article?
[0]: http://nasawatch.com/archives/2020/09/phosphine-detec.html
[0] https://earthsky.org/space/life-on-venus-astrobiology-phosph...
I've never in my life seen someone fake a document that good. It's close to impossible under current conditions to appear in the wild. The Russians might be able to, for instance, but there's no circumstances they would, the cost to reward is way to high.
(Assuming you mean - https://archive.is/L7MT1#selection-1846.0-1846.1)
I'd like to see the best faked document you have ever seen.
I'd suspect the best is a real document but with changes.
Total entropy of documents is very high.
So, I suppose we'll find out tomorrow.
Journalists got the release early and several of them tweeted out hints.
But I guess we will find out for sure on the 14th.
Different from gravitational waves.
https://webcache.googleusercontent.com/search?q=cache:dUWrpm...
Simply put, a gas that shouldn’t be there, and on Earth is considered a conclusive biosignature: phosphine, a very stinky gas. As far as scientists know, there are only two ways to produce it, either artificially in a lab, or by certain kinds of microbes that live in oxygen-free environments. Since it is rather unlikely there any alien labs on Venus, that leaves microbes."
Or it reveals, that we still don't really know what is going on on venus, which chaotic atmosphere and vulcanic activity might very well result in the specific "lab conditions" to create phosphine.
So, it is a very interesting find, worth investigating, but I just for the existence of a gas, I would not shout "proof of alien life", yet.
> As far as scientists know, there are only two ways to produce it, either artificially in a lab, or by certain kinds of microbes that live in oxygen-free environments.
https://en.wikipedia.org/wiki/Phosphine
Philippe Gengembre (1764–1838), a student of Lavoisier, first obtained phosphine in 1783 by heating phosphorus in an aqueous solution of potash (potassium carbonate).[4][5]
The second preparation method in Wikipedia looks more plausible https://en.wikipedia.org/wiki/Phosphine#Laboratory_routes
> 4 H3PO3 → PH3 + 3 H3PO4
> Phosphine evolution occurs around 200 °C (400°F).
But I only have a Chemistry specialization in my secondary school and I am not an astrogeologer.
Even if this were the case, it would still be quite amazing.
That would be a amazing sensation. Terraforming would then be much, much easier, than expected. But I doubt it.
I think it was maybe Carl Sagan who said (something like): if we find life in our solar system it's probably game over for us, as it means the great filter is likely ahead of us, not behind us.
Though, you can take one look at the world right now, and not see how easy it would be to just destroy it if we aren't careful (and we're not being careful).
Though it's quite possible that if there is something on Venus or Mars it's Earth-origined, since conditions here 4 billion years ago look better for abiogenesis.
If there are several filters, then they may differ in effectiveness by many multiples, and then it's semantics as to whether you say any beyond the largest are "great".
I think a more interesting concept would be exchange of microbes between Venus and Earth at some point in their distant past, and then could we might be able to date that (those) event (s) via their molecular clocks (https://en.m.wikipedia.org/wiki/Molecular_clock)
In this case, the universe basically must teem with life in one form or another.
These might be the biggest ifs one could imagine but I'm really excited for the follow-ups...
(Cross-posted from another thread, as the other doesn't seem to gain traction)
Very exciting news, I'm hoping that it is proof of life as that will give increase interest and funding for space exploration.
See also the Silurian Hypothesis [0], which I think just got a lot more interesting as a thought experiment.
[0]: https://www.theatlantic.com/science/archive/2018/04/are-we-e...
Betteridge's Law confirmed. We can track down fossils billions of year back by observing the way they shaped the encasing rocks, and not once have we noticed a ceramic shard, a metal bit or the silhouette of a plastic object.
> There are fossils, of course. But the fraction of life that gets fossilized is always minuscule and varies a lot depending on time and habitat. It would be easy, therefore, to miss an industrial civilization that lasted only 100,000 years—which would be 500 times longer than our industrial civilization has made it so far.
Sandstones. Sandstones originate as far as hundreds of million years in the past. Occasionally they harbor fossils, which are indeed rare. But a lot of sandstone is made of sanded up organic material which we can readily identify, even if we can't point to the specific organism they originated from. We only need a tiny industrial-related grain of sand (ceramic, glass, metal, plastic traces) to point to a past civilization. Nobody ever noticed such a grain of sand.
> So it might take both dedicated and novel detection methods to find evidence of a truly short-lived event in ancient sediments. In other words, if you’re not explicitly looking for it, you might not see it. That recognition was, perhaps, the most concrete conclusion of our study.
I'm not bullish on pre-historic civilization, and neither is the article, but the takeaway is we may not have reason to expect that we'd have found these tiny industrialized traces without a search aimed specifically at them. As far as I know, such searches have not been carried out in earnest to date.
So not a truly short-lived event in ancient sediments then.
Here's a good read on the subject: https://waitbutwhy.com/2014/05/fermi-paradox.html
For the same reason the large dinosaurs died out. Life as we know it operates best within fairly narrow mass scales and energy level ranges. Those are both several orders of magnitude away from the quantities needed to produce effects observable at interstellar distances.
The universe should be teeming with life but isn't.
We currently have no good evidence that it is. That doesn't mean it isn't, just that our detection methods aren't yet up to the challenge. Basic information theory suggests that they may never be. Advanced civilizations will use coherent EM radiation for a limited time only. The radiation they do generate in the long term probably won't be wasted by letting it escape isotropically into space.
Also, at some point they may come to understand that drawing attention to themselves isn't a good survival strategy. A civilization that is advanced enough for us to observe is also advanced enough to hide from us.
Not really true. There are more signs of life than just radio waves. One - like in the article - is chemistry. Planets that seem to be very far from chemical equilibrium are objects of interest, as this may imply there is a complex system that's actively fighting entropy. I.e. life. For instance, aliens with powerful telescopes and good understanding of geology could conclude Earth has life on it by observing it keeps a surprising amount of oxygen in the atmosphere, where it should have already oxidized everything instead.
Admittedly Earth's oxygen signature would be a lot easier to detect than a minute quantity of PH3 on Venus. But we wouldn't have been able to look for that either until just a few years ago. Even to a seasoned RF engineer, ALMA and JCMT are indistinguishable from magic.
If we assume life is abundant in the Universe, then we should be able to pick up signs of others, such as radio signals, or bio-indicators in other planets' atmospheres, and so, we ask where the aliens are.
Since we don't find any, we then assume that there is something preventing this abundance of life from developing into something we can detect, and something's called the Great Filter.
As of yet, we only have a single point of data, and since we're still here there's some speculation that we've allready passed through the filter. Another data point would mess up the math a bit and we could, statistically speaking, end up with a scenario meaning we still haven't passed the filter, and that we might still have an apocalyptic event wiping us out.
Life on Venus would give us a better idea of what to look for in other places, and that might help us narrow down the search a bit and find other places with life.
Intelligent life is a different matter. We don't know how common it is for
1) a planet to have formed around a star with the right composition of materials 2) have the exact right conditions for life to form early 3) for that life to survive for billions of years while 4) building up large reserves of substances that can 5) be used as fuel by a tool using bunch of talking apes 6) propel their civilization's technology far enough to match ours 7) send a signal that can reach our specific little dot 8) for that signal to be reach us during the miniscule time-frame that we've been able to pick it up.
I mean, what if the glory days of the Milky Way was 500 million years ago and we're developed just a little to late to be able to see the last remnants of galactic civilization crumble to dust? What if we just happen to be the first, and we develop past such technology before anyone else develops it?
That leaves these possible obvious filters: single cell to multicellular life or planetary resources exhaustion.
Evolution of eukaryotes from prokaryotes is a more plausible bottleneck. (Disclaimer: I am not an expert on any of this.)
We're a matter of years from originating von Neumann machines ourselves, so any civilization with thousands or millions of years head start should have incredible galactic spread.
No, we're saying that that life didn't even reach "civilization". Humans are a blip in time compared to the dinosaurs, for example - we may well be the anomaly, but life still be abundant.
https://www.nytimes.com/2020/04/28/us/pentagon-ufo-videos.ht...
holy shit.
When was the last time you heard of a real genius? Or something genuinely new, rather than just slightly better than what came before it?
I'm not saying there is no new tech, it just all seems incremental, not revolutionary. When I was younger every day it seemed there was something new. Today, not so much.
(I'm being overly dramatic, but it had severe flaws)
I personally am not a fan of the AI destruction theory because I'd expect AI to replace us and expand into the solar system. If it got to the point where it could kill all organic life, then I'd bet it's unlikely for AI to die off with us as well. Just my opinion though...
Disregard this if you mean “0 or 1 AI makes it out of here”
A bacteria analogue is possibly more of a risk; those can be less fussy.
The patches were first observed by ground-based telescopes more than a century ago. They ebb and flow over time, changing their distributions and contrasts.
“The particles that make up the dark splotches, have been suggested to be ferric chloride, allotropes of sulfur, disulfur dioxide and so on, but none of these, so far, are able to satisfactorily explain their formation and absorption properties,” explains Yeon Joo Lee, the senior author of the new report.
On the other hand, Limaye notes observations that the particles are about the same size and have the same light-absorbing properties as microorganisms found in Earth’s atmosphere, and scientists, beginning with the noted biophysicist Harold Morowitz and astronomer Carl Sagan, have long speculated about the possibility that the shadowy patches in the clouds of Venus are, in fact, microscopic life." https://news.wisc.edu/mysterious-cloud-absorbers-seen-to-dri...
It's tempting to think something in the lines of "oh but if it happened here in our little shitty solar system, it can't be very special". But that's more or less the anthropic principle.
Most scientists believe that even if the star is encased in Dyson sphere that there would be excess infrared emissions as the sphere would need to vent heat. It would be hotter than surrounding space and thus visible.
They are thus trying to detect such stars with higher mass and IR excess than expected, but so far there are not many candidates.
You know that. But it bears mention, for others following along, that rampant artificial intelligence or similar does not count as a great filter candidate, because it would be just as visible as the life it's replacing.
That doesn't leave a lot of fast-acting filters that could still be in our future, to be honest. Nuclear war? Sure, but we've avoided it too long for that to be a good one either.
75 years is an infinitessimal blip of time in cosmic terms.
Or energy is not such a big deal anymore once you've reached a certain stage of technological advancement, so it's not the right criteria.
I always wonder, when I read this and similar claims, how on earth the tone of 100% certainty is justified. It seems pure bluff.
Sounds probable, but I can see many possible reasons not to bother. Not to mention it is speculating about technology so far ahead of our own that it seems silly. 50's predictions of rocket belts and nuclear powered cars come to mind.
These are different kind of predictions. Rocket belts could work, but they don't make economic sense and there's a strong safety argument against it. It's the same reason we don't have flying cars either.
Nuclear-powered cars could have worked; the failure wasn't predicting technology or its feasibility, but that nobody figured out humanity will collectively go insane and irrationally refuse to develop use of nuclear energy.
Dyson spheres are a pretty obvious thing to do - every star is a free, self-maintaining fusion generator that just wastes almost 100% of its output. So the argument is really that when a civilization's need for energy gets larger than what can be supplied by burning whatever stuff they have on their planet, the next obvious step is their star. Barring some magic tech breakthroughs like pulling energy from "subspace" or whatever, you have a rather solid argument that's essentially: "as long as life is not limited from growing, it will eventually start blotting out the sun it orbits".
I don't disagree that the core idea of harnessing the suns energy seems likely. As the parent poster said, it's just the absolute confidence that people seem to have on the subject that's a bit curious.
Maybe breakthroughs in energy generation will make it not worth the effort? Maybe becoming interstellar makes it obsolete since the energy requirements for a given civilization are spread thinner? Maybe there are other ways to harness the solar energy that would not show the same signs as we predict? Maybe civilizations trend to energy efficiency instead of just increased usage?
Maybe not.
https://wiki.lesswrong.com/wiki/Basic_AI_drives
The above link is about AI, but it could apply to any alien species just as well.
Any organism living in a thermodynamic universe and subject to competition and evolutionary pressures will develop instinctual drives that align with resource acquisition, replication, and survival. As the above link details this surprisingly holds true even when you remove evolution and consider designed minds.
Even if a hypothetical civilization didn’t care about resource acquisition, replication and survival, they’d be out-competed by one which did. So where is that civilization’s ever expanding sphere of Dyson clouds?
Even with the most advanced technology we can imagine, you can't expect to be able to detect a neighboring civilization, cross the gap between stars with an invading fleet, and arrive with enough power to overwhelm defenses every single time. Local development of solar system resources is inherently an exponential process, whereas mustering of interstellar resources is quadratic. A potential dark forest / wolf entity (I much prefer Alastair Reynolds over Liu Cixin) would have to arrive right within the (cosmically brief) window of opportunity in which a developing civilization announces its presence but before it achieves Type II status on the Kardashev scale. Statistically, someone will eventually be lucky enough to avoid the wolves long enough to get that far, and then they'd have the capability to defend themselves from any plausible enemy.
Where are the Dyson spheres of those civilizations?
It should be emphasized that the existence of convergent instrumental reasons, even if they apply to and are recognized by a particular agent, does not imply that the agent’s behavior is easily predictable. An agent might well think of ways of pursuing the relevant instrumental values that do not readily occur to us. This is especially true for a superintelligence, which could devise extremely clever but counterintuitive plans to realize its goals, possibly even exploiting as-yet undiscovered physical phenomena. What is predictable is that the convergent instrumental values would be pursued and used to realize the agent’s final goals, not the specific actions that the agent would take to achieve this.
1) The Drake Equation is wrong and its difficult to detect advanced civilizations.
2) We have detected other civilizations but we haven't recognized their signals properly.
3) We have detected other civilizations and the government is concealing it from us.
4) The UFO footage released recently by the Pentagon is proof of detection.
Unfortunately people still think very teleologically, as if nature works in a progressive fashion towards some structured end; this tendency is deep in western thought all the way back to Plato (and probably beyond), and it's all over science fiction.
That said, IMO there's a lot of things that could confound the usefulness of increased foresight. After a certain point (which humanity has likely passed) foresight is not a particularly visible measure of fitness except in those rare extinction events that require significant cooperation to survive. I suppose that even given that foresight is the most valuable trait for long-term survival of a species, it's very rare that it is selected for beyond a certain point because the events that it allows a species to survive are too rare to be selected against.
My point is that the "omg great filter confirmed" is a bit premature, and is a misunderstanding of the argument.
EDIT: Re-reading your comment, maybe this isn't contradictory to your point. Finding out that there is an abundance of life does indeed eliminate at least one major candidate great filter. I'm not sure that would somehow move the odds of a real one being ahead of us though.
I dug out the section in Bostrom's paper:
"What has all this got to do with finding life on Mars? Consider the implications of discovering that life had evolved independently on Mars (or some other planet in our solar system). That discovery would suggest that the emergence of life is not a very improbable event. If it happened independently twice here in our own back yard, it must surely have happened millions times across the galaxy. This would mean that the Great Filter is less likely to occur in the early life of planets and is therefore more likely still to come.
If we discovered some very simple life forms on Mars in its soil or under the ice at the polar caps, it would show that the Great Filter must exist somewhere after that period in evolution. This would be disturbing, but we might still hope that the Great Filter was located in our past. If we discovered a more advanced life‐form, such as some kind of multi‐cellular organism, that would eliminate a much larger stretch of potential locations where the Great Filter could be. The effect would be to shift the probability more strongly to the hypothesis that the Great Filter is ahead of us, not behind us. And if we discovered the fossils of some very complex life form, such as of some vertebrate‐like creature, we would have to conclude that the probability is very great that the bulk of the Great Filter is ahead of us. Such a discovery would be a crushing blow. It would be by far the worst news ever printed on a newspaper cover."
It took evolution on earth four billion years to result in a single civilization-capable species. The potential of filters along the way seem incomprehensible. And four billion years is a meaningful timespan even in astronomical terms.
And the intelligence part is also like an elephant in the room. Even given vertebrate creatures with nervous systems, we've had those for hundreds of millions of years. The secret sauce for advanced civilization is still only possessed by a single species, and not even it understands how it happened. How do you map a transition like that on a linear timeline of filters?
1) How can we determine whether Venusian and Terran life share a common ancestor? A seemingly clear signal would be a different genetic basis for Venusian life than DNA, but would the converse be true, or just a sign of convergent evolution?
2) How hard would it be to send a probe there that could perform a preliminary analysis of the life form? How hard would it be to bring a sample back to Earth?
3) This would be an indicator of life existing in the habitable zone of Venus' atmosphere. How should that change our estimate of the likelihood of other forms to exist on the surface of Venus? Earth extremophiles can exist at >100C, but the surface of Venus is >450C. On the other hand, there'd be a continuum which would allow evolutionary processes to work their magic. Acidity is also an issue, but the life forms in the habitable zone already be living at levels impossible for any known Earth species.
Regarding #2, bringing a sample back to Earth is way too dangerous. At least, I'm certain NASA will see it that way, and I doubt any other space agency has the capability to execute a sample return mission within the next 10 years without NASA assistance.
We know how to manage risk - we can process the sample on the space station if needs be. The issue here is probably contamination of the Venusian atmosphere.
3) What is more interesting to me is if there is bacterial life on Venus, is there anything more complicated?
Venus has a zone above the clouds where the atmosphere is not that cruel and the temperature livable. There is always the chance of airborne microorganisms living in the oasis layer above the hell that is the near-surface of Venus.
Just to add to this, it's a similar temperature and pressure to earth, but the main gas is CO2. In other words, almost ideal for anaerobic organisms (bar the absence of water), which are the kind that generate phosphene, i.e. the biosignature that was detected.
Also there is no water on venus.
My point was that Venus is not comparable to a gas giant.
Someone might want to very quickly correct that to "Astrobiology". This whole presentation, of going from a tweet to a Quora Q&A obviously posted by the same person, is a bit weird.
1) NASA scientists published a paper that showed just how difficult it would be to find evidence of a past, advanced civilization on Earth.
2) There was, if I understand correctly, a window of time where Venus was potentially inhabitable.
So, the idea I’ve wondered is: is it possible that Venus had, at one point, an advanced civilization that triggered a runaway greenhouse effect?
EDIT: Venesian satellites would have been detected, if that's not clear.
In addition, besides needing a boost to maintain orbit (solar panels that function for 750 million years?) some forces have acted to slow and reverse Venus’ rotation and it is hard to imagine satellites wouldn’t be significantly affected over long time scales.
A space program isn’t necessarily a natural consequence of CO2 production anyway. That might be especially true for creatures who don’t have the benefit of a moon.
What if we are all just refugee Venusians who have evolved into different life forms. :D "And all of this has happened before, and will happen again."
Youtube stream of the press release: https://www.youtube.com/watch?v=5IIj3e5BFp0
There’s always the ISS.
So a moon base or more realistically something orbiting Moon would be a better candidate.
I.e. who's to say that the lander that made planetfall a while ago wasn't contaminated with a hardy strain of bacteria?
-Image Backup: https://imgur.com/a/uiTcA4Q
-WayBack Archive Backup: https://web.archive.org/web/20200914003530/https://webcache....
Julia Child Cooks Primordial Soup (1973)
https://news.ycombinator.com/item?id=24467695
Walter White had a quick and easy recipe (which doesn't actually work in reality):
https://breakingbad.fandom.com/wiki/Phosphine_gas
Breaking bad red phosphorous scene
https://mobile.twitter.com/brianroemmele/status/128777130722...
Here is what this looks like when doing this with light of the sun: https://en.wikipedia.org/wiki/Fraunhofer_lines
"This was an experiment made out of pure curiosity, really, taking advantage of JCMT’s powerful technology, and thinking about future instruments. I thought we’d just be able to rule out extreme scenarios, like the clouds being stuffed full of organisms. When we got the first hints of phosphine in Venus’ spectrum, it was a shock!"