Ok, so we can explain this plus Dark Matter in one shot. Basically, planets slightly larger than Earth are practically guaranteed to evolve intelligent life. Intelligent life eventually develops technology that allows them to shield the existence of their planet, or even entire stellar system, from the probes of the Evil AI Lifedestroyer. So, all that Dark Matter is just the intelligent life in the universe, using normal prudence to keep out EAILD (see above), more or less like most humans live in houses with walls.
So, any system that is not part of Dark Matter yet is either:
1) unconducive to life (or complex life, anyway)
2) was already zapped by the EAILD
3) like us, is in a transient state where the EAILD hasn't arrived yet, but we haven't learned how to cloak our solar system yet either
Again, the key here is that planets just slightly larger than Earth are the most likely to evolve intelligent life, so they nearly always end up cloaking, and thus we don't see them.
You heard it here first folks, there's so many Earth-sized planets they add up to many times the mass of the rest of the universe. Just a couple billion per star.
I'd like to see the math behind the orbital parameters here. The most I've seen is one million Earths in a single system[1], and so I'm curious how you could get a few orders of magnitude more.
Fun fact: in the first hour after I made it, this comment racked up about 25 HN "points", presumably from people who thought, "ha! that's goofy, I like it". Then, in the ten hours or so since then, it has fallen down to 17, presumably because the conversation turned from absurd to, "well, does this theory actually make sense?"
Which, given that HN points don't actually buy you anything, is fine. But, I wonder what it means that the first hour was mostly upvoting and the hours since then mostly downvoting. Maybe people are in a more positive mood in the morning? Or maybe it doesn't seem worth downvoting until a bunch of other people have commented on it.
Or, of course, perhaps the EAILD is attempting to bury it with 'bot downvotes. In which case, I guess we're already doomed...
I have a theory: your initial post, in isolation, is funny and interesting. However as it accretes more replies and becomes the biggest thread in the topic, people downvote it because they find the entire discussion annoying.
The problem with this (very interesting and fun) theory is that Earth would have to somehow be the very last planet to develop such intelligence amongst the large list of planets within detection range, which seems unlikely.
Well, another option is that it takes - say - 200 years to get from the stage of "we're producing enough radio output to be visible" to "we developed cloaking" or "we switch to other tech that is intentionally or not - not visible".
If that's true, only a very small fraction of planets with intelligent life would land in the window where we can observe them.
Another option is that you might have many civilisations that are just as intelligent, and just as developed, but not in the same fashion - imagine 99% of intelligent species out there are more like dolphins than like humans.
Or their atmosphere is just a bit more hazy than ours, so they are not aware of the night sky filled with sky, so with less curiosity to imagine the world outside of theirs.
Well, if you want to get technical, the major problem with this theory is that MACHOs are not a good candidate for dark matter: https://en.wikipedia.org/wiki/Massive_compact_halo_object#Th... Even if you imagine they were all hiding, their previous effects on the universe are missing.
Another problem is that the effectiveness of the cloaking devices would have to be extraordinarily high across an extraordinarily large number of instances.
looking at the data, it’s like we’re trying our damndest to be last. Defunding education, limiting what can be taught (ex: Texas removing critical thinking), etc all seem like we just enjoy tripping on our own shoe laces
You're focusing on the wrong scale. Intelligence has skyrocketed in the past thousand years. Policy decisions in our lifetime, do not matter or they end all human matters at once.
So they can't be seen visually, but can be detected gravitationally? That doesn't sound like very effective cloaking to me.. especially not against some hypothetically advanced intelligence.
Alternative theory: the EALD use said planets as incubation for their offspring. We are a natural progression in the growth of an individual EALD in the same way that cell division and growth of gut bacteria are a natural progression in the growth of a human. A more mature EALD uses all resources available on an Earth-sized planet in order to grow up into a fully mature EALD.
Ooooohhh, this has potential. The EAILD prefers planets that are still rocky (not gas giants), but naturally goes for the bigger ones first. It just hasn't gotten around to planets as small as us yet. I like it.
I have a more readily falsifiable idea. My reclusive neighbor is a witch, she sometimes alters data away from expected predictions so that scientists have something to puzzle over.
It's just as likely that dark matter is the byproduct or containment technology of EALID destroying intelligent life's planet, or capturing it in something analogous to how a spider wraps a fly stuck in its web.
Ah! Perhaps it's just sticking all the intelligence-generating planets, and the stellar systems they came from, into a pocket universe, or something. Maybe it's a form of plague quarantine. Lots of possibilities.
Wouldn't gravity be a good explanation? Once your rocky core grows beyond a certain size, you start retaining some gas molecule X. If you are too small, the thermal velocity for the gas X is bigger than escape velocity and thus you can't retain it. So you generally don't have planets right at the small end of the X retaining size. They always grow bigger because they sweep all of X. Also it makes them heavier so they can hold onto X better, even if, say the sun becomes brighter. What is X? Helium?
This is indeed one of the possible theories to explain the Fulton gap, as far as I understand it. If you have a rocky core that accretes more and more atmosphere, the atmosphere collapses once it contains about as much mass as the core and you become much more efficient at accreting more gas and you form a gas giant.
If this is true, would that mean that life is rare in the Universe? I would mean that we are an anomaly in that we have the perfect size and core materials to be able to hold onto some of our atmosphere, but not so big so as to turn into a gas giant.
Kinda sad to think that there may be nothing but space out there.
A planet can have a atmosphere that is sufficient for life, but of negligable mass compared to the core. In our solar system we have at least 2.5 examples of that: Earth, Venus and Mars. And that is not counting ocean moons with an ice crust such as Europa that might be hospitable to life as well.
Go to http://exoplanet.eu/diagrams/ and select "Semi-major axis" for the X axis (this is the appropriate analog of "radius" for an ellipse) and "Planetary Mass" for the Y Axis. Note that the bottom right corner is empty because we can not yet detect stuff there. All of the solar systems planets would be in that corner. The Fulton gap is the lower density region at 0.1 to 0.2 jupiter masses.
Since a lot of people seem to have problems with that plot I have uploaded an annotated version to https://imagebin.ca/v/4hQOkAKo27fq . The black dots are data and are correct. The colorful annotations are by me and might be wrong as I am a plasma physicist, not a planetary scientist. And unfortunately I can not get the dots for the solar system in there using the plot interface of exoplanet.eu. But they would be in the bottom right triangle.
I'm not really seeing anything in the non-log scaled y-axis data. But the log scales of both data do seem to show three clear 'islands' of planetary sizes.
EDIT: These' islands' in the data correspond to 3 planetary types (kindaaaa): Big and heavy super-gas-giants, small and lighter rocky planets, and heavy and smaller-ish gas giants. It's interesting to see there is a gap between the gas giant sizes and that it's not continious, despite them all being the same-ish mass.
If you check the histogram plot at exoplanet.eu (also at https://imagebin.ca/v/4hRAHBxEtEbv for your convenience) you see that the density is quite a bit lower. And "Fulton gap" is simply a better name than "Fulton's possibly lower density mass range".
You can get rid of the gas giant in your analysis by excluding everything further out than 0.2 AU. The distribution then separates more clearly into to peaks with a gap in between. But that is something I can not get in a minute or two in the online plotting tool.
Also you should be aware that astronomy and astrophysics has quite different conventions for naming things than say condensed matter. Part of the reason is that historically they were a separate science from physics. Part of the reason is that most of the knowledge is gained from (passive) observations, not actively controlled experiments.
Extra fun example: astronomy, especially radio astronomy definies left and right handed circular polarization exactly the opposite way to how optics does it...
For those following along at home: I had difficulty seeing it when the y-axis is on a log scale, because the gap between 0.1 and 0.2 Mjup is so small. I turned off log scale on the y-axis, then zoomed in so that the gap between 0.1 and 0.2 Mjup was actually discernible, and there I could see it. There's a lot of points that look to be basically on 0, which I assume are the planets below 0.1 Mjup. But for all points that don't look to be basically 0, there's an invisible asymptote they don't cross; there is not a smooth transition of points between basically 0 and clearly above 0.
I was especially confused when they were talking about "size" multiples one minute and "radius" multiple the next. Unclear from the article itself if we're talking mass, volume, or diameter.
I wonder if a simulation could be made of planet formation in a solar system based on current data of the different stages for each type and size of star and the distribution of clouds of gas and matter. Run billions of simulations and see under what conditions similar gaps appear in planet mass and size. Perhaps that could provide a clue.
People are running models of planet formation. And some people run their model often enough to do statistics over the outcomes.
The problem is that modelling the formation all the way from micron sized dust to 100000 km diameter planets is hard (14 order of magnitude in length scale). No single model does all steps well, most of them do not include some steps at all.
Note: this does not mean that the models are useless. There is some things we can already learn and smart people work on improving the models. But as usual, HN overestimates the power of numerical models. Modeling real life is a bit harder than launching a ruby web app. And takes MUCH more compute power.
This is so interesting. Because it can't be this hard to do this kind of physics simulation at the correct level of fidelity if you want to apply RL to physical problems
What does RL have to do with this? The laws governing gravity are already well understood and specialized code will always be more computationally efficient while having less unexplainable behavior. Why would you use a slower, more opaque method to accomplish the same thing?
The issue is that there's some force or factor at play that we don't understand - which means that it can't be modeled. If the behavior was emergent from the physics that we do understand, researchers would likely have recreated that behavior by now.
It's a bit harder than that. We don't understand the effect, so we don't have a good _high level_ model of it. That does not mean we can not model it using more fundamental physics. But of course that leads to much more expensive simulations. And you have to work much harder to understand the output.
Let me reply to that we another example: If you fly an aircraft in GTA you are not doing a million-core-hour direct numerical simulation of the air flow around the jet. That doesn't mean it's not cool and playing with simplified models might still allow you to study the dynamics of 2 on 2 aircraft fights, but it is not the same as a physically self-consistent simulation starting from basic principles that we understand.
Another example to illustrate the difference between "physics based and good enough" to "accurate but expensive" would be the algorithm by Jos Stam in a paper title "stable fluids". It is fast enough to run real time fluid simulations e.g. for water in a computer game, but is very dissipative, i.e. it removes small eddies. So while a ship moving through water simulated with that algorithm is going to LOOK great, you will get a totally wrong and inconsistent estimate of the drag on the hull. Not something you care about for a computer game, but something that might change your results if you try to do science with it.
Do you have more information on that? "Hot jupiters" are close in gas planets and the should appear at low semi-major axis, above the Fulton gap. (Disclaimer: I am not a planetary scientist, but my office mate is and I learned just enough to be annoying)
For those who don't know (I don't think it's a common unit): 1 AU is the distance between the earth and the sun (Astronomical Unit). So apparently [citation needed] we're blind for earth-sized planets at an earth's distance from its star.
I am not a planetary scientist (my office mate is) and didn't spend much time looking at the literature. "A Revised Exoplanet Yield from the Transiting Exoplanet Survey Satellite (TESS)" by Barclay et al. (https://iopscience.iop.org/article/10.3847/1538-4365/aae3e9) might be the citation you are looking for. Figure 14 shows that anything below 1.5 Earth radii is basically invisible to TESS. I can not find a good chart for the detection limit in the planet size vs star distance plane.
I'm not sure that's relevant - the fact that we can detect enough earth-ish sized planets to reveal a consistent bimodal size distribution is compelling on its own.
I've been reading The Wheel of Time at a feverish pace over the last couple of months. Seeing a headline about a gap in the Pattern was a confusing experience complete with shock and a sense of dread and a triple-take.
For one brief moment I thought some fool scientist had opened up the Bore. Light!
I know very little physics, but perhaps objects have a stable orbit w.r.t. their mass and
objects in the Fulton gap have the highest probability to interfere with each other and as a consequence distribute their mass to the outer and inner orbit?
Orbits are stable and not sensitive to the objects mass, as long as the mass is much less than parent star. There is even experimental prove of that. An upper stage from the Apollo programm ended up in an orbit around that sun that was basically identical to the Earth orbit.
Nah, it's probably just aliens destroying planets of the dangerous, life-harboring, variety. And we're next!
On a serious note; I wonder whether the size of planets has much bearing on whether life could be started or sustained, or if this is usually trumped by other factors.
It would make for good Sci-Fi premise as an explanation for the Great Filter[1]. Some advanced civilization keeps destroying planets that have life or are ideal for it but the first heuristic they use to do it fast doesn't catch all cases. Earth is below the threshold so we get by, for now...
It (and the whole trilogy) have a handful of really good ideas. The translation at times seemed clunky, the pacing was, uneven and the plotting was not quite as tight as I would have liked. But the handful fo good ideas were good enough that the book stayed with me for a while.
I didn't find any of it good besides the introduction which motivated me to look into Chinese history more. The author thinks too much of himself and tries too hard to appear smart. This is tedious. I can draw a sharp contrast between this author and Neal Stephenson, who is brilliant and introduces many new ideas / explains computing in a way that has motivated many people to study it.
TBP's characters are comical. Not much else to say - the womanizer slacker obsessing over the quiet girl was too much to keep reading. Well, that, and some of the "brilliant defense strategies."
Honestly. Maybe it was the hype train that ruined it for me before I read it, but I just couldn't get into that one.The science definitely didn't do anything for me.
For reference, my current favorite SF is the Night's Dawn Trilogy. Not sure if that flavors my 'review' for anyone.
Diamond Age (doesn't deal with aliens), Anathem (very long-winded), A Deepness in the Sky (this is the closest to the Three Body Problem theme-wise, but also the weakest scientifically, though still better science than the Three Body Problem)
What type of books are you interested in? Since you didn't specify, I am going random: Martin Eden by Jack London, anything BESIDES All Quiet on the Western Front by Erich Remarque, Neuromancer by Gibson.
If you are fishing for me to run out of books that are "better" than TBP, honestly, it would be a long list. If you are genuinely interested, tell me what kind of books you like, and I will be glad to give you more.
Well, my first reaction to your critique of the "Three body problem" was to argue because I liked it, but on the second thought I've decided to ask you for the reading recomendations :)
I guess I'm looking for sci-fi involving grand picture of the universe or 4X-style books, but not necessarily limited to it.
Out of the books you've named, I've read Diamond Age and Neuromancer and while I can't say anything bad about them I still like the Liu Cixin's book more.
"Deepness in the Sky" is on my to read list.
I haven't read Martin Iden, but liked Alaska stories a lot. Remarque is good, but I like Heinrich Böll much more.
I read through your posts because I was wondering who you are, just heads up. Anyway, I actually don't know of too many books that deal with that scale, maybe Asimov's Foundation series, but I am guessing you read that already. I find it hard to compare the TBD problem to anything because I just thought it was utter tripe, on the level of Brandon Sanderson's / Roger Zelazny's books - a lot of content, very little substance (with the exception of "This Immortal" by Zelazny, which is supposedly the inspiration for Planescape: Torment, which I can wholeheartedly recommend to any teenager).
Of course, you might also enjoy Piknik na Obochine, Trudno Bit Bogom, and Neukratimaya Planeta, as people of your particular background tend to do ;^)
Though that last one didn't really age well as I grew up. Oh, and Chekov is amazing when compared to the other famous Russian authors imo.
Your turn for some recommendations, i.e. your top 3, since I am looking for stuff to read. Not necessarily in this genre.
I've read a lot of Azimov, including the Foundation series, and nearly all books by the Strugatsky brothers. And I too loved Harry Harrisons's Deathworld when I was a schoolboy :)
Reading Chekhov makes me genuinely sad, maybe I take the lives of his heroes too close to heart.
I am not sure about top 3, but if I had to reread something I've read before, I'd start with Dostoevsky's 'Idiot', continue with "За миллиард лет до конца света" by Strugatsky brothers, and maybe I'll reread the Permutation City by Greg Egan.
As for the Three Body Problem, I find it unique in that it realisticly represents the humanity's place in the galaxy (a fly on the wind shield). Lui Cixin's cosmic sociology [0] rings true to me too. The idea of laws of physics being the result of the activity of advanced civilizations, while not original (see Lem's “The New Cosmogony”), is fascinating nonetheless. The story of how 'right' moral choices in the context of that world lead to the end of humanity is another original bit.
Slow reply because I was looking for an author I found out a few years ago through a friend, read one book by, thought it was great, and then completely forgot his name:
I might have one more author, if it turns out the book wasn't by the guy above. Unfortunately, I don't even remember the name, and I don't see it in his bibliography.
No problem.
Which book was that?
Pelevin used to be good, but I haven't liked a couple of his more recent books, in fact, couldn't even finish reading.
Why are so many people so in love with the idea that the solution to the fermi paradox is sapiocide on a cosmic scale? It neither fits the data nor does it hold any philosophical merit.
The game Grey Goo did this. Also the only game where the human faction is basically the Culture - there's a fantastic line in one of the cinematics of a human captive getting free and commenting "no signs of AI or nanotechnology. They still use bullets in their guns."
My (totally uneducated) guess is, in the early formation of a solar system the material is hot and volatile it is all moving around a lot. There are a lot of large / medium sized bodies moving around they are running into each other, joining, breaking apart, moving around, etc. In all that chaos, the available material is tossed around and "excess" material is toss out of the inner planet orbit.
I am imagining it like pouring a cup of sugar on a dinner plate and shaking the plate around until the amount of sugar on the plate is sort of stable. The excess material ends up outside the solar system (Oort cloud / kuiper belt) or part of gas giant cores and moons.
With that, there is only so much material in the inner solar system to work with and the law of averages works out and we end up with similar sized planets.
I would assert a hypothesis that a ratio of material in the inner solar system is linked, in some way, to the size of the star. That it is unlikely there will be massive earths out there in the inner solar system because of this natural distribution of material around a star.
I have no formal training at all. Just an IT nerd that watches a lot of Kurzgesagt.
That would be compelling if there were planets up to a certain size. However, that's not the case. You have increasingly large planets, a big gap, and then increasingly large planets again. It's a bimodal distribution, which implies some other factor at hand than just the law of averages.
Sounds to me like putting sugar on a plate and vibrating it at a certain frequency. The same patterns always form for the same frequency. Why should solar systems be any different, given the overall mass of the star and raw material?
Maybe more like shaking a plate of magnets around. Shake a little, they start to clump up. Shake long enough, there's only one large magnet stack. If the shake time follows a pattern, then most places will have similar planetary distribution e.g. few small planets and a couple of big ones?
There is no (known) selection effect that would account for that gap. (And scientists have looked to find such selection effects). And yes, there is other gaps, e.g. a lack of systems with a planet at 0.2 AU (or rather in the range from 0.1 to 1.0 AU, separating the "hot jupiters" far in from the "normal" gas giants further out that we know from our solar system).
Can someone explain this recurring pattern of elaborate art images produced for rinky-dink articles? Is that just to try to keep eyes on the page or something?
Why? A key part of physics is collecting data. All the line means is the data are incomplete but as of now suggest a gap that may be interesting to keep an eye on as new data are observed.
Yes, agreed. We now have a prediction. We will collect more data to see if that prediction holds. If it does, we'll work on theories to explain it. (Of course, these two processes will actually happen in tandem, as how things work in practice is much messier.) They are not looking at the data set and saying "This anomaly will certainly hold when we get more data, it is now established fact." They are looking at the data set and saying "This looks funny, we should keep an eye on it." That is good science.
I actually find it hard to imagine the model of science that some people seem to have is supposed to work, where, apparently, you are supposed to never look at the real data already collected out in the world and somehow just come up with hypotheses to be tested from... uhh... err... nothing, apparently, because looking at pre-existing data is somehow cheating, and, what else is there?
The "standard model" of science that seems to be embedded in the heads of the Greater Internet Commetariat is pretty ludicrously nonsensical in a number of places.
If your data sample is far from being significant you don't jump to conclusions or ridiculous hypotheses. For example, if you roll a dice just 10 times and find out that 6 does not come out at all, do you jump to "scientists wonder why 6 never comes up. There must be something we don't understand". No, you just did not collect enough data, that is all.
There's more to life than statistical significance. We all act on lots of qualitative information all the time, and it doesn't cause us to be catastrophic morons. In fact, we spend inordinate amounts of time trying to teach computers to be good at understanding those qualitative differences.
So, any system that is not part of Dark Matter yet is either: 1) unconducive to life (or complex life, anyway) 2) was already zapped by the EAILD 3) like us, is in a transient state where the EAILD hasn't arrived yet, but we haven't learned how to cloak our solar system yet either
Again, the key here is that planets just slightly larger than Earth are the most likely to evolve intelligent life, so they nearly always end up cloaking, and thus we don't see them.
Enjoy.