what is the most interesting about that theory, is that it took so much time to get proposed as a solution to the Fermi Paradox.
But it make perfect sense
I think honestly all the handwringing about why we can’t detect aliens may point to something else. Maybe the kinds of technology that would enable us to gather enough material to build Dyson spheres and escape the solar system simply are not feasible. If the best speed we can make is 75% of the speed of light, even the short distance to the nearest Star system becomes a generational journey. And getting up to that speed is going to take a lot of energy. As much as I love my space opera, I just don’t see it as a plausible future. What seems possible is akin to the maximum ground speed on earth being limited to walking speed. At such a speed knowing about tribes a thousand miles away just isn’t going to happen, long distance communication makes no sense when the entire civilization might well be trapped in the nearest star system and maybe if super advanced, tge one next to theirs. They don’t need to broadcast anything beyond that, so they’re not going to develop it. What would we detect? Unless we somehow manage to detect them directly, there’s nothing to see, and nothing to hear. The paradox seems to rest on the assumption of interstellar travel being feasible. If it’s not, Theres no paradox. They’re here, but too far away to hear or see.
The paradox take into account the vast distance between stars. The idea is that in the billion of year of the universe, even when going very slow, even if it take 1000+ year to get to the next star with a generational ship, and then another 1000 year to build a society on that planet before launching the next ship, the univers is so old, that if there was an intelligent alien, it must already have colonized ALL the milky way. ALL of it, every star, and there are a lot. As big is the space, the age of the universe is far far bigger. Another counter argument, beside the usual (earth is a zoo monitored by hidden alien; life is super rare; intelligence is super rare and we are the first; there is a great filter that kill any intelligent life during their time, alien dont care to expand as in the article..) ; so another one is from kurzgesagt : It state that life appears so fast on earth, and grew so fast, that it must have been already a long way into its evolution. The first microbe was already super complex. So, may be it took the billions of years of the universe to get to that first microbe. So we are amongst the first intelligent life that can exist, because life took so long to get the first microbe. And only now can start the colonization for every intelligent species
Wouldn’t life have to spring up pretty quickly to make this feasible? To get from primordial cells to us took 5 billion years. Then it’s 2K years per system, which might mean 2.5 million stars 10 billion years after life begins on the planet in question. There are 100 billion in just the Milky Way (and I think anyone outside of that could safely be neglected as we cannot possibly detect them. So less than 1% of all stars in a galaxy within several billion years? I just don’t understand why anyone was asking the question.
Because in popular culture HG Wells postulated Martians to explain the (non-existent) canals, "little green men" started populating science fiction and the CIA used an "alien crash" at Roswell to provide a cover story for Project Mogul, thereby launching an outsized pop culture trend. Meanwhile, theoretical physics was still so young that Fermi, Teller, York and Konopinski could all be hanging out at UChicago but old enough that the age of the sun could be known at around 5 billion years, the age of the planet at around 3 billion years and the age of the universe at around 14. So on the one hand, popular culture insisted that everything weird was little green men but on the other hand, those with a grounding in physics or astronomy knew that the little green men had a substantial head start. Considering the rapid technological progress the human race was currently experiencing (cotton gin to nuclear weapons in 150 years), Fermi was having a hard time squaring eleven billion years of technological progress with how thin aliens were on the ground. I just don’t understand why anyone was asking the question.
You might be right. I never looked at the calculation, just report what I read. I suppose it is about the exponential of the growth, every planet you reach launch a new ship: 1 planet -> 2 planet -> 4 planet- 8,16,32... ... by the 36th time (72k years in my example) you did that you're at 34 billions planets. And that not even counting the fact, that the first planets can continue to launch new ships in the meantime. So the paradox is : since none of that happened, what prevented it. You can tweak the time to reach planet , rate of new planet conquest, and stuff and it still should have happened, so there must one fondamental reason it didnt, hence the article about living in equilibrium with your planet
The universe is 14 billion years old. I’m not sure how long it would take for the first truly habitable planets to form. You need to cycle through enough stars to form heavy elements and AFAIK you need the building blocks of carbon based matter so it might take 5 billion years just to get to the point of life being possible, let alone complex life, we’re talking just barely enough to support E. coli. Life on earth took 5 billion years to go from E. Coli to Elon Musk and being able to go to the moon and hopefully Mars. Being optimistic, I think you might have a window of opportunity from 10 billion years ago to a couple billion years in the future. It might be that you need more than just a marginally habitable planet. We might be lucky because we have outer planets to stop asteroids from hitting the earth, we have a moon to create seasons, we aren’t tidally locked, and we have lots of liquid water. If you get all life on the planet destroyed by asteroids and comets, or the seasons are too short, or only the twilight zones between the super hot tidally locked zone and the frozen night zone— all of this might make it hard to start life and might make colonization difficult.
No, at v=0.75c you get 𝛾=1.51 (𝛾 := 1/Sqrt[1 - (v/c)²]) and the time that passes for ship's passengers is t'=d/(𝛾v), where d is distance in light years. At d=4.3 ly to Alpha Centauri gives passenger's time as t'=3.8 years. Lorenz transforms for the ship reference frame are d'=𝛾(d-vt) and t' = 𝛾(t-vd/c²), do the wangjangling, and get t'=𝛾(d/v - vd/c²)=d/(𝛾v) I used above. I also calculated this thing for kb a while back, for scale:If the best speed we can make is 75% of the speed of light, even the short distance to the nearest Star system becomes a generational journey.
Dude you know the article is un-serious the minute you see the words "Kardashev scale." There are at least two books that I know of that are nothing but solutions to the Fermi Paradox because the absolute dearth of hard information leads to an absolute cornucopia of theory. It's pretty useless stuff from a scientific standpoint because it's nonsense divided by nonsense raised to the power of nonsense squared. From an anthropological standpoint, though, it's an entertaining mirror to hold up to society. One of the things that's always amused me about SETI is that it's always focused on the it-girl of whatever our technology is. I remember an article arguing that obviously we should be looking at tight-beam red lasers back in like '89; there was another one claiming we should be looking at x-ray lasers like five years later. One of the other things that's always amused me is how everyone pooh-poohs spherical decay as if the farm report from Tau Ceti is gonna make it here accidentally with any kind of signal to noise ratio we'd be able to detect. But you need to justify your time on the radiotelescope, right? So we make up some shit. This whole "let's turn inward" thing is going to become more and more common as more people read The Dawn of Everything, kinda how Spin doesn't get written without Gray Goo being on the tip of everyone's brain. Frankly, both Dyson Spheres and the Kardashev Scale came of age in an era where energy seemed unlimited; if you'd told Freeman Dyson back when he was working on Project Orion that the world was gonna studiously fail to develop fusion power for the next 70 years he'd never have believed you.
Well, the alternative is looking for things we can't name or (even approximately) explain, which is a much tougher sell since we most likely can't even measure them. I'd be down for hunting self-propagating spacetime defects and parasitic patterns in dark matter, but LIGO lacks around 9 orders of magnitude in resolution.I remember an article arguing that obviously we should be looking at tight-beam red lasers back in like '89; there was another one claiming we should be looking at x-ray lasers like five years later.
But you need to justify your time on the radiotelescope, right?
So funny story. LIGO's number two guy was my best friend's dad, and I was there with them both at Caltech when they were still messing around with their demo gadget, rather than the geographical array. Who shows up but another guy I knew from high school, who I tried real hard not to get recognized by because he's really annoying. He did, of course, but not before expressing his skepticism that LIGO was going to be sensitive enough to detect anything; he ended up not going to Caltech because in his opinion, LIGO was "around six orders of magnitude" too insensitive to detect a neutron star.
I can see that, though not where he got six orders of magnitude. Gravitational waves could have been dissipating and losing coherency a lot faster than they turned out to do, sure, but that's about four more than I could conjure (assuming 10^3-10^4 ly distance to a binary). It wouldn't be surprising if my approximation would be equally garbage, since these were my doodles on Xeelee, but that's the unfortunate truth about the horizons of science: it's not that far from "it's like, your opinion, man" with math until there's an observation. Always glad to hear these kinds of stories. By the way, I want to stress that I don't endorse Baxter, from horrible character writing through goofy names to being nowhere near as scientifically accurate as many tout, but I got interested when someone recommended Flux with "a society of primitive posthumans inside a neutron star deals with impending ecological collapse."he ended up not going to Caltech because in his opinion, LIGO was "around six orders of magnitude" too insensitive to detect a neutron star.
Everyone was an undergrad once. The undergrad in question, of course, denies the discussion ever happened.By the way, I want to stress that I don't endorse Baxter,
I guess my point is that I don’t think there’s actually much of a paradox to be has here. Space is extremely big, and for most types of communication and transport, there’s no reason to even start with us being able to see or hear anything. If travel to the nearest star is measured in years at speeds that don’t need eye-watering amounts of energy, weird matter, etc. there’s no reason to even start looking for aliens. It would be like Native Americans in 1300 using their best technology to look for humans in Europe and formulating lots of theories about why they never see anything to indicate intelligent life in Europe. They probably are out there, not even hiding, just that in 1300 nobody could possibly cross the ocean and they weren’t really trying to communicate across the Atlantic. The Fermi paradox only matters because it’s an easy way to fleece money out of the scifi nerds who believe that Star Trek represents a realistic future in space. It’s why the people running NASA and SETI and other similar agencies have an operating budget despite doing nothing other than being make-work projects for nerds. I don’t expect to see humans on Mars as anything other than a photo opportunity in this century and maybe the next. I just mostly find the theory-making amusing. Maybe they’re hiding? Maybe they’re using super-secret technology. Maybe they’ve gone into a higher levels of being and aren’t physical anymore. Maybe they’ve gone Borg, maybe the Grey goo got them. It’s just anything to avoid dealing with the obvious— space is simply too big for aliens or us to effectively colonize or control and thus communicate that crosses tge nearest heliopause is unnecessary.
I think everyone in the community has a firm barrier between "things are fun" and "things are real." Many of our working sci fi writers these days are big science nerds who have a firm grasp of reality but explore the impossible corners because they're entertaining to think about. I think if you asked 100 trekkies whether Star Trek represents "a realistic future in space" about 95 of them would aver. They know in their hearts that warp drives and replicators have no more basis in fact than magic wands and ruby slippers but they can go what if and enjoy themselves and that's totally fine. The problem is our paradigm for "meeting strangers" is generally "after crossing an ocean" so the ocean has to be challenging but not impossible to cross. You're right - from a realistic standpoint there's orders of magnitude more logistics in crossing light years than there is in crossing leagues but this graph or its friends will tell any creative writer that where there's a will there's a way, wave hands get plausible deniability and move on to the fun stuff. MY beef is that articles like this one are generally written by people without the creativity to write the fiction and without the smarts to write the fact so we end up with wrinkled-forehead prognostications about the Kardashev scale. The Fermi Paradox white papers are often scientists messing about with science fiction but this is... something else. It kinda looks like the author heard about the noosphere while ripping on a bong in his undergrad and never let go.
I mean if we were talking about science fiction fans in the 1989s, I’d agree with you for the most part. The problem is that as science education has declined for the general population (alongside mathematical and general literacy) I’m seeing more and more often that fans of these series have no idea what actual space looks like and the hard limits on speed. It doesn’t help when grifters like Albucurre come along with a mathematical curiosity in a physics equation and goes “Behold the Warp Theory”. I don’t blame NASA for playing along, they need those fanboys calling congress to fund them. What’s disturbing is how many people are taking the idea seriously.
I think survivorship bias tends to make the past look more sensible than it was. The biggest thing on goddamn television when I was a kid was "the lizard people have come for our water... and our WOMEN" As far as I'm concerned I'd rather see money spent on Alicuberre drives than fuckin' LLMs. At least magic warp drives have some questions left to answer; The whole of AI is all about "smooth jazz, only nobody had to make it OR listen to it!"
I think the Alicuberre drive is worse because it’s expensive science working on a project that violates known scientific principles in multiple ways. At minimum LLM has some good uses in business and to create boiler plate journalism. It might turn into something more eventually. Alibucurre drives can only end in futility because none of the stuff proposed can exist. Negative mass and negative energy are fiction. The theory of relativity closes off FTL travel and must do so to preserve causality.
In relativity, we assume that the speed of light in the vacuum (which, in the mathematical and physical sense also means there isn't anything for it to be relative to) is the same in every frame of reference. This is what Michelson–Morley experiment measured, and it is remarkable. It is unintuitive, because if you were throwing someone a ball at rest vs from a moving car, the moving one would have a different velocity. But that doesn't happen like that with light. Regardless if you're stationary or moving away or toward me at 0.9c, we'll both see both c as c. What we can't do is accelerate things to the speed of light if they were sub-luminal for the same reason we can't decelerate super-luminal objects to the speed of light: it requires infinite energy. By the way, doing that to light in either direction is equally difficult and for the same reason. This, however, doesn't mean that FTL travel is impossible. To be precise, relativity describes it. It doesn't describe how to jump over the light speed barrier, not how to treat the light speed as some unbreachable limit of the universe. Why FTL could happen and how it relates to mass? Where do I even start, Higgs fields? QCD binding energy? Affine spaces? Maybe, but I doubt you'd read it. No, I'll just restate this one more time: it doesn't have to forbid or preserve a thing. It can't, on its own, explain how we go from sub-luminal to light speed or super-luminal down to light speed, or how to jump over the speed of light in either direction, but it doesn't prohibit faster than light travel. It literally describes time travel in both directions, not how to move over discontinuities. Which, mind you, could be purely mathematical artefacts. I'll give you one better: the problem with wormholes isn't that we can't figure out negative energy or transit stability, it's that we wouldn't be able to make them connect specific points in spacetime. It's for a similar reason why you wouldn't be able to steer Alcubierre bubble as we understand it, not why they couldn't exist.The theory of relativity closes off FTL travel and must do so to preserve causality.
My understanding of the reason FTL travel is impossible even if (huge if because it requires infinite energy to start and stop) we could somehow figure out the boundaries, is that it breaks causality. Causality travels at the speed of information and to my understanding that is at c. If you launch a ship in response to a signal, and the ship goes faster than light, you have the potential for tge ship to arrive before the signal summoning it is sent. And this assumes that all the negative energy and negative mass and space debris problems are actually surmountable by beings anywhere in the universe. If you’re talking about breaking causality, either we admit that we know literally nothing about anything in physics, or we admit that we’re likely talking about a fantasy and we’d get equal results by spending billions to try and mix Floo powder and travel across Europe by fireplace. As for wormhole theory, I’m not sure it actually fairs much better, unless we’re going to start dosing up pilots with worm-puke gas until they turn into fish-like superhumans who can predict the future.
If you really get into the ins and outs of theoretical physics down there where the "Theoretical" has a capital T and the "physics" is in italics, you start tripping over weirder shit: - Quantum entanglement is instantaneous and what keeps it from transmitting communication is the observer effect - The observer effect is some hand-wavey shit along the same lines as wave particle duality, IE "shit that was made up so that undergrads could move on" - The theory of relativity says you can't accelerate something TO the speed of light. It also says you can't decelerate something FROM the speed of light. Which means that anything going faster than the speed of light can't be made to go slower and anything going slower than the speed of light can't be made to go faster which means they can never interact. It does NOT forbid either from existing. The speed of light is just where the asymptote lives. There are asymptotes throughout mathematics. One can, with confidence, say that there are iron-clad laws preventing information or matter from traveling past the speed of light. One cannot, however, point at theoretical physics and say "because all this shit is absolutely rock-solid." Edwin Hubble turned the Andromeda Nebula into the Andromeda Galaxy barely 100 years ago. Superconductivity was discovered in 1911, but superconductors you could wow your physics class with showed up in VWR Scientific when I was in high school. The age of the universe has gained two decimal points of precision since I started college. Not saying warp drive is right around the corner, saying that "faster than light travel appears to be impossible" is likely a safer thing to say than "faster than light travel is impossible" based simply on scientific progress.
I don't think they're fashionable, it's that I accept the fact we're observing only one part of GR without having to blast string theory out of every co-tangent orfice bundle. Here I jumped onto the 'closes off' and 'must', since relativity a) doesn't show to do the former, and b) doesn't care about or explicitly enforce the latter. It's a bit like every time I hear someone talk about theory of everything only have them add exclusionary clauses and asterisks each time I open my mouth.
RANT ON Perhaps "fashionable" is the wrong phrase. How about "orthodox?" The basic issue, as highlighted by this article, is that some ideas are acceptable to papal doctrine and some aren't. Those ideas very much follow the Planck maxim of "science advances one funeral at a time." Scientists capable of creativity tend to tuck their crazier ideas into short stories, which is hella fun. Scientists incapable of creativity tend to tuck their crazier ideas into weird little papers in neglected corners of academia, which is hella tedious. Max Tegmark even has a ratio; in order to keep tenure he does one hare-brained paper per 19 normie ones. Analog Magazine used to publish speculative fact. It was usually awesome, tooled for a lay audience and written in a conversational tone that was invariably thought-provoking. On the other hand, modern speculative papers are dry AF and couched in all sorts of plausible deniability which means a lack of scientific rigor is easily hidden (see above). So what we're left with is blogs discussing idiots when we used to get Sagan arguing that there wasn't life on earth (based on current scientific methods). So now we're at "is it vaguely thought-provoking? give it to the crazies" and "does it reinforce doctrine? Make Neil DeGrasse-Tyson talk about it on Good Morning America." Even if it's nutrition - especially if it's nutrition. And the thing of it is? It's the science fiction that pushed the envelope. It's the science fiction that the scientists read. Enrico Fermi wasn't known for his ruminations on little green men and yet the autocomplete on everyone's phone for Fermi isn't "-on" it's "Paradox." But god help you if you try and push a boundary or two. Nobody reads science fiction anymore, it's all Hunger Games ripoffs and Chinese propaganda. So we don't talk about the black spots in mars rover tracks. And we don't talk about the platinum-iridium wire Avi Loeb dragged up from the ocean. But ZOMFG the UAPs RANT OFF