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| https://askanearthspacescientist.asu.edu/explore/finding-aliens |
A Sense of Doubt blog post #2865 - Where are the aliens?
Just this image, first.
Like, maybe, going back to this very recent article:
| https://www.science.org.au/curious/space-time/search-life-beyond-earth |
https://entertainment.slashdot.org/story/22/08/23/2131212/congress-admits-ufos-not-man-made-says-threats-increasing-exponentially
Congress Admits UFOs Not 'Man-Made,' Says 'Threats' Increasing 'Exponentially' (vice.com)
The admission is stunning chiefly because, as more information about the U.S. government's study of UFOs has become public, many politicians have stopped just short of claiming the unidentified objects were extraterrestrial or extradimensional in origin. The standard line is typically that, if UFOs exist, then they're likely advanced -- although human-made -- vehicles. Obama refused to confirm the existence of aliens but did say that people have seen a lot of strange stuff in the sky lately when asked directly on The Late Show with James Corden, for example. But now Congress seems to want to specifically distinguish between objects that are "man-made" and those that are not. The admission is stunning chiefly because, as more information about the U.S. government's study of UFOs has become public, many politicians have stopped just short of claiming the unidentified objects were extraterrestrial or extradimensional in origin.
A large question, of course, is why Congress is seemingly admitting this now, in public. After all, lawmakers are privy to classified information that the general public isn't. "It strains credulity to believe that lawmakers would include such extraordinary language in public legislation without compelling evidence," Marik von Rennenkampff, an Obama-era DoD official, said in an op-ed in The Hill about the budget. According to the op-ed, the comments were first noticed by UFO researcher Douglas Johnson. "This implies that members of the Senate Intelligence Committee believe (on a unanimous, bipartisan basis) that some UFOs have non-human origins," von Rennenkampff continued. "After all, why would Congress establish and task a powerful new office with investigating non-'man-made' UFOs if such objects did not exist?" "Make no mistake: One branch of the American government implying that UFOs have non-human origins is an explosive development."
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| https://www.science.org.au/curious/space-time/search-life-beyond-earth |
Five Possible Reasons We Haven’t Been Visited By Aliens (Yet)
James Davis Nicoll
Late in 2020—remember 2020? We had so much fun—astronomers reported radio signals from Proxima Centauri, which, as you know, is at present the closest star to the Sun. This sort of thing cannot be due to aliens (of course)… but just suppose it were.
If the signal is from entities native to the Proximan system (which is now known to have at least two worlds, one of which is a terrestrial world in the liquid water zone) then either we got stupendously lucky or technological life is very, very common. If the aliens are not native to Proxima, then they got there somehow, which strongly suggests that:
A: they are much more technologically advanced than we are, and
B: they have possibly expanded through some/much/all of our galaxy.
The second possibility raises another question, which is: if some civilization has spread throughout our galaxy, why haven’t they visited us?
There are at least five plausible explanations.
Zoo Hypothesis
The aliens are aware of us but prefer for some reason to actively avoid overt contact. Possible reasons:
- In Anne McCaffrey’s Decision at Doona, a first contact gone horribly wrong has left an interstellar polity with an extreme reluctance to interact with other civilizations.
- Scientific detachment. Let’s see how these humans develop. No fair contaminating the experiment.
- Humans are icky.
- Nature preserve. There’s something interesting about the Solar System and it isn’t us.
Stagnation
Sure, the aliens have starflight but they are perfectly happy with the territory they have and see no reason to seek out the headaches of incorporating new worlds. Especially new worlds with potentially obstreperous natives. Example: Lindsay Ellis’ 2020 novel Axiom’s End. The aliens that the Americans have codenamed Pequod are quite aware of the Earth, but since Earth is mildly inconvenient to reach and offers nothing they want that they cannot acquire more easily at home, they’ve been content to ignore us. This is entirely to our benefit, as demonstrated by the very limited first contact that shapes the plot of the novel.
Been Here, But…
The Earth is four and a half billion years old. Perhaps it does get visited from time to time, but at such intervals that the physical evidence has thus far been erased by geological processes. In Julian May’s Saga of Pliocene Exile, for example, the Tanu and the Firvulag aliens colonized Earth six million years in the past. All evidence of this alien sojourn had been erased by the present day, which meant that 21st-century human time travellers have a delightful surprise waiting for them at the other end of the one-way time gate to 6,000,000 BCE.
Other worlds in the Solar System lack Earth’s robust weather and geology, so perhaps the key to finding evidence of visitors is to check the more pristine bodies, like our Moon.
Overlooked for Good Reason
Perhaps the aliens’ body of experience suggests that the Solar System is unlikely to have worlds of interest. Many sources will suggest that the Sun is an unremarkable star. In fact, this not true at all. The Sun is much larger than the average star. Consequently, not only is its time on the main sequence much shorter than average but its luminosity varies dramatically over time—the Sun may be a third brighter than it was four and a half billion years ago.
This was the reason the Sun was ignored in Hal Clement’s Still River: nothing in the Galactics’ experience suggested there could be life, let alone intelligent life, on a world orbiting a rapidly brightening star, particularly on a world already so overheated that H20 was liquid.
Note that Proxima is small and dim, unlike our star, and that while one of its known worlds is within the liquid water zone, the other one is very much not.
Have Not… Yet
Perhaps we’ve simply been overlooked… thus far. In their paper A Simple Model of Grabby Aliens, Robin Hanson, Daniel Martin, Calvin McCarter, and Jonathan Paulson suggest that we are simply the beneficiaries of dumb luck. For all we know, the Milky Way is even now being carved up by a few inexorably expanding civilizations, but thanks to our location out here in the unfashionable boonies, they have yet to reach us. The operative word being “yet.”
Perhaps, as in Housuke Nojiri’s Usurper of the Sun, in which the Solar System is reshaped to suit enigmatic alien goals, we are due for a very rude awakening. It may be *very bad news* for us if those really are alien signals from the star right next door. In a few years, we may remember 2020 as a comparative golden age…
***
No doubt you have your own favourite explanations for our isolation, explanations I have overlooked. The comments section is below and awaits your submissions.
In the words of Wikipedia editor TexasAndroid, prolific book reviewer and perennial Darwin Award nominee James Davis Nicoll is of “questionable notability.” His work has appeared in Publishers Weekly and Romantic Times as well as on his own websites, James Nicoll Reviews and Young People Read Old SFF(where he is assisted by editor Karen Lofstrom and web person Adrienne L. Travis). He is a four-time finalist for the Best Fan Writer Hugo Award and is surprisingly flammable.
Footnotes
1: STARS MOVE.
2: Yes, technically the Sun is the closest star to the Sun.
3: Also, that the challenging environment presented by a red dwarf like Proxima is no barrier to the appearance of complex life on one of its worlds.
4: See also Game Designer Workshop’s “Traveller,” in which it turned out the only reason the Ziru Sirka AKA Grand Empire of Stars didn’t utterly crush Earth back in our Classical Period is because around the time the wheels were falling off the Western Roman Empire the Ziru Sirka solidified its borders just short of the Solar System. A pity for the Ziru Sirka, because not only was Earth peculiarly well suited to their form of life for reasons I won’t get into, the Terrans eventually developed indigenous star flight, which turned out very badly for the Grand Empire of Stars.
77 Comments
Alien-Hunting Astronomer Says There May Be a Second Interstellar Object On Earth In New Study (vice.com)
"We don't have a large enough sample to say how much stronger interstellar objects are than solar system objects, but we can say that they are stronger," Siraj said in an email. "The odds of randomly drawing two objects in the top 3 out of 273 is 1 in 10 thousand. And when we look at the specific numbers relative to the distribution of objects, we find that the Gaussian odds are more like 1 in a million." This makes IM2 "an outlier in material strength," Loeb added in a follow-up call with Siraj. "To us, it means that the source is different from planetary systems like the solar system."
Loeb has attracted widespread attention in recent years over his speculation that the first interstellar object ever identified, known as 'Oumuamua, was an artifact of alien technology. Spotted in 2017, 'Oumuamua sped through the solar system and was up to a quarter-mile in scale, making it much larger than the interstellar meteor candidates identified by Siraj and Loeb, which are a few feet across. Loeb's claims of an artificial origin for 'Oumuamua have provoked substantial pushback from many scientists who do not consider a technological explanation to be likely. Loeb also thinks these interstellar meteor candidates could be alien artifacts, though he and Siraj present a mind-boggling natural explanation for the strangely robust objects in the study: The meteors may be a kind of interstellar shrapnel produced by the explosions of large stars, called supernovae. [...] Loeb, of course, is keeping his mind open. "We don't say, necessarily, that it is artificial," Loeb said in the call, referring to the supernovae explanation. But, he added, "obviously, there is a possibility that a spacecraft was designed to sustain such harsh conditions as passing through the Earth's atmosphere, so we should allow for that."
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- Bloggery committed by chris tower - 2212.22 - 10:10
- Days ago = 2729 days ago
- New note - On 1807.06, I ceased daily transmission of my Hey Mom feature after three years of daily conversations. I plan to continue Hey Mom posts at least twice per week but will continue to post the days since ("Days Ago") count on my blog each day. The blog entry numbering in the title has changed to reflect total Sense of Doubt posts since I began the blog on 0705.04, which include Hey Mom posts, Daily Bowie posts, and Sense of Doubt posts. Hey Mom posts will still be numbered sequentially. New Hey Mom posts will use the same format as all the other Hey Mom posts; all other posts will feature this format seen here.
From the amount of people who claim to be abducted over and over again to be examined when humans aren’t that complex as physical beings, I’d say we are the pickled frogs for teenaged alien school science projects. Those that disappear rather than being returned are probably college-level dissections.
Maybe nobody has figured out interstellar travel at near light speed. Apparently, a speck of space dust at the right speed can derail your trip real quick.
I dunno, maybe we’re the first intelligent (for certain definitions of “intelligent”) species to arise? Someone has to be first.
3: that’s reasonable but wouldn’t explain artificial radio signals from Proxima.
Actually, thought of a sixth reason: the standard method of getting around requires a receiver at the destination, and until we can build one, nobody is coming to visit.
For a similar thought to number three, see the Silurian Hypothesis, which explores what detectable traces a modern humanish tech level civilization might have left that would be detectable over a geologically significant period of time. Of course that’s not necessarily the same as the traces that might be left by an extraterrestial species arriving and colonizing the place.
Hmm. I wonder what sort of evidence one would look for to determine if one’s planet had been the subject of intensive artificial terraforming (or, if you like, xenoforming) efforts…
@4
I vaguely recall reading a story where the Important Radio Signals From Space were actually reflected (somehow) signals from Earth.
0:
In those books a surprising amount of evidence that this sojourn occurred still exists in the present (as the very recognizable names Tanu and Firvulag might suggest) – it’s just not been interpreted as evidence of alien colonization.
(this series also uses the Zoo hypothesis – by the present day, the very few alien races in the Galaxy are part of a single political organization that enforces its no-meddling rules firmly)
I think the 2nd footnote went a bit wonky. If the text had been “closest to the Earth” and the footnote said “the Sun is the closest star to the Earth,” then it would make sense, but it looks like someone changed “Earth” to “Sun” in the text and in the footnote and now it doesn’t make sense. “Yes, technically the Sun is the closest star to the Sun” just doesn’t make sense.
Also, I think the reason that we haven’t been visited by aliens yet was explained by The Hitchhiker’s Guide to the Galaxy: Space is big. Really big.
Very weird to see that post-Galactic Milieu Trilogy cover for _The Many-Colo(u)red Land_, btw. But sticking with the Julian May theme, _Intervention_ contains several scenes of the aliens coming to visit incognito and try to figure out whether those humans will ever be ready for interspecies contact, or indeed if they will even survive that long. (And I don’t think it’s spoiling too much to note that the climax of that novel is when some of the humans call for help and the aliens, who have been waiting for this moment, suddenly appear. In 2012.)
Other species might be content to stay where they are instead of conquering everything.
It’s actually quite disappointing that UFOs sightings have dramatically declined :/
Once DVD boxed sets became reasonably priced, the aliens didn’t need to hang around waiting for reruns of their favourite shows.
@12 – I don’t know. Did you see all the documents the CIA released?
I think Aliens have been watching our tv broadcasts that we’ve been beaming into space for the last sixty or so years, and have decided that there is no way in hell they are going to deal with us until we grow the hell up. They’ve probably got their tentacles crossed that we wipe ourselves out before we start lowering the galactic house prices with our trash selves.
@11 – possible but unlikely. Life tends to try to expand its reach as much as possible.
@12 – Smartphones are the reason for this.
I suspect the real reason is either space is big in both time and, well, space and space travel is slow. Or if some civilization out there has developed FTL travel, and has done so during the relatively brief window of time that human civilization has existed, they view us somewhere between the way we view mosquitos and Arkansas.
They already know about us and they’re sneakily preparing us for harvest.
See e.g.
The Cuddly Menace
16: There must be an abundance of photos of UFOs, in the sense that all that is required for an FO to U is for the witness not to know what it is. A golden age for meteorologists, no doubt.
The 2002 book If the Universe is Teeming with Aliens…Where is Everybody? offers 50 possible explanations to why we haven’t been contacted by aliens yet. (The book’s 2nd edition increases the number of possible explanations covered to 75.)
One key point the book makes is that many of these explanations are not mutually exclusive. So while one alien civilization might ignore Earth because of their version of the Prime Directive, other aliens may be silicon-based and have no desire to interact with carbon-based life forms, and yet another set of aliens might lack the specific technology to travel/communicate across interstellar distances. It seems plausible to me that the reason we haven’t been visited is the result of multiple explanations.
@7: Carl Sagan’s “Contact” begins with a signal from space which becomes video… of Hitler at the televised Munich Olympics. But, digital. Not the only story where the space signal isn’t necessarily a message from another star…
And indeed, @5: when the signal is instructions to build… it. Someone wants to see what happens, so they build it… Please don’t build it near me.
Douglas Adams had an “actual” alien mention others, “teasers” who like to find an isolated victim and “strut up and down in front of him wearing silly antennas on their head and making beep beep noises”.
How confident can we be that our planet wasn’t terraformed? I mean before we got to work on it ourselves.
Or there’s the Monty Python reason.
“On second thought, let’s not go to Earth. ‘Tis a silly place.”
The RPG 2300AD has an FTL drive that works by jumping from star to star, with restrictions on how far the jumps are. James Nicoll himself has found that if you look at real nearby stars, you can only jump to three stars from the Sun before hitting a gap about twice the mean separation of stars. If the range of your jump drive is about seven light years, you get a network with thousands of stars, but not including the Solar System. Maybe that’s the explanation, it’s possible to get to Earth by slower-than-light travel, but everywhere else is much more convenient. Of course that only works until the relative motion of the stars changes the pattern.
My theory is that they are here, but busy visiting all of the whales and dolphins- they don’t see us land-based types as sentient.
2300 AD‘s Stutterwarp drive limits were pretty clearly fine tuned to create interesting maps for the players. Too short and you can’t get anywhere, too long and there are few meaningful limits on routes.
What I did, though, was to use a 3D map of the Near Stars with Classic Traveller‘s Jump Drive, which is a little different from Stutterwarp. I only recently discovered something I believed about CT was in fact a detail I picked up from the related board Game, Imperium: that jumps have to end near stars. In Imperium they do, but not in standard CT. Oh well.
Restricting it to stars does seem to make a more interesting setting. You could even have a variant of the Zoo hypothesis, but based on natural isolation, like a island ecology on Earth.
@9 : You can’t get closer to the Sun than the Sun itself. Zero is the smallest possible measurement of distance. I predict the footnote reads exactly as James wanted it to read.
Here’s a different hypothesis: The universe is a simulation. Including more than one sentient species in a simulation would vastly increase the needed resources, and the guys running the simulation just can’t afford it.
I guess this is just the “we’re alone” hypothesis but it gives a possible reason we’re alone.
@24: According to the wiki (who appear to be drawing from the GURPS splatbooks), the Ziru Sirka didn’t use deep space depots in the Solomani Rim campaigns until the Sixth Interstellar War. All in all, the Vilani made the Hongxi Emperor look like Henry the Navigator.
There is a rather awful possibility there is nobody out there. Or at least within visiting range.
-Terry Pratchett, Hogfather.
The science-experiment explanation was the one Iain Banks used in State of the Art, and the don’t-have-the-right-gear is done in Contact.
@30: in “State of the Art”, it was one part experiment to nine parts being a massive dick.
@29 Great, we’re living in the freebie demo restricted edition of the universe. The fluctuations in the Cosmic Background Radiation is a watermark.
I’m in the Douglas Adams camp here, along with Capper (@9): space is really big and intelligent aliens are really rare.
By all known physics[1], FTL is impossible, and STL is incredibly energy intensive and slow enough so that many of those STL travellers will be, de facto, on one-way trips unless their species is very long-lived and their culture very static. In a few decades, with no physics breakthroughs, be able to send a vehicle to Proxima[2]. If there are people on it they’ll either be a) immortal (and get very bored), b) in suspended animation (which is not known to be possible within primate biology) or c) a multi-generational community as the round trip would be at a stunning 0.01 c (which is about 40 times faster than the fastest man-made, macroscopic object, the Parker Solar Probe)
In all three cases, the society left behind won’t be static. People in prison for extended periods have difficulty adjusting to social and technological changes. How well would somebody from 1160 cope if moved into 2021?
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1: Yes, I do know about Krasnikov tunnels and Alcubierre bubbles. Exotic matter is hard, quite likely impossible, to find.
2: Freeman Dyson claimed that a Orion-style space ship (massing only few hundred thousand tonnes) could reach Proxima in about 400 years.
The Cosmoquest Forum (https://forum.cosmoquest.org/forum.php) has quite a long and occasionally heated thread on this topic (https://forum.cosmoquest.org/showthread.php?171348-What-do-you-think-is-the-most-likely-explanation-for-the-Fermi-paradox).
I don’t know whether aliens are out there or not (nor does anyone else; there’s no evidence).
The explanation’s already been given.
<a href=”https://www.mit.edu/people/dpolicar/writing/prose/text/thinkingMeat.html”>Cruel. But you said it yourself, who wants to meet meat?</a>
#33:
See Sturgeon’s “The Claustrophile” for how not to be bored by space travel. The answer is to be the sort of nerd who’s fascinated by working things out. Sturgeon didn’t even know that information can be made very lightweight so that there can be even more to think about.
I could lose my job for commenting (thank you VPN), but the short field OU is simply teeming with biosignatures (IAUWG: K-22b, K-439b, WFXRAIS-79b) and technosignatures (no way in hell). Distance and time are the only whys.
@6: There’s even an SF story about it: https://www.vice.com/en/article/3kj4y8/gavin-schmidt-fiction-under-the-sun
@24: It takes so much fuel to jump, though, that they effectively need to end at stars unless you’re willing to put up with setting up Von Braun-style fuel depot infrastructures.
Another possible reason: they’re refugees, here in hiding. cf the People stories of Zenna Henderson, or Pangborn’s A Mirror for Observers. They could be hiding because we’re monsters, or because they have ethical objections to interfering.
My theory is that civilizations have a sweet spot, a level of advancement beyond which you hit diminishing and then negative returns. That sweet spot may be well before the attainment of interstellar travel or communication.
We may have already passed it ourselves.
So no civilizations ever actually get that far, no point.
My other favorite theory is that intelligent species are so fundamentally quirky and particular to a given environment that nobody can comprehend the aliens that are out there. What’s the point in tryna strike up a convo with “glittering facet”?
For folks that feel there is no acceptable evidence for the presence of extra-terrestrial activity on past or present Earth, their criteria for face to face hand-shakes is too anthropocentric and excludes all of the trace, anecdotal, and historical evidence amassed by researchers throughout the centuries. As to why the explorer/visitors would elect to remain aloof from direct contact with Homo Sapiens, one need only quote Mr. Bowie’s alter ego, Ziggy Stardust. “They’d like to come to meet us but they’re afraid they’d blow our minds”. Which, according to many experiencers and the analysts that have interviewed them is exactly what happens when human beings are confronted with circumstances and events beyond our, admittedly, prosaic perspectives on what is and what could never be. Still, my favored explanation is due to existing agreements between the ET’s and the powers that be, that allow for unhindered use of the populace in exchange for anonymity and a few of the less dangerous bits and pieces of advanced technology given to the child-men that run things to play with.
@38: Yes, that’s a good story.
28) IIRC, the 1st Imperium had been a going concern for 5,000 years at that point? Only a deep, deep conservatism can manage to keep something going that long.
In fact, given that Earth was just two jumps away from the border, its likely that they’re were a few illegal exploration or mining expeditions. Information might have even filtered back to the central bureaucracy on Core. “Oh there’s a garden planet out beyond the borders? And the humans there have invented gunpowder? Eh, it’s five years travel away. We’ll check back in a thousand years to see if they’ve gone anywhere with that.” Cue a thousand years later and Terran starships show up…
@6,
We’ve found trace fossils of animal burrows, so I think we’d notice the remnants of a deep mine or even a strip mine.
@41: I do not think “evidence” means what you think it means.
Can we treat the Berserker hypothesis as a subset of your “Have not .. yet” group? Cause, sadly, that’s where my money is…
“Humans are icky” is kind of covered by Douglas Adams in Life, The Universe & Everything; everyone ignores Earth due to the lack of taste & respect shown by the inhabitants – of all the races in the Universe, only the English could take the most horrific war the galaxy has ever known and turn it into a dull game (i.e. cricket)
They don’t know we are here.
Marconi first used radio in 1895. So those waves have traveled (and are now highly attenuated) only 126 light-years. Just as we can draw inferences about the characteristics of exoplanets from observations, so perhaps might “they”, and they might know from chemical signatures there’s life here — but not till they get a radio broadcast will they know there’s intelligent life. If the closest “they” is, say, 10,000 light-years off, it’ll be a long time before they go, “Hey, wow, there’s something there on [whatever they call Earth].”
They came, quite some time back.
They smelled us, back before soap.
They left, leaving warning signs “Do Not Visit – Unbelievable Stench~!!~” all around our little solar system. Until we find and disable those warning messages, we won’t have any drop by company.
Reading threads like this always makes me more sympathetic to the “No intelligent life down here” meme. But I’m getting more and more uneasy about the use of the word “alien.” I recently read an early Robert Silverberg novel set in a framework of interstellar trade and espionage, and I was struck by the way that earthmen strutting around on other planets referred to the inhabitants as “aliens.” Uh, the earthmen were the aliens.
“Natives” might work, but it’s polluted by centuries of racism. Another possibility would be to use whatever name they have for themselves, but I’m betting it would translate as “human beings” or “people.” We need a better word, something shorter than the more accurate “extraterrestial.” Maybe it doesn’t matter, since we’re not likely ever to encounter people from other planets, let alone other star systems, but why not be prepared, just in case?
39: A Mirror for Observers is an awful, hateful book, though. I’m not sure “refugees” is the right word for the Salvayans, either.
Re: Douglas Adams…I don’t necessarily believe that humans are “icky”; I just wownder why would an alien species able to cross interstellar (at least) distances in a reasonable (to us) amount of time want to interact with us, a barely sentient species in a backwater in one of the spiral arms of the galaxy? Other than anthropological interest, it seems we would be kind of boring to such a civilization.
Maybe aliens have indeed visited us, have certified us as (somewhat) intelligent, but just find us incredibly tedious, much like that person you meet at a party who wants to spend 2 hours telling you about his collection of Civil War commemorative cutlery.
Maybe aliens don’t visit us for the same reason outsiders are not allowed to make contact with the North Sentinel Islanders.
I remain most fond of Liu Cixin’s “dark forest” explanation, despite it still creeping me out.
If aliens have ben monitoring 2020 TV in real time, they probably said :Nope, let’s get out of here before we are contaminated”.
My view is closest to what you label Stagnation but which I would call Satiation.
To visit us aliens would have to be technologically advanced enough to develop an FTL ship. Any aliens who could do that would be advanced enough to develop a means generate effectively unlimited energy (solar or fusion), matter transformation with that energy, and a Ringworld which would provide for all their needs. Why go elsewhere?
If we are visited it would be most likely be by alien robotic FTL probes and those might be designed to avoid contact (ala the Zoo hypothesis).
David Brin’s The Crystal Spheres has a very cool explanation. Not a *likely* one, but cool nonetheless.
The problem with the “zoo” or “avoiding us” explanations in general is they run into the problem of the time scale of life on Earth. As in, of the 3.8 billion years of life on Earth, 74% of it was comprised solely of single celled organisms. Only 5.3% of that time involved land animals, and modern humans l take up only 1/2 of 1% of that time. So any “they’re avoiding us” explanation, unless it means “They avoid any star system that has even bacterial life”, has a massively anthropocentric bias.
And then they’re the problem where assuming a unified “they” to begin with makes huge assumptions, about all aliens. All it takes is one alien race to decide that they want to colonize this Permian era Earth, for the zoo hypothesis to fail.
Terrell @40: The idea that planetary civilizations have to be extremely lucky to survive its internal crises to the point where they can perform significant interstellar exploration/expansion was dubbed “the Great Filter” by Robin Hanson.
A number of people* have suggested that social media is the great filter. I find this disturbingly plausible.
(*This observation has been credited to Elon Musk, but as with literally everything around Musk, he didn’t actually come up with the idea but takes credit anyway.)
Best answer I’ve hear is in Peter Mulvaney’s “Vlad the Astrophysicist”: https://www.youtube.com/watch?v=o9kbcGfX35M
Long story short: Civilizations are so short-lived, and distances/travel times so great, that civilizations effectively never overlap (at sublight speeds)
As in the old Firesign Theater bit: “You can’t get theah from heah.” (I’m showing my age.) I’m a strict constructionist when it comes to special relativity. Forget velocity. That’s a side effect. Any journey that you make faster than light could have made on its own recognizance is time travel (Charles Stross & Alasdair Reynolds have both used this as plot points). Worm hole, Alcubierre warp drive, whatever – you are doing time travel. If time travel is possible, POOF, there go cause and effect. Without cause and effect the universe would not function as we perceive it to. So, no faster than light journeys. Kim Stanley Robinson’s Aurora put paid to the idea that a generation starship would work.
And then there’s the number of technological civilizations. Everyone looks at civilizational self-destruction as being the great filter, when it might be a lot closer to the start of things. When I run the Drake equation (and I am compelled to state that I am not fond of Bayesian statistics), I insert an extra term for prokaryotic life making the jump to eukaryotic life, which would seem to be a requirement for a technological civilization. And my estimated probability for that is pretty low. It seems to have happened once on Earth in 4 billion years of evolution. Life evolving from amino acids is easy, if you’re satisfied with getting monocellular life without structure and that can’t be used as a building block. But if you want something that can build a socket wrench, it has to take that next step. So, I posit far fewer technological civilizations in the galaxy, which would suggest that they are farther apart, and consequently harder to sell GameStop stock to.
If tempted to imbue evolution with a purpose and posit that the evolution of multicellular life “has to happen”, evolution scientists don’t think of it that way any more. All of those old classroom posters showing increasingly large hominids culminating in wonderful us have turned out to be wrong. Punctuated Equilibrium (Stephen Jay Gould et al) shows the fallacy in that.
I wonder if you can spot the problem in this sentence, where the hubris of humanity lies, and why it does not preclude all the things you think it does? Where the error is made in your reasoning? Can you see it, can you perceive it?
@61: or perhaps your less-than-age? If Firesign said that, they got it from “Bert and I”, which used it a decade or more before.
Think about it, would you come way out to the Orion Arm to visit us?
@64 A year ago, a lot of people were saying that China was a long way away, how could a virus come all that way to visit us?
Self-reproduction is a wonderful thing, if you are interested in colonisation. And unless the expansion rate of the colonised volume was significantly less than light speed, we would never see it coming.
We would not be here to wonder about aliens, if we had not been far enough away to not be colonised yet.
@65,
Knowledgeable people, a group that includes epidemiologists, biologists, and even historians who have studied epidemics are quite aware that China’s not all that far away. Even the Venetians, before the Renaissance, were quite aware that disease travels with people.
I’m going with the Joe roan theory of ancient civilizations-the smart ones died out and got replaced with all the normal dumber ones who didn’t know how anything worked.
Sadly it’s beginning to look more and more likely we are alone. Or at best anybody out there would be so different as to preclude meaningful contact or maybe even recognition. First off it seems our solar system is far from the norm. Secondly Earth may not be the bog average planet it was presumed to be and finally that life might be the exception not the rule.
All very depressing, I hope it’s not true.
@66: And there was communication across the Pacific, not just along the Silk Road; very recent news reports the discovery of Venetian glass beads in Alaska, with remains of a cord that dated them to (IIRC) 7th century CE. ISTM that the people who thought China was far away weren’t exactly thinking — or weren’t aware that the annual flu vaccine (which takes many months to cultivate) is based on strains active at the time in Asia, on the grounds that those strains will be in the rest of the world in a year or less.
But (dreaming aside) we have no indication that getting between stars would be anywhere near as easy as getting between Venice and China a millennium ago; it’s possible that there’s just no way for anyone out there to get here.
I’ll pass along some ideas (which overlap with others), the universe is large and has been around a long time, the entirety of human civilization (not that we really have such a thing yet) is a mere blip in time:
– We’ve had radio signals and airplanes for 120 years, liquid fuel rockets for 90, masers/lasers for 60. Why do we assume any more advanced civilizations would be looking for or still using technology we can recognize now?
– Why do we assume that we would necessarily recognize an alien life form as either alive or intelligent, even if we were looking directly at it, or vice-versa?
@62. No. Because there are none. Cause and effect existed before man was around to observe them, and they will exist long after we are gone. It has nothing to do with the human PoV. Other than at the quantum level (and people err greatly when they project quantum phenomena onto larger scales where they are not appropriate), everything in the universe is based around cause and effect. The laws of physics are the same everywhere. One of my (admittedly minor) quibbles about The Expanse is that there is no advanced tech that can do away with conservation of momentum. There just isn’t. It’s a law that is hard wired into existence.
We can safely say that if there is spacefaring life, either it is not solar powered, or there are universally limiting factors to its growth other than available sunlight, the way that deserts aren’t covered in plants because there’s not enough water.
One way of rephrasing the Fermi Paradox is “will we ever meet aliens?” If interstellar travel is possible then (a) they could be here already, or have prevented our evolving and (b) even if we’re in a preserve, you’d expect a wide and observable spread through the galaxy, because life does that.
If interstellar travel is not possible then there could be many alien civilizations but we’ll never meet them.
I would bring up another David Brin concept, from the Uplift series. We are a failed experiment. A species that was brought to self-awareness, with results that the “Uplifters” didn’t like. So instead of taking responsibility to educate us and bring us into the galactic fold, they left us on our own. This is a huge crime as our uplifting wasn’t approved, and abandonment afterwards is even worse. Much later, we appear on the Galactic radar causing all sorts of issues being a “Wolfing” race. The “sin” is further enhanced when we have done our own “uplifting”.
An interesting read.
Posit an alien species that is really intelligent. As much smarter than we are, as we are smarter than goldfish. “Those Earth guys? They can’t even solve the Relativity Fallacy. How dumb can anyone get? Let them chip flint for their atomic reactors. Or whatever it is they do. Why should I bother with them? I’d rather go someplace interesting.”
@73: Humans being an orphaned uplift is what the Galactics assume because the alternative is unimaginable. I’m fairly sure we’re meant by Brin to have evolved naturally, Earth having somehow been left fallow for a long time.