[HN Gopher] 'Oumuamua: An analysis of the debate regarding the f...
       ___________________________________________________________________
        
       'Oumuamua: An analysis of the debate regarding the first
       interstellar visitor
        
       Author : Breadmaker
       Score  : 73 points
       Date   : 2023-01-11 19:55 UTC (3 hours ago)
        
 (HTM) web link (uu.diva-portal.org)
 (TXT) w3m dump (uu.diva-portal.org)
        
       | czbond wrote:
       | One of the author's conclusions to "find out more" (my
       | paraphrase) suggest a rocket using a gravity well to go after it.
       | 
       | Are there any options for using a Voyager 1/2 or radio based
       | telescopes to observe it? (I'm a CompScience guy - not an
       | Astrophysicist so that's my best way to describe my question)
        
         | mhh__ wrote:
         | Voyager 1/2 are both basically EOL at this point so I think at
         | best you could _maybe_ turn the instruments back on for one
         | last hurrah but they 're an awfully long way away from Kansas
         | now so even a suicide mission of sorts could overwhelm them.
        
           | tablespoon wrote:
           | > Voyager 1/2 are both basically EOL at this point so I think
           | at best you could maybe turn the instruments back on for one
           | last hurrah but they're an awfully long way away from Kansas
           | now so even a suicide mission of sorts could overwhelm them.
           | 
           | I don't even have to look it up to be 100% sure that Voyager
           | 1/2 are in the wrong place, going in the wrong direction,
           | with the wrong instruments to observe Oumuamua. Their
           | batteries are also nearly dead and they never had enough
           | propellant to go anywhere except approximately where they're
           | going now. The best they could ever do is make small
           | corrections to slingshot off something else, and there's
           | nothing to slingshot off of anymore. Also, I think they're
           | almost out of propellant, too.
        
         | readonlybarbie wrote:
         | [dead]
        
       | jacobsenscott wrote:
       | Clearly we need to launch Bezos, Musk, and Branson toward this
       | object so they can inspect it for us and radio back what it is.
        
       | whycome wrote:
       | Is the mark "first interstellar visitor" universally agreed upon
       | (as far as we know)? That alone is kinda cool.
        
         | Rastonbury wrote:
         | I believe so, so far we only know of two
        
           | edfletcher_t137 wrote:
           | Apparently (TIL!) it's three now, with a meteor that burned
           | up in 2014 having been confirmed in just April 2022 as
           | interstellar! https://en.wikipedia.org/wiki/CNEOS_2014-01-08
           | 
           | And who was part of the team that first reported its
           | existence? "CNEOS 2014-01-08 is an interstellar object
           | reported in June 2019 by astronomers Amir Siraj and Abraham
           | Loeb"
        
         | pengaru wrote:
         | Not only is it kinda cool, it's also why it's particularly
         | annoying we didn't get better data while it was near enough to
         | do so. We missed what _may_ have been quite an exceptional
         | opportunity.
        
           | rwmj wrote:
           | Probably. But also it was detected within the first 10 years
           | of operation of the Pan STARRS 1 telescope so perhaps similar
           | things should be expected every decade or so?
        
         | chongli wrote:
         | First confirmed interstellar visitor. Who knows how much
         | interstellar dust and other small stuff we've run into over the
         | eons.
        
           | di456 wrote:
           | Pretty much every element from lithium and up came from
           | another star's death. The fusion reaction of a star goes from
           | H -> He -> and on up the periodic table until the star
           | implodes and/or goes supernova, creating gold and other
           | heavier elements.
           | 
           | Most of the matter on our current planet has interstellar
           | origins, including humans. We are all made of star dust!
        
       | 1970-01-01 wrote:
       | Consider the statistics of it being an alien probe. Now consider
       | the statistics of it being a rock. It's a rock.
        
         | david927 wrote:
         | What is that called? Occam's Blindfold?
         | 
         | We don't know it's a rock. We don't really know what it is,
         | other than it's the first _thing_ we 've picked up from an
         | interstellar trajectory, is bizarrely shaped, didn't reflect
         | the pull from the sun, swung by the Earth and then accelerated
         | away.
        
         | daveslash wrote:
         | Stand back, this guy/gal's using Occam's Razor! They'll cut
         | you!
        
       | aaron695 wrote:
       | [dead]
        
       | IAmGraydon wrote:
       | If Oumaumau is in fact of extraterrestrial origin, it could be
       | the only evidence of life outside of earth that will ever pass
       | through our solar system. We'll never know.
        
         | distortionfield wrote:
         | Let's slingshot a probe to it and find out! I'm only half-
         | kidding. I think it would be super worthwhile to do, though.
         | Especially to attempt to solve the mystery of why it sped up by
         | 17 m/s for no visible reason.
        
       | andrewstuart wrote:
       | I believe in aliens from a statistical standpoint.
       | 
       | But I don't believe in interstellar travel at all. I don't think
       | people grasp the distances between stars. The longest distance a
       | human has traveled through space is to the moon. If, for scale,
       | this was about 2 millimeters, then the nearest star would be
       | another 200 kilometers/124 miles away. Here's a great video to
       | illustrate https://www.youtube.com/watch?v=dCSIXLIzhzk
       | 
       | IMO Oumuamua was a rock.
       | 
       | However, it's fun to think about it being alien, and it's
       | remarkably similar to Arthur Clarke's Rama story.
       | 
       | Presumably the speed and trajectory of Oumuamua is known? Has
       | this been traced back to give a potential origin if it is fro
       | another star system?
       | 
       | "Two of NASA's space telescopes (Hubble and Spitzer) tracked the
       | object traveling about 85,700 miles per hour (38.3 kilometers per
       | second) relative to the Sun. Its outbound path is about 20
       | degrees above the plane of planets that orbit the Sun."
       | https://solarsystem.nasa.gov/asteroids-comets-and-meteors/co...
       | 
       | If the distance to the nearest star is 40,208,000,000,000 then:
       | 
       | 40,208,000,000,000 / 38 (km per second) / 3600 seconds per hour /
       | 24 hours per day 365 days per year = 33552 years if it had come
       | from closest star
       | 
       | Do I have those numbers right? Maths isn't a strength.
        
         | s1artibartfast wrote:
         | I dont get why people get hung up on distance. It only takes
         | time to traverse and it isn't exactly in short supply. Whats
         | the rush?
        
           | andrewstuart wrote:
           | It's a good point.
           | 
           | Humans have existed for about 300,000 years.
           | 
           | Sharks have existed for about 450 million years.
           | 
           | I suppose its possible that humans could exist for hundreds
           | of millions of years? If so then several hundred thousand
           | years robot probe missions might make sense.
        
         | gfodor wrote:
         | An interstellar object created by aliens arriving here doesn't
         | imply interstellar travel, if you meant that to mean "manned
         | craft."
        
         | zeitgeistcowboy wrote:
         | One of the arguments for Oumuamua being more than just a "rock"
         | was it's detected dimension. If I recall correctly, it was very
         | long and skinny and thus not very rock-like in a traditional
         | sense. I think Avi Loeb put forth the idea that structurally an
         | object like this could be a a piece of space junk. Maybe a
         | piece of a space ship that would be able to be held together
         | while spinning even with a long and skinny dimension. You'd
         | imagine less stable pieces of rock to collapse into themselves
         | and become more sphere like. Oumuamua was potentially a long
         | skinny object that had been spinning around through the
         | universe for a very long time.
        
         | detritus wrote:
         | Yeah, for me this is the sad reality of getting older and
         | replacing somewhat essentially sci-fi fantasies of progression
         | with bleak, mundane reality.
         | 
         | Space is really big. Really, really big.
        
           | coldpie wrote:
           | The impossibility of interstellar travel is perhaps the only
           | fact that I find so depressing that I simply refuse to
           | believe it. The universe is just so much more _interesting_
           | if FTL is possible. It helps that being wrong about this fact
           | doesn 't really impact one's life either way.
        
             | api wrote:
             | Okay, then I'll cheer you up just a bit: interstellar
             | travel is quite possible. In fact it's easy... if you can
             | cold hibernate.
             | 
             | It would be very easy for an AI that could simply turn
             | itself off for tens of thousands of years. It might be a
             | do-able for an alien biological entity with a different
             | biology that finds it easier to survive cryogenic deep
             | freeze, something like a big smart tardigrade.
             | 
             | Managing sleep and wake is pretty easy too. No internal
             | timing mechanisms needed. Just let your proximity to a star
             | do it for you. When you leave the vicinity of a star you
             | have no energy and you go night-night. Your temperature
             | will fall down to as low as a few kelvin. This basically
             | stops time in terms of any chemical degradation, though the
             | most sensitive bits will need to be wrapped in radiation
             | shielding against cosmic rays to prevent cumulative damage
             | over the aeons. When you approach another star the
             | temperature starts to go up and solar power will power
             | everything up.
             | 
             | Interstellar travel is only hard for us because we have
             | short life spans and can't survive being frozen. Unless we
             | can figure out how to successfully freeze a human down to
             | liquid helium temperatures and then revive them it's
             | unlikely that humans will ever leave the solar system.
             | 
             | The AIs we build might though. This would include
             | "uploaded" minds if we ever figure out how to do that.
             | 
             | If anything ever does visit us my money would be on it
             | being an AI.
             | 
             | If you find humans being stuck in the solar system
             | depressing, consider that the solar system is absolutely
             | gigantic and we could explore and settle it for aeons and
             | aeons without getting close to exhausting that frontier.
        
           | daveslash wrote:
           | _You just won 't believe how vastly, hugely, mind-bogglingly
           | big it is. I mean, you may think it's a long way down the
           | road to the chemist's, but that's just peanuts to space._ ~
           | Douglas Adams
        
         | sien wrote:
         | Have you had a look at Project Daedalus ?
         | 
         | https://en.wikipedia.org/wiki/Project_Daedalus
         | 
         | Or Project Orion :
         | 
         | https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
         | 
         | and the excellent book on Project Orion
         | 
         | https://www.amazon.com/Project-Orion-Story-Atomic-Spaceship/...
        
         | jiggawatts wrote:
         | A nice visualisation I like to use is this: if the orbit of the
         | Earth was scaled down to the size of a coin, then the average
         | distance between stars is about a mile.
         | 
         | EDIT: Corrected the maths.
        
           | postalrat wrote:
           | And yet we pretty much have the technology right now to send
           | a probe to Alpha Centauri. The Parker Solar Probe would make
           | it there in about 8000 years. We could probably make a probe
           | that makes it there in much less time if we wanted (by taking
           | much longer to accelerate and de-accelerate). Then it just
           | needs to survive a few thousand years dormant.
        
         | [deleted]
        
         | haskellandchill wrote:
         | Interstellar travel would be possible if we learn how to
         | manipulate consciousness and then transport consciousness as
         | data using light. The first part may be accomplished without
         | continuity for the original but as a seamless experience for
         | the copy.
        
       | david927 wrote:
       | This is an interesting paper and Oumuamua will remain fascinating
       | for a long time.
       | 
       | Maybe the answer to the Fermi Paradox (or 'Where the hell are
       | they?') is that they're around and doing interstellar drive-bys
       | and we're just starting to notice.
        
         | idiotsecant wrote:
         | I think the most convincing answer to Fermi is the dark forest
         | theory. The reason no one speaks up is that there is good
         | incentive not to - you get to survive as a species if you stay
         | small and quiet.
        
           | vecter wrote:
           | The Dark Forest is a fun idea but sounds so clearly illogical
           | to me for so many reasons:
           | 
           | 1. The cost of interstellar travel is so obscenely high that
           | the threat posed by the discovery of an alien species on
           | their home planet would be so miniscule to us and them
           | 
           | 2. The cost of remotely annihilating an entire species is so
           | absurdly high as to be obviously impractical and basically
           | impossible.
           | 
           | [Spoiler alert] The Dark Forest by Liu Cixin renders all of
           | this irrelevant by the use of science _fiction_ : it purports
           | the existence of interstellar world-destroying weapons that
           | any lowly member of a species can casually "flick" at a "star
           | plucker" to obliterate them. That is not how physics or
           | reality works.
           | 
           | We don't even send our trash to space because just getting it
           | out of Earth's orbit is so ridiculously expensive, yet we're
           | thinking about sending enough explosives to destroy an entire
           | civilization some 100+ light-years away?
        
             | oblak wrote:
             | I guess enough time has passed since major Carter blew up a
             | sun, since people are no longer talking about it
        
             | rcoveson wrote:
             | Are you arguing that advances in science that would look
             | like impossible magic to us today are confined to fiction
             | forever? Why do you believe that (1) and (2) are true at
             | every stage of technological advancement in our distant
             | future, which may be the technological present of our
             | galactic peers?
             | 
             | A handful of people today can casually "flick" entire
             | cities out of existence, and enough such flicks could
             | eradicate our species, and even if not it would certainly
             | eradicate many. That would have been an absurd notion to
             | somebody a thousand years ago. But the idea that we'll be
             | able to destroy stars just as easily in a million years is
             | somehow just fiction?
        
               | vecter wrote:
               | No, I am simply arguing that FTL travel is extremely
               | unlikely since whatever physics we discover in the future
               | will almost certainly not overturn special relativity.
               | 
               | This thinking along the lines of "things in the past that
               | were believed to be impossible are now possible,
               | therefore things in the future that we now believe
               | impossible may actually happen" is pretty poor reasoning.
               | In the past, our understanding of the fundamental laws of
               | physics was quite lacking. Today, although it is
               | incomplete, our understanding of physics is considerably
               | more advanced to preclude a lot of physically impossible
               | things.
        
             | sophacles wrote:
             | Interesting that you assume physics and engineering are
             | "done" and that there are no unknowns, and that there are
             | no new inventions that will happen moving forward. I don't
             | know any physicists or engineers who believe any such
             | thing.
             | 
             | 500 years ago your argument would have been: We cant even
             | get to china in 12 weeks without considerable danger and
             | expense, and you expect me to believe its routine for
             | peasants to do so in 12 hours? That anyone can make a near
             | perfect painting and send it to anyone else no matter where
             | they are in a heartbeat - we don't even make bad paintings
             | of anyone who isn't extremely rich because of the absurd
             | expense of it.
        
               | vecter wrote:
               | I did not assume that "physics and engineering are
               | 'done'". I assume instead that the known laws of physics
               | which seem to prevent faster-than-light travel hold and
               | are inviolable, despite how smart any species may be.
               | 
               | The analogy with the the argument 500 years ago doesn't
               | apply because 500 years ago we did not have the
               | understanding of physics and chemistry that we have
               | today. Of course we still have a lot of physics left to
               | discover, but it's extremely unlikely that whatever new
               | physics we discover will violate special relativity.
        
               | postalrat wrote:
               | You don't need faster than light travel to cover the
               | entire galaxy. Using it as a roadblock doesn't make
               | sense.
        
               | vecter wrote:
               | It does when traveling interstellar distances. Even
               | traveling at 10% the speed of light, it would take a ship
               | one million years to cross the galaxy. The energy
               | required to accelerate to that speed (and then decelerate
               | to rest) is absurdly high. Once you realize how large the
               | costs become for interstellar travel, simple economics
               | makes most of these arguments moot. The outcome is not
               | worth the cost for almost anything you want to achieve.
        
             | unsupp0rted wrote:
             | > the threat posed by the discovery of an alien species on
             | their home planet would be so miniscule
             | 
             | That species, left unchecked, could fill up its galaxy in
             | the blink of an eye, by galactic timescales.
        
             | ericb wrote:
             | We've already been sent the world destroying bomb. It is an
             | information bomb built on tragedy of the commons to ensure
             | we overheat our planet before we become interplanetary. Its
             | name is Bitcoin.
        
           | pklausler wrote:
           | The most convincing answer to Fermi's paradox is that since
           | the galaxy is not saturated with Bracewell - von Neumann
           | self-replicating slow interstellar probes, no civilization
           | has yet launched one, and thus there has not yet been a
           | civilization in our galaxy capable of launching one.
           | 
           | The launch of a working BvN probe is basically a permanent
           | phase change for a galaxy.
        
           | jjallen wrote:
           | Except we are already violating this by sending things out
           | into interstellar space.
        
             | coredog64 wrote:
             | Not just "some things": Nudes, a mix tape, and directions
             | back to our house.
        
               | [deleted]
        
             | catskul2 wrote:
             | If you haven't already, read "the 3-body problem".
        
             | SketchySeaBeast wrote:
             | Yeah, seems to me there'd be a bit of time in there before
             | any civilizations decided it was better to stay silent. But
             | that time might not be astronomically relevant.
        
         | newZWhoDis wrote:
         | My pet theory is they're using gravity waves for coms and we're
         | the dumb apes still looking around in the electromagnetic
         | spectrum.
         | 
         | Once we can reliably detect and generate gravity waves much of
         | our knowledge of electromagnetic waves can apply. 802.11gr
         | anyone?
        
           | thriftwy wrote:
           | Gravity is so many orders of magnitude weaker than
           | electromagnetism that it is not even funny.
        
             | buildbot wrote:
             | True, but you can theoretically format a gravity wave to
             | not follow the inverse square law - these are called
             | solitons (apparently, I just looked this up)
        
               | jerf wrote:
               | Yes.
               | 
               | Now look into how you construct a soliton, and try to
               | figure out what monstrous levels of control you'd have to
               | exert over solar-system sized quantities of degenerate
               | matter to create them, and how much energy it would take.
               | 
               | Now compute how much laser light you can generate for,
               | oh, let's say, 6 orders of magnitude less energy. And how
               | tightly you'd expect a civilization that apparently can
               | casually wiggle dozens of solar masses at multiple Hz, in
               | a modulated manner no less (so just a several Hz orbit is
               | not sufficent, we are wiggling these things under power),
               | to be able to collimate such a beam.
               | 
               | This is the problem with gravity waves. It isn't some
               | sort of supreme cheat code of the universe for super
               | awesome communication. It's transparently obviously
               | idiotic. Like, not just, "well, it's not necessarily the
               | best way, but even if it's not great someone may have
               | tried it", like, you're burning _dozens_ of orders of
               | magnitude more energy per bit. Plural dozens, of _orders
               | of magnitude_. Not dozens of times, _ten to the power of_
               | dozens. This is not sensible no matter how advanced the
               | civilization. We 're talking levels of stupid that would
               | _greatly_ exceed spending the entire output of Earth 's
               | collective industrial civilization for all of history on
               | a single pack of Skittles. This is not a bright thing to
               | do, and it only gets dumber the smarter you suppose the
               | aliens are.
        
               | marginalia_nu wrote:
               | To be fair, because we don't know how to construct
               | gravity waves does not mean such a means does not exist.
               | 
               | Keep in mind, not too long ago we thought we needed to
               | heat up a fillament surrounded by an inert gas in order
               | to make artificial light, and our understanding of
               | gravity is fairly poor (to the point where it's largely
               | considered an unsolved problem quite how it fits together
               | with other parts of physics).
        
               | SketchySeaBeast wrote:
               | If we make assumptions like that then the sky is the
               | limit for other baseless assumptions, right? We're
               | basically just picking our favourite pseudomagical
               | science and arguing for it?
        
               | marginalia_nu wrote:
               | Well that is the basic posture of all science,
               | uncertainty. We must assume we don't know until we are
               | convinced otherwise.
        
               | SketchySeaBeast wrote:
               | But you don't use that to suggest new unsupported ideas.
               | In that case why can't I postulate for FTL communication
               | by form of anti protons to be the best communication
               | method?
        
               | marginalia_nu wrote:
               | I've never talked about FTL communication.
        
               | SketchySeaBeast wrote:
               | I didn't say you were. I was trying to make the point
               | we're both suggesting science fiction now and it's not
               | terribly helpful when trying to talk about the current
               | science.
        
               | jerf wrote:
               | I believe it is important to separate flights of fancy
               | from things grounded in real science, no matter how
               | speculative.
               | 
               | I can't _prove_ that I can 't generate gravity waves by
               | the proper chanting of a spell. I'm serious, not just
               | being silly. The simulation hypothesis certainly admits
               | of such things being built into an otherwise sensible
               | simulation (at the risk of a bit of a spoiler,
               | https://qntm.org/ra ). If you want to talk about what
               | could be if we bend what we understand this way, by all
               | means, be my guest. I'm a big fan, actually.
               | 
               | However, I think we should be _clear_ that we are doing
               | that, and specify the rule changes we 're considering.
               | 
               | In the real universe, we do "know" how to generate
               | gravity waves. We can't _do_ it at any sensible scale,
               | but we know how. The energy computations are trivial
               | extensions of Einsteinian relativity, suitable for
               | assigning an undergraduate for homework.
               | 
               | Besides, the way of making gravity waves has to not just
               | be like three or four times better than wiggling a
               | neutron star, to beat light, it needs to be the
               | aforementioned dozens of orders of magnitude better. Just
               | like lasers, you'd be looking at the thing being a great
               | weapon rather than just a communication mechanism. It's
               | actually a lot of orders of magnitude improvement
               | necessary. A fire on the end of a stick versus the
               | brightest modern stadium lights don't even begin to cover
               | the magnitude range.
               | 
               | People keep acting like light is some sort of terrible
               | communication mechanism that we need to somehow level up
               | from. The reality is that the only improvement you could
               | practically ask of it is to go faster. It is otherwise
               | _unbelievably_ good at communication. It is hard to even
               | conceive of what could be better in anything like our
               | real universe.
        
             | all2 wrote:
             | Yes, but does it propagate faster than the speed of light?
             | Even if a gravitic field is weak, it would be my preferred
             | mode of communication if it propagated "instantly" across
             | space/time. And it moves at the speed of light [0] so
             | there's no speed advantage here.
             | 
             | I see no reason a sufficiently advanced species would
             | choose gravitic waves over any other EM wave. Does someone
             | with a clue (not me) have any ideas why this would be the
             | case?
             | 
             | [0] https://en.wikipedia.org/wiki/Speed_of_gravity
        
               | jerf wrote:
               | It does not. The concrete evidence of this is relatively
               | recent; theoretically nobody has expected that it would
               | for a long time, but it has been theory.
               | 
               | But yes, we've coordinated detections between LIGO and
               | radar astronomy now, and there's no reason to believe
               | gravity travels FTL. As always, there are error bars, but
               | they're tight enough not to get excited about. That is,
               | who cares if gravity travels at 1.00000000000001 the
               | speed of light? (The theoreticians would go absolutely
               | _ballistic_ , but pragmatically that would mean nothing.)
        
             | raverbashing wrote:
             | This is the answer
             | 
             | Something like a neutrino bean sounds more plausible as a
             | communication medium than gravitational waves
        
           | jjtheblunt wrote:
           | we generate gravity waves every time we move something with
           | nonzero mass, don't we?
        
           | JohnBooty wrote:
           | What would be the advantage of that?
        
             | Reason077 wrote:
             | Unlike radio waves or light, gravity waves aren't impeded
             | by obstacles like stars, planets, interstellar dust, or
             | anything else that might be out there. Nothing could block
             | or jam them and you'd always have a clear signal.
        
               | vecter wrote:
               | It takes so much energy to create gravity waves and so
               | much effort to detect them that it's silly to try to use
               | them as a medium of communication.
        
               | lowbloodsugar wrote:
               | *For Kardashev Type 1 civilizations like us. (And we're
               | only 0.74 not even 1)
        
           | landswipe wrote:
           | It'll be more likely something subatomic, like they're chain
           | entangling photons, we just don't know how to interpret it
           | yet.
        
           | whycome wrote:
           | They keep ringing our sun and we never even respond! And now
           | they're just annoyed with us and won't respond when we
           | eventually call back.
        
         | distortionfield wrote:
         | I firmly believe that the chance humans have been visited by
         | aliens is (admittedly) slim but _not non-zero_. I would say the
         | chance has a few leading zeros of precision, and I understand
         | that the universe is _huge_, but by the same logic, the
         | universe is _huge_.
        
           | Teever wrote:
           | What does 'visit' mean to you?
           | 
           | While I find it unlikely that aliens have travelled to our
           | solar system specifically to visit humans, I find it
           | incredibly unlikely that human activity have not been
           | detected by a Sentinel probe and that this probe has not
           | relayed this info to its creators.
        
             | [deleted]
        
             | distortionfield wrote:
             | "Visit" to me means either they entered or observed our
             | solar system with some decent degree of resolution. Enough
             | to get a baseline of information about us, I think.
        
         | basch wrote:
         | Or they exist at a completely different scale than us. Their
         | neurons are the size of galaxies or they live in Whoville in a
         | snowflake.
        
           | jerf wrote:
           | Neurons the size of galaxies, even if one stipulates them
           | magically coming into existence as early as possible,
           | couldn't have hardly thought "hello" to themselves since the
           | universe began. In the meantime, on that time scale,
           | _incredible_ violence has occurred througout the universe.
           | Round trip times of millions of years for the simplest
           | communications are not feasible in this era of spacetime. You
           | 'll need to be waiting many tens or hundreds more billions of
           | years before that is conceivable, in the long quiet dark
           | before heat death.
           | 
           | The snowflake hypothesis is at least in the range of the
           | "things we can't disprove", at least if by "snowflake" you
           | mean neutron star surfaces:
           | https://en.wikipedia.org/wiki/Dragon%27s_Egg Of course, one
           | must consider that I'm citing a science fiction book, with
           | all understanding of what that means. But that is at least
           | one hypothesis I don't think we can disprove at the current
           | time, unlike most other ideas put forth. I'd still call it an
           | absolute long shot, and an even longer shot that such beings
           | could leave their star.
        
           | TheOtherHobbes wrote:
           | I'm fascinated by the idea that the same creatures can live
           | in the same universe and have very different experiences of
           | it. Ants, cats, and humans are all going to perceive the same
           | objects in very different ways. And only humans can
           | understand what human-specific objects are for.
           | 
           | A cat will see a book as a flat surface which probably smells
           | of its owner and go to sleep on it. It has no other concept
           | of "book." And if it sees an open book it can't see the
           | contents as writing, because it has no concept of writing.
           | 
           | The fascinating part is that a human will _see the same
           | object_ but perceive it very differently because of the added
           | human-specific knowledge and cognition.
           | 
           | Unless you're going to make the very bold claim that humans
           | are the most sophisticated and advanced life in the universe,
           | our perceptions will be limited in an analogous way.
           | 
           | We see clouds of dust and gas, star systems, and random
           | background noise. An intelligence a few million years ahead
           | of us may see the same objects as [symbol] and [relationship]
           | in ways we literally can't imagine.
        
             | unsupp0rted wrote:
             | > Ants, cats, and humans are all going to perceive the same
             | objects in very different ways.
             | 
             | Probably in very similar ways, given how many ways there
             | are to perceive something.
             | 
             | Ants, cats, and humans are all carbon-based lifeforms with
             | eyes, nervous-systems, and brains.
             | 
             | Imagine how a cat perceives a bird vs. how a human
             | perceives a bird vs. how a cloud of neutrons perceives a
             | bird.
        
             | shostack wrote:
             | That's what I love about the Children of Time series. The
             | skill of the author with immersing you in that truly alien
             | perspective of different biological capabilities, sensory
             | organs, etc. is remarkable.
        
         | [deleted]
        
         | redeux wrote:
         | I worry that this is the case. The idea that we're in some
         | advanced species sphere of influence is a bit unnerving. Given
         | the ability to create deep space probes, it should be fairly
         | easy for someone to keep tabs on a large swatch of the galaxy.
         | 
         | If a species had a mere 1 million year technological lead on
         | us, they'd certainly have nothing to fear and would only need
         | to do a drive by every ten-thousand years or so, to keep tabs
         | on things.
         | 
         | Perhaps more concerning is that we could be in between two
         | competing species and they're monitoring to make sure the other
         | hasn't colonized this system.
         | 
         | When it comes to aliens there are many possibilities, and few
         | of them are good for us imo.
        
           | Reason077 wrote:
           | At least Oumuamua's light sail will only accelerate it to
           | 15-20% of the speed of light. Unless they have some kind of
           | warp drive we haven't seen yet, that should give us (at very
           | least) 20-30 years before the invasion fleet gets here.
           | Probably much longer.
        
             | yojo wrote:
             | Unless it seeded a little self-replicating factory on the
             | way by. The invasion force could already be growing
             | exponentially out in the Oort Cloud.
             | 
             | Or not. To paraphrase: sometimes a cigar-shaped
             | interstellar mass is just a cigar-shaped interstellar mass.
        
           | jjtheblunt wrote:
           | why worry that interstellar drive by visits might be real?
           | 
           | also, might you presume such possibilities are rarely good
           | for us because of implicit recognition how bad we humans are
           | to other species?
        
         | floxy wrote:
         | Dark sector. 85% of the mass of the universe. Those dark sector
         | astrophysicists have a tougher time, since their book keeping
         | is only 15% off, and everyone just thinks they aren't measuring
         | things precise enough.
        
       | terran57 wrote:
       | I firmly believe that we're not alone in the universe, but
       | advanced alien civilizations capable of interstellar travel would
       | probably look at us like we look at mold - at best, with
       | indifference and at worst, something to remove. But, it is fun to
       | imagine how our belief systems would have been shaken up if
       | scientists were able to show Oumuamua was an interstellar probe
       | ("Rendezvous with Rama" anybody?)
        
         | xmonkee wrote:
         | >but advanced alien civilizations capable of interstellar
         | travel would probably look at us like we look at mold
         | 
         | Why? An advanced civilization wouldn't have cultural curiosity?
         | They wouldn't want to study us from all the different
         | perspectives we study people and literature and philosophy and
         | even biology and neurology etc etc?
        
           | simonh wrote:
           | Bear in mind we study mould. It's some people's life's work.
        
             | Karawebnetwork wrote:
             | We even use slime mold on representations of maps to see if
             | it would have done things the same way we do. For all we
             | know, perhaps we are in a galactic petri dish and the
             | entire point of our existence is to test out the growth of
             | life for some great universal scientist! (tongue in cheek
             | comment)
             | 
             | https://www.livescience.com/8035-slime-mold-beats-humans-
             | per...
        
           | wcarss wrote:
           | The argument would maybe be more readily taken if instead of
           | mold, the GP had said "birds". We think birds are kinda neat,
           | but most people hold a perspective with inbuilt human-
           | exceptionalism, and birds are fundamentally not humans.
           | 
           | Birds may communicate complex things to each other, they may
           | construct homes, feel emotions, dream, and even do some
           | things we can't, like fly -- but they don't have Shakespeare
           | or the Primes so if it comes down to us or them, it's us. A
           | lot of humans believe only humans possess "souls".
           | 
           | To fully go into the argument: an alien species may well hold
           | their own form of self-exceptionalism, and they'll have their
           | own practices and history which we can't compete with. It is
           | perfectly possible that there is nothing we could accomplish
           | which would make us read as peers, as opposed to birds,
           | gorillas, or... mold.
           | 
           | (edit: I do think the "at best" above may be unreasonably
           | gloomy -- at best in this outlook, aliens might regard us
           | with compassionate curiosity, as some humans do toward the
           | species we share the earth with. That would be pretty lucky,
           | but not impossible!)
        
         | unsupp0rted wrote:
         | If we were an advanced alien civilization capable of
         | interstellar travel, how would we look at a planet/species like
         | 2023 Earth?
        
           | teekert wrote:
           | Something like: hmm these guys went from horseback riding to
           | cell phones, internet and a mars helicopter in the time we
           | took to travel to their star. Perhaps we should keep an eye
           | on them.
        
             | unsupp0rted wrote:
             | It's that last thing that's most concerning: "hmm, these
             | guys aren't going to be contained to their own rock for
             | long"
        
         | exitb wrote:
         | Not necessarily a probe, maybe just a piece of cosmic junk? An
         | equivalent of our rocket booster or a Tesla Roadster on its way
         | to Mars.
        
         | janef0421 wrote:
         | If 'Oumuamua is a probe, it appears that it would be a fairly
         | simple one. To a sufficiently advanced civilisation, it would
         | probably be relatively low-cost. If an alien civilisation has a
         | reasonable degree of curiosity, sending a cheap probe to
         | examine another star system is likely worthwhile.
        
         | StanislavPetrov wrote:
         | This presupposes an advanced alien civilization only sends out
         | probes to places they find interesting. I think it is just as
         | plausible that an advanced civilization would just shoot out a
         | billion probes at random to zoom through the universe
         | collecting data.
        
           | namrog84 wrote:
           | To compound this. Its not unreasonable to think said probes
           | could find appropriate asteroid belts with appropriate
           | materials(e.g. metals) mine them and replicate more and send
           | them out. Potential exponential growth of drones across the
           | galaxies.
        
         | narrator wrote:
         | I've got a better theory. Interstellar civilizations have
         | probably fought wars over habitable planets and in the
         | aftermath of those wars they probably have set up some rules
         | for a long time about what you're allowed to do on habitable
         | planets in a galactic framework. In fact, the reason this
         | planet is not strip-mined and every living thing on it dead
         | thousands of years ago is they probably have some rights in
         | there given to life that evolved on a planet.
         | 
         | Besides, E.Ts can probably do ok in deep space or underground
         | on lifeless planets if they can do interstellar travel.
        
           | pasquinelli wrote:
           | i've got a better better theory! interstellar civilizations
           | have never and will never exist.
        
             | NovaVeles wrote:
             | It is a reasonable conclusion. Resource limitations means
             | civilizations, burn up too much of their energy/materials
             | before they ever get truly space bound.
             | 
             | They could all be just like us. A few space probes manage
             | to escape the energy well but they are so small that no one
             | else ever detects them again. I mean, it is not uncommon to
             | sight life ending asteroids days after they have passed
             | earth, the odds of us detecting any sort probe/device the
             | size of a fridge - is nearly zero.
             | 
             | Best analogy I heard came from Stephen Harrod Bruhner.
             | Civilizations are just like plants. A plant is at its
             | fullest just as it is about to produce seed and die off.
             | During the peak of our energy use, we have been sending
             | probes into space. It is a neat thought experiment.
        
               | kelipso wrote:
               | All that probably but main thing is faster than light
               | travel turns out to be actually impossible.
        
         | morepork wrote:
         | If we found mould on mars or anywhere without terrestrial
         | origins it would be the subject on intense scientific curiosity
        
         | trts wrote:
         | Earth has been around for about 4.5 billion years, about 1/3rd
         | of the age of the universe. If another technological
         | civilization that is more advanced than us by even 1M years is
         | watching earth, and suddenly this planet starts spitting up
         | rockets, satellites, nuclear explosions etc., that seems pretty
         | interesting. That's one species out of 2+ million on earth,
         | which is one of trillions & trillions of dead planets, that
         | manages to transcend the atmosphere.
         | 
         | But to your point, I guess at the scale of even just the known
         | universe it's hard to assert that anything is common or rare.
        
         | yyyk wrote:
         | >But, it is fun to imagine how our belief systems would have
         | been shaken up if scientists were able to show Oumuamua was an
         | interstellar probe
         | 
         | Just about every ancient tradition has some form of non-human
         | intelligent beings who are not god(s). Polls suggests almost
         | 50% of Americans believe in ghosts[0]. I don't see why any
         | belief system would change too much given what people already
         | believe.
         | 
         | The only people who perhaps should worry are the aliens -
         | surely a significant portion of humanity will find some way of
         | blaming all our problems on them.
         | 
         | [0] https://www.newsweek.com/more-45-percent-americans-
         | believe-d...
         | 
         | https://www.nytimes.com/2021/10/28/style/do-you-believe-in-g...
        
       | babelfish wrote:
       | Here is the PDF linked by the page for those getting 'hug of
       | death' http://uu.diva-
       | portal.org/smash/get/diva2:1721987/FULLTEXT01...
        
       | Jimmc414 wrote:
       | Katz's attempts to delegitimize Loeb as a scientist makes his
       | argument less credible. Aliens or not, it's disingenuous to deny
       | that some aspects of Oumuamua don't yet have satisfactory
       | explanation.
        
         | jerf wrote:
         | "Doesn't yet have a satisfactory explanation -> Must be aliens"
         | has a long history, long enough that the rest of us are
         | entitled to draw the inductive conclusion that it's a weak
         | argument very unlikely to be true.
         | 
         | It is inductive, not deductive, so this bothers people laboring
         | under the misapprehension that science deals with deductive
         | reasoning. But science is ultimately inductive; we happen to
         | sometimes get to deduce things within its framework but it all
         | lives in an inductive framework.
        
           | Finnucane wrote:
           | That's just one step down from "Doesn't yet have a
           | satisfactory explanation -> Must be supernatural.'
        
         | ProAm wrote:
         | It's a passive aggressive funding fight. Just politics and
         | business. I'm pretty sure Loeb isn't as crazy as his latest
         | claims make it seem, but without outlandish bold claims no one
         | will fund future observation and scientific work on it. At
         | least that's been my take on Loeb's behavior.
        
         | [deleted]
        
         | echelon wrote:
         | Scientists are people subject to the same foibles as the rest
         | of us.
        
           | 0xdeadbeefbabe wrote:
           | But, the abstract promises a direct challenge:
           | 
           | > one of them is Jonathan I. Katz who challenges Loeb's
           | hypothesis directly
        
       | cmoscoe wrote:
       | Hugged to death?
        
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