[HN Gopher] Asteroid crater 520km in diameter buried in southeas... ___________________________________________________________________ Asteroid crater 520km in diameter buried in southeast Australia, scientists say Author : mafro Score : 270 points Date : 2023-08-17 10:39 UTC (12 hours ago) (HTM) web link (www.australiangeographic.com.au) (TXT) w3m dump (www.australiangeographic.com.au) | botanical wrote: | Wow that's a huge crater. It's bigger than the Vredefort impact | structure in South Africa. The Vredefort dome is the second | oldest at 2 billion years old that can be seen here: | | https://upload.wikimedia.org/wikipedia/commons/b/b5/Vredefor... | | And the full-sized version: | | https://upload.wikimedia.org/wikipedia/commons/5/52/Vredefor... | | https://en.wikipedia.org/wiki/Vredefort_impact_structure | vidanay wrote: | > The impact structure was formed during the Paleoproterozoic | Era, 2.023 billion (+- 4 million) years ago. | | > The asteroid that hit Vredefort is estimated to have been one | of the largest ever to strike Earth since the Hadean Eon some | four billion years ago... | | Let that sink in (ugh) for a while. The Vredefort impact was so | long ago, it's almost completely eroded away today. And yet, | when it occurred the Hadean Eon was as ancient then as the | Vredefort is to us today. The mind boggles. | lordfrito wrote: | Article says the center of the impact crater is (was?) around | 30km deep. Curious how big they think the asteroid that caused | this was. The article doesn't mention anything, and a lazy search | online came up with nothing. | | Wondering just how big of an asteriod this was, and how capable | we are of seeing candidate asteroids of this size. | hu3 wrote: | http://simulator.down2earth.eu/planet.html?lang=en | | According to this calculator you get a 446km diameter crater if | you input: | | - 15km asteroid diameter | | - 90o Angle | | - 80km/s | | - Dense Rock asteroid | | - Hitting on Water at level 10m | m3kw9 wrote: | Would be wild if aliens had cameras on every planet and one | day decides to show us what this looked like | Cthulhu_ wrote: | Little grey dudes sitting us down in the slideshow room to | show their holiday pictures from a few million years ago, | lol. "And this is when [?]10[?][?] nearly got eaten by a | dinosaur!" | aintgonnatakeit wrote: | FYI these are the maximums you can input to get the largest | possible crater using this simulator. | irrational wrote: | We're going to need a bigger calculator. | FireBeyond wrote: | ... not great, not terrible. | jacquesm wrote: | Hehe. That's a great scene. Meanwhile, I think it was big | enough to do the job. | hu3 wrote: | Yeah I had to max inputs on that calculator. Pretty wild. | jvm___ wrote: | 15kms at 80km/s | | So, for a quarter of a second or less it was touching the | ground and almost double the height of Everest (8.8kms). | jacquesm wrote: | And it still only went down to about twice its diameter. | Makes you really respect how tough the Earth's crust is. | jvm___ wrote: | The deepest borehole, about the size of a coffee can, is | only 12km deep before the tooling started melting - can't | drill with a liquid bit... | | So 30km down it would be hitting liquid rock and a lot of | heat. | jacquesm wrote: | Yes, the mantle is about that thick. And much thinner in | some places even. Which makes me wonder how they detected | this crater and what the crater is formed _in_. This is | the relevant bit from the article: | | "Between 1995 and 2000, Tony Yeates suggested magnetic | patterns beneath the Murray Basin in New South Wales | likely represented a massive, buried impact structure. An | analysis of the region's updated geophysical data between | 2015 and 2020 confirmed the existence of a 520km diameter | structure with a seismically defined dome at its centre. | | The Deniliquin structure has all the features that would | be expected from a large-scale impact structure. For | instance, magnetic readings of the area reveal a | symmetrical rippling pattern in the crust around the | structure's core. This was likely produced during the | impact as extremely high temperatures created intense | magnetic forces." | | But they would not able to verify that at that depth | without a lot of drilling and the end of the article | suggests that they have yet to do so. | tomatotomato37 wrote: | It makes me wonder what an impactor like that would do if | intercepted by the moon; that may be even enough mass to | cause a temporary ring field just from the debris | Cthulhu_ wrote: | I wonder if just the atmosphere would've caused it to | explode already. At those speeds it'd go through the | atmosphere within a second though. | pmayrgundter wrote: | Got me thinking, What happens, when and where. | | A column of air weighs ~1kg/cm^2 (handy!), and the | example has a 15km span of "Dense Rock" which I've seen | mean "Dense Rock Equivalent" in the Volcanic Explosivity | Index, where it has a density of 2,500 kg/m^3. Assuming | that, a column of the asteroid is | | 2500kg/cm^2/(100cm/m * 100cm/m) = .25kg/m * 15km = | 3,750kg | | The kinetic energy per column of the impactor is 1/2mv^2, | or 0.5 * 3750 * 80000m/s^2, or | | 1875 * 6.4e9m^2/s^2 = 1.2e13 Joules | | Which is about 20 gallons of gasoline equivalent. As you | say, that's absorbed in ~1s (space is 100km up, so 80km/s | is just about right). If so that warms up and starts | melting the surface of the asteroid, but not much more I | guess. | pmayrgundter wrote: | Whoops, I carried down the wrong number to the gasoline | conversion.. I left off the 1875 | | The _whole impact_ is like 40000 gallons of gasoline per | cm^2 of surface, or I think like 2kt TNT. | | So then, not sure what the kinetics/kinematics is there. | How much is released by the atmosphere impact vs then the | surface stopping the asteroid. | pmayrgundter wrote: | Ok! ChatG4 is amazing! | | https://chat.openai.com/share/25e4cef6-321a-43f7-8d13-40d | 1fd... | | Summary: my initial math checks out for the total KE of | the asteroid, and then we used that to look at the | surface heating by the compressed atmosphere and then the | Fourier heat analysis of conduction into the asteroid | surface | | Answer: Tho the atmosphere would be heated to 100k | degrees and that's 1000x more than needed for | vaporization of e.g. granite, the duration of ~1s means | that only a few millimeters of surface would be vaporized | by the time of impact. | serf wrote: | does it give the same answer repeatedly? every time i've | tried to solve problems like that with chatgpt i've been | given beautifully worded garbage that doesn't commpute by | hand, and won't be repeated if I retry the prompt. | pmayrgundter wrote: | That's my experience with ChatGPT 3.5. But with 4.. well, | as far as I'm concerned, this is AGI. | | I just did a compacted single-shot request in a new | session and got the same answer! | | It basically elided the simplifying analysis, went | directly for the heat diffusion equation and based its | conclusion on that. Impressive. | | https://chat.openai.com/share/0c857ebd-779a-4f40-93a9-c35 | cd2... | Filligree wrote: | It would be exploding for the duration, but at that size | you just can't get through much of the asteroid before it | touches the ground. | dylan604 wrote: | That's why "dense rock" setting was used. Imagine if they | had selected "solid iron". I don't know what settings are | available for the calculator used, but "loose bunch of | rocks" would probably fall apart in the atmo, dense rock | would hold together until impact, and solid iron would | just keep burrowing further | kijin wrote: | A 15km chunk of solid iron, now that's the kind of bunker | buster you throw around in an interplanetary war. | | Would it do more damage to the surface than a rocky | asteriod of comparable mass, though? If it burrows | deeper, it means it transfers more of its energy to the | mantle and core of the Earth, and less to the crust. It | will be like a full metal jacket bullet that goes | straight through the target and transfers most of its | energy to the wall on the other side, versus a regular | bullet that tumbles and expands as soon as it hits the | target. | davidwritesbugs wrote: | Throwing Meteors as interplanetary weapons was a | storyline from The Expanse books/TV series if I recall. | mekkkkkk wrote: | Yeah. Bad guy mounted thrusters on large asteroids from | the belts. Not technically meteors, but close enough. | | Neat sci-fi. | jvm___ wrote: | Deorbiting a multi-million dollar satellite as a weapon | was the plot of of a Tom Clancy book. The bad guy was | going to launch a nuke from his ship and the only thing | that could get there in time was the super special | satellite. | jacquesm wrote: | Much too large for that. Under 50 meters or so you can | get airbursts, after that it is direct impact. | RetroTechie wrote: | For such a size impactor, atmosphere does nothing. Might | as well be vacuum. | | Sure, milliseconds before impact the atmosphere might be | super-compressed (and super-heated). Perhaps even exert | considerable force. But compared with kinetic energy of | that size impactor, at such speed: negligable. | | Small objects 'feel' the atmosphere much stronger. | Surface area vs. volume. | jacquesm wrote: | Whatever parts of the atmosphere were involved in the | direct vicinity of the impactor would be heated to | plasma. It is just too much energy, you're talking about | the equivalent of a massive number of H-Bombs all going | off at roughly the same time. | jvm___ wrote: | It would probably punch a 15km wide hole in the | atmosphere, no? Which would then rapidly collapse from | the sides and collide with whatever was ejected... would | be fun to watch while parked somewhere safe in orbit. | jacquesm wrote: | Better not be LEO... I wonder how high the ejecta would | go and how far they would reach across the planet. | TacticalCoder wrote: | Well the article and the title here on HN both says "520km in | diameter", which gives an idea (although there's more than the | diameter to estimate the damaged caused by an asteroid, but | 520km in diameter is quite something). | ceejayoz wrote: | That's the crater diameter, which'll be much larger than the | impactor. | ChoHag wrote: | [dead] | moomoo11 wrote: | This kinda discovery is why I hold out hope there were super | advanced ancient civilizations on earth. They just happened to | figure out Stargates and peaced out entire cities to safer off- | world locations. | TearsInTheRain wrote: | Do you think a stargate is easier to figure out than | redirecting an asteroid? | moomoo11 wrote: | Yes. One shot vs n. | | Besides, Earth isn't the only planet suitable for us :) | layer8 wrote: | They obviously didn't do the latter, so it must have been the | former. ;) | phkahler wrote: | I have always thought Lake Michigan/Huron look mighty round if | you follow from the north end down through Green Bay and the Fox | river to the west, and cut into Canada along the Niagara | Escarpment [1] on the East. There seem to be signs of a round | structure all the way down in Ohio. But while this does form a | roundish structure, the history is quite different than an | impact: | | [1] https://en.wikipedia.org/wiki/Niagara_Escarpment | | Still I wonder, what if this other stuff happened in this shape | because of a giant impact crater billions of years ago before all | that? | jacquesm wrote: | There is the Sudbury crater. | | https://en.wikipedia.org/wiki/Sudbury_Basin | | Just North-East of Lake Huron. | throwaway5752 wrote: | It's not related to the escarpment, that is a glacial feature. | Their origin is not impact related, either, it is tectonic (the | rift valley from a failed continental rift): | https://en.wikipedia.org/wiki/Midcontinent_Rift_System | sdflhasjd wrote: | There's also the "Nastapoka arc"[0] of Hudson Bay that looks a | bit cratery, but is apparently of a different origin. | | [0] https://en.m.wikipedia.org/wiki/Nastapoka_arc | dboreham wrote: | Craterish? | layer8 wrote: | crater-like | IIsi50MHz wrote: | The Crater-ion Collection [cue logo, cue greyscale film | of various impact events] | webnrrd2k wrote: | Crateroid? | foota wrote: | Apparently arcuate is the preferred term | evah wrote: | It's very distinctive on an elevation map. | | https://mrgris.com/projects/oilslick/ | | I remember thinking there's no way that's not a crater. | greggsy wrote: | Thought to be formed as a result of lithospheric flexure | during the Trans-Hudson orogeny, apparently. | zhengiszen wrote: | More important than the size, I think, is the angle of impact... | Still huge numbers we could just fathom.... | spenczar5 wrote: | Composition matters a lot too (rubble pile vs monolith). Many | things affect whether it will be a bolide, and at what | altitude. | | But size is the most important feature because it is unbounded. | You can't be more direct than a perpendicular impact, but | asteroids can always be bigger. And a 10km rock at pretty much | any angle is much more energetic than a 10m rock, no matter | what you do. | baq wrote: | yeah at that size it's going to be a huge-ass almost | literally earth-shattering explosion no matter the | composition... | throwbadubadu wrote: | Depends, but in general would say no.. energy is speed times | mass, and mass is cubic in the size, while speed is linear. | | Angle is complicated, I mean unless it is very shallow all will | still go into earth? I wonder if and at which angle it could | impact earth's rotation, but for that then direction is also | relevant (: | | *: Ah, interesting, the neal.fun/asteroid-launcher also gives | same energy for different angles except very shallow ones. | alexpotato wrote: | I believe that all other factors kept the same, angle does | matter b/c of the amount and time you spend going through the | atmosphere. | | e.g. a shallower angle means you pass through more atmosphere | which leads to more heating time which in turn means to | "icier" asteroids burning off more of the ice. | | I can also imagine a scenario where the asteroid passes so | close that it passes through the atmosphere but doesn't | actually hit the earth. | pmayrgundter wrote: | Doesn't the ratio of mass of asteroid to atmosphere | dominate? The larger the asteroid, the proportionally less | momentum it loses to the atmosphere. Not sure how much a | column of air the radius of a mountain weighs, but seems | relatively very small? | irrational wrote: | I think the hypothesis is Uranus is tilted 90 degrees because | of a collision. Crazy to think of a similar thing happening | to the earth. | adolph wrote: | _Uranus is the only planet whose equator is nearly at a | right angle to its orbit, with a tilt of 97.77 degrees - | possibly the result of a collision with an Earth-sized | object long ago. This unique tilt causes the most extreme | seasons in the solar system. For nearly a quarter of each | Uranian year, the Sun shines directly over each pole, | plunging the other half of the planet into a 21-year-long, | dark winter._ | | _Uranus is also one of just two planets that rotate in the | opposite direction than most of the planets (Venus is the | other one), from east to west._ | | https://solarsystem.nasa.gov/planets/uranus/in-depth/ | ridgeguy wrote: | Energy is (1/2) _(mass)_ (speed)^2. That ^2 term is | important. | Jyaif wrote: | > energy is speed times mass, and mass is cubic in the size, | while speed is linear. | | https://en.wikipedia.org/wiki/Kinetic_energy#Kinetic_energy_. | .. | CoastalCoder wrote: | This sounds like the starting point for a cringey song | about physics. | mastax wrote: | Looking at that map, it's wild how many "confirmed impact | structures more than 100km wide" there are _just in Australia_. | There must be dozens of mass extinction events that we don 't | know about because the fossil record is so unclear past 500Mya. | | [0]: https://en.wikipedia.org/wiki/Extinction_event | | [1]: https://en.wikipedia.org/wiki/Chicxulub_crater | | [2]: https://en.wikipedia.org/wiki/Earth#Natural_history | greatpostman wrote: | Every 26k years we pass through an asteroid belt with a high | probability of impact | echelon wrote: | Is there a source for this? I wasn't aware of that, and it | sounds interesting. | eesmith wrote: | 26,000 years sounds more like the period for Earth's axial | precession. https://en.wikipedia.org/wiki/Axial_precession . | | What you describe doesn't make sense. The Earth's orbit is | effectively constant at that timescale, as are the asteroids | in the main asteroid belt - otherwise interactions with | Earth's would have changed the orbit. | | There are conjectures of regular extinction events on 30-60M | year intervals, but the data for that isn't strong. https://e | n.wikipedia.org/wiki/Extinction_event#Patterns_in_f... | blahburn wrote: | Google "Chicxulub crater" for a fun animation | [deleted] | jader201 wrote: | For the lazy: | https://www.google.com/search?q=Chicxulub+crater | hindsightbias wrote: | So New Zealand might not be the best place to bug out to if | Australia is a meteor magnet. | eesmith wrote: | Not that meteor magnets exist, but https://en.wikipedia.org/w | iki/List_of_impact_craters_on_Eart... says there are more | known impact craters in Europe than Australia. | Tronno wrote: | That's fun to think about, but Precambrian life was generally | microscopic. Many impact craters across the world date from | that era, so any extinctions they caused would not be visible | to the naked eye. | jandrese wrote: | Also imagine how many hit the oceans. A water hit can be even | more catastrophic than a land hit, especially on shallow water | like the continental shelf. | cubefox wrote: | Given that land mass is smaller than oceans, there was probably | an even bigger asteroid which fell into the ocean. | echelon wrote: | We might have found the biggest one, which could have led to | the formation of the moon: | | https://www.express.co.uk/news/science/1606365/science-news-... | | https://phys.org/news/2021-03-theory-large-blobs-material-ea... | | https://www.science.org/content/article/remains-impact-creat... | autokad wrote: | you can find large asteroid impacts by looking at Vulcanic traps | and looking on the opposite side of the globe during that time. | coryfklein wrote: | I know it's buried deep, but it's kind of weird for the reporting | to not even show an image of the area? Perhaps a map with a | little pin indicating where the Deniliquin structure is? | | They say it's near the city of Deniliquin, which is here [0]. | Oddly, that spot doesn't even show on the map of yellow dots of | likely impact structures! Did they forget to mark their newly | discovered largest-impact-crater-in-the-world on the map? | | [0] https://goo.gl/maps/shvRY2CiEs3eR8iw5 | teddyh wrote: | > _I know it 's buried deep, but it's kind of weird for the | reporting to not even show an image of the area?_ | | It's something I have seen becoming the _norm_ nowadays. | Articles about art or photographs without a single image. | Political articles about borders without a single map. Articles | about some thing some scientist has done, maybe with a picture | of the scientist, but not of the actual thing. And it's not a | technical limitation of the medium; most articles _will_ have | numerous (but _irrelevant_ ) images. | | I suspect that SEO measurement has told people that it doesn't | matter _what_ images an article has, as long as it has _some_ | images, optimally interspersed with the text. Spending any | money on getting _relevant_ images thus becomes an unnecessary | expense. Readers will still click on the article (because of | the click-bait headline), and will still read (or at least | scroll through) the article if the text is broken up by images | by an optimal amount. | fragmede wrote: | I think you're right. We know ChatGPT-4 can do image | analysis, so all Google has to do is say that they're down | ranking articles that don't have relevant images, and we'll | be back to having useful images in artichokes again. | CamperBob2 wrote: | Could be as simple as the fact that images make the page take | longer to load. Google penalizes that, as I understand it. | foota wrote: | Maybe it's not yet considered likely? | progrus wrote: | Seems like maybe our ability to find and divert these asteroids | might make all that burning of energy worth it, no? | CoastalCoder wrote: | Well, maybe. It really comes down to the specific numbers. (At | least for the objective part of the consideration.) | thelittleone wrote: | How realistic it to divert an asteroid of this size? | sebzim4500 wrote: | If you know find out years in advance then you barely have to | change it's velocity to make it miss Earth. Probably a | kinetic impactor would be sufficient, otherwise thermonuclear | warheads exist. | dylan604 wrote: | when did we learn it was heading our way, and how far away is | it at detection? hours, days, months, years before impact? | that's key things to know. | hoorayimhelping wrote: | Capable with current technology if intercepted early enough. | I think most people visualize an asteroid hitting earth like | a ball hitting the ground when dropped at arm's length. In | reality, orbits of celestial objects are elliptical, and | they're constantly moving. A small force, like that produced | by an ion thruster, applied to an asteroid 15km in diameter | for months or years would be enough to change it's orbit such | that it wouldn't impact earth. | SkyPuncher wrote: | It doesn't necessarily need to be diverted entirely. Simply | breaking it up into smaller components significantly reduces | it's impact force. | | Smaller pieces burn up more readily in the atmosphere and | create smaller impacts (I believe exponentially smaller) | HeyLaughingBoy wrote: | Now you're begging the question of how hard it is to break | it up! | thfuran wrote: | Significantly harder than diverting it slightly. | gremlinsinc wrote: | some of these asteroids we only have days warning. that's | the scary part. To divert an asteroid you need to do it | before it comes near so it has a long path to begin | drifting in a new direction. ie it's only gonna nudge it | slightly. Slightly adds up over many millions of miles, not | so much when its a week out. | Capricorn2481 wrote: | Not really, since there are only a few known instances of | asteroids hitting earth in hundreds of millions of years, but | climate change is an immediate threat within the next 50. The | odds we live to see an asteroid hit us are slim. | slibhb wrote: | > The odds we live to see an asteroid hit us are slim. | | Presumably this is based on a belief that humans are likely | to go extinct. I don't agree; I think we're extremely | unlikely to go extinct and, following from this, an impact is | definitely something worth worrying about. | | It doesn't even have to be a "planet-killer," a smallish | impactor could wipe out a city. | suby wrote: | The question is really how likely are we to be hit within | the relevant time period. Had we taken a slower growth | curve, we'd avoid climate change at the cost of an extra 50 | or 100 years before being able to divert asteroids. That | seems like a good bet. I am much more worried about climate | change and irreversible destruction of ecosystems than | getting hit with an asteroid in a very limited time period | progrus wrote: | [flagged] | Cthulhu_ wrote: | Slim, but not zero; we can and probably should do both. | bryanmgreen wrote: | Lets say the same asteroid hit the same place in Australia | today.... | | How many people would both directly from impact/shockwave and | indirectly die (infrastructure collapse, tsunamis on beach towns, | climate change, etc) from this, do we think? | not2b wrote: | This was bigger than the dinosaur-killer, which killed almost | all land animals; only a tiny fraction survived. So almost | everyone would die, all over the world. The shock wave would be | extremely hot and kill pretty much anything that's outside, and | the fires would be massive. | dmbche wrote: | No sunlight for years, no photosynthesis - same pronostic of | 95% loss of life id guess | ourmandave wrote: | _I think it may have triggered what's called the Hirnantian | glaciation stage, which lasted between 445.2 and 443.8 million | years ago... | | This huge glaciation and mass extinction event eliminated about | 85% of the planet's species. | | It was more than double the scale of the Chicxulub impact that | killed off the dinosaurs._ | barbariangrunge wrote: | What percent of species have humans killed so far? Are we going | to eventually outcompete an asteroid causing over a million | years of ice age? | | https://www.un.org/sustainabledevelopment/blog/2019/05/natur... | | https://amp.theguardian.com/environment/2018/oct/30/humanity... | someplaceguy wrote: | Imagine an asteroid causing a glaciation event on Earth that | lasts 1.4 million years. | | That's mindblowing. | jacquesm wrote: | You can expect one of the really big (Chicxulub-size) impact | every 100 million years or so (there is enough uncertainty | here that experts all have their own ideas on the exact | frequency but typically 25 to 500 million years seems to be | the agreed upon range. We keep finding new craters though and | then have to increase the estimate). | | https://www.thespacereview.com/article/761/1 | | https://skyandtelescope.org/astronomy-news/how-often-do- | chic... | | And endless papers on the subject. TEOTWAKI is a fun rabbit | hole to dive in to. | someplaceguy wrote: | > You can expect one of the really big (Chicxulub-size) | impact every 100 million years or so | | Still, the Chicxulub asteroid is estimated to have caused a | global cooling of the surface by around a decade, not | 1,400,000 years. | jacquesm wrote: | Sure, ask the dinosaurs how that went. The point is: that | was _only_ a decade and only a relatively small asteroid | and the effect was that the dominant species of the time | was wiped out. Size is inversely correlated with | frequency, so those smaller ones happen far more | frequent. Anything larger than that and it is definitely | game over. | _joel wrote: | I think it goes to show just how short of a blink of the | cosmic eye, that humanity has really existed for and the need | to spread our bets by exploring the universe. | localplume wrote: | [dead] | dsign wrote: | [flagged] | Cthulhu_ wrote: | Only if you want the species to survive, if you're more | nihilistic like me, it just doesn't seem to matter. Or if | you're optimistic, WE don't matter because there's loads of | other life and societies out there. | | It does make you wonder whether life as we know it was a | preceding civilization that launched life into the wider | universe for the continued existence of life. But on | tectonic timescales, any traces that e.g. a carrying vessel | would have left behind are long gone. | networkchad wrote: | [dead] | _joel wrote: | Probably one of the best episodes of Trek imho - | https://www.imdb.com/title/tt0708803/ | gloria_mundi wrote: | Another related Trek episode - the one I expected you to | link: VOY's "Distant Origin" - | https://wikipedia.org/wiki/Distant_Origin | CaptArmchair wrote: | > Only if you want the species to survive | | Paradoxically, "survival" assumes adapting to ever- | changing circumstances, which means that homo sapiens, | given enough time, is bound to evolve into one or | multiple new species given enough time. Regardless of | that happening elsewhere or on Earth. | | Arguably, a species is just a mode of survival for a | genome; a convenient vessel through time as the genome | reproduces. The language we use is, ultimately, a social | construct, but biological speaking by and large | inconsequential in so far that language is a trait that | fosters survival. Evolution isn't opinionated, it just | 'is'. | | The fate of the Neanderthal people feels apt here. While | the species is extinct, our Sapiens genome still caries | 1-4% of Neanderthal genes to date. Some of that | influences traits in modern humans, some of that just | doesn't. (Evolution is messy, in that regard) Now, maybe | Neanderthals wondered - just like us today - what would | become of them aeons in the future. Little did they know | that we, Sapiens, are distant relatives to them. | | In the same vain, our written record and collective | memories spanning no longer then a few millennia, distant | relatives in the far future may look back at our detritus | in the soil and in their genes and maybe wonder the exact | same thing. | | Maybe the Great Filter isn't some civilization destroying | event. Maybe it's just evolution. Maybe become a space- | faring species might be the biggest mistake we could | make. I think more then a few sci-fi authors coined the | notion of the arrival of malevolent alien species in a | distant future which turned out to be our distant | relatives from space-faring humans who left Earth eons | ago. Of course, that's just speculation. But there's some | poetic food for thought there, it's a probability one | can't readily exclude. | stOneskull wrote: | circle symmetry like petals round a flower a galaxy's | earths | samus wrote: | There's plenty that could have gone wrong in the last | century that could have led to humanity's extinction. The | next challenge is how to deal with exceeding the capacity | of the planet to sustain our civilization. You're | definitely on to something with your last paragraph. | Andrex wrote: | > It does make you wonder whether life as we know it was | a preceding civilization that launched life into the | wider universe for the continued existence of life. | | There's data out there about the First Ancestral Race but | AFAIK they've never released the unredacted version of | the Secret Dead Sea Scrolls, so it's hard for the public | to say. | VHRanger wrote: | That's a question in geology and archaeology called the | Silurian Hypothesis: Could we even detect a millions-of- | years old civilization in the geological record? | | 1. https://arxiv.org/abs/1804.03748 | pacoverdi wrote: | Related science fiction novel: The Ice People (La Nuit | des Temps) by Barjavel | | https://en.wikipedia.org/wiki/The_Ice_People_(Barjavel_no | vel... | NoMoreNicksLeft wrote: | An Earth-originating civilization would have left our | species bereft of the natural resources to industrialize | with. | | Coal was only made once. Maybe if abiotic theory of | petroleum is true, you get that back over immense | timescales, but you don't get a second shot at coal. | Without coal, you can't even do metallurgy at scale. Is | there some gotcha that I'm missing? | px43 wrote: | Maybe that is what happened, and we somehow managed to | make due without energon deposits and vibranium. | [deleted] | jacquesm wrote: | On those timescales plenty of natural resources would be | replenished, but not all. 500 million years is a long, | long time. | thfuran wrote: | Coal probably wouldn't and is pretty significant. | | Edit: actually it seems like the coal resulting from lack | of tree-consuming microbes theory isn't so widely | supported these days. | goatlover wrote: | But life hadn't evolved on land 500 million years ago. | jacquesm wrote: | Yes, that was sort of the point. So you get 100's of | millions of years during which things can rearrange | themselves. Whoever - or even whatever - inherits the | Earth after the next big impact will find it changed | dramatically compared to how it is today. By the time | they evolve intelligence (optional) have toolmaking needs | (optional) and are living on land (optional) they will | have plenty of time to figure out where it is going to | come from, the earths crust will be rearranged enough | that you can expect all kinds of stuff to have risen to | the surface that is now inaccessible. | | Heck even the Himalayas have formed only 50 million years | ago. | Retric wrote: | Coal was only made once because the earth basically ran | out of carbon to turn into coal. There's 1,100,000 | million tons of economically viable coal and we're | running into environmental issues by burning ~1/1,000th | of it. | | Most projections suggest coal use is going to plummet | over the next 50 years, both because we have better | options and because we have little choice. | | There's enough coal in the ground to make earths | atmosphere actively lethal to humanity. At ~70,000 ppm | people are rendered unconscious in minutes and there's | enough coal go well over 100,000 ppm. There's no way for | humanity to use up the worlds coal as fuel, perhaps we | could ship it into space as carbon source but that seems | unlikely. | NoMoreNicksLeft wrote: | > Most projections suggest coal use is going to plummet | over the next 50 years, both because we have better | options and because we have little choice. | | Sure. Already industrialized civilizations have better | options. But if you're starting from scratch, you don't | get to jump immediately to photovoltaics or whatever. | | > and we're running into environmental issues by burning | ~1/1,000th of it. | | But which 1/1000th? We didn't dig out the deepest coal | first. "Economically viable coal" by 21st century | standards isn't the same "economically viable coal" by | the standards at the dawn of the industrial revolution. | Retric wrote: | > But which 1/1000th? We didn't dig out the deepest coal | first. "Economically viable coal" by 21st century | standards isn't the same "economically viable coal" by | the standards at the dawn of the industrial revolution. | | Across geologic timescales what's accessible changes. It | makes a huge difference if deposits are above or below | sea level for example. The Industrial Revolution kicked | off in a small geological area which would have looked | very different even 100k years before. | | Even beyond that we're actually more selective not less | when it comes to coal mines. Unlike say | copper/silver/gold/etc there's so much coal that what | would have been a perfectly viable mine 150 years ago | simply isn't today. Larger equipment means fewer workers | but it also requires thicker coal seams. Similarly we're | a lot more picky about sulfur content etc. | | That's also somewhat true of stuff copper, gold, etc. The | minimum concentration required to make ore viable has | decreased dramatically, but only when there's huge | quantities of ore. Plenty of potential mines could be | worked by hand, but can't complete with industrial scale | mines or be used as one. | | PS: It's worth remembering even if things aren't quite as | efficient they can be viable. Building canals takes more | effort than rail lines but they can still transport bulk | goods on the cheap using minimal technology. Similarly | solar smelting can reach extreme temperatures, just not | 24/7. Wood plus just about any rock can get you to steel | with enough effort and know how. It might take slightly | longer but our history isn't the only way to get to | transistors and spacecraft etc. | jacquesm wrote: | Carbon sink? (instead of source...) Depends on your | perspective I guess. | DenisM wrote: | If they wanted to be remembered they would encode a | message in the DNA. | | Or left it on the moon, I guess. | samus wrote: | DNA sequences are undergoing frequent changes if there is | no evolutionary pressure on them. The message would | quickly be scrambled. They would have to encode it into | highly conserved gene sequences, i.e., completely | reinvent life as we know it. | | The moon is a harsh environment and (like most places in | the solar system) exposed to significant danger from | meteorites over geological timescales. | goatlover wrote: | Make use of the horseshoe crab genome then. | Jibbedeyeah wrote: | [dead] | xwdv wrote: | Before social media I thought yes this was something we | should do. | | But now after being exposed to the true collective nature | of mankind, it doesn't matter. This species is a net | negative for the universe. Just a bunch of monkeys | squabbling over stupid things. | goatlover wrote: | The universe doesn't care one way or another. There's no | such thing as a net negative for the universe itself. | It's amoral and has no values. | NoMoreNicksLeft wrote: | > This species is a net negative for the universe. | | We're not important enough to be net negative, nor have | we been around long enough. I am still hopeful that 10 | million years from now, we'll have rampaged across the | supercluster, spreading despair and wickedness in our | wake. | | Then, and only then, will we have achieved net | negativity. Do your part, help us become that. | shakna wrote: | We're certainly setting a record at destroying this planet. | rapht wrote: | > We're certainly setting a record at destroying this | planet. | | In the grand scheme of things, I'm tempted to say: if | that's the price to pay to expand beyond it, then so | what? It's not like it's the only planet in the Universe. | hutzlibu wrote: | "It's not like it's the only planet in the Universe. " | | But so far it is the only known planet with conditions | where we can live. | | And I doubt we can make the jump to another planet we | first have to find and then somehow survive getting there | - when we cannot take care of our own planet. | | (Btw. no matter how much we mess up earth, it will | allways be way more hospital than mars) | goatlover wrote: | Are we though? We're altering the planet's weather and | ecosystem, but that's not the same as destroying. Plus | there have been several large impacts in the past that | acted quicker to alter the planet, and life found a way. | Loughla wrote: | We're certainly setting a record at destroying | _ourselves_. | | It's seems like a pedantic distinction, but it's | important. Earth doesn't care if we're here or not. The | universe doesn't care if we're here or not. We are the | only ones who should care, and we seem not to. | | The planet will be fine, eventually, after we die out. | Life will continue after we're long gone. | | But we'll be long gone, and it's like we've all decided | that's okay. | SamPatt wrote: | Destroying ourselves, as measured by population, which is | the highest in the history of our species? | | Or measured by longevity, or leisure time, or other | living standards, all of which are drastically higher | than they were only a few generations ago? | krisoft wrote: | Those are all true! And they are important to remember. | It is also important to remember that if you are driving | a car to a brick wall, almost every metric will be | perfect right until you hit it. | SamPatt wrote: | It's also important to remember that history is full of | people claiming we're about to run into a brick wall | (Malthus, Erlich and company), yet things just keep | getting better. | | Perhaps humans are better drivers than you think? | samus wrote: | Malthus was essentially correct, but wrong about the when | and how. Industrializing societies can play whack-a-mole | with constraints that limit their population growth, | successfully so far. | | What saved us was the surprising phenomenon that those | societies tend to have quite low birthrates. Multiple | possible reasons for that: | | * high cost of living and raising children,* | | * availability of birth control, | | * waning social pressure of getting many children, | | * no immediate economic benefits of raising children (in | agrarian societies, they are essentially free labor on | the farm, and a huge young population makes it easier to | bootstrap an industrial economy). Of course, eventually | there will be a problem when a huge percentage of the | population is too old to work. | | We will be fine as long as we can sustain agriculture: | | * oil must be a-plenty to run farming equipment. It will | be a long time before electricity has taken over | | * we need farmland with intact soil and water | | * we need fertilizer (phosphorus is running low soon, and | oil is required as well) | | * we need pollinators for many crops. Hand-pollinating is | expensive | | * We must not run out of pesticides to maintain yields | | And probably some more requirements. If any of them is | not fulfilled, society collapses and things can get ugly | quickly. These things partly contribute to recent wars in | Africa, the Middle East, and other places. | | Edit: | | *: low child mortality makes it necessary to actually | support most children all the way to adulthood | SamPatt wrote: | >What saved us was the surprising phenomenon... | | It's only surprising if you (like Malthus and Erlich) had | the intellectual arrogance to believe you could predict | the future. | | I cannot predict humanity's future, but I can look at our | past, and our progress looks excellent so far. Betting | against our continued success seems to require serious | mental gymnastics. | DesiLurker wrote: | I've always hated this smartass retort from Carlin (who | was awesome otherwise). this is indeed a pedantic | distinction. there may be billions of planets like earth | around but what make it special is the life on it & we | are destroying that for some imaginary 'capital' that | wont matter in large scheme of things anyways. | | The other significant problem with this punchline is that | it is still heavily human centric. we are not gonna go | away without a major fight in/against biosphere. and | guess what since we dont ascribe any value to it other | than how its useful to us its going to take the brunt of | destruction. at this point if we hold our population & | resource utilzation where we are and eventually settle | down to a smaller size I'd be okay with it as long as we | give the rest of biosphere a chance but we all know thats | not going to happen. We _need_ to keep growing, thats the | system we are in. And sure there will be some targeted | geoengineering & green energy hopium for us to hang our | concerns on but at the end of day we'd end up in the same | place. | | there was a line I read somewhere that made me realize | our current predicament, it goes -- if a distant | civilization just looks at the rise in atmospheric | greenhouse gas composition of the planet, they wont be | able to tell if its a intelligent species consuming | fossil fuels or a bacteria that just learnt metabolize | fossils and just growing exponentially. its the same | curve largely. So much for human discretion & | intelligence. | | /rant end. | oceanplexian wrote: | > We're certainly setting a record at destroying | ourselves. | | I know things are bad but historically, I don't know how | you can say that. In the 60's, 70s, and 80's we actually | were, no-bullshit, on the brink of turning the world into | a radioactive glass hellscape. | | Despite all the turmoil in the world, I think things are | looking up for humanity. | hutzlibu wrote: | "In the 60's, 70s, and 80's we actually were, no- | bullshit, on the brink of turning the world into a | radioactive glass hellscape" | | Have you watched the news lately? | | I think there was something war related and people | arguing about first strike and red lines. | | Just because we are now used to the threat, does not mean | it went away. | jklinger410 wrote: | > and the need to spread our bets by exploring the | universe. | | I would like for us to get our house in order before we | start this process. | prox wrote: | I feel this is a why-not-both thing. We should fix our | house and explore. We have enough people and capability | to do both if we are politically and mentally willing. | bradgessler wrote: | Yeah. If anything, not having our house in order is even | more motivation to create offsite backups. | d12345m wrote: | Which problems do we need to solve before you would deem | our species worthy of survival? | mulmen wrote: | This is such a tired and simplistic take. The space | program has been helpful in tidying our home. It's not an | either or choice. | JumpinJack_Cash wrote: | That is a lie that is conveniently told to preserve the | legacy of the Apollo program and the morale of the | Nation, as well as the legacy of one of the most beloved | figures in the history of the Nation: JFK , who by the | way, when you start to dig deeper emerges to be just a | younger Trump. | mulmen wrote: | We literally have satellites in space that monitor the | atmosphere and detect greenhouse gas emissions. | JumpinJack_Cash wrote: | > > We literally have satellites in space that monitor | the atmosphere and detect greenhouse gas emissions. | | So monitor stuff that you can't do nothing about. Great | | As far as weather goes you don't need satellites. | Baloons, planes, radars, drones, buoys do exist and paint | a picture which is 99% the same. | | The Apollo program failed to repay itself, plain and | simple. Unlike the Manhattan project and the rocket | designs stolen from the Nazis and developed by Von Braun | which kept us safe for 50 years now. | javajosh wrote: | We can and should do both. Our emphasis should indeed be | on not shitting the bed. But we should also look for new | beds. The big problem is that Mars at its best is worse | than Earth at its worst. The Earth in "The Road", or | almost any post-apocalyptic story, is still infinitely | more livable than Mars! | short_sells_poo wrote: | I agree with you and I'm saddened by the nihilist (and | defeatist!) outlook that many people seem to have here. I'm | fundamentally a humanist. I want humanity to survive and | thrive. | | I never understood the defeatism. It seems to arise from | having the intellect to recognize that humans can (and do) | have impact on their environment, and in the same breath | resign on that impact being only negative and thus | declaring that humans as a species should go extinct. | | But there's so much good in this world that people do, | isn't that worth saving? We know our capabilities are only | limited by our own imagination, so why not strive for a | grander human civilization that can span at least the solar | system, if not the galaxy? | | We can try, and we may still fail. Nothing is certain, | except the way to ensure our demise by accepting that our | fate is to go extinct and do nothing about it. | NoMoreNicksLeft wrote: | > I never understood the defeatism. It seems to arise | from having the intellect to recognize that humans can | | It actually correlates really well with the advent of | teaching young children to be guilty about the | civilization which gave birth to them. Maybe we shouldn't | be slamming first graders with the ideas that everyone | who came before them were supervillains and that they | must shoulder the burden of correcting long dead | injustices. | | In any event, doesn't much matter. Every week there's a | new article about how one nation or another has below- | replacement fertility that doesn't seem to have any real | prospect for reversing (tied to, more than anything else | I think, what was described above). We are probably | already a dying species, or at least heading into a post- | civilization phase, and just don't know it yet. | [deleted] | lazide wrote: | Eh, frankly it's giving too much rational basis to | emotional states IMO. | | People posting on web forums, especially engineers, like | to poke holes in things and aren't big into expansion and | exploration at the moment. Probably a bit depressed from | sitting in front of their computers all day too. | | Ask someone who just spent a month on the pacific coast | trail, or who is about to go to Antarctica the question, | and you'll get a different set of answers. | oceanplexian wrote: | I think it's more than the web but the way media is being | curated. I'm one of those people who's really optimistic | about society. However being a positive person is | actually a lot of work. | | I basically have to tune out all modern movies, | television, news. Every new TV show is about some | dystopia or the end of the world or a Zombie apocalypse | or whatever. I watch mostly old TV shows from the 50s and | 60s and read science fiction. In rare cases I'll watch a | new show that's actually positive. You have to be careful | though, even long-running franchises can quickly turn | toxic when Hollywood gets a hold of it; Star Trek was | headed that way until Strange New Worlds came out. | tuyiown wrote: | I think you are over-reading it. The nihilistic mindset | is not necessarily defeatism, it's just accepting that it | does not matter in the universe-wide grand scheme of | things. | | I personally think that it's the most pragmatic view, if | not the most rationale: with such an approach, only | actions that are truly achievable retains attentions, if | we try something, let's do the things that matters in the | long run instead of trying literals shot in the stars. | | Also, given the systematic and very damaging polarisation | of all debates, I like being able to distance myself: it | does not matter in the long run, so if the toxics | annihilation has to happen, I won't be part of it, and | it's probably the best I can actually _do_. | safety1st wrote: | Nihilism is a nuanced concept that many great thinkers | have grappled with but "web forum nihilism" isn't. | Internet nihilism usually just reads like someone who is | suffering from some sort of depressive or anxiety | disorder and expressing their symptoms, like | catastrophization, over the 'net. | | What I submit is that we are living in a society with a | record level of depression, anxiety and other mental | illnesses (the US for example is prescribing record | levels of antidepressants). This record level of mental | illness is simply spilling over onto the Internet. Why so | many people in our society are ill is left as an exercise | for the reader. | bornfreddy wrote: | > (the US for example is prescribing record levels of | antidepressants) | | I would argue that this is mostly very (too) efficient | marketing and sales though, cynical as it sounds. | w10-1 wrote: | > it may have triggered what's called the Hirnantian glaciation | stage | | Maybe. but per the Brittanica article cited: | | > No concentration of iridium has been identified near the | extinction that would suggest a bolide (meteorite or comet) | impact like the one identified at the end of the Cretaceous | Period. | [deleted] ___________________________________________________________________ (page generated 2023-08-17 23:00 UTC)