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What made Earth a giant snowball 700M years ago? Scientists have an answer
- neogodless 3y agoSee also: https://news.ycombinator.com/item?id=39315378 https://news.ycombinator.com/item?id=39315378 (An extreme ice-age climate 700M years ago) What Turned Earth Into A Giant Snowball 700 Million Years Ago? (astrobiology.com) 4 days ago (81+ points / 89+ comments)
- itronitron 3y agoSeems like a low risk approach for taking over a planet would be to just park a large shade between the planet and it's star then let it enter a deep freeze. Then you could just remove the shade and let the planet warm back up before settling down.
- swader999 3y agoThey tried that with the moon but parked it in the wrong spot.
- baxtr 3y agoHave you done the calculation how much material is required for such an endeavor? I bet there are more cost effective approaches.
- hyperhello 3y agoOkay, like what exactly?
- kzrdude 3y ago"You're in the way of a construction project, sorry, but please evacuate the planet". The fake notice costs you next to nothing. "The plans for demolition have been available on Alpha Centauri which is only 4 light years away you know."
- lukas099 3y agoI like the idea of the solar system getting eminent domained for a scifi
- wincy 3y agoThis is literally the plot of Hitchhiker’s Guide to the Galaxy. It’s a great read.
- InitialLastName 3y agoHere you go: https://en.wikipedia.org/wiki/The_Hitchhiker%27s_Guide_to_the_Galaxy https://en.wikipedia.org/wiki/The_Hitchhiker%27s_Guide_to_th...
- baxtr 3y agoThis is dangerous talk. Aliens might be crawling HN and feed their AI models to find our weak spots! Beware.
- GolfPopper 3y agoNo worries there - their AIs will spin them hallucination-riddled nonsense, just like our do.
- WarOnPrivacy 3y ago> Have you done the calculation how much material is required for such an endeavor? It's a tiny fraction of what's required for a proper Dyson sphere. And we know civilizations can afford those because we can no longer see their stars. For anyone who's hung up on saving nickle, we could do a low budget Worldring² or even thriftier Shadow Squares®. ²Nivenlarry ®Larry Niven
- SketchySeaBeast 3y ago> And we know civilizations can afford those because we can no longer see their stars. That's a giant claim you just made like it's fact.
- WarOnPrivacy 3y ago> That's a giant claim you just made like it's fact. You are correct. That is absolutely a thing I did.
- SketchySeaBeast 3y agoBut it doesn't make any sense, given we do not have good evidence of alien civilizations, not to mention Dyson spheres.
- WarOnPrivacy 3y ago> But it doesn't make any sense, given we do not have good evidence of alien civilizations, not to mention Dyson spheres. Also correct. Even past that, we haven't been mass-cataloging stars long enough for a Dyson sphere to be constructed and remove a star from our view.
- SketchySeaBeast 3y agoSo why make the initial claim "And we know civilizations can afford those because we can no longer see their stars."? Is it humor or irony I'm missing?
- Maxion 3y agoIt doesn't have to be very thick at all. Harder part would be to keep it in place, as it would act as a sail.
- IggleSniggle 3y agoSure if you've got unlimited time
- vmfunction 3y agoBetter than nuclear weapon, no nasty fall out. Better than death star, you still have a planet afterwards.
- yusml 3y agoIf they had made the death star bigger, they could have done this tbh.
- reportgunner 3y agoWouldn't moving the death star closer to the sun sort that out ?
- itronitron 3y agoCloser to the star would only help if the star's size was similar to the death star. And if the death star was made larger then it wouldn't be mistaken for a small moon.
- vmfunction 3y agoToo expensive!! Stratospheric aerosol injection are way cheaper! https://en.wikipedia.org/wiki/Stratospheric_aerosol_injection https://en.wikipedia.org/wiki/Stratospheric_aerosol_injectio...
- Georgelemental 3y agoYou have to make sure it doesn't drift away from the Langrange point, which is unstable…
- Maxion 3y agoWell, assuming an alien species that can deal with interstellat travel I am sure they can figure out a way to stay at a lagrange point.
- deleted 3y ago[deleted]
- foobarbecue 3y agoWhat do you mean it's unstable? You orbit the Lagrange point, right? Sure you might have to spend some fuel maintaining the orbit, but we have a bunch of spacecraft at Earth sun L2 doing that just fine (e.g. the Webb). Is L1 less stable than L2 for some reason? edit: SOHO is at L1
- deleted 3y ago[deleted]
- nullhole 3y agoThat'd make for a good story setup: aliens park a shadeship (c) at L1 and wait. They block out most but not all of the sun. After some time (months? years?), conditions on Earth become unbearable, so earthlings have to mount an attack. Kind of like the movie Sunshine, but with more believable physics. Edit: as a bonus, it could take place in ~50-100 years, when global warming has gotten worse. The aliens could disguise their motives for a while, claiming to be there to help counteract global warming. Warnings from a lone scientist would be ignored. Then, as things start getting too cold, their true purpose would become clear to all.
- ljf 3y agoLove this idea for a story. As an alternative - it could be the oil producing countries, not aliens - seeking shade earth to disrupt solar and wind energy, and return to oil dominance.
- BirAdam 3y agoWell, if Exxon builds a space ship…
- saalweachter 3y agoNah, you just need a simple Bond Villain Plot. Step One: build a machine that can cool the Earth, solving global warming Once and For All. Step Two: demand the governments of the Earth pay you $1 trillion to turn it off at the appropriate time.
- slashdev 3y agoOr you could just smack it with a really big rock. That nicely sterlizes the planet too, so you can reseed it with life from your planet after to make it more comfortable. Honestly it's all kind of silly because distances are so vast. It makes little sense to travel to a distant star - much better to build space habitats in your own star system. And even if you were going to do that for some crazy reason, there's no shortage of uninhabited planets out there. There's no need to commit planetary genocide of an alien race. Also if you have that kind of tech level, space habitats make more sense than planets anyway. Finally if you seed distant star systems with your own species, you risk that species going to war with you later (see how that played out on Earth just across the oceans.)
- itronitron 3y agoI was thinking the deep freeze might be useful in preserving some potential food sources, assuming it happens quickly enough. But I agree sterilizing the planet provides some advantage as well.
- slashdev 3y agoAliens probably would not be able to eat Earth life.
- dsign 3y agoYou are correct, but it's capitalism and the adrenaline kick. We are culturally conditioned folk, and all scripts about alien invasions that end up in movies follow a completely implausible scenario. Most don't even bother any longer to give a reason for invasion. I would blame the writers of those scripts, but movies without violence don't give the adrenaline kick and don't sell well. Here is an idea for any writers reading this who want to break the violence cycle: whenever you feel you need to have a character kill another in a gratuitously violent way, twist the plot so that they instead end up having steamy sex. The readers will get an intense hormone rush that way too.
- slashdev 3y agoAmerican viewers love gory violence, but get offended at steamy sex scenes. That makes no sense to me.
- Forgeties79 3y agoI can’t believe I remember this. You jogged an old memory of Angry Beavers loose. IIRC in one episode they were tasked to save the day Armageddon style but started getting pulled into the sun because they strayed too far into its gravitational field and couldn’t boost out. So the beavers went out and built a dam in space to block it, which saved them but then Mission Control calls them up and says they’ve launched a new ice age. This is all from memory and frankly I’m finding it fun trying it recall it without confirming it haha
- Archelaos 3y ago"Just parking" between would not be possible without putting really a lot of energy into maintining the position of the shade. Due to orbital speed differences depending on the distance to the sun[1] and the pressure of the light[2] and solar wind[3] on the shade and Earth's gravitational interference. And the shade must be very much larger in diameter than the planet in order to cover it. How large depends on the distance from the planet. [1] See https://en.wikipedia.org/wiki/Orbital_speed#Planets https://en.wikipedia.org/wiki/Orbital_speed#Planets [2] See https://en.wikipedia.org/wiki/Radiation_pressure https://en.wikipedia.org/wiki/Radiation_pressure [3] See https://en.wikipedia.org/wiki/Solar_wind https://en.wikipedia.org/wiki/Solar_wind
- tempestn 3y agoYou would want to place it slightly on the sun side of the L1 point, where gravitational and solar wind forces cancel out.
- nostrademons 3y agoReminds me of this HN story from yesterday: https://news.ycombinator.com/item?id=39361279 https://news.ycombinator.com/item?id=39361279
- MR4D 3y agoI wonder how that would look from a feasibility perspective... Let's see - Earth's radius is 6,378 km. Area exposed to the sun therefore would be 6,378 * 6,378 * 3.14 = 127,731,695 [1] If you wanted to block just 1% of the light, that would take a shade of 1 million square kilometers, which would be equivalent to a shade that is 1,130 km on a side. Seems like it would be tough to do given all the dust and rocks floating around the sun. Also, you're only covering 1%, which is much less than cloud cover. I'd assume you'd aim to block at the equator since that would have the most direct impact on the intensity of the sun over the course of a year. [1] - I'm calculating the projection as a flat surface here, so the numbers aren't exact but close enough.
- mberger 3y agoInteresting. That area would be roughly one million Sunjammers[1]. One Sunjammer is 1200 m^2 and wights 32 kg. To lift all this would be 32 million kg or 32000 tons. One Starship launch is designed for 250 metric tons when expendable so it would take 128 launches. Add in some fudge factor for orbital burns and I figure 150 launches would do it. Doesn't seem insurmountable. Edit: Seems I misread the Starship capacity. This is probably only to LEO. Its hard to estimate but going by the geostationary payload, it would be one third of that, so triple the amount of flights. At a cadence of 2 launches per week it would take 4.5 years to launch all of it. ( 450 launches / 2 launches per week / 50 weeks a year) 1. https://en.wikipedia.org/wiki/Sunjammer_(spacecraft) https://en.wikipedia.org/wiki/Sunjammer_(spacecraft)
- jandrese 3y agoIf you are clever with cabling through your shade and launch in the right orbit you can use the Earths magnetic field to keep the things oriented properly. Astronomers would hate you though. I'd guess it would be far more efficient to launch more of these into regular orbit than trying to assemble them out in L1 and keep them from drifting off, even though you would need to launch at least twice as many for the same amount of coverage.
- mberger 3y ago
- interestica 3y agoWhat if the aliens already set the snowball on this planet and haven't come back yet
- blindriver 3y agoWhat if we are the aliens and have been back for millions of years?
- OnlyMortal 3y ago“space toupee”
- snakeyjake 3y agoAny sentient species that can generate, store, and then convert the amount of energy to either move a sunshade or move the infrastructure needed to construct and then deploy a sunshade at the distances needed to reach inhabitable worlds no longer cares about planets. They can use that same technology to create, on a whim, inhabitable structures of arbitrary size and composition around any star- converting gas giants (or gas clouds or the solar winds) into perfectly positioned and constructed habitats in ideal locations. Competition over planets would probably be as foreign and incomprehensible to them as what occurred in the universe prior to the Planck epoch is currently to us.
- FrustratedMonky 3y agoSo, Ice Ball or Venus. Seems like climate is more sensitive than we think. Man made impact or not, the whole system seems on a knifes edge of tipping towards the extremes. That we are living right now is rare in-between point.
- boomboomsubban 3y agoThe process they described took millions of years. Yeah, we're probably in a somewhat rare in-between point. That "point" is still unimaginably long.
- somenameforme 3y agoSediment cores show extreme temperature oscillations over far shorter time frames. This [1] is 5 million years of temperature reconstructions based on the Vostok ice cores. Keep in mind the scale, the difference between the peaks and valleys is 10 degrees celsius! But the really interesting thing is that that derived from this [2], which is Earth's temperature over the past 65 million years. Those previous extremes just blur, because now you're talking about a temperature difference of 20 degrees celcius, no ice on the planet, and giant beasts roaming in lush greenery. Greenery which was basically everywhere, even Antarctica! [3] ---- [1] - https://en.wikipedia.org/wiki/Geologic_temperature_record#/media/File:Five_Myr_Climate_Change.png https://en.wikipedia.org/wiki/Geologic_temperature_record#/m... [2] - https://en.wikipedia.org/wiki/Geologic_temperature_record#/media/File:65_Myr_Climate_Change.png https://en.wikipedia.org/wiki/Geologic_temperature_record#/m... [3] - https://en.wikipedia.org/wiki/Eocene#/media/File:Ypresian_Earth_50_mya.jpg https://en.wikipedia.org/wiki/Eocene#/media/File:Ypresian_Ea...
- deepnet 3y agoThis balance is quite probably a very strong filter on the Drake equation. Climate and Biosphere is delicate with lots of tipping points and cascades to uninhabitable. A few billion years ago, the inner planets of the Sol system were capable of supporting abundant surface life - now only Terra.
- pfdietz 3y ago
- jimmySixDOF 3y agoThere is a fantastic BBC Horizons documentary from the 90s called Snowball Earth that was easy to find on YouTube the last time I looked, but just now I see a hot mess of search results and if it's still in there somewhere I can't find it. EDIT: found it on dailymotion and its a great story of how the radical theory was rejected then accepted. https://www.dailymotion.com/video/x7o0b66 https://www.dailymotion.com/video/x7o0b66
- degenerate 3y agoI briefly searched and couldn't find it either - here is the IMDB for others to reference: https://www.imdb.com/title/tt0605181/ https://www.imdb.com/title/tt0605181/
- WarOnPrivacy 3y agoFirst result from Kagi. https://www.dailymotion.com/video/xw5nro https://www.dailymotion.com/video/xw5nro (am also annoying about Thinkpads, FreeTaxUSA)
- mikhailfranco 3y agoGoogle is dead and frozen, a lifeless snowball planet of searchy permafrost. From Page Rank primacy to worthless enshittified commercial crap, all in a Silicon Valley heartbeat. As one tech commentator put it, very politely, to a GOOG exec in a podcast: I used to find Google fantastic for answering my questions, but now it is only good for finding things to buy, not for finding out what I don't know. Someone please put us out of our misery, and put Google down. P.S. As a small start, Brave+DDG is infinitely better than Chrome+Google.
- goodSteveramos 3y agoBrave Search is just as good as DDG in my opinion.
- yusml 3y ago[flagged]
- chefandy 3y agoGreat spam. Will add your domain to my /etc/hosts localhost list today.
- duxup 3y agoA recent PBS documentary did a great job talking about all the changes the earth has gone through: https://www.pbs.org/wgbh/nova/article/the-history-of-earth-in-five-epic-chapters/ https://www.pbs.org/wgbh/nova/article/the-history-of-earth-i... They had a series on planets and some of their history too. Growing up I honestly thought that planets evolved into a sort of natural stable state that I guess I assumed would last until the sun or other external force decided otherwise. But it’s interesting how throughout time the earth has dramatically changed due to “minor” changes like volcanic activity changes, the introduction of, water, oxygen, or bacteria or other chemicals. I had thought the sun and distance from it really was the determining factor as far as the temperature generally goes.
- JohnFen 3y ago> Growing up I honestly thought that planets evolved into a sort of natural stable state that I guess I assumed would last This seems to be another expression of the truth that "people tend to mistake the limits of their view for the limits of the world."
- macintux 3y agoRumsfeld’s unknown unknowns.
- js2 3y agoRumsfeld is famous for the quip, but it's basically an expression of the first stage of the four stages of competence: 1. You don't know what you don't know. 2. You know what you don't know. 3. You know what you know. 4. You don't know what you know. https://en.wikipedia.org/wiki/Four_stages_of_competence https://en.wikipedia.org/wiki/Four_stages_of_competence
- psunavy03 3y agoNo, it is much closer to the Cynefin framework's understanding that complex systems are affected by the influence of variables which are too small for us to measure or even know they exist until after they act.
- Retric 3y agoNot mentioned but still important, the Sun’s output very slowly rises over time and so was significantly lower 600 million years. We are in a ~2 billion year wide sweet spot where multicellular life can thrive in a high oxygen low CO2 atmosphere.
- incognition 3y agoThe Fermi paradox definitely underappreciates the Goldilocks hypothesis
- twojacobtwo 3y ago> Co-author Professor Dietmar Müller from the University of Sydney said: Geology ruled climate at this time. We think the Sturtian ice age kicked in due to a double whammy: a plate tectonic reorganisation brought volcanic degassing to a minimum, while simultaneously a continental volcanic province in Canada started eroding away, consuming atmospheric CO2. Research: > Duration of Sturtian “Snowball Earth” glaciation linked to exceptionally low mid-ocean ridge outgassing’, Dutkiewicz, A. et al (Geology, 2024). DOI: 10.1130/G51669.1
- apothegm 3y agoHow would erosion consume CO2?
- philipkglass 3y agoIt's the carbonate-silicate cycle. Erosion of silicate rocks (which form most of the Earth's crust) by chemical weathering consumes CO2 from the atmosphere and turns it into thermodynamically stable carbonates. Those carbonates can eventually be subducted and their CO2 released again by heat from the Earth's interior. https://personal.ems.psu.edu/~jfk4/PersonalPage/ResInt2.htm https://personal.ems.psu.edu/~jfk4/PersonalPage/ResInt2.htm The carbonate-silicate cycle, which plays a key role in stabilizing Earth's climate over long time scales, is shown in Fig. 2. The cycle begins when atmospheric CO2 dissolves in rainwater, forming carbonic acid, H2CO3. Through a process termed "weathering", this weak acid dissolves silicate rocks on the continents, releasing Ca++, Mg++, HCO3- (bicarbonate), and SiO2 (dissolved silica) into solution. The products of weathering make their way down to the oceans in streams and rivers. There, organisms such as the planktonic foraminifera that live in the surface ocean use them to make shells out of calcium carbonate (CaCO3). When the organisms die, they fall down into the deep ocean, where most of the shells redissolve. Some of the calcium carbonate survives, however, and is buried in sediments on the seafloor. The seafloor spreads from the midocean ridges and, at some plate margins, is carried down subduction zones. The carbonate minerals recombine with SiO2, which by this time is the mineral quartz, to reform calcium and magnesium silicates and release gaseous CO2. This CO2 is vented into the atmosphere through volcanoes, thereby completing the cycle.
- pfdietz 3y agoThe paper: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G51669.1/633748/Duration-of-Sturtian-Snowball-Earth-glaciation https://pubs.geoscienceworld.org/gsa/geology/article/doi/10....
- Slava_Propanei 3y ago[dead]
- senkora 3y agoThe linked GPlates software seems interesting: https://www.gplates.org/ https://www.gplates.org/
- indus 3y agoFeels like a very believable setup for Andy Weir’s next novel.
- Timber-6539 3y agoFrom the article: "The team's work raises intriguing questions about Earth's long-term future. A recent theory proposed that over the next 250 million years, Earth would evolve towards Pangea Ultima, a supercontinent so hot that mammals might become extinct." I'll keep this handy as a smart quip next time someone tries to convince me that human-led climate warming is a thing.
- mcguire 3y ago250 million years vs five decades.
- t00 3y agoFrom what I could gather from the paper, low CO2 leads to a potential ice age. Why the worldwide rush to reduce CO2 then?
- chefandy 3y ago> potential ice age > Why the worldwide rush to reduce CO2 then? Illustrated answer: https://xkcd.com/1732/ https://xkcd.com/1732/
- JohnFen 3y agoToo little would be bad, yes, but too much is also bad. We can reduce CO2 by a huge amount and still have more than the amount needed for a temperate world. We are so far over the desired greenhouse gas levels that it's a crisis and reducing it is necessary if we're to continue being able to live in relative comfort. We're not even near the ballpark of having so little greenhouse gas that this would be a worry.
- macintux 3y agoRush to reduce the dangerous growth of CO2. Reducing CO2 is a pipe dream right now.
- gotbeans 3y agoClick bait title
- downsplat 3y agoI remember it was one of the remarkable take-away points of nonlinear system dynamics, aka chaos theory: the weather/climate system doesn't even have an "average regime" that it converges on. You can average over longer periods of time, and the resulting sequence doesn't necessarily converge to a single limit. Pretty mind boggling when you think about it. Long term enough, "this place's climate" doesn't even exist.
- digging 3y agoThis is clear even without that knowledge if you take a long enough view. The sun will eventually boil our oceans, and then later the solar system will spend the vast majority of its existence in total darkness.
- mcguire 3y agoCoincidentally, I was just watching Myron Cook's video on the Great Unconformity (https://en.wikipedia.org/wiki/Great_Unconformity https://en.wikipedia.org/wiki/Great_Unconformity, although that page only briefly discusses the "Snowball Earth" connection). https://www.youtube.com/watch?v=LXzDfQyUlLg https://www.youtube.com/watch?v=LXzDfQyUlLg Beautiful scenery and an excellent discussion of geological strata.
- mmmBacon 3y agoThe more that we learn about the evolution of Earth as a planet, the more I think that the development of complex life is an exceedingly low probability event. So many things had to go “just right” for conditions on Earth to allow the formation of life. It’s mind blowing to me that one of those things is the collision of a proto Earth that created the Moon which was just the right size to stabilize the Earth’s rotation. On top of that, life on Earth required, vulcanism, plate tectonics, carbon cycle, magnetic field, collection of water, location and size of Jupiter and clearing of asteroids, near extinction events that were survivable by some life, etc….
- wrycoder 3y agoIn other theories, volcanoes emit sulfurous material, which causes global cooling.