Super-Earths

[@NickPoeschek]

As someone who has been listening for what, 5 years, your pronunciation after speech therapy has grown by leaps and bounds. If people can’t handle the occasional mention of Orth, they don’t deserve all the amazing content you produce.

[@r0cketplumber]

I'm kinda deaf and subtitles are my friend. It's the interesting content that matters, I don't give a damn about accents or speech impediments.

[@pakzgames1421]

I concur, his speech has improved alot.. Im glad he never hired a voice actor, like he had wanted to.

[@thewholesomegrail6722]

The speech impediment is soothing to me lol

[@spxdesu]

I'm not native English speaking and if he didn't always add the disclaimer, i wouldn't even notice it other than being maybe just one of many English accents lol

[@shadow67876]

I thought he was just an eastern european who moved to america and had a weird fusion of accents.

[@linuxgeex]

@Isaac Arthur: when considering earth-like planets with increased mass and same contents, you also need to consider the effect of the trans-uranics on the geology, ie volcanism and plate tectonics. If you have twice the mass and only 57% more surface area then the core is going to be a lot hotter, the mantle a lot thinner. That may lead to either taller or shorter mountains. Hard to say as a weak mantle may mean that there's no support for taller mountains esp. in the face of higher gravity.

[@isaacarthurSFIA]

That's a good point, less surface area per volume/mass and way more binding gravitational energy per unit of mass too, so a lot slower to cool in general.

[@djdrack4681]

Good points but also remember that our current 'stable' geological setup is probably not the norm. A super-earth during somehting like the Hadrian epoch or before could be significantly different. If they reach their 'super Earth' mass via collision/aggregation of many planetesimals/protoplanets etc: it could be that a super-Earth with a thick mantle and very hot core could have multiple 'cores'. That is the cores would be the remnants of those protoplanets etc slowly melting in the mantle. In such a situation it is hard to predict how long it would take to melt something big in a mantle: 10k years or 100million years? If the stellar nebulae that housed the solar system before it formed was deficient in transition metals this could drastically affect not just the composition and behavior of the planet's geologic cycle: but could be a minor filter in its own right: a planet highly deficient in iron to begin would probably not give rise to any sort of life that is highly dependent on it.

[@FLPhotoCatcher]

@@isaacarthurSFIA A note about Pluto... The "heart" most people see is much more like a footprint. You can even see the toe prints. I'm guessing the footprint signifies Pluto having been kicked out of the planet club.

[@linuxgeex]

@@isaacarthurSFIA with a thin and unstable mantle, high water, and high gravity, such a planet's only solid surfaces would likely be atolls and icecaps

[@Dragrath1]

Also probably worth noting that transuranic elements are a but more complicated than heavy elements sink to the core as chemistry's role in differentiation means that actinides which have a strong chemical affinity for oxygen tend to actually differentiate upwards with the lighter oxygen based material oxide rocks. Remember Actinides chemically behave like rare Earth Lanthanides and thus preferentially differentiate into silicate rocks. This is to say the likes of Thorium Uranium and Plutonium are chemically incompatible with iron. As such the actinides induced radioactive decay will preferentially heat the upper mantle and or crust where oxide rocks concentrate rather than the metallic core which is very counterintuitive but has been confirmed to be true on Earth Mars, and Vesta. Incidentally Mars according to NASA's INSIGHT mission seems to have surprisingly extreme actinide concentration in its crust which may partly explain why Mars seems to still be more volcanically active than expected.

[@prosaicGodowsky]

can we all just appreciate the rise in quality of the visuals? Isaac Arthur you've come a long way

[@deus_ex_machina_]

Unfortunately some of the jank from the stuff he adds in the edit (title font and like, subscribe and share 'buttons') still remains.

[@patrickbyrne5070]

@@deus_ex_machina_ I like the jank stuff- you know where you are with the Arthur-jank . Everything else has improved so having a little of the funk left makes me kinda happy

[@rudyrobles8294]

Sir Isaac is the King of Thursdays.

[@josephlawson1796]

Newton or Arthur? either way is a win

[@renderproductions1032]

Yes

[@renderproductions1032]

@@josephlawson1796 ¿Porque no los dos?

[@ManuelGonzalez-kq4gi]

Doug demuro

[@eatinglightcookingenlighte1608]

Because it's Arthursday

[@TheSwanvillan]

👍Personally, Mr. Arthur, I enjoy the way you speak (6:00). Your rhythm of speech as well as your noteworthy pronunciation are relaxing IMO. TFS🙏

[@mill2712]

The types of super earths timestamps. (SFIA-26) 10:29 11:31 15:22 (SFIA-200) 17:07 (Hydro-30) 20:09 (Ares-10) 20:33

[@PerfectAlibi1]

Those are just examples though

[@vincentcleaver1925]

@@PerfectAlibi1 your assignment for the class is to set up a spread sheet of examples at .1 Earth mass intervals up to 30 Earths and densities at half g/cc intervals from one to seven....about four thousand 8-P

[@dominusbalial835]

Nice comment to leave, helping me more quickly to decide how large I want the capital world of my chaos space marine empire in Warhammer 40k

[@JoshJustGames]

Man. I admire issac so much. Your speech has improved so much over the years I have been watching. And I would imagine tackling Sci fi and space terminology is possibly one of the hardest things to do. Kudos man Life time fan 👍

[@zell9058]

Glad to share this planet with you. Happy Arthursday folks.

[@slabrankle9588]

Genetically engineered Sargassum for raft continents on ocean worlds. It would be self repairing, unsinkable, edible, and the underside would make a tremendous habitat for introduced sea life. It would also be a massive oxygen pump, ocean water filter and carbon sink.

[@FLPhotoCatcher]

Nothing is unsinkable. Didn't you watch the movie Titanic? haha

[@TheArtofFugue]

@@FLPhotoCatcher genetically engineered sargassum would be unsinkable.

[@slabrankle9588]

@@FLPhotoCatcher I forgot to mention it's also iceberg proof.

[@acadiano10]

@@slabrankle9588 it is a biological equivalent of an iceberg. It sinks icebergs!

[@CCNorse]

The trouble is that if you’ve got a kilometer’s deep ancient ocean with no significant seamounts, the nutrients necessary for life would be trapped in the abyss and the water at the surface would be nearly pure. One would have to introduce nutrients and minerals in order to support the mats, either with pumps or by dropping pulverized asteroids into the planetary oceans (see the recent Cody’s Lab video on meteoric seeding of nutrients)

[@cannonfodder4376]

A splendidly informative video on this topic as always Isaac.

[@andrewbutler926]

I would love to see a breakdown of how we could actually shell over Saturn and position it correctly to be used as a mega earth. For that matter how could we feasibly utilize all of our gas giants for that purpose and what would be the pros and cons of setting up a solar system that way?

[@andrewbutler926]

Thanks again for putting out such quality content. I always look forward to new videos from you.

[@stefanr8232]

It is based on the orbital ring system. The idea was first published by Paul Birch in the early 1980s.

[@samlosco8441]

Constructing shell worlds around gas giants would provide almost endless living space for humans. It's one of my favourite science fiction premises

[@Obsidian762]

After a rough week, i needed a new video from Isaac! Thank you for the great content.

[@petervanhavermaat9839]

D1

[@isaacarthurSFIA]

Sorry to hear that, I hope the rest of the week is a bit smoother :)

[@Jake-ms9dr]

I showed this channel to my younger cousin who was deaf and has a lisp. She was very excited to see someone who has the same difficulties she does be able to work through it. You gained a new subscriber from her!

[@dracoargentum9783]

Wow. So far this episode has covered two topics that I had researched JUST THIS WEEK, for completely different reasons: the formula to double the volume of a sphere and the pressure of water in comparison to the depth.

[@mikotalik]

I'm so glad I found your channel. It's insane how many high quality videos on different exciting topics you produce. This is exactly the kind of stuff that makes me excited for the future beyond my lifetime. I feel like a kid again when listening you talk about such topics. Can't wait to watch this one! I have a question - what is, or was, your occupation before youtube? You really know your stuff. Such a wide range of scientific topics. I'm curious and imagine some scientist/engineer.

[@stefanr8232]

Isaac worked for the election board in Ohio. (not sure if he stopped working there). He was a physics graduate student before serving in the army. Isaac is married and they have bees on their farm.

[@BastionMarshall]

You're still understandable and l love the way you talk. It's so soothing.

[@francoislacombe9071]

I heard a planetary scientist in a documentary say that many super earths might not have strong magnetic fields. Their higher masses, and thus higher pressures in their cores, would force the liquid metal there to solidify, like what happens in Earth's inner core. This would stop any real magnetic field from forming on such worlds.

[@scottd3025]

@Issac Arthur. I just discovered your awesome body of work. Your content, delivery, and production savvy are exceptional. I absolutely love your voice. It is a unique strength that makes you “one of a kind”. You are an inspiration. Your formula is perfect. Don’t change a thing.

[@grantfomin6829]

Ive been waiting for this. I've been working on a scifi series involving an alien race living on high gravity planets.

[@whitephantom.2107]

Nice 👍 good luck bro, is it out yet or are you still still developing your series?

[@metaverseplayer]

Yes keep us posted. We’ll support you 👍🏾

[@shakagod3779]

I'm one of your channels long time supporter's who also likes to fall asleep listening to you're voice. Respectfully of course. Keep up the wonderful content.

[@StuffandThings_]

Damn, seems like we got lucky with Earth's gravity. Weak enough that humans and Earth based life can survive in 0g reasonably well (and probably thrive as we get more adept at managing such environments), yet strong enough that we're adapted to handle quite a lot of force and could probably survive on a reasonable amount of rocky planets gravity-wise. It seems pretty damn hard to get a surface gravity significantly larger than Earth's, and probably won't be like the *biggest* concern at the very least (beyond all the other drastic effects mentioned of course. Seems like the gravitational force on the human body at least wouldn't be a massive concern by comparison). Not to mention that we can survive a pretty appreciable range of pressures as long as the gas mixture is adjusted appropriately.

[@Daniel-wr9ql]

We didn't just "get lucky" with Earth. We just adapted to its conditions.

[@StuffandThings_]

@@Daniel-wr9ql Yes, its lucky that these were the conditions we adapted to, instead of say deep within a gas giant, where the pressures would make space travel nearly impossible.

[@lamhuynh7201]

For super earth!!!! Oh wait wrong show

[@MantraHerbInchSin]

I often spend several hours at night trying to fall asleep. I can't stress how much more enjoyable my nights became 2 years ago or so when I found this channel. I have started listening to 40K lore as well, and that was because Isaac here has mentioned good things about 40K

[@laresilience5829]

If you like 40k and narration go check occulus imperia Absolute must

[@1FatLittleMonkey]

Regarding ocean depths. There's coincidences in the height of Earth's continents that suggests the level of the continents is related to sea-level in a way that means you can't say "bigger planet has 1km-height more water, therefore 1km-height less land." They aren't independent variables. Continental tectonic plates are around 35km thick and oceanic plates just a couple of kilometres, but the tops of the two kinds of plates are nearly level with each other. To a degree that is beyond coincidental. Similarly, the cratons (the old, eroded parts of the continental plates) are all within a few hundred metres above sea-level, and all the continental shelves are within a few hundred metres below. Ie, the continental plates erode to just above sea-level, but no further, except for a small percentage around the edges that gets directly eroded by oceans, but those areas (once below sea-level) erode no further. Doesn't matter how big the craton is, how old it is, whether it's surrounded by mountain building tectonics, or isolated directly against the ocean plates, they're all roughly the same. It's just too much of a coincident that all continents just happen to be around the same height above/below sea-level. It must, therefore, be caused _by_ the sea-level (at least, on average, over billions of years), rather just a happenstance of the quantity of water and the thickness of the plates. Perhaps the energy of erosion is related to height/depth relative to sea-level, the lower the craton, the less erosion is possible. Such mechanisms are likely to work on a world with more water. Therefore you can't just say "there's a kilometre-height equivalent more water, hence the oceans will cover a kilometre-height more of the continents." If the oceans are higher, the land won't erode below that. In which case the cratons (and hence the continents) will be roughly the same height above/below sea-levels as they are on Earth. Some differences because mountains will be broader, valleys shallower, due to higher gravity, but overall, it should be roughly similar.

[@mikebrennan5802]

I am new to thaw video’s, maybe 6 months or so. I have learned so much. I am so impressed with all the information in each video, but also it’s explained in a way that is easily understood & doesn’t sound like an academic book which some of the videos are like. There video’s are AMAZING.. Thank Yoi for making them & educating all of us. really an INCREDIBLE job producing these

[@brianstoner5424]

You have the most fascinating channel on KZbin thank you

[@cosmicboogerspoon8507]

Wurd, brother

[@RustyBrusher]

Hey man, your voice is wonderful to listen to. Don’t worry so much about how you sound, cause you sound just fine to me and I’m sure many of your fans feel the same :)

[@aatsiii]

I like how you accept and clearly don't mind the fact some people listen this content and fall asleep :) it happened more than once to me, but I usually come back to finish the episode later. I find these videos very interesting, but listening to your calm voice late at night it's just unavoidable. Thanks for what you're doing and for being such a wonderful person :)

[@AnyOtherNamePlease]

21:40 Would the effect of gravitational compression not lead to higher densities on planets more massive than Earth but with a similar composition? I think there are graphs that plot out radius-to-mass for given planetary compositions factoring that in

[@Dragrath1]

Yep exactly it is a pretty big detail as this is exactly why earth is more dense than Mars and why Jupiter is much more dense than Saturn. There are indeed graphs which factor this in though they tend to be pretty complex as they need to account for lots of possibilities to make the same mass planet so maybe he thought it was too messy to show as a visual? If that was the case then it is a bit disappointing then that he doesn't think his audience could handle that nuance.

[@AnyOtherNamePlease]

Artifexian did a good video on the concept called: Build Your Own Terrestrial Planet if anyone is interested

[@jimmysroom5132]

There's nothing wrong with your speech! Your videos are great 🙂

[@norm3380]

I have a question. How do they know all the mass of the super earth is all one planet? Couldn't some of the "extra" mass be a moon or multiple moons? Being so relatively close to the planet.

[@esquilax5563]

If they detected via transit, I imagine there would be clues to that in the light curves. See David Kipping's videos on exomoon detection, on the Cool Worlds channel, for more info. But if they detected by radial velocity, then indeed I doubt it would be possible to tell - gravity of 2 medium masses is the same as that of 1 large mass

[@ceterfo]

@@esquilax5563 he11 yeah now that's a comment. Gold star. I hope you are having a good day. Party on dude.

[@MaiMontfort]

Your pronunciation is just fine, and your explanations are spectacular.

[@adamh1228]

i love these kinds of episodes! good detailed investigation of the variety of places

[@rhuiah]

Great episode. I would absolutely love to see what kind of megafauna a lower-gravity 'super earth' has (from a safe distance, of course). Heck, even mile-high trees would be a spectacular sight.

[@scientchahming5]

On a planet with more gravity than Earth, trees would be shorter, not taller.

[@Dragrath1]

@@scientchahming5 Read their comment again they are talking about a lower density world i.e. less surface gravity not more.

[@freedomhq4075]

This is a really cool episode, never thought about the size of earth, gravity, and the atmosphere the same way since.

[@389293912]

I wouldn't be too concerned about your speech anomaly. It's part of your success as it gives your narrations a lot of unique character.

[@StarBoundFables]

Hey, Isaac, I was watching this episode over on Nebula & I came over to comment that I believe your pronunciation of Earth to be absolutely clear (I'd even say it's pretty good 😃) I look forward to watching the Oceans in Space episode. Underwater, habitable, self-sufficient ocean cities are such a cool concept 🏙 🌊❤

[@singletona082]

I can hear the opening Narration for Caiphas Cain 'to boldly go to strange new worlds. To seek out new life and new civilizations..... and then wipe them from the face of the galaxy for the good of the imperium'

[@bustead2]

He thought it will be a relaxing research mission. But the world he visits turns out to be a necron tomb world being attacked by the Tyranids. Just his luck.

[@akasha9141]

I am a simple man. Isaac releases a video, and I immediately like and listen

[@nelzelpher7158]

Your dedication to this specific pronunciation cannot be topped.

[@lenorepaladino8632]

I've been listening for so long I forget about your speech pattern, just seems right to me. You're the best Isaac!

[@RabidIrishGuy88]

Just wanted to chime in on any random video of yours and shout out a thanks for making such long form content that avoids sensationalism and clickbait that plagues our global culture today. I never feel insulted on this channel with flashy bullshit, insultingly choppy editing, etc. it's old fashioned long form content that is well researched and script-written and never falls into those traps. Keep doing what you're doing, you've found the right folks who respect that. I've been watching for years on and off

[@itsfonk]

I’ve wondered, on planets so large that it’s gravity prohibits escape via rocket propulsion, might wholly different mechanisms and technologies be developed by its higher life forms as they also shoot for the stars…

[@rykazasan]

They might get to experiment with exotic denser versions of our materials, so maybe they get fusion sooner.

[@Bullshitvol2]

Higher gravity is going to lock intelligent life forms for a very long time maybe forever. If you need twice the escape velocity of eath to leave a planet this doesn't mean you get away with a rocket twice as big. You would need a rocket 6-10 times a big than what we are using now. The only technology we have to get into orbit on such a planet wout be nuclear impuls propulsion (Project Orion)

[@sevex9]

Isaacs earlier videos have answers to that. Maybe the launch loop. kzbin.info/www/bejne/gGKwcppmiqZ0fsk But basically some kind of structure using active support would be the only way I believe.

[@psmirage8584]

3:07 At first, I thought, "Wow! What a fantastic render." But then, I noted several elliptical craters. The problem is, that a crater is generally about twenty times the diameter of the original impactor, so the impactors would be very large. The energy of those impacts would be absolutely gargantuan. As an impacting object disintegrates and is stopped, most of that energy is converted into heat - and that would be a titanic explosion - centered on the point most of that mass came to a stop. So, even if there was an elliptical impact zone at first, it would be instantly obliterated by the explosion - leaving a circular crater.

[@freddyjosereginomontalvo4667]

Excellent content as always 🌍💯💖

[@KilnFirelink]

I used to watch your videos years ago and ended up stumbling on this video, its a hell of a lot easier to make out what you are saying now and good job as always

[@RealBradMiller]

6:05 Nah man, you say it however you say it. It's not a big deal, you put yourself out there to bring information and entertainment to tons of people, and you are successful at it.

[@mill2712]

This video as of me writing this was released 28 minutes ago and is over 32 minutes long. So it's likely no one finished this video yet unless you spead it up. So I'm pleased to find the commenters making meaningful discussions on the topic.

[@AllFather-TheStoicGod]

Or it could be others received their push notifications a few seconds or a minute before you and started sooner.

[@mill2712]

@@AllFather-TheStoicGod That too.

[@stefanr8232]

Nebula subscribers get to see the episode earlier than us plebians.

[@nobodyherepal3292]

How many different nations do you think could populate a inhabited super earth?

[@sciencerscientifico310]

That depends, there's hundreds of cultures and ethnic groups on Earth that make up various nations. You could have as many if not more nations on a super earth As to nations as in nation-states, as defined by the land each central government claims a monopoly on the legal use of force over, that would depend on the political systems in place on a given planet. The idea of a centralized country is a relatively new one, as with the exception of empires, humans largely lived in tribes and small city states.

[@jacobv3396]

Could be as little as one.

[@mikelfunderburk5912]

Arthursday! Thanks to all involved.

[@urphakeandgey6308]

On the subject of size, density, and gravity, there was a video of Saturn colliding with Earth where so many comments were pretentiously arguing Saturn would orbit the Earth because it's less dense. If that were true, the Earth should orbit these people because they're extremely dense. *_Mass_* determines gravity. Saturn is more massive.

[@deus_ex_machina_]

Savage!

[@aaronhancock9864]

This channel makes Thursdays enjoyable!

[@vaishakm6]

5:54 hey man its all cool you are doing great work trying to provide us with these information one bad pronunciation wont ruin and you even went a mile ahead in providing the subtitles

[@doug2424]

We got alot to learn about, thanks for the info.

[@SeminarChauffeur]

I want a smaller version of Earth actually, but not too small that it screws up life-sustaining factors that are tied to its size like gravity.

[@BI-11y_TheStormTrooper]

So something in-between Mars and Earth size but Earth like in terrain, composition and atmosphere .

[@1FatLittleMonkey]

Lower gravity + thicker atmosphere. So that both flight (including animal flight) and orbital launch are easier. (Not sure how to combine the two in practice, if it's a warm world, it's close enough to the sun to strip the atmosphere. But it's a fun thought-experiment.)

[@jayf6360]

Buddy your speech is excellent. Man I use your videos as a sleep aid. I mean that in a good way.

[@jayf6360]

Ps No homo

[@StuffandThings_]

Honestly I'd say best case scenario would be a mars density planet with a higher radius, that way you could get an Earth-like gravity (which of course is nice for all sorts of reasons) _and_ have more surface area to play around with. Plus Mars likely had at least a somewhat active geology in the past and isn't exactly some weird gas ball we'd have to build a shell around or anything, so it would probably manage to be vaguely familiar too.

[@RickeyBowers]

I'm fascinated by the idea of hot Earths. We know that low density materials (like Aerogels) can insulate in an extreme way. This has me imagining creatures that evolved low density insulation - maybe a shell that wears away and is replenished like skin shedding. Compacting might create a hard surface or exoskeleton to withstand greater gravity without limiting structural growth.

[@ceterfo]

I try to watch every episode a few times. once well reading comments, Second for well paying more attention and God knows how many Welst I fall asleep. I hope whom ever reads this is having a good day and if not "tomorrow is a new day."

[@serrece]

I have never had a problem with his speach it reminds me that even when your different you can achieve great things as does Issac Author Nick Poeschek and I enjoy listen its a soothing voice

[@lancerhalsey4816]

For Super Earth! For freedom, justice, and prosperity! Spread democracy across the galaxy! Onward Helldivers, to victory! Sorry, can't help but think of Helldivers when I saw the title.

[@richardaitkenhead]

I love the voice, its unique and is in no way hard to understand..... there is nothing worse than being the same as everyone else.

[@Barnardrab]

Planet habitability is my favorite topic. Could you do an episode on building habitable planets from the raw material of comets, asteroids and existing planets? The benefit of this would be that the engineers would know and control the exact makeup of the planet, resulting in more stable geology and climate. Several years ago, I saw a movie called Titan AE, which ended in a habitable planet being artificially created by alien technology. I think this movie is what inspired me to become so fascinated with your content. What's the fastest way to achieve such a task with known physics?

[@stefanr8232]

The colonizing Titan episode talks about ripping a planet apart. Same tools but in reverse lets you assemble one. You can retrieve the energy too. The primary time constraint is radiating off all the heat generated.

[@Barnardrab]

@@stefanr8232 I imagine that wouldn't be a problem for assembling the core. We would probably want to assemble the iron first and we would want that to be hot for the magnetic field. I think we would want to slow down when assembling the crust. Doing it this way, the elements wouldn't be mixed, but would be layered. Due to heat dissipation, I would think that the crust is where we would want to slow down.

[@virutech32]

if you're building a mass-gravity planet it pretty much always makes more sense to make a shell world. makes for a way more stable crust to live on & way cheaper since most of ur mass can be hydrogen/helium.

[@benpaterson2237]

I envision a lot of high gravity lifeforms supporting themselves with pneumatic honeycombed skeletal structure similar to terran birds and dinosaurs, even being buoyant biological airships full of synthesized hydrogen swimming through the thick dense atmosphere amid aerial kelp forests.

[@marvinmauldin4361]

I only went through a couple of hundred comments (unlike those who look at no comments before repeating the ones that have been repeated already), and found no concerns about encountering Ice Nine after the mention of Ice Seven.

[@jakubcesarzdakos5442]

Speech therapy? Your voice and speaking is one of my favourite on KZbin, I love listening to you even without how interesting the videos you make are

[@jakubcesarzdakos5442]

Although it might be because I'm not a native and might not notice some thing natives would

[@joyempire462]

Now just waiting for Bat-Earth

[@danielvest9602]

Thanks for clearing up these issues. The news always bungles this stuff.

[@loturzelrestaurant]

Flat-Earthers misunderstood had what Super-Earths are and then got debunked and corrected by Sci Man Dan. It's fun, so go check it out.

[@hovant6666]

Stoked for oceanic space habs, like the Mario 64 drown house

[@cyruspowers7355]

I love this channel so much.

[@AtlasReburdened]

Oh snap, it's Thursday and I have the day off. Time to grab the coffee.

[@GuardsmanBass]

I'd stick two caveats on to SFIA-26's land and ocean area: 1. SFIA-26 presumably has plate tectonics. On Earth, plate tectonics actually causes surface water to get drawn down into the mantle, chemically bound into rock, and then sometimes put back up via volcanism - but on net, it seems to draw down more water than it puts back out, to the tune of a cubic kilometer of water per year IIRC. SFIA-26 might have more surface water, but it's also going to have a larger surface and considerably larger volume of mantle to draw down surface water into. Its oceans might not be as deep as we might otherwise think. 2. Since continents don't really erode if they're below sea, I think you'd see a fair percentage of the surface with land even if it's flatter on average due to erosion.

[@stefanr8232]

The continental crust is lifted by buoyancy if it is underwater too. The extra ocean depth pushes down on the subducting plate.

[@Dragrath1]

Yep thanks for pointing out the Plate tectonics drawdown effect in fact there is evidence to suggest that prior to 3 billion years ago there was very little if any of the continents sticking out of the water. Moreover when you factor in the ecological competition between various photosynthetic metabolic pathways aerobic photosynthesis can be shown to have a strong ecological disadvantage relative to anaerobic photosynthetic pathways due to the amount of energy needed to extract free molecular hydrogen from water molecules compared to hydrogen sulfide or electron transfers to convert dissolved hydrogen cations(protons) back into molecular hydrogen to perform carbon fixation. This downside which is a side effect of the same large electronegativity that makes oxygen so efficient for respiration means splitting water as a source for molecular hydrogen requires more energy than chemosynthetic pathways or lower energy infrared light can provide making it only viable in the upper water column. Since without land the only source of nutrients is passive upwards diffusion of mineral nutrients from the seafloor into the water column this gives anaerobic carbon fixation pathways an inherit advantage in deep water as they can exhaust the nutrients diffusing into the seawater from below before they can reach the photic zone. Combining this biological constraint with the gradual drawdown of the sea levels in the oceans allows you to naturally reproduce the observed billion year delay between the oldest evidence of aerobic photosynthesis and the Great Oxygenation Event. Additionally there is a temperature driven phase transition which allows the formation of relatively lower density mineral hydrate plumes around the mantle transition zone which carry mineral nutrients leeched from the subducted sea floor crust this happens to match up with the timing of the second oxygenation event that ended the so called boring billion setting off the rapid explosion of complex life that eventually led to us. Molecular clock estimates support this association of when Hydrous mantle plumes became possible to the timing of when the oldest extant pelagic(open water) cyanobacteria and eukaryotic algae lineages split off from their shallower costal water and or freshwater cousins. In other words it seems that the drawdown of water into Earth's mantle may be the primary mechanism which delayed the emergence of complex life on Earth and since the percentage of water which can become mineral hydrates is driven primarily by the temperature of the mantle this suggests the hydration of the mantle and subsequently the emergence of complex life are controlled by the rate of which Earth's mantle cooled over time. This potentially suggests that it might be possible to somewhat guestimate how long it takes for complex life to emerge based off the rate of cooling for a planet relative to Earth.

[@hordebucket8971]

Thanks man I remember requesting this. Only just clicked on it so I'm quite excited to watch this. This is gonna be awesome 👍👍

[@frankroquemore4946]

If Isaac Arthur started his own science publication, I think it would very well be the most interesting, thoughtful, and accurate one around. I love your videos Isaac, but there simply aren’t enough of them. You gotta delegate, collaborate, and lead more people in order to satisfy my hunger for your content lol

[@isaacarthurSFIA]

:) Thanks, though other folks do help edit and sometimes even help write our episodes here, but I usually encourage anyone who does to start their own channel, blog, or novel.

[@randomuser778]

I like the way you pronounce words, Isaac. You don't need to change a thing.

[@peeperleviathan2839]

21:45 The larger planets are the greater the density (until they become mini Neptune’s) which means planets of earth composition at about 2X earth mass would have a density of around 5.7-5.9 G/CM3

[@UrdnotChuckles]

Massive floating platforms on ocean worlds are certainly a neat concept, as are ones that float in the air just above the water should you want to go that far. If there's lots of water then you've got no shortage of hydrogen!

[@bananajoe8980]

Isaac you need to stop apologizing for you voice it what make the show iconic and why I love it

[@michaelhensley4169]

This was a fun episode.

[@guyvelvet1980]

Dude !! I love your voice and understand everything you say ...

[@hunam_1]

Isaac Arthur: apologizes for his mispronunciation of Earth Also Isaac Arthur: makes an entire episode just to practice on it Keep doing you and making fantastic content, you magnificent bastard.

[@johnsmith-vn9cs]

I feel lightning, and therefor temperature, is the easiest to adjust: just a few orbital mirrors would allow you to increase or decrease the amount of light it receives.

[@DavidEvans_dle]

Another great episode, it's like a seminar on how to live on "Super Earths." But, it seems like I missed the lecture, on how to travel space to get to one. LOL

[@stefanr8232]

There is an upward bound series and an outward bound series.

[@DeltaVTX]

It is inconceivable to me that this moment, as I contemplate our place in this universe, that there is not some thinking creature somewhere in this galaxy looking at the stars and wondering if they are alone. I hope that our species survives long enough to find out.

[@dgd947a15fl]

I think a video on the technological/scientific impacts of asteroid mining (ie what sort of technologies could be both technologically possible and economically viable once rare earths are cheap and abundant) would be cool. For example, all sorts of batteries and solar panels could become both better and cheaper with a 100m diameter chunk of the right stuff.

[@ModernandVintageWatches]

Super great, as always.

[@stefanr8232]

Added water pushes down more on the oceanic crust. Alternatively could say the continents get added buoyancy. Subduction gets driven faster by higher gravity. There is more heat trapped in a super-Earth so more convection.

[@hordebucket8971]

If there is more convection what does that mean ?

[@Moontanman]

I am currently working on a story about a world that is 2.5 times earth's diameter with 2X earth's gravity. This video helped me flesh out the details of my planet... thank you.

[@peeperleviathan2839]

That’s a very massive and low density planet

[@Moontanman]

@@peeperleviathan2839 About 12.5 times Earth's mass, if my math is correct.

[@JayLock77]

Your pronunciation of 'Earth' seems fine to me. I didn't even notice anything til' you mentioned it. Or, maybe I'm just used to the voice. 🤔

[@savagesarethebest7251]

I have seen almost every video (bu the livestreams) and I do not notice any problems with the speech, neither does my girlfriend who have rewatched most with me

[@itsfonk]

Earth. Orth. Arth. Yurth? We’re all mites riding the same beast, no matter what it’s called.

[@marciserota2295]

Hi Isaac love your videos

[@lordjulian4263]

uh I liked this one. Some really interesting things in here I never really thought about. Also I am looking forward to the marine-habitats. That is also a thought that never occured to me but that only makes it more intriguing.

[@yodorob]

It would be interesting to investigate Earth-like planets with barely more than half of Earth's gravity and a diameter barely more than 75% that of Earth - in short, the opposite of Super Earths. Those smaller Earths fascinate me even more than the bigger Earths.

[@romankrhounek5974]

You're the best sir love listening

[@scottdorfler2551]

You found a way to say Uranus that doesn't make me laugh like a 12 year old." Your ran us" Brilliant 👏

[@richardgreen7225]

Wow! So many variables! That tends to make Earth's geology/ecology seem less probable. However, the additional degrees of freedom also expands the parameter space. I would need to write a Monte Carlo to properly sample the parameter space and see what it does to the Fermi paradox.

[@Dragrath1]

Indeed it gets even less probable in some respects when you look at the evidence coming from recent years such as the surprises of our various efforts probing the interior structures of planets beyond Earth and our Moon namely Saturn Jupiter and Mars respectively all indicating they are far less differentiated internally than Earth or our Moon. Evidence of isotopic ratios strongly suggesting the terrestrial planets volatile contents being almost entirely native material i.e. present during the planets formation with observations of protoplanetary disks via radio interferometry and the New Horizons flyby of 486958 Arrokoth both pointing towards a direct collapse/disk fragmentation model for first generation planetesimal formation which occurs much earlier during the star formation process than has been conventionally assumed. It may be that to get an earthlike planet at all you need a direct collision between two 1st generation planets energetic enough to entirely or near entirely vaporize both parent bodies but not energetic enough that said material gets dispersed allowing it to remain gravitationally bound and reprecipitate out into a differentiated world or worlds depending on the angular momentum budget. Basically much more complete collision models which account for phase transitions and fluid dynamics strongly suggest both the proto -Earth and Theia were vaporized into a rapidly spinning disk that as it cooled precipitated out to form the Earth and at the far edges its Moon as a angular momentum sink allowing the rest of the material not lost to space to condense back into the Earth. There is a much wider range of initial conditions which can reproduce an Earth Moon system while accounting for axial tilt and orbital inclination in a way that older less sophisticated or less computationally intensive models could not.

[@sarcasmo57]

This Earth will always be super to me. Except for all the jerks.

[@stevenfaber3896]

Great video like always Sir! 😉

[@PhilipMurphy8Extra]

Isaac Arthur is the king of Thursday for sure.

[@loturzelrestaurant]

Flat-Earthers misunderstood had what Super-Earths are and then got debunked and corrected by Sci Man Dan. It's fun, so go check it out.

[@agalah408]

One of the Jack Vace planets was bigger than earth, with few metals and low density, giving it an Earth-similar gravity. For some reason he called his book 'Big Planet'.

[@prakadox]

V. Nice episode. Keep up the great work, SFIA!