The NEW SCIENCE of Moon Formation

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Einstein once asked whether “the moon exists only when I look at it?". It was rhetorical objection to the idea that measurement in quantum mechanics causes reality to become real. But there was a time when the moon didn’t exist, and then hours later suddenly did. At least, according to the latest simulations of its formation.
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Опубликовано:

10 янв 2023

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Комментарии : 1,9 тыс.

@Skip6235 Год назад

I’m just trying to wrap my head around a column of molten rock several hundred thousand miles high raining down onto the surface of the planet in less than 24 hours. The sheer violence of such a thing is unimaginable.

@krabkit Год назад

noticeably less violent than the preceding impact

@saturnexplorers Год назад

Welcome to the universe

@bottlekruiser Год назад

smart people: violence is not a solution also smart people when asked how the moon came to be:

@JoshWiniberg Год назад

It's mind-blowing isn't it? And that's tame compared to many cosmological events.

@tinygriffy Год назад

I find that's peanuts compared to the next best Quasar out there..

@TheoriesofEverything Год назад

Thanks Matt. It was an honor. Looking forward to speaking again.

@jacobthompson6592 Год назад

I was surprised you mentioned the lunar seismometers. My grandfather helped build the radioisotope heater units for the seismometers that were installed during the Apollo 11 mission.

@BaloneySansWits Год назад

I worked at Marquardt, the company that made the R4d thrusters that one can see in fours on the sides of the Service and Lunar Excursion Modules

@itzelpretzel Год назад

Your grandfathers fingerprints (metaphorically, im sure it was all sterilized) were on the moon. Wow! Thats a beautiful legacy.

@calebdunlap7566 Год назад

My fiancées great grandfather helped make the first US space boot

@harbirsingh7266 Год назад

18:00 "Some animals do have hands large enough to swim in a gas. They're called birds." This just blew my mind. How did I never think of that? Haha.

@joansparky4439 Год назад

here is another one for you - we are living at the bottom of a gas ocean.

@bazpearce9993 Год назад

@@joansparky4439 We are Crab people lol.

@DriantX Год назад

@@joansparky4439 And a gas ocean is living at the bottom of me. sorry

@markzambelli Год назад

And Penguins 'fly' through water

@twistedtachyon5877 Год назад

No respect for bats smh

@billbill6094 Год назад

This is by far the easiest to understand SpaceTime episode and most awesome topic yet. Imagine going back just shy of 54 years ago and telling someone not only are the moon and the Earth formed from the same two planets in the same orbit colliding, but in just _a single day_ there might have been _two_ moons, one even bigger. Absolutely mind blowing.

@chriskennedy2846 Год назад

I agree, great topic. It goes to show there is plenty of fascinating science within our field of view that allows us to keep learning while being intrigued by the remaining mysteries yet to be solved. By contrast, we certainly don't need any more: black hole, worm hole, dark matter or dark energy videos for awhile. Great job. More science - please.

@tehpw7574 Год назад

...and yet, there are idiots who publicly claim 'Teh World is flat'. :/ This theory, in how the moon was formed should be embraced at defacto-fact: Nothing else seems as accurate when it's visualized like it is in this video. Also, who is to say that electro-magnetism has much to say in the formation? Isn't that a after effect, not a cause (like gravity)? [Disclaimer, I'm a Gen-X Veteran Mechanic, not a scientist. WTF do I know about SCIENCE!?]

@zes7215 Год назад

wrrg

@Rydonittelo Год назад

It's so sad that 30% of adults in the UK couldn't answer the question " What is bigger, the sun or the moon?" If you find this shocking as I did, ask people and you'll be astonished that some grown adults don't know the answer to this less than basic general knowledge question. Its mind blowing

@Rydonittelo Год назад

@Repent and believe in Jesus Christ The creature could not bear the wrong done to its creator, therefore the sun withdrew its rays so it would not behold the deeds of the wicked. Crystophusis ☀️🌤⛅🌥☁️🌫✝️

@firebladetenn6633 Год назад

It's always a good day when Spacetime uploads.

@firebladetenn6633 Год назад

@sethevermanoff I didn't know I needed this today, but thanks.

@crispymidget8531 Год назад

Indeed!

@zes7215 Год назад

wrrg

@nellym46664 Год назад

It's crazy how such a random event possibly turned what may have remained a barren rock in space into the only known sanctuary for complex life in this universe. Pouring one out for Theia tonight.🙇‍♂

@garmtpug Год назад

I wouldn't assume we are the only place where complex life exists. There are many possibilities for life that don't necessarily have to be Earth-like. I'm a firm believer that life can arise in numerous conditions, as we have even seen on our planet. Various forms of life on Earth have been found in the most inhospitable places that we once assumed could not develop nor harbor any type of life forms. But life has been found in them! It does find a way! So, looking at that, it's easy to picture life forming in all kinds of planetary conditions throughout the Universe.

@colterhikel9819 Год назад

Is life very robust and able to form in lots of adverse conditions, or is life fragile but able to adapt to harsh conditions after getting a foothold?

@flintdavis2 Год назад

Or the process wasn’t “random “ but by design. Elementary my dear.

@99names16 Год назад

Life is not robust. And it is not a force- it does not *have* to exist. I think we are far more lucky/special than we realize.

@garmtpug Год назад

@@99names16 Explain

@TheScrubExpress Год назад

Wild to think about such a big thing happening in...less than two days. In a universe where things usually happen over many thousands or millions of years, that's lightning quick.

@edwardlazell3157 Год назад

There's an XKCD cartoon about how weird it is when something in astronomy occurs on a human scale, rather than being enormous/tiny or happening instantaneously/over billennia.

@theexchipmunk Год назад

@@edwardlazell3157 Do you have a link?

@pizzainc.1465 Год назад

Billennia is a cool word, but it’s actually gigannum (or giga year). The real structure of million is milli- -on, not Mil- -lion. This is a common misconception, and it is ok in English (it’s already deformed), but not in Latin. Latin already has a structure, so you can’t make up words based on how you think they are assembled. The real word is: gig{a}- -{a}nn- -[suffix] Or gigannum

@pizzainc.1465 Год назад

-MWAHAHAHAHHAHAAHAHA- **silence**

@thezipcreator Год назад

@@theexchipmunk it's xkcd #2707

@MofoMan2000 Год назад

One correction: Neptune's moon is Triton. Titan is one of Saturn's moons.

@the_dark_one6052 Год назад

Beat me to it

@LuisAldamiz Год назад

It was not probably an actual error but rather his Australian accent.

@donlevoneshabanov4437 Год назад

The subtitles say Triton but I don't hear the "r"

@LuisAldamiz Год назад

@@donlevoneshabanov4437 - It's Australian accent but BBC accent also lacks rhotics, it's a common (and confusing) feature in English language.

@orsonzedd Год назад

Same thing

@realzachfluke1 Год назад

This is my favorite episode to date. Beautifully done, Space Time team.

@osmosisjones4912 Год назад

Here is the full clip : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-I7S74SxIjn4.html

@filonin2 Год назад

@@osmosisjones4912 So you're a bot now?

@memofromessex Год назад

Yeah, I understood 99% of that!

@bazpearce9993 Год назад

Mine too.

@subhanusaxena7199 Год назад

I hadn’t realised until I saw these videos that I should have played more attention to my fluid dynamics classes at college, as it seems central to many cosmological phenomena. Then I heard Leonard Susskind suggest that gravity is the hydrodynamics of entanglement, which blew my mind. Can we have a video on this please as I am really trying to get my head around what he meant. Thank you for these great videos

@flaviusclaudius7510 Год назад

I love these n-body particle simulations. Best part of undergrad astro was getting to watch so many of them!

@spectator5709 Год назад

Could we take a moment and appreciate whoever makes the graphics for SpaceTime? You're a hero! 🙂 Thanks for all the good stuff! 💫📈🚀

@ryanswanson126 Год назад

That clip of Theia getting larger and larger just before impact was terrifying. Kudos to the cgi folks for sure.

@jus_sanguinis Год назад

@dv2915 Год назад

The clumsy animation that appears at 11:06 was actually made by me, like, 20 years ago. I can't even remember what software (or hardware) I used to create it. Perhaps, a ZX Spectrum?

@freddan6fly Год назад

@@dv2915 For being 20 years back you did an excellent job with the limited resources of the time.

@vblaas246 Год назад

Andrew Kornhaber is your principal hero.

@xovvo3950 Год назад

18:06 Bats. You're thinking of bats. Bat wings are formed from membranous extensions from palm to fingertip between digits two through five. Bird hands are actually very small and have completely fused together into a structure called the carpometaparpus, tipped by greatly reduced digits II and III (digit I bearing the alula, anterior to the rest of the carpometacarpus). Birds just have very long feathers to form their flight surface!

@anarchyantz1564 Год назад

Additionally Pterosaurs as well.

@XKloosyvv Год назад

Birds still "swim" though the air around us. Yes, bats do as well but Matt didn't say it was only birds. There's plenty of organisms capable of flight on earth.

@Ezullof Год назад

@@XKloosyvv Birds don't swim with their *hands* though, they use modified arms (with feathers). Which is the point that Xovvo is making. Similarly, flying insects also swim in the air, but not with hands.

@XKloosyvv Год назад

@@Ezullof quoting them.... "Bird hands are actually very small and have completely fused..." Birds have hands, but evolution has changed them dramatically. They still "swim" in the same concept as bats and insects.

@JillianJolley Год назад

Yes!!! I f***ing love people, like you @xovvo3950

@Ricalloo Год назад

I'd love to see a collision simulation in real time, that is at the speed it actually happened. I assume the ones we saw in this video were sped up by a lot.

@N.M.E. Год назад

yeah. You can assume the rotation speed of the earth after the collision should be close to 24h

@genkibob Год назад

If you have 2 or 3 days to sit and watch the video, sure.

@doctorbeet3339 Год назад

@@N.M.E. Unfortunately not. With the presence of a water ocean, the tidal bulges which are displaced in the direction of Earth's rotation transfer angular momentum from the Earth to moon, increasing the diameter of it's orbit and slowing the Earth down in the process. See Tidal Acceleration on Wiki: "This geological record is consistent with these conditions 620 million years ago: the day was 21.9±0.4 hours"

@Shadowkey392 Год назад

@@N.M.E. it would actually have been much faster.

@N.M.E. Год назад

@@doctorbeet3339 Interesting! Thanks for the correction. I guessed it would've been somewhat faster, but didn't know to what extent. Still somewhat in the ballpark though.

@brandtreppond2167 Год назад

That protoplanet soaring towards us was probably one of the scariest images I'll ever see

@passintogracegoldenyearnin6310 Год назад

It's a great time for you to watch Moonfall then.

@N.M.E. Год назад

I shall suggest the Lars von Trier movie "Melancholia" (2011) with Kirsten Dunst then. (Although the visuals of the Planet are surely not the main thing this movie offers)

@theexchipmunk Год назад

@@N.M.E. Seconded. Good movie that one.

@Simp_Zone Год назад

@@passintogracegoldenyearnin6310 You mean that steaming pile of garbage? No thanks.

@CaptainCuttlefish74 Год назад

I sent this to my grandmother I expect some of the more technical stuff will go over her head but she's expressed interest in stuff like this, and I figure this is one of the few Space Time videos she would have a good chance of understanding

@Lupita311 Год назад

She won't understand it because she is a woman, or simply because she is a grandma, that the topic is too technical or is it that her small little brain can't understand the science but she'll be amused by the colorful pictures. Maybe it is me who doesn't get the joke in my tiny little brain.

@CaptainCuttlefish74 Год назад

@@Lupita311 woah What is wrong with ypu

@matteosposato9448 Год назад

@@Lupita311 wait wut?

@The1oldfox Год назад

@@Lupita311 easy girl

@william41017 Год назад

So, what did your grandma say?

@rlosable Год назад

I've been wondering for a while: does the Thea event explain also why Earth has such a strong magnetic field (due to the larger iron core and additional energy/momentum imparted) and at least be part of the reason why Earth has such active plate tectonics? It would also mean a single explanation for many of the differences between Earth and its neighbors. If so, this single event would have played a huge role in creating the conditions for life to develop. And dialing "rare earth" up to 11 as a solution to the Fermi Paradox.

@shoego Год назад

Earth would probably be a dry dead rock without this impact. Possibly, most of our mantle would have cooled by now.

@gobblinal Год назад

I still posit that there's enough out there that we are not alone, but maybe we're reaching the limit of only one intelligent species per galaxy (or two if we're REALLY lucky, or more if galaxies collide?), so it just _feels_ really lonely.

@matt2027 Год назад

Are Thea events actually rare? Do we really know enough about solar system formation to say for sure one way or the other?

@gobblinal Год назад

@@matt2027 At this moment, we do not. But, maybe with some of this hi-res modelling we might be able to get some idea of what it would take to happen. But seeing it "for real"? I have _no_ idea when that'll ever happen.

@dankuchar6821 Год назад

Very possibly, yes!

@nachoijp Год назад

I never knew that two proto planets could form in the same orbit... I always thought that we were weirdly lucky to have a planet just hit earth, but this makes it a lot more credible

@ericstromquist9458 Год назад

I’ve always loved your show (having been a physics major long ago) but this episode is among the best. I’ve certainly heard of Theia and the collision hypothesis but your episode 1) systematically goes through the evidence to select the best scenario, and before watching I wasn’t aware that accretion at different radii from the sun had distinct isotopic signatures; and 2) highlights new research, showing the reference so you can go and download the paper to read. Absolutely excellent!

@ChefSalad Год назад

There is an intermediate between solids and liquids, for some materials, specifically binary alloys. Sort of. For binary alloys, there are two temperatures involved in melting: the liquidus point, the temperature above which the material is fully molten, and the solidus point, the temperature below which the material is completely solid. For eutectic binary alloys, those temperatures are the same, but for non-eutectic alloys, the temperatures are different. Eutectic means that the melting point is as low as is goes and occurs when the solidus and liquidus temperatures are equal. (When you mix two materials together, the mixture will have a lower melting point than either component by themselves. At a certain ratio (the eutectic ratio), you get a minimum melting point.) The state between the solidus and liquidus temperatures (sometimes called the solidus phase) is a mixture of solid crystals suspended in liquid metal. It behaves kind of like a gel. It'll flow a bit, but also retain its basic shape. This is very important in soldering since, when using non-eutectic solders, moving the joint during the solidus phase will result in bad solder joints, since parts the workpiece can move without the solder flowing back in behind it. The effect is similar to a dry solder joint, but not quite the same and a bit harder to detect. This is why (near) eutectic solders are often preferred during hand-soldering. Eutectic solders go straight from liquid to solid as they cool, without any time between to harden.

@AnderGdeT Год назад

Amorphous polymers would also fit that criteria? They are solids with fixed forms, but can flow at higher temperatures while maintaing solid properties, don't really have a melting point but a "Glass Transition" point...

@ChefSalad Год назад

@@AnderGdeT not really the same thing. Similar though. With amorphous solids, the transition from liquid to solid is at a specific temperature, it's just that close to but below that temperature, the amorphous thing will be very, very flexible. This seems like flowing, but it's not really. With glass, you can get it really bendy, but to get two pieces to join, you need to get the joint just a bit hotter for the pieces to melt together. Even though they're soft, they won't flow together unless they're actually liquid at the joint. Or at least that's my understanding.

@MrClickity Год назад

TIL that Solidus Snake from Metal Gear Solid 2 got his name from an actual term and not just a word that Kojima made up because he thought it sounded cool.

@rosemarymuthoni5853 Год назад

@@AnderGdeT how about non-Newtonian fluids?

@dracoargentum9783 Год назад

As a quick follow-up question for soldering [new solderer here], if you NEED to move a non-eutectic solder, I take it you should heat the bend back up before bending?

@wrylycoyote6940 Год назад

I finally have caught up on binge watching 7 years worth of PBS Spacetime, and can finally comment on a video. My brain feels heavy like a waterlogged sack of dirty laundry. I feel like I made it to the finish line even though the line keeps moving forward every 2 weeks (making it harder to catch-up). Ok, I admit I skipped some of the videos on aliens, because it's never aliens.

@NoMusiciansInMusicAnymore Год назад

I absolutely love the sense of humour in this series, it more than makes up for my inability to understand half of the subject matter

@ihsahnakerfeldt9280 5 месяцев назад

And his delivery is completely dry lol

@Kelly_Z Год назад

Thank you so much for the captions in your videos! Yall cover such complicated topics that it's very useful to me to be able to listen and read what yall are saying so that I can absorb the information and keep following along, although usually by the skin of my teeth. Anyhow, thank you again, yall are awesome! I love learning about this kind of stuff

@HebaruSan Год назад

7:23 - Triton, not Titan, right?

@wingracer1614 Год назад

Correct

@MCsCreations Год назад

Fascinating indeed. Moon's fast delivery!

@dankuchar6821 Год назад

Thank you Matt and PBS FaceTime for all your hard work! It is appreciated. I wish this had been available when I was teaching physics.

@nagualdesign Год назад

PBS FaceTime! 🤭

@octavianova1300 Год назад

The possibility that the Gaia-Theia impact resulted in second, larger moon that then crashed back down into the earth definitely gets me thinking about the hypothesis that the LLSVPs are remnants of the giant impact. IDK how indicated such a connection is by this result, but on the surface at least it's an intriguing idea.

@nagualdesign Год назад

Don't confuse the Gaia hypothesis with the giant-impact hypothesis. Theia impacted the _proto-Earth._ Gaia developed millions of years later after considerable cooling.

@ArawnOfAnnwn Год назад

LLSVP?...

@Neloish Год назад

That is exactly what I was thinking, it could explain the gravitational anomalies.

@Neloish Год назад

@@ArawnOfAnnwn Large low-shear-velocity provinces

@passintogracegoldenyearnin6310 Год назад

Jupiter's Red Spot could be an impact site. Apparently some hundreds of years ago it wasn't there, and it is slowly getting smaller. The mix of elements dredged up from below are also different from the typical outer layers. It could be the case that our planets have not cleared their orbital paths as much as we'd hoped.

@panagiotisantonakas9603 Год назад

Mat I am hydrodynamic engineer/ astronomy lover and your video just made me wonder if we can make not only a Sim but a real hydro experiment.

@ChemEDan Год назад

Surface tension would probably be a big problem for experiments on a reasonable scale, same with trying to simulate self-gravitation. Maybe some sort of hybrid experiment could be developed e.g. many parallel hydro experiments used to simulate parts of the whole. Just need a mass-producible experimental apparatus that can generate the necessary Coriolis forces, and gravity could be approximated by earth's natural gravity and corrected for by scaling the resolution. So test volumes closer to proto earth would be physically smaller and visa versa, even though the apparatuses are all the same

@T3sl4 Год назад

@@ChemEDan It's interesting really, that gravity serves a very similar purpose as surface tension; the problem is, it's a much more diffuse force, whereas surface tension is, well, at the surface. Specifically, the internal pressure within a gravitationally bound body is proportional to depth, whereas with surface tension, the pressure is approximately equal, dropping suddenly to zero in the surface layer (which is probably a Debye scattering depth or something like that). So it's no accident that the simulation shows droplets, but the way they flow is very different.

@Nobody-df4is Год назад

The Moon is so weird, it played an integral part in the evolution of life.

@FussyPickles Год назад

I love how this channel goes from basic stuff like 'darker stuff' lighter stuff.. oxygen is for breathing etc. to here's a million things you will need a phd for, like ya know, supercritical gas boundry and obviously the transitional scale between the mediums is super simple to understand

@ChocoboProduction Год назад

So, what I gathered from the explanation on whether or not it's possible to swim in superfluids: You'd need a creature that is basically gigantic and almost completely wings/fins. Soooooo... giant manta rays? Sounds cool to me :D

@passintogracegoldenyearnin6310 Год назад

DnD ahead of science with its space mantas and space turtles swimming through the ether.

@bertoray5497 Год назад

Happy New Year Matt, and to all the fabulous crew at PBS Space Time. This content is actually consistent with what I envisioned the Internet tool would herald, lo, many moons ago.

@scottslotterbeck3796 Год назад

Ha ha. Bad pun

@gobblinal Год назад

As someone else points out, this could potentially add a few more parameters to the Drake equation. Is this what's needed in order to make a large enough magnetic field to protect a planet enough that life even has a chance to form, let alone multi-cellular and eventually "intelligence"? We've proven that our solar system is not unusual in that most stars appear to have planets, so that part of the equation is now a lot closer to 1 that might've previously been thought. But there's also the question of if inner rocky planets REQUIRE outer gas giants to keep space "clear"? And now we need multiple planets in the SAME orbit to collide and make a strong enough magnetic field to further protect the planet from the sun? Not to mention a moon big enough to make tides. So far most solar systems have only had gas giants or LARGE rocky planets so it's hard to determine where the little inner rocky planets are, so it's a while yet before we'll be able to determine if there's any systems with 1-orbit-2-planet systems. Is that dependent on age? Does it only happen in the first 0.1 billion years? So finding such an example is going to be very tricky. However, if there's one thing I know about the universe, nothing is unique. If it's happened once, it most definitely can happen again, so there is still hope for an Earth-2 out there, somewhere, potentially a LOT further away than originally supposed.

@escapevelocity8092 Год назад

Have you considered that earth may have been in another star system originally? There's quite a bit of information to support this idea

@gobblinal Год назад

@@escapevelocity8092 Well, it WAS another star system originally. That's why we've got carbon and iron and all the other must-have atoms. We are second (at least?) generation star that went KABLOOEY and then when it's nebula cooled, we got our star and system. But if you are trying to suggest that the earth was a rogue planet that crashed into Theia and then stayed in orbit, that's an interesting suggestion. I'd like to see the models on that.

@escapevelocity8092 Год назад

@gobblinal OK nice bit of sense you're talking, I'm suggesting nothing more ridiculous than this. Now, rogue planet idea, getting close indeed. I want you to imagine a petri dish with a chemical in it, we then introduce another reactive agent while looking through the microscope into the dish. To our eye, we see molecules smashing against molecules, creating new formations, charges being exchanged, looks like organised chaos no doubt, eventually a new order results. We are even aware of a world even smaller which isn't visible but we can measure its effects, atoms kicking out protons and exchanging electrons, all obeying physics which produces orbits out of attraction and repulsion. Is it such a stretch to conceive that what appears to us as a gigantic, chaotic clattering of heavenly bodies, actually lives within the intent of another form of consciousness, and thus planets are terra formed for purposes beyond our comprehension. Why should we sit at the top of the dominance hierarchy? If the universe is infinite then why would the energy apex end? Just because a species can't comprehend the next rung up, most prey die not knowing what predated on them...

@escapevelocity8092 Год назад

@gobblinal we needn't prostrate ourselves at the feet of a deity to appreciate that maybe we are not the only 'self aware' consciousness in existence. Aren't we ourselves trying to 'seed' other planets right now, because we may destroy our own in the future. Its not hard to imagine that we are the way the universe can observe itself, and the physical expression of reality is a challenge. A separation into duality, separation always brings pain, and pain always brings growth.

@milferdjones2573 Год назад

@@gobblinal Theia and Earth had to share the same building materials improbable for anything that originated outside of the Earth orbit.

@seb10wijngek Год назад

Best episode so far, in my opinion. Very cool simulations, clear and concise info. Lots of fun!

@zacharywong483 Год назад

Absolutely lovely video! Logical, understandable explanations paired with intriguing discussion! Great job, Space Time team!

@devinfaux6987 Год назад

I like to think that the immediate aftermath of an impact like this is the only sort of situation you would find and environment similar to the asteroid fields depicted in popular sci-fi like Star Wars. It wouldn't last for that long, but for just a little while you could lead TIE Fighters on a merry chase through it.

@mutercim Год назад

Not necessarily. You could lead your pursuers through something like Saturn's rings. Would be exactly the same, I imagine, as long as you stay in the thickest parts.

@N.M.E. Год назад

@@mutercim nah, as far as i know, the majority of particles in Saturns rings are far far smaller than your "usual asteroids"! More akin to dust and pebbles (largest particles are a few meters across)... aint no fun in flying through that. Also the denser rings are only about 5 - 100 m (max.) thick.

@brenorocha6687 Год назад

"[...] so, whatever." Seriously, seeing how you explain complex scientific concepts while using informal jargon and expressions is so pleasant. Specially because it doesn't feel forced or unnatural in any way.

@franck3279 Год назад

He works as an university teacher to practice for those videos.

@alexandrel4569 Год назад

Really love this episode that isn't as complicated as most of the time but EXTREMELY interesting

@camicus-3249 Год назад

You're telling me Rome wasn't built in a day, but the whole entire Moon was?

@PeterGaunt Год назад

More of this kind of stuff from time to time Matt!

@RajeshYadav-to5zq Год назад

Wassup homie

@ashleydaniel1446 Год назад

Happy new year Dr o'dowd , can't wait for the videos you bring us

@davidthane9002 Год назад

About the metallic Hydrogen question: Metallic properties does not specifically mean "free moving electrons". The electrons in solids made up of covalent bonds (like diamond) are free moving as well. (some scientist argue that covalent and metal bonds in solids aren't really different anyway) The real catch is the electron's ability to have a change in "speed" (or "momentum") which leads to electrical conductivity. The main requirement are empty electronic energy states at the Fermi level. (i.e. the 'band' isn't completely filled and 'crosses' the Fermi level) . Which in turn leads to the simple picture of the "Valence-band" and "Conductorband" touching. (in contrast to the semi-conductor/isolator solids which show a band-gap. Incidentally solid hydrogen in its ground state has one band, (made from the 1s-electron orbitals) which is filled about 50%. So the Fermi-level and the half filled band directly intersect and the electrons have quire a few energy states available for change in impulse. And so it has the typical metallic properties of high electrical/thermal conductivity, metallic sheen (from absorbing and emitting light through the electrons) etc.

@cloudzero2049 Год назад

Universal Sandbox on Steam is a fun simulator were you can make solar systems and crash planets together. It's really detailed.

@MrDino1953 Год назад

Thanks for posting this. It got me interested, so I bought the game a few minutes ago and I've already ruined the rings around Saturn 🤐.

@8beef4u Год назад

There's also one proposed theory that explains the "smoothness" of the Earth-facing side of the moon. It proports that a large satellite the size of Ceres collided with the moon, causing debris to rain down on the opposite side, explaining the smoothness of one side of the moon and also the disparity in crust thickness between the two sides. The new impact scenario could also help explain differences in the isotopes of potassium, phosphorus and rare-earth elements like tungsten-182 measured on the surfaces of Earth and the moon.

@tracyh5751 Год назад

17:57 jokes like these really deserve to be made into youtube shorts. That kind of humor would really stand out in the sea of youtube shorts and could draw more people to your channel who might not have considered it otherwise.

@boredgrass Год назад

A happy new year, and fair winds and following seas for your channel!

@tavelaine2914 Год назад

I like this ep! I composited all the vfx shots on Our Universe's episode about this. Yes we had the same simulation 👍

@tomkerruish2982 Год назад

This could also explain why Earth has the highest density of the planets, since much of the lower-density material was blown into space, never to return.

@YouTubist666 Год назад

Maybe we should give a nod to Hartmann and Davis, the two scientists who suffered the ridicule of their short sighted, closed minded colleagues when they first put forth their theory, but who persevered with the best theory of how the moon formed.

@TheIrf33 Год назад

Glad to see you uploading again. this channel is awesome

@Eris123451 Год назад

I've just finished reading Lee Smolin's book The Trouble with Physics which pretty much explains the real extent to which physics is currently at something of an impasse; no Supersymmetry, no SU5, no real clue about the nature Dark Energy or Dark Matter and of course the by now well known problems with String Theory but especially that it's not a complete or testable. It's an interesting and not over demanding book one which I'd highly recommend.

@nasonguy Год назад

Forget Schrodinger's Cat, we need to make Einstein's Moon the new totally misunderstood meme/thought experiment.

@osmosisjones4912 Год назад

Color exist even when our eyes and Brain don't detect them . And emotions are impulse signal waves. Hormones aren't even chemical reactions they push bottoms on the cells that are reactions

@DrVictorVasconcelos Год назад

It's not every day that we make a list of hypotheses for a natural phenomenon, and the winner hypothesis is the coolest one. Props to those involved.

@zwerko Год назад

The response to the last question on cats being simultaneously solid and liquid is-chef's kiss!

@luudest Год назад

Einstein just shows up everywhere.

@HaloForgeUltra Год назад

Ignore the bot. The video its sharing is just some stupid animal video. Here, I have an actual video of the moons formation conveniently ready, animated and 15 minutes long, with explanations. Or is it just a rickroll? You decide: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-6SrsZVdU740.html

@thomascaldwell184 Год назад

Damn I love PBS Space Time. Pretty much everything about it. Especially today the wry humor. (And/or humour for most of the rest of the English speaking world.)

@bobmin1782 Год назад

That animation of the moon crashing into earth around 8:54 is spectacular. Thank you.

@kin0cho Год назад

Love this cross-genre episode, keep up the fantastic work 👏

@baumgartnerwm Год назад

After reading Azimov's Extraterrestial Civilizations on the Drake equation I wondered if the Earth's oversized Iron core was due to us steeling Theia's core. This is the first time I've seen that confirmed. The earth's powerful magnetic field is stronger because of the iron we stole from Theia. So many subtleties of that collision were essential to our existence.

@Nobody-df4is Год назад

It was donated. Not stolen.

@ericeaton2386 Год назад

“Confirmed” is a little strong, but it certainly seems plausible!

@zuthalsoraniz6764 Год назад

And having a large moon is probably also at least very helpful for developing complex life/technological civilisation. Both because it stabilises the axial tilt and thus the climate (Earth's tilt varies only by about two degrees on a 41000-year cycle, versus about 20 degrees over a 53000-Mars-year cycle on Mars), and because the tidal forms formed by the relatively strong tides such a large moon causes provide a good jumping-off point for life to make the transition from living in the oceans to living on land. Plus of course, a large moon will also deflect or intercept a lot of potential asteroid/comet impacts, which is again helpful for climate stability.

@Boomer08888 Год назад

Matt, did you chip a tooth? Hope you're alright!

@ravenwolf7128 Год назад

best episode ever--clear, to the point and what an awesome topic.

@whuzzzup Год назад

It would be kinda neat to actually link your sources. Then I could actually use them for teaching more easily.

@travishunter8573 Год назад

Just a correction you said "Neptune's moon Titan" at 7:23 either this should be "Neptune's moon Triton" or "Saturn's moon Titan"

@LuisAldamiz Год назад

Accent: does he even pronounce rhotics at all?

@ewetoob1924 Год назад

@@LuisAldamiz Rhotic is only dropped after a vowel, e.g. in Mars, not in Triton.

@LuisAldamiz Год назад

@@ewetoob1924 - I'm pretty sure that depends on speaker/dialect, I can really see how some English native speakers drop the "r" in Triton, making it sound like "Titan" (a/o letters also tend to merge phonetically in this position). Other English speakers, notably from Scotland, may instead overemphasize the rhotic instead, with an almost but not quite identical sound to southern European languages like Spanish ("trrriton"), a quite strong thrill. I prefer that rhotics are pronounced, mind you, in all localities, but I have to live with what life offers me, not always at my leisure. I also had difficulties with another of Matt's videos in which he constantly and alternately pronounced the words "micro" and "macro" exactly the same ("a" and "i" totally merged into what most would identify as an "i" sound as in the Southern USA, which is almost "aa"), so much that I had to activate the subtitles. But in this case it's a very minor single "offense".

@ewetoob1924 Год назад

@@LuisAldamiz Matt just mistakenly said Titan instead of Triton, nothing to do with accent. Easy mistake. Try this for understanding micro/macro: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rrZtQY_HA-s.html The two words sound similar in both US and Australian accents. And note that not all British are non-rhotic, just as not all Americans are rhotic. Been to Boston?

@theGoogol Год назад

"Reality is fake", said the photon.

@Bassotronics Год назад

‘Reality doesn’t exist” says the photon.

@osmosisjones4912 Год назад

Color exist even if our brains don't pick them up

@CafeenMan Год назад

"No one was there to see the moon form." Just because you weren't there doesn't mean nobody was. I kind of enjoyed watching that show.

@Yewbzee Год назад

Damn, at last, I've managed to understand a full video on PBS. I'm off to celebrate with a bottle of wine or two.

@thiagocastrodias2 Год назад

Wow, that was probably the best video about Moon Formation I've ever seen. Thank you!

@franck3279 Год назад

Lets use a scale from moonfall to pbs spacetime in the future

@WoAzMM Год назад

A new PBS Space Time episode? The time must be tooth hurty (sorry Matt, hope it doesn't hurt and gets fixed soon!)

@hugomzo Год назад

I thought I was the only one to notice! I've seen so many episodes, it threw me off immediately

@wk8219 Год назад

@@hugomzo It seemed to have happen just before the episode before this. Last episode only one person mentioned it but 8+ on this one. I dont see any reason mentioned. I hope he's ok.

@Hermes_Agoraeus Год назад

@@wk8219 My similar question from the last video didn't get upvoted, so I deleted it thinking I was mistaken--but here we are!

@scottdahneke1031 Год назад

Moon pun: "I'm Buzz Aldrin, second man on the moon. Neil before me."

@Flugmorph Год назад

i liked that hidden schroedingers cat joke at the end there

@MichaelKire Год назад

Never clicked a video so fast

@theconstructortheorist3554 Год назад

same;-)

@anarchyantz1564 Год назад

Happy New Orbital Revolution around our nearest celestial object! Fantastic visuals today, your team really hit the moon out of the orbit.

@captainsarahbee Год назад

Great video to kick off the new year!

@markmuir7338 Год назад

My experimental observations on cat solid/liquid simultaneity: if I pick up my cat and hold him close to my chest, over the course of about 20-40s, my body heat will raise his temperature above the critical point and he begins to flow through my arms and land on the floor, where he rapidly regains his cool.

@DataSmithy Год назад

Thank you for doing this episode. The uniqueness of the formation of the Earth/Moon system has always intrigued me. The moon has always seemed to have a lot to do and to be important to the origin of life. I have always wondered if the uniqueness of our moon was in fact one of the great filters for the origin of life on Earth The Moon causes tides, and stabilizes Earth's orbit. The collision with Thea probably has a lot to do with the formation of our strong magnetic field, and circulating layers of magma in our core and mantle, and removing a lot of extra crust into orbit may have something to do with a thinner crust, and allowing the formation of tectonic plates, which is important for the formation of life, especially land life.

@NewMessage Год назад

I dunno if I could gain that much weight in 24 hours.. but I'm willing to give it a go next Thanksgiving!

@BattleBunny1979 Год назад

you might end up having your own moon if you do it well enough!

@isobarkley Год назад

i absolutely love this new theory! i can't wait for further simulations

@aalhard Год назад

Hope your holiday was great. Thanks for coming back 😗

@AdrianBoyko Год назад

Poll time. Which is more correct? 1) “different to” 2) “different than”

@douglasfrompa593 Год назад

Different from?

@NeonVisual Год назад

It took me 14 years to get my mooning right.

@-SRM- Год назад

It's a process.

@LordPhobos6502 Год назад

That was amazing, especially the ground view of Theia coming for a visit... Now we just need to convince Dr Who to take a trip back and get some footage... from a safe distance, of course.

@peterkelley6344 Год назад

Should not be that hard as they are both from the BBC

@NiffirgkcaJ Год назад

10:37 "Yet." This gave me goosebumps.

@ramuk1933 Год назад

Wait... it couldn't have happened over months because the moon, and therefore months, didn't exist yet!

@JillianJolley Год назад

Tehehe

@firstcynic92 Год назад

7:20. Neptune's moon Triton, not Titan. 11:10 Theia crashes into the Proto-Earth, not Theia crashes into the moon.

@mikecatterson1 Год назад

Yes. The moon only renders when observed.

@franck3279 Год назад

And it’s conviniently tid1l locked to save on textures.

@EnglishMike Год назад

@@franck3279 And updating to Unreal Engine version 5 really helped in the handling of the various levels of detail required when using telescopes of different sizes.

@nightmareTomek Год назад

I feel like the language of SpaceTime to communicate us all the exciting stuff changed a bit to better convey how certain scientists are with their findings and their theses, and I like it. It gives us a better understanding how much work has been done and how much there's still to explore. I know I'm quite nitpicky, but it's important to me and I like the more precise approach. Anyway, another very interesting video!

@hp127 Год назад

Wonderful explanations of procedures and the 'how do we know. Thanks

@a51mj12 Год назад

Is his tooth chipped? If so, is it easily fixable...

@jakeuren8688 Год назад

We missed you! Hope you all had a great new year

@adamthompson4072 Год назад

I remember seeing something a couple years ago that suggested we had 2 moons for a while after the formed but before they had cooled. It apparently explained why the the far side of the moon looks so different from the close side by saying the 2 moons had a very slow speed collision because one was chasing the other

@diomedesabcmnxyz7299 Год назад

~ I deduce that the moon primarily formed from the ashes of the collision between both preexisting Proto-Earth & Theia, along the same orbit around the Sun. Which is a factor associated with the fact that ashes have a lesser density, so they are affected less by gravity & more by temperature & expansive entropy. ~ An additional factor would also have to do with the orbital gravitational effects of Venus & Mars/satellites, which would tend to maintain both Proto-Earth & Theia, before & after collision, along their pre-existing & post-existing orbit around the Sun.

@planexshifter Год назад

That new simulation was amazing looking and quite mind blowing!

@Aut0mati0n Год назад

Oh that's such a cool simulation. It looks SO GOOD!

@stewartmartin7376 Год назад

It is quite amazing all these things that had to go right in order to get us

@cordial001 Год назад

Just a tiny nitpick; Neptune's moon is Triton, not Titan as stated.

@majorburly2007 Год назад

Fascinating study. Wonder how long production and release took because it was great.

@lexinwonderland5741 Год назад

Okay, the segue to the ad was hilarious, I'm actually impressed.

@TerryBollinger Год назад

Thank you! This is an impressive and persuasive simulation result, and you presented it beautifully. I particularly liked the indirect invocation of a three-body resolution to the orbital problem, even if the three bodies formed from the collision of two. That provides the kind of "aha!" moment that makes a result especially persuasive.

@TerryBollinger Год назад

@discipleofkrolm excellent point! Simulations can exhibit computational artifacts much like those of pixel images. You could, for example, get the equivalent of resonance effect at a certain granularity of simulation, which in turn would give rise to persuasive false artifacts such as the three bodies. Such effects tend to be unpredictably emergent, so there's no simple universal solution for making sure you don't have them. One must, at least, verify that the interaction is scale independent and think carefully about whether the simulation results make sense physically. One helpful technique is simulating at slightly different scales. If there's a wild divergence of results over a small change in simulation precision, then there's a good chance you are looking at a computational artifact. Conversely, if the interesting results stay consistent and robust over a range of simulation precision scales, the odds go way up that you're looking at meaningful simulation results that simply required the simulation of more detailed internals of a system. That can happen because low-granularity simulations are a lot like erasers, wiping out details that could prove extremely important to getting a physically plausible result.