Mars Rovers On The Moon, Satellite Management, Life Near Blue Giants | Q&A 250

what if NASA sent perseverance to the Moon where should I send my scientific discoveries to get them looked at and do bright super giant stars have habitable zones all this and more in this week's question show Welcome to the question show your questions my answers as always wherever you are across my channel if a question Pops in your brain just write it down in the YouTube comments and I will gather them up and I will answer them here baby maker what if NASA built another person perseverance and instead of sending it to Mars Landed It On The Moon including the sample caching for astronauts to go and collect when we get there rtgs so you don't have to worry about the day night cycle and even when we go back we can continue to do so it's finding things to be checked out by people well this is a terrific idea uh why not send a Rover like curiosity or perseverance to the moon and you're exactly right that one of the big challenges with sending spacecraft to the Moon is that it gets really really cold during the daytime the temperatures are incredibly high and then the moment the sun goes down at the end of that 2 we day night cycle then temperatures plunge hundreds of degrees and now it's incredibly cold and this is what knocks out most of the Landers and The Rovers they're solar powered they're able to make hay while the sun shines they've got their solar panels out and they're able to keep themselves cool and run all their experiments and transmit data back to home but then the moment the sun goes down then they start to get cold and as soon as the temperature drops too low they're not able to maintain the internal temperature on their batteries then the batteries die and when the batteries die the spacecraft is dead even when the sun returns uh two weeks later the batteries are dead it can't refill its batteries the solar panels are worthless the mission is over and so if you could send something like perseverance or curiosity to the moon now you've got a Rover that's equipped with a a radioisotope thermoelectric generator which is a chunk of decaying plutonium which can then be used to uh keep both the Rover warm and also uh allow it to provide enough electricity to do whatever job that it wants to do and there are good examples of these rtgs doing this task I mean think about all of the like New Horizons the Voyer spacecraft they're equipped with rtgs they stay warm so why not do it well it's just that it's hasn't been a priority a a nuclear powered or I guess a nuclear battery powered Rover would be super duper on the moon and it could get a lot of work done now that said you know we are having humans go back to the Moon relatively soon although the Chinese have done sample return missions we should be having humans doing sample return missions anytime soon now but I think the idea is perfectly valid uh there's no reason why not to I mean part of it is that there's a slight shortage of the rtgs now um there was like a total shortage a couple of years ago and people had to come up with clever ideas like the Juno Mission the Europa Clipper these use solar panels and not rtgs they would have loved to have been able to use rtgs but they didn't have enough of them so no reason why not uh you've also got sort of the the kind of terrain that you're dealing with like we know that there was no long-term presence of water on the surface of the Moon and so the kinds of samples that you would be taking with your Rover are are going to have totally different purposes like you're going to want to learn the geological history of the moon but not as like was there ever life there was there ever water there it's just like what's it made out of you know how is it connected to what earth is made of and then the most interesting place that you're going to want to go is to the South Pole of the Moon and in fact NASA is planning a mission that's going to go to the South Pole of the Moon that is the upcoming Viper Mission which is going to be going to the South Pole it's going to be examining the regula trying to find out evidence of water ice mixed in with the regolith and what's interesting is it is a solar powered Rover but their plan is for it to operate for a 100 days so it's going to go through multiple lunar cycles and still survive through this process uh and it's going to have a very large battery it's going to sort of hunker down and really try to hold onto its heat and try to make it through that lunar night so we'll see if this strategy works I'm sure you've noticed the Star Trek planet name that appeared above my shoulder and this is a way for you to vote for you to tell us what you thought was the best question best answer best combo whatever entertained you so we will post a different Star Trek planet name up above my shoulder for each one of the questions and so watch through the whole show and then at the end uh put in the comments down below the name of the planet that you thought was the best and we'll put in like in the show notes you'll see what all the planet names are so go ahead and do that now the winning vote last week was for Jesus Solace if satellites are the first products used for a space economy what would be the next product it was a fascinating question and I'm really glad everyone enjoyed the question and the answer and tonis carpos where should I send my scientific discovery to be checked promoted to be known to other scientists now I'm going to assume that you're not a scientist because a scientist will already know the answer to that which is to publish your results any scientific journal the more prominent the journal the better if you can get your research published in nature or in science uh then you've got a really good chance of other scientists looking through your work examining it and then basing their work on what your work is double-checking it or trying to find problems in it now if you're not a scientist you're an amateur and you have figured out some kind of discovery that you're then hoping to pass along to the scientific Community I've got bad news for you which is you're going to have a really hard time getting any scientists to listen to you and it's not that scientists don't want to have really cool out of the box thinking ideas that come from other sources you know when you've got a eight billion brains thinking about problems people are going to come up with really clever solutions to problems the challenge is that 99% of those ideas 99.999% of those ideas are going to be wrong that there are very simple reasons that anyone who has actually gone through this scientific process who understands all of the fundamentals of how this you know if you're talking about what dark matter is or where the universe came from or how you can unite quantum mechanics and gravity that you know 10,000 ideas you will be able to rule them out as you learn the fundamentals of how the science works and so generally the first thing to do if you like if you've got an idea about some concept in physics or astronomy or whatever the first thing that you should do is learn all of the underlying physics and astronomy to the point that you understand what is the consensus opinion of the current scientific community and it doesn't mean that you have to go and get a PhD in astronomy that's ridiculous get your hands on the textbooks that the scientists are going to be using the physics are going to be using you know there's there's a great textbook for like when I went to engineering uh there's a physics for engineers textbook and you learned a ton of physics a ton of of of sort of engineering related physics um and and then you're you're going to want to do some other you know calculus and then you're going to want to do specific like if it's Quantum mechanic type stuff you're going to want it to go through and do a whole bunch of challenging problems in quantum mechanics if it's relativity you're going to want to go through you know general relativity and you're going to want to go through the current understanding and my guess is you'll get to a point where you're like oh I see where I'm wrong here right like someone already thought of this in 1932 and then they did an experiment and it showed that it wasn't true and so now they they rejected that idea now I know why I have to reject that idea and I'm going to go back to the drawing board now with all this physics knowledge so um you're not and so the assumption is like that is your ante that's like the first thing you want to do to get into the physics game into the solving the big problems of the Universe game is to do the work to get to the point that you have the same level of of just like basic knowledge as scientists and if you go through that process and you come out the other side and you have been able to show to yourself that this idea still holds then you're going to have a much better chance of going to a scientist and saying look like here's my notebook here's all here's me going through and doing all of the equations of the engineering physics textbook and here's all my quantum mechanics and here's all my relativity and I'm up the other side and I understand and here's how I understand what this is and here's the math then a scientist will look at you and go respect good you know that you you're serious okay let's take a look at what you've got to say um but then the other way to go is to find a collaborator find a scientist who's working in this field convince them and then you can publish a paper together where that will then get into the hands of other scientists and they'll be able to look at it so you know I I would say like like for anyone who's got like a big idea you need about a Year's work to go through a very compressed curriculum to bring yourself up to speed on the current consensus of the scientific knowledge and whatever is the field that you're attempting to to contribute to and when you come out the other side if your idea still you can't get out of your head then keep going Zinga I'm curious about the brightness of stars like blue super Giants wouldn't they be so bright that any Planet within a gravitational hold couldn't possibly Harbor life due to the incredible brightness well theoretically every single star has a habitable zone because the habitable zone is just a distance from the Star where liquid water can exist on the surface of a planet not whether or not liquid water actually exists on the surface of a planet it's you know it's just a a probability and so for example here in the solar system our habitable zone extends from the orbit of Venus out to the orbit of Mars and so both Venus Earth and Mars are in the habitable zone around the Sun now obviously Venus is not habitable Mars is not habitable Earth is habitable but you could if you change the chemical characteristics of both of those planets you could have a place that is habitable so there is a habitable zone around Red Door Stars that's really close into the star and there's a habitable zone around blue super Giants so before this show I did sort of looked up one example and that is Riel which is one of the most bright stars in the sky that we can see and it is dramatically more massive and larger than the Sun and it is a blue super giant star and so I punched in the mass of Riel I punched in the radius of Riel because those are sort of like the two numbers that you need and I punched in the surface temperature of Riel once you have the surface temperature and you have the radius of the star you could then calculate where the habitable zone is around that star and I got that the inner area is 3.25 astronomical units so 3.25 times farther than the Earth is from the Sun and the outer limit is 4.68 astronomical units which is pretty far away like that's out past it's like Jupiter is and so you're going to have this big region where liquid water could exist on the surface of planets but blue super Giants are nasty so there's a couple of problems going for them first thing is is that they're putting out a lot of their radiation in ultraviolet that hot temperature they are like 12,000 Kelvin while the sun is 5800 Kelvin so they are more Kelvin and so that pushes the wavelength of the light from these blue super Giants towards the ultraviolet and so you've got this ultraviolet radiation and it is dangerous like ultraviolet radiation interacts with the atmosphere can destroy the atmosphere crush the ozone layer there's a lot of reasons why we don't want more ultraviolet light coming from the Sun so the kind of radiation which I which you sort of um talk about the incredible brightness and yeah the kind of radiation sort of pushes it in one realm um they can also have really nasty flares and we saw like what happened with say Bal juu where we had a flare you know bju can have flares that obscure the entire star from our perspective so uh blue super Giants can be can be very volatile as well and then the the other thing is they're very short-lived so blue super Giants you know any stars that are significantly more massive than the sun they're only going to live for 10 million years 1 million years uh they're not going to live for very long so you've got to go and have this life set up in this on this planet in this incredibly hostile environment they've got to be able to survive this ultraviolet they got be able to survive all these flares and then they've got 10 million years to get the job done which is pretty tough so you know we will almost certainly find earth-sized worlds in the habitable zone of blue super Giants but chances of them being actually habitable are pretty low but we should still look FPL Mikel is the reason for the firmy Paradox due to the Earth being unique due to its ability to support a fire as far as I know no other planet nor moon has the right abundance of oxygen nor the right atmospheric pressure to support a fire and given how important controlling fire was for humans to develop skills and later on the combustion engine can it ever be done in other environments yeah so the concept that you're talking about is known as the oxygen bottleneck and this is the fact that on Earth we need the minimum of 18% oxygen for combustion and without combustion then you can't have fires and without fires you can't have industry and so you can imagine that not being able to have enough oxygen in the atmosphere puts a damper on on some technological civilization attempting to come up with ways to leave their planet and that is the title of a paper by Adam Frank and some other people I interviewed Adam Frank fairly recently and we talked briefly about the oxygen bottleneck and at the same time though if you've got an intelligent civilization you can imagine that they come up with Creative Solutions to problems like this and so maybe they come up with a chemical based solution solution or maybe they come up with a volcano based solution to be able to solve some of these industrial processes and you can imagine some civilization figuring out how to extract oxygen from the Rocks all around them and then use that to enrich the flame and maybe they figured how to make fire after all like if we had to Crunch up rocks and pump the oxygen into furnaces to be able to make them work we could do that you know think about Rockets Rockets carry their oxidizer with them so the paper is great very readable and it's very you know it's a very clever idea you know the problem that I always have with the firy Paradox it's just like whatever this thing is it has to explain everything has to explain the the reason we don't see life or intelligent life anywhere and so even if you have any one explanation for something as long as some other civilization isn't hampered by it then they're going to create this ever expanding Galactic Federation Empire that just obscures the Guys Without fire so uh you know whatever it is whatever the fir Paradox is it's got to take out all civilizations it's got to keep them all on the surface of their planets without access to technology gasan do you advise me to study journalism at University that's tricky um I didn't study journalism at University I studied engineering and then I studied computer science and engineering and then became a journalist afterwards being a journalist isn't that hard I mean it just requires a lot of work and a lot of practice and so there isn't any really specialized knowledge that that a university can teach you that you couldn't pick up just doing the work so you know the thing that matters in journalism and any kind of thing that requires writing is just doing a lot of work work like being able to write a lot of material it's interesting I use grammarly to check my spelling and grammar mistakes and so I get a report every week of how much I write and I write the equivalent of a novel every month with all the writing that I do so um you don't see it because I'm just talking but actually most of the time I spend is writing and so I write about 25,000 words a week I about 5,000 words a day when it all averages so I spent a lot of time writing a lot of words and I have just uh practiced a lot you know my one of my writing mentors he you know I asked him because he would write like 5,000 words a day and I asked him like how do you do this like because I would like write a 300w essay and be exhausted and he's like you just sit down and you just do the work you just and you learn to write fast and by learning to write fast you put out a lot of work and then you learn to write well and you know apart from that like what is journalism journalism is is is hearing somebody's story and then reporting on it and writing it in a form that other people can understand and that's just practice so I think it would be more useful to like study some specific science that you can't just learn through practice like astronomy or biology or computer science or physics or whatever because the concepts that are part of that process require that specialized knowledge to be able to do and I'm limited all the time by what I can and can't report very well by my own knowledge you know my knowledge is very broad I can explain lots and lots of stuff but you know if I was going to have a conversation with someone like Scott Manley about rocket science he would just do circles around me um or if I was going to talk to matad OD Dow from PBS SpaceTime about cosm ology again you'd be doing circles around me because I just don't have that depth of knowledge and so I think if you want to study study you know pick a subject that you're really interested in study that at University so that you can become very knowledgeable about it and then be able to communicate that out to a wider audience and a lot of universities offer Communications courses but just at the end of the day just a lot of writing right right right or other kinds of Journalism that you like to do Ted Spears do you have any thoughts about Robin Hansen's grabby aliens model yeah so I've interviewed Robin Hansen here on the channel about grabby aliens and we talked about it for quite a while so I didn't really understand it until I talked to him um although I sort of intuitively understood and been thinking about a lot of the same problems with the grabby aliens model what Hansen is saying is that if an intelligent civilization gets going then that Civilization is going to go out into its surrounding space very rapidly approaching the speed of light you know imagine self-replicating robot probes that are going to a new star system they are crunching down the star system they're setting out more robot probes they're going to the next star system they're crunching more rob you know material down they're building more robot probes they're just going in this ever expanding sphere of exploration and then they are turning whatever it is they find into the most practical purpose for their needs so they are covering up Stars in Dyson spheres or maybe they're dismantling stars and turning them into small red dwarfs which is more efficient for their uses or maybe they're rearranging the Stars into positions that are more economical for them to be able to send spacecraft back and forth that uh an advanced enough civilization should be interacting with the universe as its environment in the same way that Humanity interacts with planet Earth right you can tell that humans are here because you can see our cities you can definitely see them at night and so the assumption is is that if there was an advanced enough civilization they would be having an impact on the cosmos that we would be able to see and yet when we look out into the universe in all directions we just see Wilderness we don't see a rapidly expanding civilization we don't see multiple rapidly expanding civilizations in all directions with their borders bumping up against each other and so Robin says well that's useful that tells us something about where we are in the universe the fact that we don't see Advanced civilizations allows us to try and figure out how many civilizations there are there out there and how far away it is to the closest one because we wouldn't see one of these civilizations until they swept past us at close to the speed of light with their front of Von nyman probes dismantling star systems as they go and so I like that idea I mean I don't like that I mean I don't I don't like the idea of a of a expanding swarm of Van Von nman probes dismantling star systems as they sweep out in all directions I don't like that idea at all but I but but like philosophically that idea does resonate with me when I have conversations with people about the FY Paradox like I know what their answers are going to be and you're thinking them right now right right here right no we've just barely started look for alien civilizations oh Space is really big and nobody can ever go anywhere um you know why would they choose to go out into the universe when they might just want to stay home and so on and so forth right there are all these like everything that you can think of has been proposed and there are answers to every single one of those things and so I always say that I Think We're Alone in the universe Robin disagrees with me on that one but he just thinks that they're far enough away that we haven't encountered them yet but they're coming in our direction from all directions at close to the speed of light and just a matter of time before they get here um I hope not because that would be scary there's a great description of the grabby aliens from rational animations which is such a good Channel like if you like kurts cag's uh animations for stuff about space and stuff I highly recommend you go and check out rational animations they're really good so uh they've got a great explanation on the grabby aliens model and uh and it's great I think it's I think it's really clever if you want to support the work we do at Universe today consider joining our patreon club your support lets us have a minimum of ads and no sponsorship messages patrons get no ads on university.com for Life want the extra parts of the live stream that aren't in this edited version it's an hour more you can sign up for a special Patron only podcast feed and get the overtime segments as well as other special behind the scenes episodes including our monthly Patron only question show thanks to everyone who has already subscribed and Welcome to our recent newcomers Eric snow seals MCB Terry Robinson Frank Stewart Peter G halson Andrew loss sander hbr P Sprout SRI Ram Doren B Reed Robinson and Bob cook join the club at patreon.com Universe today K Swiss with all these companies sending up all these tiny data satellites will they have to stay at different altitudes how do they stay safe nobody knows so this is going to be a big problem which is that although Space is really big it's right there in the name um the space in low earth orbit where these various communication satellites are going is becoming more and more congested over time and it's not just the satellites themselves it's all of the defunct the dead satellites that are there that are no longer able to reorient themselves it's all of the space junk it's estimated that there are millions of pieces of space debris that are like a millimeter or larger orbiting the Earth at various altitudes and a 1 mm chunk of metal moving at 288,000 kilometers per hour hitting a spacecraft can cause damage and then it could cause damage to that spacecraft that spacecraft could shut down it could get hit by other debris it could break up into more debris so there is a very large concern that over time we will have more and more space debris and any satellites that are in orbit around the Earth at various altitudes will be at greater and greater risk and eventually it will become just not feasible to launch satellites because there's so much buzzing metal around the earth that anything you try to launch into that altitude is just going to get torn apart and add to the problem and so this is known as the kler syndrome like what's the solution the solution is to negotiate you know for the lowest orbits the stuff that's say around the altitude of the International Space Station and Below stuff there deorbit relatively quickly there's still atmosphere there and so these bits and pieces of debris get slowed down by the atmosphere they reenter they burn up and so it's sort of a self-cleaning mechanism but at higher altitudes this stuff will last for decades and eventually it'll last for centuries and then eventually to last for Millennia and eventually to last effectively forever and so those higher orbits even though they're bigger it would be so such a bad thing to have tons and tons of satellites tearing themselves apart in that orbit because there's no cleaning it up ever and it's never going to get cleaned up by the Earth's atmosphere you're just you're done you're stuck with it you've you've got this orbit that is filled with metal that is you know buzzing around and if you try to put anything there for any amount of time um then you've got a problem now will probably never be cut off from space because you know if you go quickly through these various orbits the chance of you interacting with anything is incredibly low but it's really you're going to try to stay there so Space is really big and the orbit are on earth there's tons and tons of space you could like when we think about how aircraft work how shipping lanes work there's a lane that you take through the Pacific Ocean or the Atlantic Ocean when you're going to go from North America to Europe and then you take a different Lane to go from Europe to North America and these lanes are separated by large distances and all the boats are going in One Direction all the boats are going in the other direction same thing with airplanes airplanes follow various tracks that are pre-planned in advance and they stay in corridors that are away from each other and so if someone you know some International Community was willing to just sit down and go okay you know here is one ring where all the satellites go together in this direction and then here's this other ring where all the satellites go and then you and because you can work in three dimensions you can have them be separated you can have them move in ways that they'll never interact with each other and it would be incredibly safe compared to what we've got right now like there's just there's no rules right now right now you just you just launch wherever you want to go do whatever you want uh countries don't talk about it and and we know that this is unsustainable like the amount of satellites that you could launch is like a few every year and to make lower Thor be sustainable and we're Way Beyond that so uh yeah somebody's got to talk and figure this out or the problem is just going to get worse and worse and worse Tomy 36 why is the Stellar Mass black hole merger Theory more popular than the direct collapse theory for super massive black hole formation the only way that we know to get a black hole is to have an implosion of a star that it's not enough to just have a lot of material collect it into a small area and then have that area collapse under its own gravity that's how you get a star and the problem is is that there is a limit to the size of the largest star so beyond about a 100 times the mass of the Sun as material is a creting down onto the star the star is getting so hot it's so large it's getting these outflowing winds and jets that are blowing away from the Star and then no more infalling material can fall down onto the star and so that's why like the limits the largest stars that we've ever found are like 150 times the mass of the Sun and even that is sort of up for grabs and when a star that is say 100 times the mass of sun detonates as a supernova it doesn't even create a black hole they're called um par and stability explosions and so there's no Remnant left behind and so you need the right size star to be able to get a black hole and it is you know you're going to end up with a black hole that is some number of times the mass of the Sun and then you're going to need to have those two stars find each other and they're going to need to merge into a larger black hole and then those are going to need to merge into others to merge into a bigger black hole and so on and so forth the direct collapse method where you just have an enormous amount of material and then somehow that material can come together and form an object that has so much gravity that it doesn't even turn into a star it just turns directly into a black hole this is abs absolutely a mainstream concept but the question is we see stars today that refuse to get bigger than 100 150 times the mass of the Sun and so how could you get one that is a million times the mass of the Sun four million times the mass of the Sun to get that super massive black hole and so the the one possibility is that there's something different about primordial hydrogen and helium left over from The Big Bang that the Stars today they're polluted with other heavier elements Like Oxygen or carbon and somehow that pollution is the cause for stars not being able to form to become super massive and maybe when you just have pure hydrogen and helium you can get these super massive stars but other people don't think that they think that yeah you would get larger stars but they would also live very short lives they would explode a supernova and they just wouldn't get a million times the mass of the Sun but the sort of interesting Theory and there's some evidence for this now thanks to James web is that you know there needs to be some mechanism that is preventing the outflow winds from stopping the like from from the Star being able to to Halt its growth and that there could be some kind of process in the early Universe with these primordial stars that they're able to prevent the outflows and so they do just keep a creating mass a creating mass until they become a super massive black hole and having the direct collapse of super massive black holes would solve so many problems right it would explain how you have super massive black holes at the hearts of almost every Galaxy out there it could explain why we're seeing such big galaxies early on in these James web observations like there's a lot of stuff that the direct collapse solution to the problem solves but it's just we don't see stars doing it today why would stars have done it in the past this is the question and that's why astronomers are skeptical that direct collapse is the answer but if one day someone sees one in action we see a direct collapsed black hole starting to come together and they understand the mechanism that stops IT from halting its growth then that will be the that will be the accepted scientific consensus Dawn on Campbell when do you think we'll become a kardashev type 1 civilization so kardashev civilizations type one type one type type one type two type three type one is where a civilization is using up all of the energy that falls on its Planet you imagine like all of the sunlight falling on Earth if we were able to cover Earth in solar panels we would be a kardashev type one civilization now obviously that's not what you'll do you'll you'll have have all kinds of space stations and solar power generating stations you'll have O'Neal cylinders and all kinds of stuff orbiting around the Earth but the crazy part is that it won't take us that long if you just take the growth of humanity you look you go back 10,000 years you can chart on a logarithmic graph on an exponential graph how how we are increasing our energy usage over time and you can then take that line and then you can chart it into the future you can say okay in about 200 years or so if our energy usage continues then we will reach kardashev one level scale in other words we will be all of humanity will be using the equivalent of all of the sunlight that falls on planet Earth and I know that sounds crazy right that sounds Bonkers that's like too much energy what are we going to do with all that energy so we don't know right that exponential curves sometimes turn into s-curves so they rise at an exponential rate and then they slow down and then they flatten off and so we could be at the turning point of the S curve and now our energy use is going to go down and then it's going to flatten out and then maybe it's even just going to drop or maybe like all of human history we will come up with new ways to use energy into the future and we'll just keep doing that forever and so if we reach that type 1 civilization in a couple of hundred years then your your question might be like when are we going to hit a type two civilization when are we going to build a Dyson Sphere and use all of the energy that is being expended by our sun and so you can just take that same energy growth and you can just keep charting it forward and the point that you get to all of the energy being put out by the sun is just a couple of thousand years from now which is not that long right like when you think about all of human history a couple thousand years ago uh humans were roughly the same as we are today you know with less technology but couple thousand years from now having using up all of the Power so again at some point it's going to turn into an scurve and then our power use is going to Decline and we'll live in sort of perfect sustainability with our planet or maybe we will just keep going and figure out new ways maybe we'll you know come up with more powerful computers who knows and then the next question is when are we going to create a cardish shev 3 civilization where we're using up all of the energy of our entire galaxy and the problem there actually is that it's the speed of light is the challenge that we you know it's going to take you years thousands of years it would take you even moving at the speed of light it would take you about say 100,000 years to reach every star system in the Milky Way and so the at the bare minimum like if all of the stars in the Milky Way were compacted really close together it would only take a couple of thousand years after that to use up all those stars but because we have to travel to them all you pretty much then have to make the speed of light be your limiting factor so a couple hundred thousand years from now we or our robot overlords come on let's be honest um will be a type three civilization unless the power curve flattens out and this is back to that comment that we had earlier about that Robin Hansen about the grabby aliens that if it's only going to take us a couple hundred thousand years to become a type3 civilization why don't we see the type three civilizations out there in the universe we just don't it's a paradox Jim Jeff I keep hearing the size of the universe was at one time spherical a basketball for instance if you if you use that how could it possibly be flat did it flatten out as it expanded all right so there's like a bunch of Concepts in there that I'm going to have to dismantle one by one so the first thing is that you hear that the shape of the universe was one time spherical and then a basketball for instance so I think what you're conflating here is that at one point in the past the observable universe this sphere of universe that is centered on you Jim Jeff um was once the size of a basketball and that is theoretically correct according to our current models of the expansion of the universe that this thing that is now 462 billion years to your right and this thing that is 462 billion Lighty years to your left were once this far apart that is true that is mindblowing right and that over the 13.8 billion years you've had all this expansion and these things have moved away and away and away but that is just your observable universe and so I in on Vancouver Island in Canada I see a different observable universe I see a slightly different sphere than what you see and so the basketball siiz universe that I saw at the beginning of the universe was a slightly different sphere than the one that you see and that means that there was actually more un you our universes were overlapping and yet you know we sort of saw a different universe un and that's because there's just more Universe outside of what you could see and what I could see back at the beginning of the universe if we could which we didn't unless we're Time Travelers which we're not it's thought that in fact the actual universe is hundreds maybe thousands of times bigger like volume wise than the universe that we can see today and it could very well be infinite and so that is like a separate conversation from the flatness of the universe and when astronomers talk about the flatness of the universe all they're really talking about is do parallel lines stay parallel in the universe the way parallel lines don't remain parallel on the surface of the Earth so that's maybe that's a question for a different time perceive chiasa what does it mean that some planets have no surface well think about the giant planets here in the solar system like Jupiter and Saturn and Uranus and Neptune if you could visit the surface of Jupiter which is considered a gas giant and it's made mostly of hydrogen and helium the same stuff that you would find on the surface of the Sun and you were to stand on the surface of Jupiter um you would fall because you know even though you know it's Cloud tops and you would be falling into the clouds and then you would fall and you'd fall and you'd fall and then the pressure and the temperature around you would increase because you've got all of this hydrogen and helium that is under intense gravitational Pole from the from the planet and so it would become more and more soupy even though it's still just hydrogen and helium and eventually it would be incredibly hot like you would die because it's so hot and it would just keep getting hotter and hotter and hotter that the scent of Jupiter is tens of thousands of Kelvin foret it's like 50,000 Kelvin and like that's hotter than the surface of the Sun like many times hotter that's hotter than the surface of Riel that we talked about earlier on that's only merely 12,000 Calin so that is incredibly hot and that's just because Jupiter has an enormous amount of gravity and temperature and pressure and things just heat up and heat up inside as you get closer and closer to the center and if you make Jupiter bigger then it would have more mass and then it would be able to have an even hotter core and at a certain point that core would be so dense and so hot that it would start to ignite Fusion in the middle of that planet and now you would have a star so you know Jupiter doesn't have any surface that you could walk on but you know if you tried you would just fall into the cloud Toops but you would find very quickly that actually Things become very hot and dense inside the planet and same thing goes for Saturn same thing goes for Uranus same thing goes for Neptune pet pleased which costs more preserving Earth's environment or exploring space for a new habitat consider facings like funding sources project Scopes and long-term objectives preserving Earth's environment is the best investment we could Pro possibly make for the long-term sustainability of the human existence not to mention all of the biodiversity all of the animals and so on like it's really hard to get across to people how awful everywhere but Earth is like if you take Mars which is like the most habitable place in the solar system still um there's a almost no atmosphere on the surface the gravity is a fraction of what you have on Earth gravity it is bombarded by radiation from space uh there's no water on the surface there's no air you can breathe there's you know very difficult to access resources that you could use it's a terrible terrible place to live and that a place like Antarctica is so much more habitable than Mars um and so like I don't even think it makes sense like like I think that if people are make this straw man argument on the internet where they say well if people want to go to space that means that they don't want to preserve the Earth but I mean it's kind of like saying if you want a to climb a mountain that means that you don't want to clean your house like you're not climbing the mountain so that you can get away from your house you're you're climbing the mountain to climb the mountain and you if you left the dishes undone when you get back to your house you're going to have to do the dishes because you're not going to live on the mountain you're not going to live on Mount Everest Mount Everest is trying to kill you that you get Beyond a certain point at altitude on Mount Everest and you're in the death zone and you're living on borrow time and all you've got is the food that you brought with you and the supplies and you're going to be you know you're going to run out of gas to heat your food up and you're going to freeze to death and you got to get to the top of that mountain you got to get home and once you're home and you've got nice comfortable temperature and you've got food in your fridge and you got your friends around and you can go for walks in the park you take your dog and it's all nice right you're going to do the dishes in your house because that's where you live and so to take that analogy to torch that analogy right that that there is just like there's no there's no connection between those things that us trying to explore a place like Mars doesn't mean that we're going to try you know if we can't sustain our environment here on Earth then we're not going to be able to do things like go and explore Mars and I guess you know if you don't wash your dishes then you won't be able to climb Mount Everest I don't know all right those are all the questions that we had this week thank you everyone who asked the questions in the YouTube comments and thanks everyone who showed up for the live show which we do every Monday at 5:00 pm Pacific Time right here on the channel I'm going to put a reminder on the channel so that you can see when the next one is going to happen and I'm sure you can like set a reminder so that you'll receive an email I promise YouTube will tell you when the next show is going to be now I'm going to continue promoting smaller YouTube channels but first I'd like to thank our patrons thanks to Abe Kingston andream gross Antonio lilara David gilon douge Stewart Dustin cable George Jeremy murn Jordan young Josh Schultz Mark a mandale mark antis Paul robrock Steven kraki Steven fer Munley and Vlad chiplin who support us at the master of the universe level and all of our other patrons all your support means the universe to us all right so I'm going to continue my campaign of trying to bring attention to smaller YouTubers and so this week I want to suggest you check out the ad astrospace Channel which is hosted by swapn Krishna and she is a space journalist who has worked for a lot of the names that you've heard before space.com wired she hasn't written for Universe today yet um but she does a great job her channel is terrific and she's been doing a lot of coverage most recently just on the ysus Lander and while I did one episode she's done a whole bunch sort of covering each point of it and so you know a really great coverage of space exploration news and you can see she's got chops uh and yet for some reason she doesn't have a lot of followers so you know it's just a matter of time you'll remember when uh you're one of the first people to subscribe to her channel so definitely check out ad astrospace and please keep sending me the names of YouTubers who have less than 10,000 subscribers people who are new to the scene or like just for some reason aren't getting a following I want to try and drive as many new subscribers as I can to those people all right we'll see you next week