Submarine for Titan, Planets Changing Size, Even Bigger LIGO | Q&A 230

could we measure the great attractor by gravitational waves could we make ligo but even bigger and is it possible that the planets are shrinking over time all this and more in this week's question show it's time for the question show your questions my answers as always wherever you are of question Pops in your brain just write it down in the YouTube comments and I will gather a bunch of them up and I'll answer them here now it's important to note this is the last episode of the question show before we go on to our summer Hiatus every year so those of you who probably know that we take off July and August for the live streams so right now it's just the question show um we still do space bites we still do the newsletter we still do a bunch of interviews and we've got a bunch of other really cool projects that we are planning things that I hope will give you that old guide to space Vibe but we just need some time to concentrate and so uh this is sort of one of the things that we do every year so uh it'll be all right have a good summer and I will see you in this format in a couple of months from now um and then who knows what time we'll record the show but this one was recorded live on Monday all right let's get into the questions J cross the great attractor is hidden by dust in the Milky Way It Is cosmically fairly nearby is it big enough that we should be seeing in excess of gravitational wave events from the objects in its galaxies could that tell us something new about this massive cluster now I've talked quite a bit about the great attractor and that it is this massive cluster of galaxies that just happens to be on the far side of the Milky Way from us astronomers always talk about this gas and dust that's at the middle of the Milky Way they call this the zone of avoidance and the great attractor whatever it is happens to be on the other side of this part and you know it's less of a mystery today thanks to powerful infrared telescopes that can peer through the gas and dust in the Milky Way and have revealed most of the galaxies that are part of the Great attractor but not all of them so the ones that are like on the other side of the densest amounts of gas and dust are still haven't been observed but every year more and more of those galaxies are discovered and announced and we report on them and so the amount of like final hidden galaxies like it's just turning out to be galaxies and the center point of the grid attractor is about 150 million light years away from Earth and so that's pretty far when you think about say andromeda's two and a half million light years away from us uh you know a lot of the galaxies that you're very familiar with are in the 10 to 50 million light year range and it's really like 150 million light years away from us that's pretty far but it is not far in the realm of gravitational wave detection like the closest detection from gravitational waves was a neutron star merger it's about a hundred and thirty million light years away so that theoretically if it happened to be within the great attractor would be close enough but then the distances jump up pretty significantly and so you know we see a lot more of these gravitational wave mergers in the 500 million light year range which is well beyond the far side of the great attractor like I thought it's you know 150 million light years away is the center but it's not that large so you know that's Way Beyond the great attractor and then there are ones that are out into the billions of light years away and so those are of no use and so for us to be able to use gravitational waves as a way to probe the shape of the great attractor is to get vastly more sensitive gravitational wave observatories that will allow us to see smaller things happening neutron stars merging with white dwarfs white dwarfs merging with each other stars colliding Supernova that are not symmetrical when they go off and it causes giant wobble but like the idea is great like you could imagine we get more and more of these gravitational wave events the gravitational waves go right through the zone of avoidance and so we are able to start mapping them it's like we could say well we can't see it but we know that two black holes merged right on the other side of the Galaxy and so that there had to be a Galaxy there and then we saw another one over here and we saw another one over there you can start to map out the shape and consistency of the great attractor even though there are parts of it that we still can't see and so I love the idea but we're going to need more powerful uh gravitational wave observatories to be able to make you know some kind of statistical measurement of the great attractor in gravitational waves or neutrinos at user bs1lr8nx1h can ligo's arms be even longer or is the earth curvature far too big for that speaking of gravitational wave observatories ligo is of course the instrument that has been detecting a lot of the recent gravitational waves in concert with Virgo and in concert with the upcoming kagra Japanese gravitational wave Observatory and ligo has arms that are four kilometers long and with the new run 04 of ligo we are seeing gravitational wave detections almost every day you can actually go to the internet and you can see the Raw Feed of gravitational wave observatories the folks behind ligo are no longer doing a lot of detailed confirmation they are just posting the results of their detections and they're letting scientists work through it to figure out is this a real gravitational event was it just a truck was somebody walking on a nearby mountain and jumped up and down like they can figure this out but still even with this new run ligo is limited to the kinds of objects that it can perceive it's going to be able to see colliding black holes colliding neutron stars it's going to be able to see a larger volume of this and it's going to be able to see more and more of these events but to really take things to the next level we're going to need an entirely next generation of gravitational wave observatories so there's a few ways to go about this one is the Pulsar timing arrays we've talked about this before I've done an interview about this um you know examples like nanograph where you've got about 100 millisecond pulsars that are really well known by astronomers these are neutron stars that are spinning hundreds of times a second in some cases almost as close as like a thousand times a second and they give a very steady regular radio pulses that allow astronomers to map their sort of position and movement very very carefully and so they will just watch one Pulsar year after year after year and just watch how this Pulsar is sort of changing in sort of shape and orientation and the redshift and it is expected that we will start to discover a background gravitational wave um in all of these Pulsar timing arrays and that's one way that astronomers are proposing that we can detect like the mergers of supermassive black holes theoretically uh nanograph could detect the mergers of supermassive black holes there's a recent run where they took like over 12 years of Pulsar timing array data but they weren't able to find any billion Mass black holes merging within 300 million light years so they're getting closer and I've even heard rumors that there might be an announcement of a detection of supermassive black holes that would be great and then the other way to go is with a space-based infrometer and this is the idea behind Lisa the laser interferometer space antenna where you've got three satellites flying information they form a triangle that is tens of thousands of kilometers long and then they are measuring as giant gravitational waves go past these three spacecraft that are in formation and so you would potentially be able to detect the very large large slow moving events like the supermassive black holes colliding but the question that you're asking is could you make ground-based telescopes bigger and the answer is yes absolutely so there's a couple of big Next Generation gravitational wave observatories that are in the works so the first one is called the Einstein telescope this would be a gravitational wave telescope a triangle where you've got three stations that are 10 kilometers apart while ligo has two separate stations with sort of arms at perpendicular and they're four kilometers long Einstein telescope would be 10 kilometers but it would just be one triangle and then another even bigger idea is the cosmic Explorer this is going to be a gravitational wave Observatory where the arms are 40 kilometers long and so like what do you do with a gravitational wave Observatory that has arms that are 40 kilometers long like you get to use all of the ideas all the great technology that was developed for ligo you know now that we're on the the fourth observing run you're able to use all the quantum squeezing the better mirrors all the stuff but now you've got arms that are 40 kilometers long and this goes the other way in the opposite direction of what the space-based observatories are going to be doing it's going to be looking for the smaller events it's going to be looking for white dwarfs merging neutron stars merging but giving you a view almost out to the very beginning of the universe and from that you get a lot of really cool things so for example you'd be able to confirm the existence of primordial black holes like if you are seeing almost out to the beginning of the universe and you're seeing black holes merging of masses that are just way too big that should have formed after stars formed well then that means that these black holes formed with the beginning of the universe you would be able to measure and sort of resolve the Hubble crisis where you've got different measurements for the expansion rate of the universe because gravitational waves give you like an independent way to measure the expansion rate of the universe you would be able to map out dark energy at all points in the universe you'll be able to see into the places that we just can't see with traditional electromagnetic radiation because the gravitational waves can pass right through you're like yes please when when do I get one and so these next Generation gravitational wave observatories are like due to come online in the 2030s but like they're building on all of the technological advancement that came with ligo like ligo's job is to figure out is this even possible can we detect gravitational waves and now we're at the point like oh yes we sure can and so now what are the different kinds of telescopes that'll take these observations to the next level so stay tuned like there are going to be so many and there's actually a bunch of gravitational wave Observatory projects coming out of the Chinese as well I've seen a lot of papers on their plans to build gravitational wave observatories as well so in the next 20 years you're going to see many many new observatories come online and they all get to work together which is great and one big Global Network Abe Kip is it possible that the Earth or other planets might be changing in size or I've expanded or contracted in size in the past is he cool yes some of the planets are changing in size I'll give you a couple of concrete examples here so the one that's most famous is Mercury and so when NASA's messenger spacecraft went to Mercury it found some really weird terrain they call this chaotic terrain and it just looks like a chunk of the planet was just kind of jumbled up and cracked up and you see these sort of weird like Cliffs that look like stairs but the key is that these things are new you don't see craters are punching down into the middle of this jumbled chaotic terrain you see that these things formed after most of the large craters formed are Mercury and the explanation is that mercury is cooling down and it's shrinking and as it you know if you had like a metal ball and you let it cool down it would shrink and in the case of mercury as it shrinks you get these cracks opening up as it's continuing to shrink it's kind of jumbled terrain on the surface of the planet and in fact we see the same thing on the moon they're very similar features these this jumbo terrain these scarps and so that tells us that in fact the Moon is shrinking a little bit until scientists tried to figure out if the same thing was happening with the Earth is the earth shrinking now the Earth is losing a little bit of mass because of its atmosphere so the atmosphere itself is shrinking but the planet itself is gaining a little bit of mass because of all of the meteorites that are striking the plant like we get like a hundred tons of meteorites hitting the planet every day that adds to the mass of the Earth and so the atmosphere is shrinking while the mass of the planet is growing but researchers actually tried to measure over a long time uh to see if the actual size of the planet is growing because of all this material is being added or if the planet is shrinking because it is cooling down like Mercury or the moon and it doesn't seem like it is so right now the planet Earth is remaining the same if you go out to the gas giants you look at Jupiter Jupiter is losing mass because it is blowing off the outer layers of its atmosphere thanks to the solar wind and so it is losing mass but losing mass for a gas giant doesn't mean that it's necessarily going to shrink in fact Jupiter is actually pretty big as gas giants go that if you added more mass to Jupiter it would make it smaller and it might be that if you took mass away from Jupiter it might also make it smaller like it all just depends on the consistency of the planet what its temperature is how it's interacting with its star and so you could end up having Stars even that have dozens of times the mass of Jupiter and yet they're actually not a lot larger than Jupiter itself so it's sort of a complicated question about whether Jupiter or Saturn or Uranus or Neptune any of those are are going through this same process but Mercury for sure definitely shrinking if you like my answers to your questions as well as the other things we do at Universe today consider joining our patreon club this allows us to keep a minimum ads for everybody and as a patron you'll get an ad-free experience on university.com for life even if you unsubscribe you can add free videos Early Access to interviews as well as other perks that are exclusive to our patreon community thanks to everyone who has already subscribed and welcome to the recent newcomers Scott Pennington John Rose pool float1980 Maverick cats Christopher Burman Dan teston Rasmus Von cyberg Atticus McQueen Thomas Hood David wilkson Chip caplov and Matthew duplante join the club at patreon.com universetoday goo goggler can we build a sub for Titan absolutely uh this is an idea that has been proposed by NASA to build a submarine that would go to Titan and this is really exciting to me there's a couple of reasons like one is that like on Titan you've got these Lakes made of liquid methane and this is a material that is produced by life so you know it is encountering lots of other organic chemicals in a liquid form and yet the Lakeshore is made of water ice where the water is so hard it's like mountains and shorelines and the part that's crazy is that the methane is clear and so if you took a submarine to tighten and you drove it around you could have like a buoy at the top that could look down and just watch the submarine moving around now I mean there might be stuff mixed in with methane it's what might be a little bit cloudy and murky but it's nothing like water is going to be it's a lot clearer and it's also clear to various kinds of electromagnetic signals and so it would be very straightforward to be able to send messages back and forth from inside the the lake from the submarine back to the surface and then from there back to Earth and there's so much fascinating science that you could do on Titan so yeah absolutely there's there was a Nyack Grant proposed to build a submarine on Titan it's you know it hasn't been turned into a mission yet but uh you know depending on what happens with the success of the dragonfly Mission which is a nuclear-powered helicopter of Titan um yeah let's have a submarine or maybe a sailboat or both or some kind of of submersible that zips around on the surface and then can dive down and look for stuff stuff uh yeah I would love to see a submarine go to Titan I can't I can't think of any other place in the solar system that you could send like a submarine too easily I mean it's not easy but relatively easy to look there's no other place so yes yes please Darren Jones anything from jwst that you were surprised by I wouldn't say specifically that I've been surprised by anything but I am surprised by by which things have been discovered at which times so obviously the one that is sort of most exciting is these large galaxies that are being seen by jbst early on in the universe and you know my expectation was this is the kind of thing that we would see after big long surveys had gone on and they'd completed the Jades survey which was like 32 days of constant observations of the universe but in fact just a few weeks in we were starting to get a sense of these really big galaxies that are being seen by jwc and part of this is just how well this telescope has performed above and beyond what astronomers were expecting I say the other thing that is sort of so surprising because we're seeing it so much is how many people are reporting evidence of the population three stars and these are of course those first Stars formed after the universe from the primordial hydrogen and helium left over from The Big Bang and we can't see them because they were enshrouded in all of these clouds of hydrogen and helium and before they started to ignite explode a supernova clear out all the material to the point that we'd actually start to see them but astronomers have seen evidence that some of them are still forming in the outskirts of these early galaxies or they're seeing how the Supernova from these population three stars have enriched nearby galaxies this was something that I wasn't expecting that we would see until many years into this where a lot of really interesting gravitational lenses have been found and Star Wars like we think we found some kind of evidence but neural like I'm seeing multiple papers a week on archive that are saying that they're seeing evidence of some kind of evidence indirect evidence of population 3 star cars and we've been reporting a ton on this on Universe today and I'm so excited about this so I would say those are those are the big ones um the planetary observations that it's made seem roughly what was expected like they found evidence of methane they found evidence of carbon dioxide they found sulfur sulfur they found various chemicals no no like glaring obvious sign biosignature like seeing another Earth it's too early in the process so so that feels pretty normal but apart from that um yeah it's just like how quickly it's delivering these kinds of results it's been amazing planning to do like a one year anniversary on jwst so it was kind of you know like the the thing that we did with with Scott and Marcus about Starship I'm planning to bring together two um YouTube hers but cosmology astrophysics related Peeps and we will talk about how we're excited about what's happened over the first year with jwst so stay tuned for that the Van Johnson Junior if there is a Galaxy like Star Wars that is 9 billion light years away and they lived 8 billion years ago could we detect their techno signatures if not what will it take for us to detect well the trick here is that you're going to be seeing the light that they emitted 8 billion light years away and there are not many things that we can see in the universe where the light has been traveling for eight billion years like quasars where you've got a supermassive black hole that is giving off more than the collective light of an entire galaxy down a jet that happens to be beaming directly at the Earth that's the kind of thing that we can see where you know you're seeing them as they looked eight billion years ago but theoretically if we had some future really gigantic telescope when you've got this technological civilization and the light has been traveling from their civilization for 8 billion years then we are seeing them as they looked eight billion years ago and so if the civilization arose nine billion years ago and they lived for a billion years um then we would be seeing them a billion years into their progress even though they've actually you know now in that galaxy far away far far away um they've been around for nine billion years so for close stuff like if we find some kind of alien civilization at Proxima Centauri and they're only 4.26 light years away we send them a message we wait nine years we get a message back you know we could probably play a very slow game of OverWatch with them but once you're going to tens of light years hundreds of light years thousands of light years it gets really hard to be able to detect their presence and also you know that whatever you're looking at has come and gone a long time ago definitely outside of the Milky Way like the farthest stretches Inside the Milky Way you're looking at maybe say 30 000 light years away so you'd be you know let's say we saw something in the very outskirts of the Milky Way on our side of the Galaxy or maybe you saw something coming from the core of the Milky Way you could be looking at tens of thousands of years ago what will we be like in tens of thousands of years from now but I do love it like can you imagine like if we had some future where we really could see what was happening out there across the universe with Incredible resolution and we really could see oh here's the civilizations that are popping up or has popped up in this galaxy and that Galaxy over there and this galaxy over there we could we could see them and watch what they're doing at different stages of evolution in the universe I love the idea but practically speaking it's going to be really a long time Gina what is the core of Jupiter made of now we don't know exactly because of course you've got a lot of Jupiter in the way to look down to try and figure out what the core of Jupiter is made out of but you know we know the overall mass and the radius of Jupiter and that tells us what the density is and then we know what it's made out of which is mostly hydrogen and helium and so we know mathematically that if you put different kinds of hydrogen and helium mashed together into different ices at different pressures As you move down within Jupiter you know sort of what they form into and so we have a very powerful clue which is that Jupiter has an extremely powerful magnetic field kind of like the same way that the Earth does but Jupiter is made of hydrogen and helium and so something inside Jupiter has to be acting like a giant rotating iron sphere like what we have inside the earth and what scientists have figured out is that Jupiter inside has a type of hydrogen called metallic hydrogen and the gist of that is is that if you can Mash down hydrogen with enough pressure and temperature it will form into a metallic lattice like metal and as it rotates it will form this giant magnetic field in the same way that Earth's iron core generates a magnetic field in fact scientists have been able to create metallic hydrogen just like briefly in the lab with these like really powerful Diamond vices where they Mash hydrogen together and they're able to turn it into metallic hydrogen or maybe not there's some controversy on whether or not but eventually I would be pretty safe to assume that that people will eventually figure out ways to create metallic hydrogen on Earth and then we can kind of start to simulate what it's like inside Jupiter the other thing that's inside Jupiter is probably several times the mass of the Earth in other metals silicon oxygen iron nickel gold old all kinds of stuff is down there inside Jupiter you've got several times the mass of the Earth just within the core Plus you've got all this metallic hydrogen and then you've got hydrogen and helium and various ices and slushes all the way through the planet Ravens rules plane spotting tell us more about the traffic system what's the next planet so the trappist-1 system this is like the most exciting exoplanetary system that astronomers have ever found you've got seven planets that are roughly earth-sized orbiting around a red dwarf star at least three maybe four of these planets are in the habitable zone around this red dwarf star astronomers have already pointed jwst at the first two so the first one was assumed it would be something like Mercury it's like really close to the star and what do you know they didn't detect an atmosphere so imagine like a planet with a massive Earth but sort of like with the behavior of mercury but the next planet Trappist 1C it was expected that this might be an analog for a Venus so something with a thick carbon dioxide atmosphere very hot like it's too close to the star to have liquid water on a surface and so astronomers pointed jwc at that and we got um no thick carbon dioxide atmosphere now there could still be a thin carbon dioxide atmosphere or it could just be another Super Mercury but this is where things get interesting so we're waiting on the data for Trappist one D and this is the first one that could potentially be in the habitable zone it could have liquid water on its surface I mentioned this in space bytes but it's like the suspense is just killing me um so the scientists got access to jwst they did all the observations on all the Trappist planets but then they've taken all that data and now they're trying to analyze it and so as they have completed each one of the planets in order then they release the data they publish their science and we move on to the next planet and so we're looking at about a two-month Delay from when the first one was announced to when the second one was announced and so we've still got probably now two months like I'll bet we will learn about the next Trappist Planet the one that potentially is in the habitable zone by the end of the summer and then we'll probably know the next one a couple months after that and then a couple of months after that and so they're just gonna drip drip drip them and like like I understand like they've got a year from when they took their data to get out that final science paper before the entire exoplanet Community just descends on this data together and begins writing a ton of papers so we have this hard end which is you know a year from when they started Gathering the data and I'm sure we're going to discover some really exciting things I hope so anyway I mean this is this is the most exciting planetary system that we know about Edwin legaspi how much mass can be at the LaGrange point before it is no longer a LaGrange point I love this we wrap up this season's question show with the LaGrange point question which seems just right um now it's important to understand like you only get the LaGrange point when you have one object with a lot of mass and then another object with less mass and then those two objects will then create the five LaGrange points where something with negligible Mass can exist inside of that region and so you can have the sun Water Mass Earth less mass and then you have those five points where you can have negligibly massive objects and negligible depends on the mass of the second body so in the case of Earth for example astronomers have detected a couple of Trojans in the earth's L4 and L5 LaGrange point but they're very small like they are dozens of meters across but you go out to look at Jupiter you've got the Sun and Jupiter and you've got its five LaGrange points and Jupiter's Trojans there is as much material in Jupiter's Trojan belts as there is in the main asteroid belt there are thousands and thousands of objects and some of them are big like some of them are tens of kilometers across hundreds kilo 100 kilometers across like they're big and so it really all depends so negligible really depends on the mass of the interacting bodies with the Earth and the moon we're going to get those five LaGrange points and so we could put satellites Into The L4 and L5 we could put like space stations Into The L4 and L5 but I wouldn't try to put like another Moon Into The L4 and L5 so as long as your thing is negligible compared to the other two objects then it works fine all right those are all the questions that we had today so this is the end of this season and we will see you next season in the early September for the next QA if you want to stay on top of all of the important space news join my weekly email newsletter I send it out every Friday to more than 60 000 people are right every word there are no ads and it's absolutely free subscribe at university.com newsletter you can also subscribe to the universe Today podcast there you can find an audio version of all of our news interviews and Q and A's as well as exclusive content subscribe at university.com podcast or search for Universe today on Apple podcast Spotify or wherever you get your podcasts a huge thanks to everyone who supports us on patreon and helps to stay independent and keeps ads at a bare minimum thanks to all the interplanetary researchers the interstellar adventurers and the Galaxy Wanderers and a special thanks to Antonio lofi Lara Dustin cable just Paul Davis Flagship Lynn Jay Dennis David Gilton and monzo George Jeremy matter Jordan young Tim Weyland Dave veriberoff Andrew Gross and Josh Schultz who support us at the master of the universe level all your support means the universe to us

Channel: Fraser Cain

Views: 42,215

Keywords: universe today, fraser cain, space, astronomy, gravitational waves, planets

Id: 8G2mh15Uaf4

Length: 31min 27sec (1887 seconds)

Published: Wed Jul 05 2023