The Future of Telescopes | Q&A 472

Which space event would I want to observe firsthand? How will artificial gravity systems work? What's the direction for future space telescopes? And in Q&A Plus, how does astronomy adopt AI? All this and more in this question show. It's time for 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. I'll gather them up and I will answer them here. All right, let's get into Paige Potter, if you could observe any single event in the universe's history firsthand without interfering, what would you choose? I mean, I wouldn't be interfering, but hopefully it would be safe for me. I would love to watch a black hole be formed. I would like to see in the moment that a star, a massive star, collapses down and becomes a black hole, because it is instantaneous That you've got this star and inside the star it is. fusing elements and it's working its way up to iron and the moment it hits iron the fusion inside the star just stops. The light pressure that is coming out of the center of the star ceases and the outer layers collapse in on it at you know approaching the speed of light. They're essentially just falling down to the middle like I think it's like 70 percent speed of light or something like So it's fast. This star goes from being the size of Jupiter to nothing over the course of two hours. That would be crazy to watch that happen. Then you get the supernova, or maybe you don't. If there's direct collapsed black holes, then the star just disappears and just becomes this empty spot in the sky, caused by it becoming this black hole. That would be absolutely incredible, and the kind of thing that you could comprehend. And it would happen in a, in a timeframe that, that you could understand. Uh, yeah, I think that's the thing that I would like to see. Telephone Jack. I keep hearing about rotating structures for gravity, but isn't there research on the Coriolis effect and how it messes with human orientation? Is it really a solution to consider? Yeah. So the. We've talked a lot about how the next big thing that space exploration needs to figure out if we want to be able to survive long-term in space is to have some kind of artificial gravity. When you read the Expanse books, they use thrust, so the spacecraft have the ability to do tremendous amounts of acceleration because they have these fusion drives, poorly named fusion drives. Um, But the drives can let you have, say, 1G or half G. And so that's enough for them to drink coffee while they're accelerating towards wherever they want to go. And then the spacecraft turns around and decelerates. And then you can continue drinking coffee and walking around in your spacecraft. And all the spacecraft in the Expanse are designed like buildings. skyscrapers, small apartment complexes. You walk around, you climb ladders to get from various floors or those elevators. And the spacecraft are always in some kind of acceleration, except when they're not, right? Except when they're having battles or when they're coasting or floating or whatever. But the energy required to be able to handle that kind of acceleration is just ridiculous. And we do not have that technology today. So instead, the technology that we do have access to Rotation, where if you rotate something, and of course you've probably experienced this, you go on a, what do you call them? You go around, spinning. Anyway, I forget what it's called. It's like a kid's toy. Think about the Gravitron, right? It's this. Thing at a fair, you get into it, thing spins up, and you are stuck to the outside of the thing. It's this centripetal pseudo force that is pushing you to the outside. Really, your body wants to continue in its normal direction, but because you're stuck by the, you can't because you're being held by the outside of this rotating machine. You are stuck to the outside of this thing and you experience gravity. And if you've ever been in this, while you are on the bottom side of it, you're kind of experiencing more gravity because you're experiencing Earth's gravity as well as the outward force that you feel from this thing. And then when you're on the top, when you're upside down, now Earth's gravity is pulling you down and you are experiencing the force that's pushing you up and you're stuck still. So this idea has been tested quite a bit by various, the Navy did some tests back in the 1960s and tried to figure out, is this a good way for us to be able to do artificial gravity in space? And so they put people in these rotating systems and for days on end, and then would spin them at different speeds to try and figure out what were the effects on the human body. And what they found is that if you sort of kept it in this kind of one to three revolutions per minute range, then people could handle it. They could be on it for days. They could go about their lives. They could, you know, sit at a chair and they could handle this rotation. But they would experience a little bit of motion sickness once you got to above three revolutions per minute. And this is down to the Coriolis effect. If you think about sort of this wheel that's spinning, and that if you're close to the center of the wheel, the distance that you take to go once around the wheel is very small. Well, if you're on the outside of the wall, the distance that you take is huge. And so if you're going to pour liquid and you're inside this spinning wheel out in space, then there is essentially outward force in the direction that you're turning that's going to cause, say, liquids to go sideways. And so this is a thing you have to start to learn to overcome. And what the researchers found was within a couple of hours, people could adapt and compensate for this Coriolis effect. And what they found was if you want to make it absolutely smooth, then you want it to be one revolution per minute. But the very limits was you could get up to 10 revolutions per minute. 10 revolutions per minute is uncomfortable. But people could adapt to it and be able to perform functions. They were able to take notes, work on computers, while they're spinning at 10 revolutions per minute. And so where this sort of turns into gravity is that if you're on a wheel and you want to have one gravity from this wheel that's turning, then the wheel needs to be about a kilometer across, 890 meters across. And that gives you one G, one gravity. But if you shrink that wheel down to nine meters, but you run it at 10 revolutions per minute, then you still have one G. You just have this intense Coriolis effect that the forces that you feel at your feet are very different from the forces that you feel at your head. So you've only got a couple of meters above your head before you've got the center of the wheel. You're experiencing a totally different rotation in your head than you are in your feet. And they found that you can you can adapt to this. So there was a couple of experiments that we were reporting on that I thought were really cool. One was this module that NASA was thinking of adding to the International Space Station was called the Nautilus X. And so it would be small, probably about a four meter diameter, but it would turn at not 10 revolutions per minute, but enough to give you some gravity, some relief from the weightlessness. Um, and then you would maybe sleep in this would be like a tube that was just rotating on the side of the international space station. And you would just sleep inside this tube that was rotating. The other idea is one that's even smaller, probably a five meter centrifuge and same deal. It would turn, maybe go even faster than 10 revolutions per minute. You can probably get up to like 15 and the astronauts would sit inside this thing. So it would be launchable from inside a Falcon 9 fairing. And then the astronauts would would go into this capsule into this module attached to the space station. And then they would just be spun inside this thing at 10 to 15 revolutions per minute. And it's endurable. It's not fun. I'm But it provides the force on your bones on your on your muscles on your starting Imagine you'd be working out in this little thing, and this was an idea for how to deal with this. So yeah, the Coriolis effect is a huge issue to that we need to address. The lack of artificial gravity is a big issue, and both of those are big limitations speak to us being able to travel in space. It's time to shout out all the new $5 patrons and above. now. Jordan Schmidt, George Zavalegos, Mark Olejniczak. Barnabas Heideck, George. Generation, Wayne C., Michael, Galactician. Join the club at patreon.com slash universe today. Caroline Magnid, do you see current and near future next generation telescopes as being more light gathering limited or resolution limited? So bigger mirrors or interferometers? Right. So we're currently in the age where all of the big telescopes on Earth are essentially monolithic telescopes. Almost all. I'll give you some examples in a second. So you've got the Subaru telescope. Which is like an 8.4 meter telescope. You've got the Gemini North, the Gemini South. Yeah. Those are individual telescopes. You've got the Grand Telescope in the Canary Islands. And that is an individual telescope. You have a lot of the big radio dishes. Like the Green Bank Observatory or the Jodrell Bank. Just a giant radio dish. But then you also have interferometers. And so you have examples like the Very Large Telescope. The Keck Interferometer, which isn't interferometer-ing anymore, but it was. And the Very Large Telescope is four separate telescopes that work together as a bigger infrared telescope that is equal to the separation of them. And then you have smaller interferometers that can sort of do the combined light. So there's the Very Large Array. Which is a series of radio telescopes. And then, of course, at the larger scales, you've got, say, the Event Horizon Telescope. So these are all examples of different telescopes designed to take advantage of sort of two directions. One is you build a big telescope. One big primary mirror. Oh, there's also the Large Binocular Telescope, which is two 8.4-meter telescopes side-by-side that act like interferometers. It's kind of the best of both worlds. With a sort of large monolithic telescope, you've got just this big mirror, it is polished. carefully, and it brings in light and gives you the best image that it can. And in this case, it's just it's brute force that the more mirror that you have, then the more you can see. And what the advantage of a monolithic telescope gives you is that you can see fainter objects. Essentially, you are able to see eventually exoplanets orbiting around other stars, you're able to see objects that are incredibly faint. That's where you want a big telescope. What an interferometer gives you is that if you can line up the wavelengths, we talk about this all the time, right? Then you get a telescope that is essentially the equivalent of the baseline between the two telescopes. So if you have one telescope over here and then one that's a kilometer away and you're able to line them up so carefully that they get down to the wavelength, then you have built a virtual telescope that is the size of the separation, which is a kilometer. You have a one kilometer telescope, but you only have the light gathering capacity of whatever the two telescopes are. So if you have two one-meter telescopes separated by one kilometer, then you have the resolution, the ability to recognize features down to whatever a one-kilometer telescope can give you, but the magnification, the brightness, the sensitivity of just the combined light of two one-meter telescopes, which isn't very much. But when you have an interferometer, you want to look at bright things. When you have a single monolithic telescope, then you want to look at faint things. But the reality is that all telescopes are interferometers, right? So when you look at, say, Vera Rubin, it looks like one big mirror. But it's just that it's been polished in such a way that it is a natural interferometer, that all the light that's coming in, it's all showing up at the same wavelength, and the telescope is able to handle that and then produce the equivalent of its size. All telescopes are actually interferometers. So the question you're asking is, like, what makes sense moving forward? Do you go with a... Bigger telescope or do you go with an interferometer? And the answer is you do both, right? So the astronomical community has been developing much, much bigger telescopes. And there's a group of three mega telescopes that are in construction right now. Two are going to be built for sure. And the third probably won't be built for a while. So you've got the Giant Magellan Telescope, which is in the kind of 30 meter class range. And that's going to be down in Chile. And then you've got the Extremely Large Telescope, and that's going to be a 39-meter telescope. So those are monster telescopes, but they're not interferometers. Although, I mean, they're interferometers in the way that all telescopes are interferometers. But then you've got the sort of other direction, which is to build an interferometer. And so the large interferometer for exoplanets, which is going to be this next generation. space telescope for hunting planets, that's planned to be an interferometer. You've got some other interesting ideas. I've talked about moon-based interferometers that are potentially in the works, but there's a lot less concrete ideas. And the reason is because aligning the wavelengths on the various telescopes in your interferometer is just so difficult. And the classic example that I give for this is the CHARA Array, which is this visible light interferometer that's in California. And this is a bunch of very small telescopes that are about, you know, in some cases, 400 meters apart. And they have, they can look at the same targets. They can look at Betelgeuse together, two telescopes. It's actually a whole bunch of telescopes. They can all look at the same target. And then to keep their wavelengths down with precision, they have to have all these carts that move back and forth that combine the light of the different telescopes. And as The target moves across the sky, the distance from the star to the telescopes changes enough that you actually have to move these carts to keep that distance exactly the same. And so it is a really complicated process. And so the technology to make bigger telescopes is ahead of the technology to make telescopes operate as an interferometer at visible wavelengths. In radio... It's a totally different story, because the wavelengths are so long, it's very easy to, or it's relatively easier to align your wavelengths. You do this after the fact. You essentially put atomic clocks on each one of your radio telescopes. You image the same object. And keep track of the time, and then you bring all of the hard drives together, and then a supercomputer just looks at the time codes and blends all of the data together, and you get the interferometer, like the Event Horizon Telescope. So we're going to see more interferometers on the radio side, on the microwave side. And then we're going to see, you know, maybe on the infrared side, but the visible light side, it's going to be a while before the technology and the logistics come together to make these things like possible. Did you know that you can watch the same video with no ads and get a bonus question over on Patreon completely for free? We call that Q&A Plus. This week's bonus question, how does astronomy adopt AI? I'll put a link down in the show notes, but you can also click this QR code to go to it directly. All right. Those were all the questions that we had this episode. I'm going to talk about Star Trek and sort of the sad deaths. But first, I'd like to thank our patrons. Thanks to Abe Kingston, Andrea Petretti, Boldazorg, I hate this place, it's the smell, Brian Bodie, Kerwin, Chuck Hawkins, Commander Bailick, David Gilson, David Matz, Evan.Pro, James Clark, Jeremy Maddern, Jim Burke, Marcel Smits, Mike Marcel, NASA Ocean Guy, NordSpace One StepForAnimals.org, Rink Kaiju, Richard Williams, Sean Sargent, Team 49, Talesubs Canada, Vlad Chiplin, Wolfgang Klotz, Zelda, Boldazorg, Your Silence is Fooling No One, who support us at the Master of the Universe level and all our patrons. All your support means the universe to us. So we had a sad couple of weeks here in the Star Trek fandom, and that is that two legendary actors of the Star Trek franchise have passed away. So from the original show, Walter Koenig, of course, he was Chekhov, and Star Trek is my show. That is my sci-fi show that really got me excited about science fiction, really about space. My parents were both sci-fi nerds and so they were watching it when I was Four years old, and we were watching black and white on this little television, and I just loved the show, and then was so excited when every new movie came out. I played video games about it. I played role-playing games about Star Trek, and just in my life when I was young, all of the cast were alive, and now we're down to two, George Takei and William Shatner, It's just heartbreaking, but I guess this is what it means to get old. The other big hit, of course, was Sir Patrick Stewart, Captain Picard from The Next Generation. While Star Trek, the old show, was the one that got me into science fiction in the first place, The Next Generation was my show. I was sort of at the perfect age. I was like 17 years old. TV was a wasteland at that point. Like, yeah, you had Doctor Who in the middle of the night sometimes, but Star Trek was a brand new science fiction show that just told this incredible positive story about humanity's future in space. And Patrick Stewart was, he was my captain. But you could see after Star Trek, he went on to play a whole bunch of other roles in X-Men, and he was not afraid to make fun of himself. And just a legendary actor, and it's a heartbreaking loss, but he was old. And the same thing, I guess, is going to happen for the next generation, pardon the pun, of the people that I loved, and eventually me. This sucks. We'll see you next time.