Refuelling the Sun, Rogue Planets Auroras, Space Nukes | Q&A 249

[@mhult5873]

Thank you Fraser, again, for another great video - as always! Also thank you for taking the time to talk to me when I became a Patreon. The discussion we had was interesting and it was nice talking to you. I am impressed with the work you and the other staff are doing. I am really impressed actually. And it´s very interesting content. Thanks again! Take care. BR //M

[@davidhenry5128]

'Eager Space' is my favourite underrated channel, it combines science, rocket engineering and related subjects in a way that is easily understood, but only has about 4.3k subscribers. The basic graphics may not be to everyone's liking, but the content is gold.

[@killerplank1]

Cait had the best question and answer. It was also great to hear about possibilities with larger rocket payloads

[@timheyes9338]

Cait please because it is so wonderfully counter intuitive! Keep up the great work. Love what you do. Thank you.

[@collemwillst1810]

My question: how cold does it get in the shadows on the Moon on the sunlit side? Does it get as cold as the night side of the moon? Also, love this channel! I've watched dozens of videos multiple times, especially if I listen to it to help me fall asleep (not out of boredom!). You just seem incredibly chill, passionate and knowledgeable, Fraser!

[@t.a.r.s4982]

So prolific, thx Mr Cain, we enjoy it (I joined lately last night, these summaries are convenient)

[@ashleyobrien4937]

I've always wondered why they weren't using lasers for high bandwidth comms. it was possible even at least ten years ago, now, it's ridiculously cheap because of the low cost of high power solid state lasers. Radio waves are not very directional, and thus heaps of energy is lost, but lasers ARE very directional and you can really crank up the bit rate and do it over multiple frequencies as well, it's a no brainer really, plus, because they are so directional, they are also much harder to intercept !. In fact, with time based crpto , they are probably 100 percent secure.

[@ashleyobrien4937]

By far the simplest way to get the water from the regolith, is simply to heat it using the sun, it gets well over 100 degrees Celsius on the sunlight up there, so it's just a matter of using solar charged vehicles to transport crushed regolith to a solar furnace and then take the steam and run that into a turbine to produce even more energy, the cooled steam then has lost enough energy to condense out, and there you have water, power all in one.

[@shanent5793]

Escape velocity is always the orbital velocity times the square root of two. So of you can get the nuclear waste out to the Oort cloud, it's still cheaper to eject it out of the solar system than to have it fall back into the sun. Nuclear waste still has a lot of energy left in it so it's probably better to put it somewhere you can reach when it becomes economically viable to recycle it.

[@jasonsinn9237]

Hey Fraser, if the NASA budget was doubled, what kinds of missions do you think we'd be seeing?

[@nzb6784]

I like the big spoon idea💡

[@shadowoftime3627]

My Question and hopefully this message isn't too long and love your work Fraser. Hey Fraser so Anton Petrov did a video not too long ago about False Vacuum Decay. Which from what I got from it was a bubble form when they cooled what I think was an element to almost absolute zero. This made me think of 2 thoughts, if we had a ship that accelerated to fast and the g forces were too much. Could you create a False Vacuum Decay bubble big enough to encompass the ship and not the rear thrusters. Then keep the outside of the bubble cooled to keep it intact but place a heating device in the center for people to be in the ship and to be even more careful, some kind of bungie like seat that would be safe to strap into. Then use that fast ship. Would the bubble theoretically absorb the g forces or enough of them to go at a faster speed then normally a person could? And again Theoretically if you could keep the bubble cooled and keep it intact? Also if able to do a second question on the same topic, there is a theory that the universe was created from a false vacuum decay. Anton mentioned how in that theory it could explain dark energy from the universe absorbing other universes. So for a second let's say it is the way the universe was created. Then that means our universe absorbs at some level. But I don't see it absorbing our water or gasses. Yes the sun throws some out due to stellar winds but I don't know if that means the universe absorbs it. And if it doesn't then, it absorbs on a different level. So if we could make a false vacuum decay bubble and keep it stable, then could we not put a device in it and try to experiment and change how that bubble absorbs in the spot on the bubble that the device is pointed. First in changing it to allow the universe to absorb it then in the opposite direction so we then have a safe way to keep it from absorbing too much of our universe. If so then in the direction the bubble is pointed we could shrink space like a balloon having it's air sucked out. Then if a ship was to leave the bubble in that direction and we reversed the polarity of that false vacuum decay, the ship would then be some distance away from the bubble. Theoretically speaking that is. Granted all this is based on if the universe was formed by a false vacuum decay. Also this could also be an experiment used to try and prove if the false vacuum decay theory of the universe is correct. Though giving how we might not be ready to even know the knowledge on how to change how a false vacuum decay bubble absorbs, this means even if we don't find a way to make it work, it doesn't mean the theory isn't correct. I lean more to the big bang but keep an open mind. Again hopefully this message isn't too long. Love your work Fraser. Also I am no scientist so I could be off on a lot of things here. Just some creative thought that popped in my head about a week or so ago.

[@alexczajka5623]

Re small channels, Parallax Nick is criminally under-subbed. His content is so unique, so well researched, and so well written. For the life of me I can't understand how his channel isn't bigger.

[@frasercain]

That's a great channel. Highly recommended.

[@azurata]

Hey Frasier, one of my favorite science communicators with under 10K subscribers is spacemog. Pretty sure I found her through one of your past videos. Thank you for all of your content!

[@lindaseel9986]

Vulcan and Remus. The entire video is fascinating,( pun intended ) but these two really taught me alot. Thank you.

[@MaXxProsTe]

Im glad for the thouhgt about the "Black forrest" when Ive been readding those awesome books I had my doubts about its premise too.

[@davidswift9120]

Interesting. I never knew that there was such a thing as a "Hubble Palette". Makes sense. You learn something new every day!

[@johnallport9565]

Let's go with Vulcan ... the answer to that question has a very high yield '''

[@evilmage42]

Hi Fraser, did you see there is a mini series of the 3 body problem coming out soon? I remember you were talking that it'd great to make this years ago, they listened :)

[@frasercain]

There's also a Chinese version that's extremely faithful. You can find it here on YT.

[@esecallum]

It will be awful with lgbtq and prooroonouns

[@threefeetofair758]

Cait! I love the idea of a swarm of red dwarf stars. Going to have to move closer to the center of the swarm, probably, but moving Earth is a trivial problem if you're able to scoop out bits of the sun.

[@erkinalp]

there is a solution to that: clusterise the stars in such a way they orbit on the surface of a sphere, and put your rocky planet in the barycentre of the cluster, which also happens to be the centre of the orbital sphere. that way you get permanent daylight too

[@papermasterpuppet9953]

Cait, it was a good question

[@guillep2k]

Hey, Fraser. Sorry to correct you: you can't broadcast anything with lasers, because lasers are by definition point-like, so you can only send information to a specific point in space (that's the good thing about them, since they do not have any appreciable apperture, you don't lose energy as the beam gets farther away). So no, anything you do with a laser is not really a broadcast. You could scatter the beam manually, or have multiple beams to reach more places, but that's a different thing (and very inneficient). A normal LED light would be better (as it will be seen from many angles and directions, which is what I would call a broadcast).

[@ReinReads]

While theoretically true, in application there is beam divergence. Depending on the distance & separation of targets, laser broadcasting is ideal. When looking looking for sources many light years off, like optical SETI, laser broadcasts would encompass our entire solar system.

[@blogsfred3187]

It’s 0.138 arc seconds best theoretical beam divergence… so 17k wide at 1 parsec. I’d say it’s highly unlikely a beam would strike earth. Assuming random angles and limited volumes of lasers per planet it still seems a vanishingly small chance.

[@Dylan-zm3ht]

Sorry to correct you but actually fraser is correct. I would know because my dad is the ceo of laser beams

[@shanent5793]

That's completely backwards. If a laser were point-like it wouldn't have a front or back so you couldn't actually point it at anything.

[@guillep2k]

@@shanent5793 The section of the laser is point-like, not in a mathematical sense, but in a practical sense; meaning that the beam is not conical like most light sources. Instead, it will keep it's diameter for very long distances (even in the Space). And because it doesn't get spread out, it doesn't "lose" energy from the stand-point of the viewer, no matter how far is it. That's the strength of the laser, and the reason you can't broadcast with it.

[@Wesley-wg2qi]

The best answer to the refueling the sun question would have been star lifting. Not impossibly breaking up the sun into 13 red dwarfs, just lifting mass from the surface, which is theoretically not implausible, especially given the time horizon we'd have to do it.

[@monsieurbenoit7698]

Betazed I enjoyed the question and the informative response. Also, I know it doesn't fit the criteria for less than 10k subscribers, but my favorite small (ish) astronomy channel is Paralax Nick. At ~35k subscribers, it's still relatively small, and I feel the channel deserves more attention. I particularly enjoy Nick's emphasis on the human perspective and history behind astronomical discoveries. Thanks.

[@doncarlodivargas5497]

Regarding how to get water out of regolith, are we not told the temperature on the moon can reach ~150C at daytime? Isn't that enough to "cook" it? Just expose it to the sunshine and catch the steam from the collected sand/regolith?

[@tryhardfpv5351]

Yes or if that's not enough just concentrate the sunlight until it is.

[@doncarlodivargas5497]

@@tryhardfpv5351 - good idea, a couple of magnifying glasses and we can reach thousands of degrees, problems solved!

[@rowshambow]

Would something like the Analemma orbiting tower concept work as a method for siphoning off the atmosphere of Venus to terraform it? If maybe the tower was hollow and hand a pump in it or something in the asteroid counterweight section.

[@Roguescienceguy]

The easiest way would be to have an army of mirrors in orbit that agitate the particles in the upper atmosphere so much that they can actually escape into space. It would take a lot of time, but it would strip the atmosphere away. Only downside is that you definitely lose all lighter elements such as hydrogen and oxygen first. Another way would be to plunge Venus into an ice age by blocking all sunlight reaching the surface, but that too would take quite some time. We Then would probably be able to actually get machinery to the surface and start working on chemically binding the different elements into more useful bonds. That being said, forget about terraforming anything in our solar-system. It's a useless exercise. Both Mars and Venus are at best bad candidates for that. Both for very different reasons. The focus should be on us becoming a space fairing species with large space stations although I am pretty sure that won't be us. I think our AGI-offspring will do that. We are probably some of the last biological generations anyway. Android like humans could very well be perfectly content with the martian atmosphere as is.

[@ianajames]

Felix's Space Time is a suggestion of a small channel. he has done good interviews, so far i have only seen tim dodd give him shoutouts

[@tayzonday]

The sun fuses eleven Empire State Buildings-per-second of Hydrogen into Helium. It fuses Earth’s mass in hydrogen roughly every 300,000 years. It would require a lot of hydrogen to refuel.

[@frasercain]

It already has all the hydrogen it needs, it's just trapped outside the core in the radiative zone. You just need a big spoon to mix up the Sun a little.

[@tayzonday]

@@frasercain That’s a good point. Red dwarves last trillions of years because the cooler burning pushes less hydrogen away from the core, allowing longer fusion.

[@redcoat4348]

As for space channels with less than 10k subscribers I would like to recommend, I gave you one already, AnthroFuturism. I also remembered that there’s also EagerSpace, though he’s got more subscribers at roughly 5k now. I’ve tried getting into smaller channels but many of the channels KZbin recommends me with low subscriber counts turn out to be AI-generated schlock so I r grown wary of trying to expand my horizons for that reason. I can assure you that the two channels I recommended are run by real people and they do more than enough due diligence in their video topics.

[@frogberthoppenheimer]

The Dart mission proved we can alter the orbits of asteroids that are loosely compacted rocks and dust like Dimorphos and Ryugu, but do asteroids of this type actually pose any threat to Earth or would they all just break up in the atmosphere anyways?

[@symmetrie_bruch]

i´m always amazed about the longevity of dark forest because for all the reasons you stated, here it´s makes not all too much sense on many levels. but what bothered me most, and which you briefly alluded to in a half sentence, is that "it´s a bit agressive" as you say. i mean what makes a technological andvanced civilization? wouldn´t that be firts of all curiousity? destroying everything you´re not familar with is pretty much antithetical to becoming technoligical advanced civilization in the first place.

[@Enkaptaton]

Does making ones orbit more elliptical also require those extreme changes in velocity? If not, could one reach the sund with an extreeeemly elliptical orbit that is so long and thin that it comes very near?

[@e5m956]

Is there any bluetooth 5.0 signals coming from any planets? And if so, are they using a lossless codec like LDAC for premium signal transfer? 🤔

[@janweyers2801]

Cait Hey Fraser. As we all know the majority of stars are red dwarf and they come with many issues in regards to the possibility of life. One factor for the development of life on earth could be our big moon. Are exomoons even feasible in a densely packed system such as Trappist 1 considering the Roche limit? Thanks and keep up the amazing content

[@douglaswilkinson5700]

Dr. David Kipping (Professor of Astrophysics at Columbia University, "Cool Worlds" channel specializes in exo moons) just won time on JWST to look for exomoons.

[@rajahua6268]

So much to learn... another great video!

[@Poult100]

So, today I learned that different stars have different access to the gas they're made of. Now I know why the dimmest stars have, by far, the longest life. Thanks Fraser 👍

[@briandoe5746]

So you turn up the volume when you do these? But during the live stream it's whisper ASMR?

[@scottyhoward4716]

Hi, I am working on a theatrical show for seven stages in Atlanta. The show is called true North, and it is about the moving magnetic poles. My question is : first, currently is the North magnetic pole close to the North Pole and second, do electrons flow out of the Earth and through the north magnetic pole out or into the magnetic pole. Thank you. Scott Howard, Florida

[@Flowmystic]

These are incredibly delightful. Thank you.

[@mario-ck3es]

Hey Fraser. When looking back at the universe. Such as things like the pillars of creation, the Tarantula. Orion nebula, the carina....just a few for example. Why is it that these clouds of gas and huge objects are still in the same place. Most look the same from the 80s and 90s to 2024. Nothings moving. Shouldnt these nebulas and exploding supernova regions be moving?It seems like the eagle nebula has looked the same since its discovery in 1745. Explain?

[@hernerweisenberg7052]

So thats why there is so much fine dust on the Moon's surface: Ancient aliens allready sorted some regolith to get the ice crystals and dumped the leftover regolith dust :D

[@beastlysnippets]

Refuelling the Sun.. would it, theoretically, be possible to turn helium back into hydrogen? And, would we need all those neutrinos that escaped through our fingernails? Btw, this is the best space youtube channel that i know :D

[@colinp2238]

If they are ining the regolith for water, is it possible that the slag from that can be used to get other useful things like iron, copper, and other minerals?

[@absolutemadlad6340]

I have a question, can a massive asteroid mostly iron based be enough to disrupt the suns ability to operate?

[@richardloewen7177]

In Heinlein's 1948 novel, Space Cadet, an interplanetary and international police force had oversight of nuclear bombs in polar orbits. Hopefully never to be used. A variant of MAD.

On the subject of refueling the Sun as some comments already mentioned one can search for the term -- Star Lifting and more specifically I would like to recommend Rejuvenating the Sun and Avoiding Other Global Catastrophes book by Martin Beech.

[@anthonym1585]

My counter point to your thoughts on the dark forest theory - couldn't an advanced civilization move from their home planet and create a new home where bio signatures wouldn't be so easily detectable?

[@Robbadobbsoldier]

This show is ultra-cool ❤

[@anniealexander9911]

Vega Astro - astronomy Alferia - weather Bluedotdweller - astronomy Geogirl - geology ParallaxNic - cosmology WeatherBox - sociology....only kidding Simon Clark - not a smaller channel but has been finding youtube difficult recently. Climate science. The ZatMan - very entertaining. Not sure if he is still making vids. Unfortunate Ends - history

[@paulwilson1529]

fraser's a genius

[@seae2030]

I'm wondering could you save money by launching the ships with balloons and once they get high enough you start up the engine and detach the balloon? Same with reentry, Would you avoid the need for an expensive heat shield if you opened a balloon to slow its descent ?

[@arnelilleseter4755]

Cheleb. You don't mention radio signals. I guess that was not really the point of the question, but if we assume that there was intelligent life on the same technological level as ourselves then we could detect the radio emitions from the planet and maybe even have some sort of communication.

[@frasercain]

Of course, that's the traditional thing people have been searching for. Optical SETI is the new concept.

[@h2o40fpv]

Great video thank you.

[@deltalima6703]

Fraser, what do mean by "surface of the planet" when referring to jupiter? I thought it was a gas giant.

[@ioresult]

Some probes used Jupiter's gravity to get close to the sun. Ulysses for example.

[@ashleyobrien4937]

Perhaps the best way for any civilization to send a deliberate message to others star(s) is NOT to construct a massive laser, but instead (and this would be easier) to construct a large optical aperture say 5 kilometers or more in total area that is akin to the matrix inside an LCD display, by applying voltage across it you can make it totally black or totally transparent having this in orbit around a star. So in effect you have a gigantic sun powered optical link. Using this you could send messages to other stars in a variety of formats. Anyone at the other end observing the source star will detect a series of on/off pulses from the star. Admittedly we couldn't discriminate any meaningful data yet with our current technology except perhaps from stars within ten or so light years but soon we will have the ability to tease out all kinds of signal data from stars...

[@Michel613]

Cheleb was the best Q.

[@ashleyobrien4937]

13:36 Well "Jason Pocklington" have you ever heard of the "Beacon Project" ? go watch "Battleship" 2012, quite a cool sci fi movie....that shows what happens when you call out to the dark inviting god knows what to come see you....seriously under rated that movie...

[@frogberthoppenheimer]

Do moons orbiting planets of a red dwarf star system have a better chance for conditions to harbor life or do they meet the same fate?

[@stephenanderle5422]

It's not refuelling the sun that is the problem. It's getting the heavy elements out of the sun so that it doesn't go into the red giant phase.

[@MusikCassette]

Re Vulcan ok, No I got more questions: how does this aquafaktorum microscopic sorting work? I kind of have a problem to imagine it scaling up. also a remark: yes supplementing ice needs a lot of Energy, but the suns Energy is for free.

[@kevinwilliams8218]

Hey , I've been studying my navel for many years and the only conclusion apparent seems that there is some sort of connection involved with existence and mortality,what do you think,answers on a postcard please🖖

[@tomhools1605]

Ah Fraser, you have the best job.

[@kylegoldston]

It's pretty unlikely that anyone has launched a nuclear device with enough shielding to be undetectable. Yes, a device could be shot down such that the possibly radioactive debris lands in the ocean. Although a shielded atomic device would likely survive re-entry at least partially intact.

[@michaelfoster8193]

One undersubscribed channel is This Week in Space

[@jiafjioawefjio3f9034]

Frasier, say “process”. Also, if you were standing on Jupiter’s moon, how big would Jupiter appear in the sky, and would you be able to see another moon? Thank you.

[@nerufer]

[vendikar] without a doubt (because of your answer) xD

[@floater81floats37]

I asked a question during the question show but i didn't have time to wait around to see if he answered it. Does he post the whole 2hr question show somewhere that i can go back and see if he got to my question?

[@frasercain]

I post a link in the Patreon post to the full livestreams. You don't have to be a member to see them. www.patreon.com/universetoday

[@alfonsopayra]

QUESTION: Do you think we will ever be able to see signs of other civilizations modifying stars, not only with Dyson spheres but perhaps by splitting suns into smaller stars to make them last longer? What could give away such activity from Earth? How do you suppose we could search for such activity out in space

[@erkinalp]

or, adding heavier-than-iron elements, which do not fuse and actually suck energy out of the star...

[@mhult5873]

Cheleb Thank you for another, as always, great video! Br //M

[@tompava3923]

Risa. Would a land based nuclear detonation send an EMP to the satellites above the explosion site?

[@AndrewJohnson-oy8oj]

When discussing the debate that would arise around biosignatures is to consider the nature of the debate. It would not be arguing about opinions. It would be an endeavor towards the highest possible rigor on such an important subject. Different parties would simply have differing views on the criteria of that rigor.

[@harleygreene1345]

Theory on star water is starting to catch up and the great flood is linked to all that

[@extropian314]

Thanks!

[@Nolan1410]

Would there be a benefit to placing a telescope in orbit close to a black hole?

[@alleneverhart4141]

Cait. The idea of removing material from the Sun to extend its life is called "star-lifting." I think there are SF novels that use that idea.

[@frasercain]

Yup

[@revmsj]

Hmm I just noticed that the Parker Solar Probe is simultaneously the fastest and the slowest object we’ve ever heaved off the planet…🤔

[@PhysicsPolice]

40:00 you talked a lot about bio-signatures but seem to have forgotten about techno-signatures. Earth’s air traffic control radio emissions would be glaringly obvious to radio SETI as it operates today.

[@frasercain]

I never shut up about technosignatures.

[@chainsawcanuck]

Glad I found your channel, love it. My middle name is Fraser from my great grandmother's maiden name from Scotland.. keep it up 👍👍

[@GRILL332]

PER YOUR CHANNEL REQUEST: Looking for IM-1 moon mission I found Ad Astra as a small channel that was pretty good. See if that is what you’re thinking of.

[@shanent5793]

Are there actually oxygen molecules in the regolith or does it get reduced by the solar hydrogen? Did it take billions of years to reach the current concentration or is it in an equilibrium that that would be restored relatively quickly after depletion?

[@LarryButler]

Mass of plasma TMBG had a correction song made lolz 25:52

[@revmsj]

When we detonated the nuke in LEO causing an EMP, it actually caused at least one satellite to die. I believe there were only like 3 at the time. Can you even imagine what the collateral damage to satellites (and down here on earth) would be today?!

[@torsteneide4915]

Scary! With the immediate aftermath of billions of bits of satellites then going on to turn the surviving satellites into rubble… back to the 19th century right quick! 😬

[@nicholascook9584]

Is it possible those rogue planets are dead or dying stars

[@devilinside6629]

What is the maximum distance could a person see our star with the naked eye before it ceases to be visible?

[@cbbcbb6803]

Very interesting.

[@peterprice2048]

How many launches are required to move 100 to 150 tons to the lunar surface? Side note that mass will be at or near the pointy bit in the cargo bay. Great Musk states SpaceX will be cheaper per launch by reducing the cost per launch only to increase the number of launches to get 1 starship(HLS) to the lunar surface. Take into consideration not only do you have to accelerate that mass to a speed to which it reaches the moons gravitational influence, you also have to do a retrograde burn to slow that mass down.

[@Chris.Davies]

More to the point, will we ever scoop metastable liquid metallic hydrogen directly from the surface of the liquid sun? It's only 6,000K or so. :) But we would do well to understand why the sun's atmosphere gets hotter with altitude, not colder, as Thermodynamics requires. What is happening in the Corona? My best guess is "fusion as we don't know it".

[@PhysicsPolice]

43:00 you talked about what you’d do and not do living in the Dark Forest. But that wasn’t the question. The question is, do you think it’s a good answer to the Fermi paradox? It’s a bleak answer. Sure. But that’s not the question.

[@TeeTekTrab]

My favorite show! 😁

[@clffeingold]

Fascinating! Thank you.

[@gpaul8062]

Vulcan

[@glassramen]

I'm still very amused that the test message was a cat video. We humans are very very predicable sometimes lol

[@LordBitememan]

Hey, for the science channels, Steven Baumann does a lot of geology on his channel and he's only got like 2K subs.

[@vordag]

oh, i can say that we realy understand how the sun is "working" :)

[@tryhardfpv5351]

How far away would the thousands of laser links between Starlink satellites be from earth?

[@e-memers9441]

Thanks for the answer

[@KGTiberius]

❓ Reusing rockets? How about use the old satellites and debris, reposition struts of ISS to lunar orbit (long, low ion thrust repositioning)? Most need repowering. Collect the old satellites, repower, and redeploy to other planets.

[@ReinReads]

Small science KZbinr to look into, Nora's Guide to the Galaxy

[@PontusEgnell]

It is actually very easy to throw nuclear waste into the sun. I've seen it being done in a documentary called Superman 4.

[@frasercain]

Superman can throw things faster than 30 km/s. :-)