Effects of Planet Alignment, Protecting Antimatter Spaceships from Dust, JWST Deep Fields | Q&A 257

How can we protect antimatter-powered rockets from space dust? Will curing cancer solve deep space travel? What happens when planets align? Does dark matter lose angular momentum? Answering all these questions and more in this week's Q&A.
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00:00 Start
00:28 [Andoria] How can we protect antimatter-powered spaceships from space dust?
06:34 [Vulcan] What will happen if all planets aligned?
09:59 [Risa] Does dark matter lose angular momentum?
15:09 [Aeturen] Are there any advantages to non-Dobsonians for rookies?
21:03 [Vendikar] Why are JWST's deep field images not dramatically better than Hubble's?
23:52 [Remus] Will space still be dangerous when we cure cancer?
25:38 [Janus] How realistic is the concept of sophons from the Three Body Problem?
27:36 [Cait] Do gravity waves come in different flavours?
30:51 [Betazed] How big can a space telescope be if it's assembled in space?
34:36 [Cheleb] Could aliens have created black holes?
37:45 [Nimbus] What's the deal with Sedna?
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[@garman1966]

I'm always pleasantly surprised that I can watch 40 something minutes of your show when I never intended to. I'm surprised you don't have more likes. You are one of the best science explainers on KZbin. Thanks for the hard work and enthusiasm!

[@WatfordCaroline]

A big shout out to the great team who add the graphics to these videos, they are fantastic and really make these shows something extra special

[@calumdooley1788]

Totally agree

[@carries6427]

Andoria was the most interesting to me of the plethora of speculations in this episode.

[@TheEducat0r]

Who knew planet alignment could have such profound effects on our universe? This Q&A just made me rethink everything I thought I knew about space!

[@averyjeromekelly5735]

The Higgins Interview was a classic. Keep 'em coming.

[@KGTiberius]

❤ Long Format is always a pleasure!

[@evasiveutopian]

Ok no one probably going to read this, but actually the Webb vs Hubble capabilities should be well understood by the scientist. And the truth is that Hubble has better resolution despite having a smaller mirror. Why is that? It is because of the angular resolution (rayleigh criterion) is smaller for Hubble, meaning that, Hubble can resolve point like sources that are closer together than Webb. Here is how to calculate it: theta = 1.22 * (wavelength / mirror diameter) So the actual reason for why Hubble has better angular resolution is due to the wavelength it observes (visible light) as opposed to infrared on Webb. My own calculations: Hubble info: Wavelength (avg): 550 nanometer Mirror diameter: 2.4 meter theta (radians) = 1.22 * (550* 10^-9 / 2.4) = approx. 2.8 * 10^-7 radians In arcseconds: 0.06 Webb info: Wavelength (avg): 2200 nanometer Mirror diameter: 6.5 meter theta = 1.22 * (2200 * 10^-9 / 6.5) = approx. 4.1 * 10^-7 radians Arcseconds: 0.08 Anyone interested for more information I recommend the channel Huygens Optics video "Telescope Resolution vs. Aperture and Wavelength" (kzbin.info/www/bejne/nYDTk4t4pdWIe7c) about 5 min and 3 sec into the video he talks about angular resolution.

[@bertpasquale5616]

Hubble was in fact designed to be upgraded in its instruments and serviceable in its modules. No one envisioned having to do the corrective optics for the telescope, that fact freaking amazing.

[@terryharding4185]

Aeturan. Thank you for all you do Fraser and team

[@loomysh]

its nice how you can respond to even the most impossible questions like aliens producing black holes :)

[@frasercain]

I think they're fun to answer, and also give opportunities to explain aspects of science with an interesting hook.

[@bbbenj]

Thanks a lot for these answers 👍

[@savetheplantet5799]

I drove 4 hrs to pick up a vintage celes 8 sonotube dob in excellent condition for 300 . Even with the crappies eyepieces money can buy, and views are breathtaking!

[@SeanLynchXY]

Thanks Fraser!

[@icecoldnut5152]

Imagine if an advanced civilization decided to build a machine capable of compressing spacetime and unintentionally compresses the universe into a small hot dense state

[@austinsapp5867]

Nimbus. I love a good Enceladus rant!

[@saquist]

Remus, That's a good question. I assume he means not radiation exposure that' immediate fatal exposure.

[@-Thauma-]

I know that moment too well dear 😊 25:49

[@nathanielbyrne1132]

Good news that the interstellar medium ablates about a millimeter of your craft per lightyear

[@bernhardjordan9200]

A thousand light years needs a meter and a million light years will eat away a kilometer of your ship

[@nirbhay_raghav]

Not really. Consider the size of a spqceship. Like the ones which will travel to stars. The surface area at the front could be in thousands of sqft. If you naively thought that adding extra layers would help you then you must be building it in space! Because even a cm of layers at that size would weight a lot.

[@oldmandoinghighkicksonlyin1368]

If we're going to have the tech to make those kind of relativistic speeds, we'll have the capacity to create an energy shield.

[@archmage_of_the_aether]

​@@bernhardjordan9200 darn, your math checks out. I wonder about the intergalactic medium compared to the interstellar one, I suppose it's possible there's rocks and dust everywhere.

[@bjornfeuerbacher5514]

@@archmage_of_the_aether As far as we know, the space between galaxies is even more empty than the space between stars inside a galaxy, so traveling between galaxies would destroy even less of the ship.

[@MelindaGreen]

Thanks for your focus on radiation, and especially for saying we've got to sample the water plumes of Enceladus or other ocean moons.

[@The13rannon]

I totally asked about JWST being able to detect light on a planet a few weeks ago on Q & A! Cool to see it really is a possibility.

[@-Thauma-]

Thank you kind sir ❤

[@AlaskaB83]

Thanks for answering my question (about sophons in the Three Body Problem novel). I wish I'd asked it a little different, because the "is it realistic" part I was mostly wondering about is if there is actually any research into unfolding particles and potential uses for that. Still, I appreciate the answer! Love the channel. One of my top favorites of any type on KZbin!

[@bjornfeuerbacher5514]

There is ni research into that. We don't even know if extra dimensions exist, and there is no idea at all how if they exist, one could "unfold" them. And even if one could unfold them, it makes little sense to say that one unfolds a particle. That part of the book was, in my opinion, complete nonsense ()BTW, I'm a physicist) and led me to abandon the whole series of books.

[@AdamosDad]

All the aliens end up like the Krell in the movie Forbidden Planet.

[@JulianMakes]

When we detect gravitational waves from merging black holes, once they merge is there a rebound motion of space time after the merger. Much like in an elastic sheet analogy. And if so can we tell anything from this frequency of vibration? Is it the viscosity of space time? Thanks

[@ioresult]

Janus: i think you overlooked how they made the huge computer in the first place: they just unfolded the higher dimensions of a proton. Liu used the string theory that hypothesises that the 7 higher dimensions are compact. Using a giant particle accelerator in a certain way, you could maybe unfold the higher dimensions. Having a proton going from 11 to 2 dimensions would make a sheet the size of a planet. Then they magically engrave computer circuits on the surface of the proton and then it can somehow refold itself.

[@peterd9698]

To protect against dust grains you probably need something even less massive, eg a wisp of gas or tiny tiny foil sheet, to destroy the dust grain before it collides with the main body of the ship. With my favourite method of interstellar travel, a beam of tiny sails or macron projected from earth and vaporising against a magnetic sail for propulsion, maybe you could allow some of this vaporised mass to pass the ship and clear a path ahead? edit: changed mascon to macron.. microscopic dust-sized particle.. very different thing :)

[@A_J_Higgins]

Yes, this is a valid strategy for shielding!

[@JAGzilla-ur3lh]

Andoria. We definitely should be sending out an interstellar mission to investigate this kind of thing in the field for future reference.

[@Mj323_bb]

Circumstances under which all planets plus the moon are all visible even in the same sky (so, approximately 170 degrees or less spanned) are rare enough to be interesting. I was fortunate enough to view such an event shortly after sunset on August 9/10, 1984, though I was not fully aware of it until a day or two later when I could confirm that Mercury was indeed visible/what I had seen and I then checked locations of the outer/dimmer planets (I of course included Pluto back then). There was a similar morning apparition on or about June 15, 2022, but I was not able to actually see that event. Mercury needs to be fairly near greatest elongation and Jupiter and Saturn typically can't be too far apart. I'll post another note when I find the next one, it's probably within the next 20 years : )

[@ioresult]

Nimbus: I read a scifi novel where a super rich space entrepreneur used a fraction of his profits to build a factory to mass produce nuclear powered ion propulsion probes and started sending them everywhere in the solar system. That would be neat. Maybe when a certain space exploration company is mass-producing a certain refuelable starship that could become a possibility?

[@pkastronomy]

A dobsonian comes with a big disadvantage of needing collimated. Especially a cheap one that doesn’t have the sturdiest mirror cell-it will be out of collimation during shipping. Asking a beginner to get in to collimating just to use it will be a major turn off. Or they won’t do it then moan that the image isn’t very sharp. For the absolute first timer a small 80mm ED doublet refractor is a better choice. These don’t need collimated (as they are pretty solid when set during manufacture) and extremely portable, can be used for terrestrial stuff like birding and have extremely contrasty images due to no central obstruction. Yep it’s not as big a light bucket but for moon/planets/brighter DSO’s it’s more than capable. A down would then be a good step up for those who are starting to get more serious. At this point they will have come across collimation and understand it’s required for the best performance from a newt. Just my opinion as an astrophotographer of 15 years

[@willemvandebeek]

The Remus question can be rephrased as: "Will swords still be dangerous when we cure stab wounds?" to get to the same answer on cancer: Medicine has improved over the centuries and has made some things less lethal, but 0% lethality is something that will never be reached.

[@ralphchang5422]

I vote for Andoria. Fraser said that being struck by millimeter sized particle at relativistic speed would probably destroy your ship. This makes sense, and if no defense existed for this threat, it could be a fatal threat to interstellar starships. However, an effective defense for a vehicle traveling at about a third of lightspeed would be using radar or lidar to detect incoming particles and then either firing a bullet or a 50 kilowatt or so laser at the incoming particles. Similar to the kinetic kill vehicle of an anti-missile missile. Of course, absolute and reliable precision would be required. By the time we have spaceships that can travel at a third the speed of light, our technology for detecting and intercepting kinetic particle threats will be far better than now.

[@coulie27]

We need multiple JWST deep fields!! Most of the other things keeping it busy are less important!

[@RectalRooter]

Help Fraser fund his Fraser Cain Space Telescope

[@bertpasquale5616]

The review process for the observations plans determine what is most important for the science community. You can in fact submit your own observation proposal!

[@RectalRooter]

@@bertpasquale5616 During the exo-moon interview. Did the scientist mention it took him a numbers of proposal submission - fix / tweaking each one to better align it to what was wanted, finally get approved. What I'm saying -- the process isn't 1 rejection and done. It seems the process is try and try again,

[@bertpasquale5616]

@@RectalRooter yup, as in most any competitive proposal process!

[@-MaXuS-]

Why no interviews lately? I’m starved for captivating content that’s not just these short news stories or q’s & a’s..?🥺

[@frasercain]

They're coming. Four already recorded. I'll put one out tomorrow

[@matthiggs3066]

Just watched an interview with a Cambridge professor who detected specific gasses on a planet 125 light years away that only exists on earth because of life. What are the chances this is life? How far along is this team in this discovery?

[@theCodyReeder]

It may take trillions of years for the olanets to line up randomly but could a civilization (who is clearly got nothing better to do) give the planets a bit of a nudge to make it happen in less time?

[@bertpasquale5616]

The new harmonic drive mounts are compact and relatively lightweight to handle a SC-8.

[@matthewa441]

My favorite question is what happens if the planets align because I had that same thought the other day lol

[@Verklunkenzwiebel]

Planet alignment? Zuul the gatekeeper will summon Gozar the mighty

[@xamishia]

Cool. About dark matter - if it doesn't interact with itself or regular matter, why are clouds of it "stuck" to galaxies etc, even after they pass each other etc...

[@guillep2k]

Talking about "flavors" of gravitational waves.... would they be subject to polarization? If they would, can that fact be used to determine if gravity is a wave/particle or just spacetime bending?

[@matthewring8301]

Discussing black holes and the Great Filter, could some black holes be the opposite. Could they be the next step after a Dyson sphere, not just using all of the central stars energy, but also absorbing the energy of the surrounding galaxy?

[@robwalker4548]

I had a chance to buy one of the early 20” Dodson scope in the early 1970s that John Dodson built and used for a week. The tube was made from a tube used to temporarily hold concrete in creating concrete piers. There was a hole in side as the first cut for the eye piece placement was not right. It did not look good but the optics were superb but have never seen one since that had optics to match it. Wish I had bought it but when I was a teenager I had no place to store it and moving it around was not easy. When I did buy one commercially it was good but the optical elements were a disappointment.

[@mrxmry3264]

36:32 the matrix comes to mind. 36:42 euclid's wall comes to mind.

[@ruspj]

you allways used to recomend a pair of astronomical binoculars for people just starting rather than a telescope but i dont think you have suggested them for ages. has something changed or would you still suggest the binoculars first before a domsonian?

[@jpaulc441]

I can't recommend any specific binoculars because I don't know enough... However I have a pair of fairly cheap ones which were not the best quality but they were good enough to see all four of Jupiter's large moons. They were just specks of light without any detail but I could see them clearly and liked observing them to see their positions change every night. A tripod or other way to keep the binoculars still is very helpful.

[@ruspj]

@@jpaulc441 wasnt looking at getting anything. just curious about the change in frasers suggestions

[@kx4532]

They lined up when I was a kid

[@TheArchimedian]

Question: As per your previous episodes there is a lot of focus on large stellar collisions using interferometers to measure gravitational waves as well as innovative ideas for trying to measure dark matter. If I were to assume primordial blackholes were black matter how small would you need to build an interferometer to see those gravitational waves from a primordial merger? Thanks!

[@ericsmith6394]

It is not ablation that scares me. It's the particle shower messing with DNA. Particle accelerators need more than a few mm shielding for good reasons.

[@Dan-Simms]

I agree, I think the Fallout show is the best video game adaptation yet, I hope more are coming, it seems like they have finally cracked that code.

[@contentsdiffer5958]

"Ignore the lore and just go with whatever."

[@peteedwards8439]

Andoria: If you take two circles of reflective coating plastic sheet and weld the edge you have a balloon when inflated in space. One will be a concave mirror, the other can be clear allowing light to pass through. The light will be reflected to a focal point and you can use it as a telescope. You can also use it to focus reflected sunlight onto asteroids or the moon for thermal mining. And you can use it to measure the micro meteoroids over the operational lifetime of the reflector. The sunlight UV light would harden the plastic sheet to the inflation shape. The loss of inflation pressure would not change the reflector shape once hardened by UV light. If you push a gas cloud out in front of your hyper velocity spacecraft you will help mitigate the effects if some of these micrmetiorites.

[@peteedwards8439]

Wait, there’s a lot more to this idea.

[@duncanbeggs4088]

I wonder if one partial explanation for the Fermi Paradox is that in the past the universe was denser and there was more dust and interstellar stuff between the stars. Billions of years ago it may have been near impossible to travel at high speeds between stars without having your spacecraft melted by micro-meteroids.

[@bjornfeuerbacher5514]

The mean density of the universe was greater billions of years ago, yes. But that was more due to galaxies being closer together, not due to the matter inside the galaxies being denser.

[@supersleepygrumpybear]

[Andoria] Can you explain the internal state of the moon in detail? I've read that the moon's mantle-surface boundary is as hot as 1'300 K, depending on Thorium-Uranium amounts. I'm also confused about the regolith and mega-regolith layers that the Apollo astronauts encountered. And if the internal structure of the moon still has warmth, should we build deep mines for our Lunar habitats? Or maybe moonquakes make lunar mines impossible? Inertia problems~

[@darrylnorman82]

Is the gravity from our sun static or does it come in waves? Can more than one gravity wave sauce create interference patterns. Also what is the name of our sun because I have heard sol, sun, star applied to other star systems.

[@oldmandoinghighkicksonlyin1368]

Our sun has no 'official' name according to the International Astronomical Union. Many astronomers have suggested "Sun" (with a capital S). The latin word for 'sun' is Solis. "Sol" is not used in scientific writings, except if the paper is written in Spanish, Portuguese, or Swedish where "sol" translates to "sun". "Sol" is also the Roman equivalent of the Greek sun god "Helios".

[@liviu-dantimar9492]

So much for relativistic Solar/Laser Sails... 4[mm]

[@Threedog1963]

I had asked a few years back if it was possible to have a transition of mercury and Venus at the same time. You replied some outrageous number of years, like 67,000. That would mean Mercury, Venus, and Earth were lined up. I can't imagine adding in the rest of the solar system, how long that would take, and I bet it wouldn't happen before the sun swallowed Venus, Mercury, and perhaps the earth in a few billion years. I also am unsure if all the planets are in the exact same ecliptic plane for it to happen anyway.

[@Shaden0040]

Now you say there are two sections of the Kuiper belt, the first section is closer into the solar system the second section is further out. is it possible that the area between the two bells is that an exclusion zone that has been cleared by a planetary sized object This planet 9 that they're looking for? we'd have to be big planet could be half earthized for all we know or smaller but could it be like when you have accretion this for new planetary systems around proto sons there's gaps is this possible one of those such gaps? and could we start training our telescopes to look at that distance and then look all around the solar system top and bottom left and right to check to see if there's some kind of object there? I'm sure somebody's looking for objects now but are they looking in that area of distance?

[@iansaint3503]

I thought Sedna's closest approach to earth was going to be 2075-76, so plenty of time to plan a mission to intercept it. A lander would be cool, as it could hitch a ride to the outer reaches of the solar system and do more science.

[@mordechai8008]

I wonder, the astronauts at the ISSI report frequent clicks when millimetric particles hit the station. No real damage at their speed. But imagine higher speed....

[@lawrencelile]

We "believe" that interstellar dust grains won't be a big deal. I'd sure hate to be flying at relativistic speeds with "belief" as my only shield. If interstellar particles follow a statistical model as to size, you hit enough of them eventually a whopper comes along with your name on it.

[@mshepard2264]

the eyepiece on a dobsonian can be in an awkward location. However you can get a-lot more telescope for your money if you get a big dobsonian. The problem with the smart telescopes i have seen is they have tiny apertures.

[@alexanderreintzsch5315]

Betazed: I like the idea of a modular telescope that is able to evolve in space. I just ask myself whether it is a preferred solution for engineers and scientists alike. I imagine that maintenance might be easier, but the costs could be higher, because you cannot streamline the manufacturing as much. At the same time, it would probably not be able to serve for multiple purposes because of the radiation of heat and shielding and its natural vibration.

[@TimRobertsen]

Question: If you were to travel up towards the speed of light, wouldn't you (or the spaceship) be fried by the CMBR being blueshifted into x-ray, or higher energy levels?

[@mreaves83]

How large was the universe when the first light was released in the form of the CMB? And how was it released everywhere all at the same time? Surely different parts of the the universe where differed temperatures and densities so the light should have been released at different times?

[@LarryMoore-hc4tk]

Clarke's solution was to send an iceberg to intercept the larger dust and follow safely in its wake.

[@Shaden0040]

hey I have a question for you we can make silicon rods correct like a kilometer long we also know that silicon crystals when squeezed create electricity piezoelectrical current now I've got two ideas can we use sex rods to detect gravity waves Like changes and voltages or output 12 if we can create electricity this way can we generate enough to help power our electric grids without having to like dig for more oil and coal and even digging up silicon for the solar cells it might be more direct way of creating electricity? and then we don't have to dot the landscape with solar cells and windmills hot water turbines etcetera etcetera? is this applause of are these plausible to do? can we detect gravity waves this way? And if so can we generate usable electricity this way? wouldn't it be much simpler if we could just plant Crystal rods on the ground and connect the collectors to them to collect the current directly and dump it into the grid and it wouldn't have to worry about sunlight or wind power or water power to do it it'd be the gravitational waves scatter all throughout the universe Coming in it is from various different locations squeezing and compressing what do you think is this plausible doable can anybody try and check it out is anybody trying to check it out? Thanks

[@ericsmith6394]

Assuming this could work I suggest you look at how much energy it takes to compress silicon by the width a gravity wave changes LIGO (about a proton). It isn't much. That's how much power you could get out with perfect efficiency. Sorry

[@oldmandoinghighkicksonlyin1368]

Sex rods? Like the ones in granny's nightstand?

[@RectalRooter]

I personally think your on the right track for us to use sex rods

[@antonvelmozhnyi7401]

Hey Fraser, lets say some advanced civilization have anti matter ships or any other ships that can move at relativistic speeds. Would not we be able to detect traces of such movements of a massive object at such hight velocities across our galaxy? Being in a form of weird light emissions or gravitational waves or neutrino or any other particle emissions that will came from this kind of space travel? Thanks!

[@UnCuddlyNINJA]

what are the big ring and giant arc? galactic super structures?

[@robwalker4548]

Estimated and believed does not give a lot of confidence but the God of the gaps might give some hope.

[@trebell885]

Do The planet's align at the northern & southern plains of the Milky way.

[@evenros]

Risa. Hey Fraser, what does a neutron star look like?

[@piderhead]

If you were on a space craft to the Andromeda Galaxy and you were half way there, what would you see if you looked out a window? Darkness? A couple of blobs of light?

[@ElitePhotobox]

later You can Put the telescope on a motorised equatorial mount !

[@phillytitan]

Where do leave questions for the Q/A? The website?

[@miraspi]

Fraser always says you can leave your question anywhere you want :)

[@hive_indicator318]

Right here is good

[@frasercain]

You did it, you asked a question.

[@RectalRooter]

@@frasercain lol cheeky bastard

[@ElitePhotobox]

having a self replicating Von Neumann machine that builds copy's of it's self out of the planets !

[@RectalRooter]

That and CERN's micro black holes eating earth -- Seem equally bad dreams

[@charleslivingston2256]

Vendikar

[@coherent911]

Question: Have we checked that there is no earth 2.0 with the exact same mass on the same trajectory as earth just on the opposite side of the sun always hidden from direct observation?

[@geneticjen9312]

Even worse with the sophons, they allow communication between entangled sophons. People call the series hard sci fi lol. The plot holes and bad science are maddening tbh

[@bjornfeuerbacher5514]

Thanks, that agrees with my thoughts. There was some nice science in the book (I only read the first one), but the complete nonsense about the sophons (which was even worse in the book than in the TV series) completely spoiled the book series for me.

[@PlatinumDoodles]

Risa Follow-up question: why CAN'T dark matter be neutrinos? I've heard they can't be, but I don't understand enough about neutrinos to understand why they're ruled out.

[@bjornfeuerbacher5514]

Neutrinos are just too fast (in the mean), they stream out of galaxies and galaxy clusters instead of forming the observed halos around galaxies. (They are so-called hot dark matter, whereas what is observed is cold dark matter.)

[@j7ndominica051]

When talking about space debris, they always say that small grains of dust in Earth's orbit cause great damage to satellites and the JWST. The starship will probably encounter some of these. Why wouldn't it? When a star system comes together to make planets, it collects stuff that was previously spread out. They will have to make a new Voyager to get out of the solar system. And it will take a lifetime. I once thought that all planets spun around the sun on the same line because they were drawn like that on illustrations. They should do the same deep field spot and compare againt Hubble.

[@rogertulk8607]

Andoria. Okay I have my own question about matter-antimatter. When matter and antimatter combine, they annihilate each other with a tremendous release of energy. This says to me that it's a zero-sum game. If the two particles annihilate where does the energy come from? Since energy is just another form of matter all is not lost!? Or is it?

[@bjornfeuerbacher5514]

The energy comes from the masses of the particles, E = mc². Nothing is lost there, and nothing is gained, it's indeed a zero-sum game.

[@mattwalter5184]

Andoria

[@JAGzilla-ur3lh]

Quick correction to a mistake you made in the Vulcan question: you said that a planetary alignment would have no effect on Earth. Technically, though, a planetary alignment will allow Hades to release the Titans from Tartarus and conquer both Earth and Olympus. So an effect might actually end up being detectable with the right instruments.

[@frasercain]

Of course, I forgot about the mythological implications.

[@KGTiberius]

❓ Reuse ISS truss, arms, solar panels, etc. and multi-year thrust to lunar platform? Why burn the hardened mass already in orbit? (Yes, burn the habitats/equipment not radiation hardened…)

[@mrxmry3264]

remember back in the 80s when all the planets were on the same side of the sun? they said all kinds of bad things would happen. and what did happen? absolutely fluffing nothing. zip. nada. zilch. instead of a schmidt-cassegrain, i'd go for a ritchie-chretien. better optics. IIRC schmidt-cassegrains have spherical mirrors while the mirror on a ritchie-chretien is parabolic.

[@johnserious706]

How does cryogenic liquid fuel behave in a vaccume of space for the purposes of transfer from own craft to another?

[@Merecir]

Regarding dark matter and the Fermi paradox. Could it be that all that hidden mass that we interpret as dark matter is actually 'ascended' alien civilizations that have stolen 95% of the total content of the universe and left a starved universe for us poor humans?

[@Smiles10130]

I saw a video where the guests basically said there's no economically feasible way to justify lunar and mars colonies. With that in mind, how would we mine the h3 on the moon or how can we do it effectively?

[@frasercain]

It's not feasible now. Too expensive. The only reason to go to the Moon right now is to explore it for science.

[@Smiles10130]

@@frasercain thank you for replying. I read that the helium just needs to be heated to be released from the regolith. So is it a density, infrastructure issue, or something else? We need more helium and the moon has always been sold as the solution.

[@supersleepygrumpybear]

You can compare the "colonies" (officially called habitats with a few military bases) on Antartica to see how the continent developed over the last century. Long-story-short: it was literally The Cold War 🤣😂

[@onedeadsaint]

if liquid water was used a shield, would interstellar travel be safer?

[@savetheplantet5799]

Wouldn't a very long exposure deep field show the dust trails from galaxies indicat e the direction they came from ? Do a fast rewind and figure out where it all began?

[@bjornfeuerbacher5514]

Dust trails from galaxies? What are you talking about?! "where it all began"? Do you mean the point where the Big Bang happened? That did not happen at a specific point _in_ space. Rather, the point of the Big Bang (if such a point even existed) became all of space, i. e. the Big Bang happened everywhere.

[@careyjones8638]

Hey Frazier what are white holes and what do they do?

[@RectalRooter]

Black and white holes are pretty much old news.. The new trending rage is all about Brown Holes -- Sometimes called Brown Eye's

[@Shaden0040]

220 meter telescopes To be placed in the L4 and L5 respective zones of the Earth's orbit that would give you one third of the Earth's rotational period of orbital. as a technical telescope because all the lights is collected by one telescope and all the light collected by the other telescope are 1/3 of the Earth's orbit apart then you deposit any of those images together like they did for the black hole array and use that to also get parallaxes much easier on nearby stars. those would be two such telescopes would be very much helpful to astronomy and it's related fields. would you rather see that they may be a third one somewhere on the moon at the north or South Pole which could be then aimed in any direction? To make three large telescopes able to survey the customs at the same time for the same targets?

[@Jmr2urbo]

During the "Risa" question you mention the bullet cluster interaction with dark matter, Wouldn't Galactic cluster take a long time to interact. I feel like it would take millennia , how are we able to observe something that would take so long?

[@EinsteinsHair]

Yes, at 11:30 it sounded as if we were watching it happen in real time. We are looking at it after the galaxies have passed through each other, and looking where everything is now.

[@entropiated9020]

What do you think the space shuttle would have looked like if NASA didn't have to build it for USAF specs for launching defense satellites?

[@brick6347]

4:05 I mean, how far away could a ship travelling at relativistic speeds spot an asteroid the size of a couch? I mean, they're probably pretty far apart, but so are icebergs. In time to avoid it, or when it smacks into the ship?

[@ericsmith6394]

About the same distance a stationary ship could or a telescope on Earth. There are estimates for near Earth object searches. The detector speed shifts all the light, so it doesn't help or hurt us pick out a rock from the background.

[@JamesCairney]

Aeturen

[@KylleinMacKellerann]

In re: Space dust @ relativistic speed collisions. Might such a spacecraft have a "bumper" in front of itself to deal with dust OR use a strong magnetic field to divert such things (ions especially?). If you are sending a spaceship out that far and that fast, it should have a fairly powerful reactor for power and perhaps thrust (captured ions accelerated in a specific direction = thrust). Yeah this sort of uses the Bussard Ramjet idea, but this would be fueled by stuff collected and stored and used for attitude change, not main thrust. And for all we know there is already some civilization using this... (basic mathematical predictive theory. Meh, just wondering.🥴

[@adamz9324]

QUESTION: Is it worth building a second JWST? Surely it would be cheaper to make a second one, now that all the new technologies are tried and tested.

[@bertpasquale5616]

A “Build to print” JWST-2 would be almost as long of a build, since the facilities would have to be re-tooled for it. If you said “do it” today, it would be 10 years and $7B, rough estimate. Instead, the plan is to build Habitable Worlds Observatory, based on much of the JWST tech, 20 years out. But it would have been efficient to build two JWSTs in parallel ( but that would have never flown being too out of budget, they both could have gotten cancelled!)

[@Shaden0040]

we want to retire the iss eventually but they also want to looters gateway station would it be possible to move the ISS into lunar orbit To occupy the lunar gateway position? is it feasible to do it orbital mechanical wise and structural wise for the ISS to be moved into lunar orbit why waste material that's already up there already built they're ready to house people for all the stuff that we've done there plus it'll keep that piece of equipment alive that much longer unless there's a structural problem with the materials where it may break down in lunar orbit because it's not protected by the Earth's magnetosphere or whatever? Can it be done is it feasible it wouldn't survive a trip out there? my thing is why waste all that technology and equipment it's already in space all you need to do is connect boosters to it that all fire at the same time making sure the whole structure moves together and can withstand the strain to get out of Earth orbit is going to be a slow like ion thrusters would probably be the best way to do it study thrust at the right time to push it out of Earth orbit into a trajectory they will take it to the moon.

[@Preciouspink]

2:08 what is this?

[@JamesField]

Your comment about dark matter having zero cross sectional area made me wonder, could dark matter have a different number of spatial dimensions to "normal" three-dimensional baryonic matter? No, I did not just watch that episode of Star Trek where the two-dimensional lifeforms somehow start dragging the Enterprise into a cosmic string...

[@bjornfeuerbacher5514]

Electrons are point particles, i. e. they have zero dimensions, but nevertheless they have non-zero cross sections for interactions. The interaction cross sections of particles do _not_ directly correspond to their actual physical sizes, but are consequences of the strengths of their interactions.