Turning Starship into 9m Telescope, Lunar Gravitational Lens, Robotic Exploration | Q&A 190

[@neurostreams]

9m Starship Telescope got me

[@frasercain]

It would be impressive.

[@rolflandale2565]

The good news, a space craft holding that 2-decade old *classic glass-umbrella* concept mirror, can be debunked modernly in refractive optic multi-cameras, in a insecta-eye parabolic alignment, to replicate JWST, without the limits of *only* Infared, leave the dish structure, to sencor detect things like, pulse gravitational waves and electromagnetic flow & messages.

[@bernhardjordan9200]

Impressive it will be if using 9m mirrors a telescope using the same technique of the JWST

[@smallpeople172]

@@bernhardjordan9200 single piece of glass cannot be made that big

[@bernhardjordan9200]

@@smallpeople172 that might be true, but I believe that you've understand what I meant. White star ship capabilities much more than 8m can be done

[@mralekito]

Thanks for all the great questions and answer shows this year. Enjoy your well earned break, you and the whole team.

[@THIS---GUY]

Thanks Fraser. Can't wait for next season. Really looking forward to the content in the meantime.

[@blurglide]

Why not do a James-Webb style segmented mirror in a Starship? The current starship fairing is 22 meters long.

[@patclark2186]

agreed. Even better. Over time have Starship ferry up truckloads of segments and and hook them together in orbit. Maybe 100 meters?

[@rulesofimgur]

I'm no expert but that is a good idea. Except that there is no need for it right now. Webb is working and hubble still operates, for now. Science is very underfunded and if we don't exactly need it, then it won't likely happen. As for the size, it may not be ideal to limit yourself to the size of the fairing. You could have a custom one made if needed, or even do an orbital construction system but that tech is still in early development.

[@mishkosimonovski23]

@@patclark2186 And put photon drive + solar collectors on the Starship....so we can propel the thing for decades to come.

[@theMuritz]

First reaction: Click bait! Second: Oh it’s Fraser, let’s binge on it. And thank you again for mentioning Cixin Liu, I never came across a more profound hard science fiction than this one. Perfect … keep recommending his work to the community … thank you!

[@massimookissed1023]

19:00 the Hubble Deep-field image took over a month to capture, and covered a part of the sky the size of a ball-point pen's ball at arm's length. Even _that_ contained over 10,000 galaxies (!)

[@MCsCreations]

Hey Fraser, have you ever read about FPV? I'm not talking about games, but FPV with rc stuff (cars, airplanes, quadcopters, etc). It works like this: you put a camera and a video transmitter on your rc vehicle and use a FPV goggles... Which has a video receiver and screens, of course. Until a while ago we had only analog FPV (which worked in NTSC or PAL), but now there are 3 HD systems in the market. And people fly pretty far with it, there's a guy who flies wings and he goes to 30+ km. Anyway, my point is: the technology already exists, it isn't used on space just yet... But there's an issue about the distance. As distant the robot is from the operator bigger is going to be the latency of the video feed. Let me put like that: you could've crashed your drone already, but you only get to see it a few seconds later. 😬 Either way, it would be really interesting indeed! Stay safe there with your family! 🖖😊

[@babaayman9658]

I would love to see water bladders designed for storage in space, that control the freezing process to form a lens. Sure right now it might sound silly, but think about how big you could make a lens with ice and it’s water, so it’s not going to be wasted.

[@garyc1777]

Water tends to boil, not freeze, in space. Also (oddly) water is very heavy to lift to space - Hubble is about 4#/ft3 (it's mostly empty volume) but water is 64#/ft3. Creative thinking, though.

[@aethelredtheready1739]

That idea was also explored, quite interestingly, in the Xeelee sequence

[@donhull2440]

Telescope magnification is controlled by the focal length of the telescope and the focal length of the viewing optics. Both Hubble and James Web have viewing optics for multiple sensors so the magnification can be different depending on which sensor is used. The useable light for sensors is controlled by both focal length and diameter of telescope and is expressed as the Focal Ratio or Aperture. Diffraction-limited resolution combined with magnification determines how small an object can be resolved and changes with the wavelength of interest. The Hubble sees shorter wavelength in the near IR, visible, and UV parts of the spectrum. James Web sees longer wavelengths in the mid and near IR regions. This gives Hubble an advantage in diffraction-limited resolution. Larger ground based telescopes have even greater theoretical resolving power but the images are blurred by the movement of air above them. Hubble: Focal length 57.6 m (189 ft), Focal ratio f/24, diffraction-limited resolution of 0.05 arcseconds, field of view is 202-by-202 arcseconds (arcsec). James Web: Focal length 131.4 meters, Focal ratio f/20.2, diffraction-limited resolution about 0.1 arcseconds, field of view is approximately 15 times the area of Hubble (I calculate this to be about 780-by-780 arcseconds).

[@olorin4317]

Hey that's cool. I'll have a follow up question next season. Have a great summer break.

[@frasercain]

See you then!

[@gonun69]

I think you could put an even more giant primary mirror inside Starship. If you Angle it at about 45°, you could fit a roughly elliptical mirror that looks out at a 90° angle out of the door, like the Holmdel Horn Antenna. The added complexity of building such a weirdly shaped mirror might not be worth it though...

[@qubingjianshen8210]

At that point you might aswell angle it 90 degrees and have the entire side of the starship open up, then you could have a slightly concave rectangle mirror that is almost as long as the ship (minus the booster portion).

[@isaacplaysbass8568]

Enjoy your gardening Fraser, It'll be fab :) Thank you for the QandA, I.

[@pingu99991]

I've heard the "get a degree in computer science" thing a lot from you. I think one good example of this is Scott Manley. He's probably helped educate hundreds of thousands of people, if not millions, about astronomy and yet he works for Apple! Would love to get his input on this topic the next time the question comes up.

[@heaslyben]

Have a great summer!

[@locutusofzork4630]

How about flying 3-5 starships with telescopes inside that can dock together to form a segmented scope/interferometer like JWST? What could a 20-30 meter-wide visible light scope be able to see?

[@robwazny9416]

Finally a useful suggestion to use starship for. That is if it ever gets into orbit without blowing up the Gulf of Mexico.

[@7heHorror]

Thanks Fraser & co.

[@33DavePaton33]

Hey Fraser, is it possible that galaxy red shift isn't a result of cosmic expansion? For example, could light be loosing energy simply as a result of traveling through space it's self? Have there been galaxy studies that measure the distances of galaxies from one another in the early universe. Compared to the average galaxy distances of the "current" universe. Some other evidence of expansion other than red shift. Looking forward to hearing what other people think! Thanks!

[@kkgt6591]

Yes I have a similar question, what's the difference between loosing intensity vs redshift?

[@33DavePaton33]

@@kkgt6591 I can answer that. So intensity would be a count of the total number of photons hitting your sensor. While red shit has to do with the loss of energy of each photon. So you could have a high intensity source, of low energy photons. Or a low intensity source, of high energy photos. Hope that helps 👍

[@simian_essence]

Looking back in time is not the only place where information lurks. It lurks in the present. We cannot know anything about those ancient galaxies in their present time. Sad but true. And if the Universe is infinite, or even if it's just bigger than we could ever detect going forward...there's so much out there that we will never ever know about.

[@ollllj]

"there is no limit in space observatory magnification" is very wrong. the maximum resolution of a image from your magnifier in space is constrained by the wavelength that you measure, correlated to the measuring distance (inverse squares for a distant photo has the minimum of your wavelength). You may measure difference over time for a lot of ovbservations for a lot of science, but thats no option for a spinning object with a cloudy atmosphere, to measure higher resolutions of rapidly changing clouds. but long before that, bloom/glare are a bigger issue to making your image fuzzy or obfuscated by a nearby bright object.

[@frasercain]

I meant that a larger telescope in space isn't influenced by the Earth's atmosphere the way that ground-based observatories are.

[@CR-iz1od]

just means you need to look out further and coincidentally removes a lot of the stuff in the way of what you want to look at. but bigger collectors also mean faster observations so sharper images and more 'real time' kind of science at other wavelengths.

[@CR-iz1od]

a starship telescope would be good for deep surveys, you can do something like the Hubble does but over wider areas and/or faster.

[@chrisediger2061]

I'm just now finishing up The Three Body Problem! It is a very good series. The

[@thebigerns]

On the Edge of the Universe question: Since looking further out into space is equivalent to looking into the past, is there any direction we can look to see the future? For the moment, let's say "no" and accept that our present moment is as close to the future as we can get. Therefore, the Edge of the Universe… the absolutely farthest thing from the Big Bang… can best be seen in the mirror that we hold up to our faces.

[@WGSMRW]

How would you take a picture and undo the effects of matter warping space time? Like, what would it look like if the planet dissappeared and stopped warping space-time? And do I warp my surroundings in a way that is noticable?

[@slaphappyduplenty2436]

Question: What would an average sized galaxy’s worth of neutrons (and only neutrons) look like? Would it be observable? Would it be held together by its gravity?

[@Raz.C]

That's a tough one to picture. Even when we have gabajillions of electrons packed together, we still can't see them. Even lightning isn't really us seeing electrons. Rather, it's a discharge that we're seeing. We're seeing the result of fermions falling back down to lower energy states. We're NOT seeing those fermions (electrons in this case) in their standard state. Even when we have Juzzawanillions of protons all packed together, we don't see the protons, really. A cathode ray tube isn't showing us protons in their base state. Again, we're seeing the energy released from protons falling back to lower energy states. And then there was one... There are a LOT of free neutrons flying around in nuclear reactors, or during the testing or deployment of nuclear weapons. despite the VAST numbers of neutrons used and the even greater number of neutrons released, we still can't see the neutrons. We can see the effect those neutrons have on film, but we can't see them directly (and even if you could, it would probably result in your eyes bleeding soon after). So, to answer you question, I would have to say... Wait! I have to go; My planet needs me!! I'll tell you when I get back...

[@NunoPereira.]

The rate of expansion of the universe is It the same in the filaments of matter where all the galaxies are and in the "voids" in between?

[@mbiru12utube]

I posted before but not on Q&A, if our solar system with our small star has 8 planets (9 if U count Pluto) wouldn't a gigantic star like Betelgeuse have hundreds of planets, which makes it more likely to have habitual worlds since its Goldilocks zone would also be much larger

[@DanFrederiksen2]

Starship couldn't just take up a 9meter scope, it could take up a 20meter scope with ease. Make one big 20meter mirror, cut it up in 3 slices and fold the two lobes. Unfold in space. Or even better make the simple tech to form a scope in space and make it 200meter diameter. Couldn't be slower than how long it takes nasa to put up a weak scope.

[@andyoates8392]

Nine metre telescope? In space? One launch? Yes. Yes. Yes. Please.

[@frasercain]

Exactly.

[@davecurtis8833]

The size of the mirror is really about resolution And light gathering ability. Eg the detail you can resolve and how faint an object you can detect and not magnification.

[@rickyderoock9821]

Hi fraser, you answered a question about the edge of the universe, but although there isn't a real edge, I still wonder: where does the space expand into? If there a multiverses, there must be "space" between them right? What would this "space" be?

[@dave4882]

What is the smallest object JWST could resolve around the Alpha Centari system? Would it be able to get a good spectrogram from a planet atmosphere?

[@MrT------5743]

The question about us looking back in time to ourselves...Everything we see is back in time. It maybe pico seconds old or millions of years old, but since light has a speed, it takes time for that light to bounce off the wall and hit my eyes. Everything we see is in the past, just like what we hear happened in the past.

[@rayreynolds7066]

Hi Fraser from England, loving the content . What is the additional magnification that can be leveraged from galaxy based gravitational lens by a space based telescope. My gut says its big & i'm wondering if Astronomers are fully exploiting this resource. Cheers.

[@frasercain]

You get a 30,000X magnification if I recall correctly.

[@Raz.C]

I rather prefer the idea of using a fold-out mirror (like the JWST) from Starship, where each side is 8m. So if you had 4 sides that each fold in, that would make a 32 meter telescope!!! Or to word it more accurately; That would make a telescope with a mirror of thirty-two meters!!! That would conform to roughly an 80,000x magnification (assuming your numbers were accurate and that they presented a linear progression). Now, if we're talking pie-in-the-sky (pun not intended, but thoroughly appreciated now that it's been noticed), I would want to see an interferometer telescope where half the parts are kept in Earth orbit and the other parts are kept in Mars orbit. We have the technological know-how to launch the pieces into Earth and Mars orbit TODAY, however, I suspect that the technical know-how necessary to link the pieces together in an actual interferometer array when the distance between the points is greater than 1 Astronomical Unit, well, that's likely beyond our capabilities. Hence "Pie-In-The-Sky." Maybe even "Pie-In-The-Sky-With-Diamonds..." But could you imagine??? An interferometer like that would give us the equivalent of a telescope with a 1 AU mirror!!!! How do you even begin to calculate the magnification capabilities of such a monstrosity????? I suspect that such a telescope could have us searching exoplanets for life the way we use Google-Earth to search for directions to the cinema...

[@robertsutton8894]

I wonder if people have had a look at the Starlink way. LISA is often at the end of launch schedules.

[@alioth5837]

What about use it to carry gigantic lenses to concentrate solar rays on the surface of Mars? A few starships orbiting the planet could warm up the surface in a decent time. Just a thought

[@RG-qw9ys]

Sans our Sun, what would the night sky look like if all the other stars in the Milky Way disappeared??

[@lenwhatever4187]

Yup, summer is only a few months, the Georgia Strait is calling. Space will still be there, next month, next year, next whatever. Have a great holiday.

[@Nk36745]

The 'how does artificial gravity work in space question' reminded me of how things would be different in a large O'Neill cylinder. Such as people could float in the middle and flying a plane in an O'Neill cylinder you would only have to overcome air friction and not generate lift except in the other direction which would require double the lift, and traveling at high speed inside an O'Neill cycling you could 'go into orbit' inside. Is that all correct and is there anything else interesting to say about it?

[@mrspaceman2764]

What's the difference between the universe expanding or everything shrinking or falling into spacetime? Could the objects being held together by their own gravity actually be tumbling through their own spacetime gravity wells?

[@DanBennett]

You rock! Thank you!

[@ZiemakAttack]

Question: Could you look at a gravitationally lensed object through another gravitationally lensed object? Is there a point at which the resolution just wouldn’t be good enough to consider, or could we theoretically do that forever as long as there was another object in our direct observation path between us and the object we’re observing?

[@AdlerMow]

I not sure if I understood, but you're asked if it can be used togheter like the many lenses of a telescope, and if the gravitacional lens in itself have losses and distortion like a common lens. I ask that myself everytime...

[@ZiemakAttack]

@@AdlerMow Yes, exactly!

[@bruinflight]

Neat idea!

[@Pssst.ByTheWay]

If you take a modular approach like James webs mirror and implemented on a ground based moon telescope the size of the mirror is probably astounding is there anything that would prevent us from making a 100 meter diameter mirror?

[@SciFiFactory]

Question: Hi Fraser! So we can not see further than to the first stars that formed from the big bang ..... could it be that our universe is much bigger and there was a second big bang somewhere far away from us .... and its light reaches us next week for the very first time?

[@IDoNotLikeHandlesOnYT]

Unless I'm just not understanding what you're getting at, that doesn't make any sense. The beginning of the universe didn't occur _within_ space. It _created_ space.

[@jakoblindman8274]

Great Content!

[@Corvaire]

Have a great summer Fraser! ;O)-

[@StarrDust0]

looking at those amazing stars, I'd give anything to travel to other habitable Earth-like planets...they say there's 10 billion of them in the Milky Way....we need to get warp drive asap.

[@johnholleran]

If you had a portal gun that could open a portal anywhere (the other end is fixed on Earth) but only one shot, where would you put the portal? LEO for free energy, Moon, Mars, another star, etc?

[@sinisterknight9696]

Question. Could our theories on the expanding universe be wrong? If our only evidence of the expansion is the redshift of light, could that redshift be caused by other things affecting the light, as it makes its long journey to earth? Paul Gardner

[@timothyhayes5580]

If we can use the James Webb and the Hubble to see the universe back in time, why can't we see up close on another planet in another system? Either back in time or present? Sorry it sounds like a silly question. But it just seems to me like we should be able to see

[@Khether0001]

I'm sorry, but I insist on andykod77's question, it *HAS* to be finite, the universe is undounbtly large, but after that galaxy, there's another, then another, but *eventually* you have to reach a point where there is simply no galaxy after that! Even if you argue the universe is spherical or anything like that, eventually you *must* reach a point that is truly empty, before the expansion has had time to reached it, the universe has to be expanding into something, _infinity is just a theoretical concept that can't really be used to explain something that is just large beyond our current comprehension_

[@frasercain]

Astronomers don't know if the Universe is finite or infinite. It's at least as big as the observable universe.

[@veggiet2009]

How large of a telescope would you need to be able to resolve potential roads on the surface of an exoplanet?

[@actaeon6463]

Starship might work for hosting an optical light telescope, but it would be a disaster for infra red (which is where you have to look to see the furthest objects). That's because any heat at all, either from a nearby planet or the spacecraft itself, will distort deep infra red images. That's why J'WST is so far away (to get away from earth) and has all that cooling equipment, so that the equipment operates at just a few degrees K.

[@MikeKinney8675]

Fraser, have a good summer. See you live in September. 👋

[@GabeTStarman]

Will James Webb be used to observe bodies within our own solar system or is it booked for interstellar exploration only?

[@pimbu936]

I know a few physics majors that would say don’t do physics at all. However, I’m doing electrical engineering and there’s a plethora of aerospace employers desperately competing for everyone in my major.

[@Matthew-by6vl]

Frasier, I know you won't reply for a while...enjoy your summer. When the lunar gateway is being constructed, will it be observable from earth with an amateur telescope, or professional observatory? And what about construction on the moon, if we actually do it?

[@calire895]

Question: Is it theoretically possible to use gravitational lensing events to observe our own solar system 4.6 Billion years ago? If so, how could this be accomplished?

[@microschandran]

Hi Fraser,if we are looking for dark matter particles, doesn't it make sense to look in dark ages time period of cosmic evolution when it dominated the universe?

[@dannypope1860]

That time machine telescope question was beyond dumb… and I think I’m being generous.

[@philochristos]

How big would a telescope mirror have to be (or how much magnification would it have to have) to be able to actually see stars like Betelguese the way we see the sun--as having a size and shape rather than just being a point source of light?

[@frasercain]

You picked a funny example. Betelgeuse is actually the only other star than the sun that can be resolved into a disk. 😀 Bigger telescopes can would be able to resolve other supergiants, but sunlike stars will be a long way away.

[@lostpony4885]

The space telescope is the most obvious gimme. Should be a first orbital launch sort of thing, make it cheap in case it blows up.

[@frasercain]

I would wait until Starship has been tested a few times. :-)

[@transpiler]

Wouldn't Starlink be a little more obvious? Those are cheap and disposable.

[@alexisdespland4939]

what orbit is the lunar gateway lickely to br in.

[@undertow2142]

Question: Could future humans theoretically create a massive solar sail/platform. Put it in orbit around the sun. Then slow the orbit down until the “push” from the sun supports the platform at a higher orbit than its orbital velocity would dictate? In other words the platform would “float” on the solar wind and the platform would experience some level of gravity from the sun. The question another way - what’s the formula that describes the relationship between surface area of the sail, orbital velocity, distance from the sun (solar wind strength at different distance) and resultant gravity at the platform?

[@frasercain]

In theory, yes. It's even cooler than that. The Sun would be gravitationally attracted to the platform, and would follow it across the universe. Google search for a Shkadov thruster

[@undertow2142]

@@frasercain love it. I’m thinking when I rule the world I’ll put them all around the sun such that we have about 3/4g at the platform and build settlements. Could we hold on to an atmosphere? It wouldn’t be as cool if I couldn’t step outside and take a deep breath literally standing in space.

[@michaelharmer5174]

What is the quickest speed we could make a satellite/starship travel using gravitational slingshots? Is there a maximum?

[@massimookissed1023]

Dr David Kipping of _Cool Worlds_ describes the _"Halo Drive"_ using black holes for slingshots. (17min) kzbin.info/www/bejne/qHfUfWx5oLOrjtk

[@MrKKUT1984]

I sure would like to know how big the black hole is in ic1101

[@istvansipos9940]

01:54 could the Hirundo Rustica II become a space telescope? She has as many successful L.E.O. missions as Starship has. But my fanboyism knows no limits. I might ask a question about the Lunar Hirundo Rustica II soon. It depends on the quality of their computer animation, obviously.

[@Bulgrim77]

If the galaxy reaches a point in time and space it "moves" from our perspective faster away than the speed of light no information reaches us

[@Kentchangar]

What would it take for the pictures taken by a telescope to be like taking ordinary pictures by a regular camera (without being photoshopped) ? More mega pixels? Faster shutter speed? Bigger telescope?

[@frasercain]

You can take pictures of the sky with a regular camera attached to a telescope. When you think of it, a camera lens is just a kind of telescope

[@Kentchangar]

@@frasercain I meant distant galaxies, black holes, etc as done by Hubble or James web.

[@ryutak4152]

What do you think is the most important parameter for space colonization? For me, it is gravity.

[@kindlin]

You mean... a lack thereof? Turning asteroids, etc. into rotating habitats is probably the fastest way to colonize the solar system. The gravity of a planet or even a moon is a substantial challenge to overcome for creating the amazing space habitats we all dream of.

[@ryutak4152]

@@kindlin I meant places where humans can live. You can take care of a lots of problems with current technology. Atmosphere and even radiation is not really such a big deal, but gravity is. You can't change it on the surface with our current understanding of physics, so I think finding world with the same gravity as Earth is the most important. The rest does not matter so I think Titan looks most promising.

[@kindlin]

@@ryutak4152 Rotating habitats are 110% where our space habitation journey is going to take us. We'll see things like 2001: A Space Odyssey, with the rotating rings, relatively soon; there are companies right now trying to design the first commercial, large scale, rotating habitats. Rotation gives us gravity; Einstein's General Theory of Relativity demands it (the equivalence principle is a founding principle of General Relativity). Not long after we have ring habitats we'll be moving on to O'Neill cylinders. You may want to go watch some of Isaac Arthur's videos, as he goes into quite a bit of detail about this throughout his backlog. Humanity has such potential in space. The Earth is so limiting.

[@matthewpalmer9820]

25:00 find a mirror 500k light years away, and point your telescope at it

[@Not_An_Alien]

I would think the military will make a telescope for Starship, if it's feasible.

[@mariop8101]

And if we made 3 of these starship visible light telescopes and use them as a interferometer?

[@rolflandale2565]

A space telescope, with its own gyroscopitic & rocket canister fuel stored boosters for maneuvering🤔? Leave it the Dr Fraser, to explain the complex mentality & dynamic thinking of SpaceX.

[@coshty]

Could we build a bunch of cheap say 4-5m space telescopes, launch and strap them together in space to create one large telescope, say 20m diameter?

[@mwvilla2953]

What about 4 Starships, three are morrows and using lasers, alight with the four to collimate the light coming from the other three. This will create a telescope with an equivalent mirror of hundred of miles. I know that this needs to be refined, but is possible?

[@philb5073]

Question: If an advanced civilization built a Dyson Sphere would that change their galaxy's protection from their heliosphere?

[@theblackswan2373]

Enjoy your break

[@abefonseca3582]

Why not just go for the big enchilada and have 18 eight-meter diameter mirrors assembled on a similar JWST structure. Build the structure first in space then fly the individual mirrors up and attached to the structure. Now, that's a telescope for the ages.

[@dropshot1967]

When we choose a location for a permanent or semi-permanent moonbase, would it be possible to negate the burdens of moondust by (partially) melting the dust using sunlight and mirrors in orbit, creating a glass/slag surface that is far less abrasive?

[@AvyScottandFlower]

You Canadians, and your summer hibernations.. 'Till next season!

[@BenSamry]

Question : Couldn't gravitational waves theoratically be techno signatures of alien civilizations using warp drives?

[@MikeKinney8675]

Damn good question, I never thought about that. Interesting idea.

[@LisaAnn777]

That's what I have thought before but it never seems to be talked about.

[@stevenzapiler5806]

What will seeing back to "the beginning" with the WEBB do to our views about the "nature of reality"?

[@medithes1279]

>> based on the track record of high resolution space telescopes and incidents of havoc why haven't there been any space telescopes with expandable modules or human habitat modules send to space when u think about it telescopes have more scientific purposes with an attached livable habitat module.

[@fico6824]

What kind of signals are we sending into space right now? Will alien SETI find them?

[@kenmallon3511]

Question: Is it more accurate to say, "Fall into a black hole" or "Fall onto a black hole"?

[@johngordon1175]

Ever means ‘a time to come’

[@lostpony4885]

Omigosh First !

[@frasercain]

You did it!

[@jasonstiletto]

Is there some fundamental reason NASA wouldn't want to develop a Voyager style probe (updated with more modern tech.) Say a 1 ton nuclear thermal powered with ion propulsion. Mass produce them like Starlink for under $5 million each, then load up falcon heavies and throw them at whatever looks interesting in bulk? 4-8 voyagers in a single repeatable under $200M mission.

[@BenjaminSteber]

If you had the technology to build a Dyson sphere then you'd have the technology necessary to make the Dyson sphere obsolete.

[@CPrzywojski]

If we could somehow theoretically "jump" 100,000ly away from Earth, and then somehow theoretically we had a telescope that could, then, see Earth 100,000ly away at some astronomically massive magnification, so that we could see people moving around, would we then be seeing what Earth was actually like 100,000 years ago? Could we theoretically see our past?

[@frasercain]

Yes. Aliens who are looking at us from 100,000 light years away see our past

[@truvc]

Gimme a James Webb but scaled up to fill a Starship

[@pi1392]

❤️ ❤️

[@vicvicious5328]

Hey Fraser, after red shift, what's next?

[@frasercain]

There are only two directions. More red and more blue.

[@smorrow]

Spaceflight question rather than astronomy, but does anyone ever use the moon for a gravity assist?

[@johnbennett1465]

Fraser, good show but you had mental glitch. Once something has fallen over the cosmic horizon, it is going faster than light relative to us, just like you said. But unlike what you said, at some point the photons will no longer reach us. Not even as radio waves. I believe you actually know this since you have gotten it right in previous episodes. Sorry to nitpick, but I want people to get the right information.

[@frasercain]

Yes, there are some objects where the light will never reach us, but for others that have already crossed into our observable Universe, they'll become redshifted into oblivion. There are objects that we can see, that we can never reach, even if we could travel at the speed of light.

[@HHXOXHH]

@@frasercain NDT clearly said that at some point, when all other galaxies are out of our observable universe, there will be no way of observing they actually existed.

[@johnbennett1465]

@@frasercain objects will be red shifted to oblivion before they disappear, but they will eventually disappear completely. At some point the space between us and an "FTL" object will expand so fast that a photon can never keep up with the expansion. Remember further equals faster applies even past the horizon.

[@HHXOXHH]

@@frasercain kzbin.infoUgkxZeiGDu65LJQmxWxDP-CbB-4VqP1tIEA2

[@manuelvale3996]

A white dwarf is extremely hot, because it's a stellar core remnant. It will cool down (over trillions of years) to the cosmic background radiation. That means, that for a few billion years, its temperature will be just right for life to evolve on its surface. What do you think of the validity of this hypothesis?

[@Zodtheimmortal]

Turning Pluto into a comet would be a waste. But how about to crash Pluto into Mars. Quick terraforming?

[@jamesgibeau7324]

How could they turn the starship into a lunar base or a mars base if they didn’t want to recover the top half

[@frasercain]

Just let it land and sit there on the Moon. Boom, instant base, with a really long drop outside the front door.