Are Dyson Spheres Actually Possible?

[@CoolWorldsLab]

Thanks for watching! Some FAQs... 1. "Isn't a sphere pointless because by this point we'd have fusion reactors?" Fusion reactions require confinement, which means incredibly high pressures and temperatures. For any fusion reactor we build, we have to provide that confinement which costs energy (as well as maintenance). The enormous mass of the Sun provides confinement for free via gravity, so it's pretty hard to beat that! Yet more, 99.9% of the mass of the Solar System is in the Sun, so it's essentially by far the largest fuel reserve. On of top that, 75% of the mass is hydrogen, the optimal element for maximizing fusion efficiency. Why build a fusion reactor when you an essentially perfect one right in front of us? 2. "Isn't it impossible to obtain enough mass to build this stuff?" The mass requirement varies from the mass of Mercury to the mass of Jupiter in the examples cited in the video, so certainly we have enough mass in the Solar System to do it. Dyson calculated that it would take 800 years of Solar luminosity to completely unbind Jupiter. Remember that Jupiter is mostly hydrogen, so it could be fused into whatever elements you want and would broadly lead to a net energy gain in doing so. Now 800 years of continuous energy to build a Dyson sphere might seem like a lot to us, but it's about one fifth of one millionth of the Sun's remaining main sequence lifetime, and that's before doing any stellar engineering to extend its lifespan. So the payback period on your investment is almost instantaneous in cosmic terms, and yields a *massive* energy profit. Thus we have the materials and motive to do such a thing. 3. "Why would anyone do this?" The video discusses two ideas, habitation and computation (focussing on the latter). But another great point in the comments is that we're essentially already building a Dyson swarm. Every satellite in space harvests solar energy to perform various functions, as we are moving towards millions of satellites in the coming years. It's just a progression at this point towards the Dyson swarm. 4. "What about getting the energy to Earth?" I should have clarified the Earth is basically gone in this picture, dismantled. Beings either digitally upload themselves into the Dyson sphere supercomputer or build a swarm/ring system with habitats instead. 5. "This is a stupid idea". I get it, the idea seems wild. But, it's somewhat the inevitable end point of energy production, as Dyson argued, as well as Kardashev and others. It might seem like science fiction to us, but tell the Victorians we'd have people on the Moon in less than a hundred years and they would they think you were bonkers too! I would think carefully about it before dismissing this idea as stupid - after all this is one of the seminal papers produced by one the most brilliant physicists to ever walk the Earth. Keep 'em coming and please do share widelt!

[@tanmay4703]

The first argument is correct why build a fusion reactor when we already have one. Just tell this all the other nation and most of the energy Criss can be solved. Rather than focusing on this they are hydrogen cars, carbon capturing machine all sorts of wired things.

[@erwinlommer197]

The first answer doesn't actually disprove the original argument. Sure the sun has huge amounts of energy. But which is actually cheaper per unit of energy? Fusion or sun? Dyson spheres is an illusion of scale. It is a bit like a steam engine that is the size of continent. A lot of energy for sure but is it really the way to go? The best solution? Not just the biggest solution? Anyways, I'll watch the video and edit as necessary...

[@MrCmon113]

​@@erwinlommer197It's more like a quadrillion steam engines set up around a source of infinite coal VS letting the coal go to waste.

[@brendalb3]

@CoolWorldsLab - isn’t it a necessary condition for a Dyson Sphere to be constructed around the entire solar system of a star? Otherwise the sphere would reduce direct sunlight and change the environments of planets outside the sphere, and probably within the sphere as well.

[@TheFos88]

Love it

[@plaguepandemic5651]

Man, a civilization living on a Dyson Sphere, facing an imminent apocalypse from an engineering problem they failed to solve in time, would make a great sci-fi novel.

[@michaeljf6472]

Yeah, and you could fix that problem in the second book

[@mk1st]

Don’t Look In

[@lucemiserlohn]

Sound a lot like a novel by Larry Niven...

[@Flannmusic]

Outer Wilds, the video gAme

[@mark6302]

"you are the chosen one, set to save our planet by turning it off and turning it back on"

[@scottbruner9266]

9:37 I love how when they collided, it was the STAR, not the sphere, that was destroyed. 😂

[@stevec7923]

Indeed. Very amusing.

[@SweepAndZone]

Triggering

[@markvwood2007]

Not too realistic.

[@frontier164]

Optimistic engineering!

[@Ludak021]

I like the idea of a computer operating while showered with most extreme radiation imaginable and staying cool because it's cold in space....Especially next to a star. /sarcasm This can never work and the "sphere" is useless. Generating energy? I am expected to live on a super thin sheet next to a star? Or are they going to wirelessly transmit all the energy to Earth? Sure, while they are at it, someone should hop to the edge of the galaxy to fetch me a beer.

[@JohnBrown-no4od]

In the book version of "Relics" (novelization of the Scotty/Dyson Sphere episode of Star Trek:TNG), there is no matter within several light years (I believe it was 100) of the star enclosed by the sphere. In the book, that accomplished two things: First, the sphere builders used all that missing matter to build the sphere, and second, that cleared the area out of any matter that could exert any unforeseen gravitational forces on the sphere.

[@AndrewJohnson-oy8oj]

That puts a rather frightening implication to the great voids like Bootes Void. Are they not voids, but actually Type 2 empires where all materials outside the Dyson constructs has been stripped to make the constructs which completely mask evidence of the enclosed stars.

[@raifsevrence]

@@AndrewJohnson-oy8oj Assuming modern science has at least a reasonable understanding of physics, there is a necessity of imperfection in our universe. If all the matter had been evenly spaced, nothing would have ever coalesced from it. These voids are consequences of that imperfection. Consequences of the gravitational framework of matter in the universe (dark matter) that has formed the topography of all things. Ostensibly at least. The idea of the voids being regions of space where all available matter was harvested is a fascinating one for sure. Though it is nearly impossible to fathom such things, to truly comprehend the scale of them, we can still imagine them. That imagination may be our greatest gift.

[@Dragrath1]

@@raifsevrence Yeah voids are a natural structure cosmically speaking. Additionally the paper by Matthew Kleban and Leonado Senatore from 2016 Inhomogeneous and anisotropic cosmology says at least in the large scale size approaches infinity or at least is much larger than the causal horizons such that a given universe can be at large scales treated as flat or open, pretty much paints a picture where as a result of the principals of mathematical continuity and calculus those anisotropies in the initial universe will propagate into the rate of cosmic expansion in such a way that ensures that any initially expanding universe no matter the initial distribution or energy density will expand without bounds at large scales because the rate of expansion depends on the local time coordinate causing said expansion to itself necessarily to become anisotropic if it is to be a valid solution to the Einstein field equations. Traditionally cosmologists have assumed these terms will cancel out i.e. that the Friedmann Lemaître Robertson Walker metric is a stable solution but the proof shows it is actually an unstable solution from which only unbounded divergence is possible if information conservation and causality preservation are to hold. This means only nonlinear anisotropic and inhomogeneous nontrivial solutions to the Einstein field equations can exist at cosmological scales(The symmetric solutions become a limiting case which applies at localized galactic or smaller scales) but as a bonus you get all the effects attributed to "dark energy" for free along with a natural explanation for the observed bulk flows as inevitable consequences of gravity in an expanding universe drastically simplifying the underlying physical models theoretically at the cost of the math becoming nonanalytically solvable. This is interesting from a prospect of Scifi/fiction as in such a model the rate of expansion becomes directionally dependent (as has been shown to be the case IRL by work such as Nathan Secrest et al 2021 which falsifies the cosmological principal assumption to 4.9 sigma meaning that there is only a 1 in 2,000,000 chance for the results to be obtained in a universe where a cosmological principal holds due to some kind of statistical fluke) so matter concentrations like our local group will inevitably flow into the Virgo supercluster if nothing is done to stop it as the rate of expansion between us and the nearby clusters in the same gravitational basin are slowing down over time unlike every other direction where the rate of expansion is accelerating over time. Additionally whatever gravitational source we are getting pulled towards is not in the local universe but rather lies at higher redshifts z>1 well beyond the Shapely supercluster in the distant universe with Laniakea just being a minor tributary in this bulk gravitational flow. From numerical modeling you will get many such gravitational watersheds of sorts with this one just being ours and the great voids acting like higher dimensional continental divides with our distant location at the edge of these vast basins being the equivalent of a slow trickling mountain brook. This surprising realization immediately suggests an anthropic constraint on habitability since most galaxies will be deep within these gravitational basins undergoing more and more frequent violent galactic collisions and what could have more fascinating implications from a sci fi setting then that? Imagine civilization turning their galaxy into a constellation of stellar engines aimed in synchrony letting them avoid falling into the gravitational torrent downstream? It no longer would be all about collecting stuff and just building bigger and better Steller system scale computers but also avoiding slipping too deep into the cosmic gravitational maelstrom. It's all fun and games until your galaxy falls into the gravitational grip of a giant elliptical galaxy at the heart of a galaxy cluster fueled by a central Ultra Massive Black Hole engine.

[@lucemiserlohn]

@@AndrewJohnson-oy8oj No, as such spheres would still need to radiate away heat. If they did not, they'd be glowing hot in no time at all. Thus, the amount of energy received from the star must be equal to the amount of energy (heat) radiated away to stay in thermal equilibrium. Hence, we would see a gigantic emission of black body radiation from the voids - which we do not.

[@AndrewJohnson-oy8oj]

@@lucemiserlohn I love the quality of engagement one gets on this channel.

[@PunchMcLightning]

The fact that you used this clip at the beginning is awesome because that's how I learned what a Dyson Sphere was in the first place and that knowledge always stood with me. I love old Star Trek so much.

[@brothermine2292]

Also worth analyzing is the "shipstar" featured in Gregory Benford's sci fi novel "Bowl of Heaven." The structure is a bowl-shaped portion of a sphere, with a hole through its center. It generates a strong magnetic field to focus the protons of the stellar wind into a fusion plasma jet through the hole. The jet accelerates both bowl & star, like a giant starship, and the bowl maintains a constant distance from the star while they both accelerate. Meanwhile, the inner surface area of the bowl, although not as large as the inner surface of a Dyson sphere with the same radius, is immense.

[@markfergerson2145]

That’s just a revision of the Shkadov thruster. That’s a bowl with no hole. The star’s radiation pushes the bowl but also pushes the star itself along with the bowl. Google “stellar engine” to have your mind blown a bit.

[@mihailmilev9909]

that's so crazy lol I love it

[@mihailmilev9909]

I never even thought about when people were mentioning moving stars or systems lol

[@bricefleckenstein9666]

Sounds like a variation on Niven's "Ringworld" concept.

[@brothermine2292]

>bricefleckenstein9666 : One could say both Ringworld and Shipstar are variations on the Dyson Sphere concept. Shipstar seems more innovative, since it's also a means for travel through space, and it has enough fuel to travel for billions of years.

[@EnneaIsInterested]

The real Dyson swarm is a gradual development, so once you have your statites, you can gradually infill. This implies that numerically, once you have an in-space industrial base, it's only a matter of time until the cultural focus is shifted from your planet to the many diverse rotating space habitat communities, indeed, beaming all the energy down to Earth would destroy the Earth, and so cannot be done.

[@derekflegg2510]

Build one around the event horizon of a singularity #DysonsHole

[@Ludak021]

How do you propose this "beaming of energy down to Earth" would work? Magic? If you think about it, Sun is already doing that, partially. I bet if we push Earth closer to the sun, solar panels would perform better. Yes yes, I know, to move the Earth we first need to build a Dyson Sphere and beam the energy back to Earth, which would destroy it. Cheers. PS. Scientists should focus on something useful and applicable, this is a waste of everyone's time.

[@EnneaIsInterested]

www.energy.gov/space-based-solar-power

[@sebsunda]

There is a big supposition here: which is you have enough energy & material to ensure viability for all living satellites in the swarm. Remember that things require maintenance and refilling. (Which is OFTEN neglected/forgotten in most of sci-fi) From all the concept proposed by Dyson, the swarm is the most "feasible" and the most efficient use of resources, but there is a limitation on maintenance & energy generation. So I would not expect a swarm to occur unless the energy generation & matter cycle maintenance are completely solved. Until then, planetary bodies will be the "default" from a cultural perspective.

[@alexsiemers7898]

@@Ludak021the ability to use microwaves to transmit energy is one Ive heard discussed before, and if that doesn’t work well it’s possible that the Dyson swarm design could be helpful since the individual sails could simply be mirrors to redirect light to solar arrays elsewhere instead of being photovoltaic panels themselves

[@raiin__4906]

yes. because i say so

[@PokerIsLife13]

Great comment

[@Eswarramesh2428]

You are gawd.

[@AGuy-x3d]

I don’t get it

[@freshtoast3879]

We will obey

[@Passos_art]

I concur

I am a big fan of Freeman Dysons work (thanks to Isaac Arthur in large part) and REALLY enjoyed this episode. It's interesting that you can actually build a Dyson sphere theoretically, though I think we would do much better to stick with what Dyson really meant and just harness the stars energy with a Swarm of satellites or habitats. a matryoshka brain is another really cool use for a star as well, Great video Cool Worlds! The playing in sandbox mode is why I often get hung up on the simulation Hypothesis. :)

[@CoolWorldsLab]

I think Dyson backtracked after seeing those letters, I really think he meant a solid sphere and lost his nerve on it

[@frankkopp4930]

😊😊😊

[@frankkopp4930]

G

[@lavenderlilacproductions]

​@@CoolWorldsLabI suppose when we get 10^23 humans living in Mckendree Cylinders spaced around 1AU, we should have enough big brains to figure out the exotic matter to make a proper Sphere. Assuming we can find enough phosphorus in the Solar system to make DNA for sextillions of people.

[@1edgeman76]

OMG, I simply CAN NOT get enough of these episodes!!! You sir and your team are AMAZING. I watch EVERY episode you and your family produce because these little thought experiments are absolutely mind-boggling, thought provoking, and inspirational. Thank you to you and your team for these gems that are educational, provocative, inspirational, and humbling all at the same time in a world full of gross sensory overload for no substantial reason. Truly AMAZING work, as always.

[@CoolWorldsLab]

Thanks so much!

[@aristideau5072]

The only issue that I have with these thought experiments is they never describe exactly where all the energy required to create these structures comes from?, yes we can source all the raw materials by procuring all matter within said region, but where does the energy come from that is required to fabricate and then position the finished structure come from?. Chemical rockets are non starters and ion drives are just too weak.

[@kathgd]

@@aristideau5072😮😮😂😮😂😢😂😮🎉😊m

[@Delibro]

@@aristideau5072 The Dyson Sphere gives nearly unlimited energy, just build it increasingly.

[@sigzil1985]

Ooh the transition to the logo in that opening

[@Nulley0]

Cool Dyson sphere

[@JohnnyWednesday]

It was excellent - I wish Cool Worlds could guest write some Trek episodes - it needs more science in its fiction!

[@ThisHandleIsNotAvailable.]

Yeah that was slick.

[@almartin6824]

Of course it’s possible, since 1991 actually….. Dyson designs and manufactures household appliances such as vacuum cleaners, air purifiers, hand dryers, bladeless fans, heaters, hair dryers, and lights.

[@HeeeyTooom]

the Dyson swarm 😂

[@NickyBlue99]

😅

[@dearthditch]

They ever come out with a vac called the Dyson Sphere?

[@earthknight60]

For anyone who wants to take a deep dive into these and other things (such as the starlifting that was mentioned briefly in this episode), pick up a copy of the 1985 book Interstellar Migration and the Human Experience. I know the name sounds hokey, but it's actually a great collection of research papers from the proceedings of the Conference on Interstellar Migration held at Los Alamos in May 1983. There are some really interesting and wild ideas in it, with the math and physics broken down and explained.

[@AndrewJohnson-oy8oj]

My biggest problem with a Dyson Construct being used for human habitation comes down to three words: Coronal Mass Ejections. The entirety of any CME would hit the Construct full-on.

[@williamsnead8397]

I think the same as well considering there is one a week and up to three a day at the height of the suns 11 year cycle and the ejection travels up to 3,000km/sec i believe this would be quite a problem.

[@Vazzini42]

That's why you just wait for it to go red dwarf first.

[@AndrewJohnson-oy8oj]

@@Vazzini42 Red dwarf is a specific type of star. No other type of star "goes red dwarf"

[@philipbrooks7640]

Maybe we would need to develop a technology that would keep the star stable and prevent ejections.

[@AndrewJohnson-oy8oj]

@philipbrooks7640 well yes, I guess if you're at the technology levels where you're building Dyson Spheres, that is a possibility.

[@kurtp2003]

I'm surprised there's no mention of using orbital rings as support members for a denser shell. For those unfamiliar: An orbital ring consists of something like an enclosed particle accelerator or mass driver moving mass in a circuit at higher than orbital velocity such that it counteracts the inward gravitational force on the whole assembly. It does require constant power and maitanence, but the former is easily solved and the latter can be designed out to a large degree. That is, so long as it's designed so no single ring failing can cause the structure to fail.

[@frankkopp4930]

See See. S6

[@davidb2380]

Very Interesting video, as usual, but I see some physics problems. OK, the reflected radiation heats the outer layers and causing them to expand. However, in expanding, work is done so the layers become cooler so the ions can then combine forming more neutral atoms. This changes the opacity, so the layers then contract and when that happens, the neutral material gets hotter and they become ions again. The process repeats so the star pulsates. In other words, we have a heat engine. Second, stars rotate so the equator bulges and we now have non-spherical star. Then because of the von Zipper effect, the outer polar regions being closer to the core will be hotter then those at the equator so we now have a non-spherical star whose outer layers will have a non-uniform temperature. As a result, the Dyson sphere will not be uniformly heated and the reflected radiation will not be uniform. That is Dyson Sphere will reflect back to the star more radiation to its polar region than the equatorial regions. Also, this non-uniformly heated Dyson Sphere will have problems stability wise from the differential heating ? At a minimum, this effect will affect the thickness of the Dyson sphere and the material used. Third, stars also have stellar winds. Over time, will these winds erode the material of the Dyson sphere ? Stellar winds also carry magnetic fields, which again puts constraints on the material used. Finally, higher mass stars have outer layers which are radiative, not convective, while low mass stars have convective outer layers. I imagine this too may be a factor, especially since the magnetic fields effect the stellar winds and they are much stronger in low mass stars. It has been a long time since I took courses in stellar interiors and atmospheres, so I would appreciate the comments from a real expert.

[@rwarren58]

Perhaps join the cool worlds team for a month. You might improve your chances of getting an answer from a Princeton Professor.

[@danlobue-wl7wv]

Dear David, stop showing off! Just kidding, nice brain!

[@helloidharbl6753]

Nanomachines.

[@bastiaan7777777]

It's the physics behind science fiction. Blabla to power computers. What would those computers compute?

[@raifsevrence]

@@bastiaan7777777 the meaning of life obviously

[@CaymenCider]

Contents like this is why I subbed to this channel 8 years ago

[@ZigamusRainbowWizard]

There IS a game called Dyson Sphere Project, in which you are an 'immortal' robot tasked with creating a self-sustaining factory to generate the 'parts' to build such a sphere as a means to harvest enough power to sustain a population of 'electronic beings' in a Matrix like simulation of life. In this game you can build it either as bands or as a solid sphere, it is fun to work on this and see what you get. Get the game and play with it a bit, you MAY want to make a new video with some of those graphics to display this concept. (Of course, WITH permission by the game Devs and or copywrite holders)

[@giin97]

A little messy on the lore, but pretty close. Post singularity humanity living in a Matrovska Brain in the Sol system, multi-layered dyson sphere computer. We need more power, so you, a specially trained human mind living in that construct, are assigned a sector of the galaxy and given remote control of an Icarus drone to pilot. You never leave the simulation, you're just remote desktoping into work. With enough success built up, you can move to a new sector and skip portions of the automated tutorial (spending metadata). All in-game lore. Also in-game lore, they expect your starting planet to be inhabited by a technologically advanced species that will surely assist you in your efforts 😂

[@poptart2nd]

it's funny that i find this video and comment while playing DSP

[@ZigamusRainbowWizard]

@@poptart2nd Did I describe it well enough? I thoroughly enjoy DSP, I'm a builder type, do not like to kill things. So this game really scratches the itch! Enjoy the game :o)

[@barrywhelchel9005]

This game is amazing. There is a rare moment when you look up at your star and see the first rings forming and you realize what you are building.

[@zefarmer]

@@giin97 Holy crap, you're telling me I can BE BOB?

[@marcocatano554]

This sort of topic entices the imagination. In the end, this may be the most valuable quality of this video. Hats off Dr. Kipping!

[@lucemiserlohn]

The problem I have with Dyson Spheres as a concept is that they would be incredibly hard to maintain. You have a rotating mass at the center, and a rotating mass at some distance away, plus a lot of other mass outside of that system. In order to stabilize that system, any perturbance of gravitational equilibrium must be instantly counteracted (which in itself is a very hard problem, even forgetting about the sheer size of the required propulsion systems for that). This means you're building a machine that is one giant inverted pendulum embedded in a multi-body-system. The computing power required to not let this end in a giant catastrophe alone would probably exceed the energy output of the star involved. Then you have the problem of thermal equilibrium, all energy received from the star must be radiated away equally, else the temperature of the sphere quickly runs away towards magnitudes unsuitable for keeping your beer cold. Even for the simpler version, Dyson swarms, this requirement still holds, and is probably the even bigger problem compared to orbital stability.

[@z-beeblebrox]

Dyson Swarms are my favorite conceptual megastructure, because unlike other Sci Fi megastructure, a Dyson Swarm is immediately beneficial to its builders even when it's only a fraction of the way done. Like, half a space elevator is just an alarmingly close asteroid and a coil of psychotically dangerous feed line. Half an O'Neal Cylinder is just a dumb open tube exposed to the vacuum of space. But if you have 0.01% of a Dyson Swarm? OH NO, you're getting a ton of free energy from that, whatever will you do?! :P

[@EnneaIsInterested]

Half a space elevator? But a non-rotating skyhook is very useful, it allows you to hit the tether with a much lower Delta-V than reaching orbit without rockets, so it could enable US to build a fleet of combined-cycle jets that are equally capable of taking you to Thailand in four hours, as it is of taking us to the tether by shifting from ramjet to scramjet mode.

[@z-beeblebrox]

@@EnneaIsInterested that’s not half a space elevator, that’s 99% of a space elevator. Look up how truly, eye wateringly looong those things need to be

[@MrCmon113]

You can build a short O Neil cylinder and gradually make it longer.

[@amai2307]

Except it isnt, it starts being beneficcial only after it transfers enough energy to outweight production and maintenance costs.

[@z-beeblebrox]

@@amai2307 You send one single solar power generation satellite into space and turn it on. Congratulations, you've begun a Dyson Swarm and it's already serving its purpose.

[@Satoruu23]

this is always a joy to watch, thanks david!

[@brianbates7572]

Why does no one ever mention the brilliant Ringworld Series? Larry Niven may not have been the first to propose the concept of 'rings' around a central sun, but it will make a person think

[@georgejones3526]

A ringworld is also unstable which is why Niven’s world had ramjets on the rims for restabilizing the ring.

[@TheRealBozz]

Loved this series as a kid. The idea of the ringworld fascinated me.

[@keithklassen5320]

​@@georgejones3526Dyson Spheres are similarly unstable.

[@serpentphoenix]

YES YES YES!!! I have been requesting and hoping you would make a video on Dyson Swarms. Thank you @coolworlds!!!

[@Alpha_Sigma01]

Fantastic upload. I do hope you use the revenue to fund your teams projects. Thanks for eloquently breaking it down. I love what you do! 🙏

[@osasunaitor]

How have I missed this channel until now?? This is a high quality production: a very interesting topic, explained in a reasonable way (scientifically accurate but not too hard to understand), nice visuals credited to well-known authors, and a beautiful speech (your neutral accent and calm intonation are so refreshing compared to the annoying voices in many other channels). I'm definitely subscribing and looking forward to the next one! Edit: also no clickbait, thanks god, it's becoming so rare these days

[@unvergebeneid]

Dyson swarms aren't just possible, they're inevitable. I don't care what goals you have as a species, the means to achieve these goals is energy.

[@zacharythomas8617]

I have cash, how do we get started?

[@unvergebeneid]

@@zacharythomas8617 I wouldn't begin with space solar before you've covered the earth's deserts in solar plants. Then, maybe a bunch of satellites in earth's orbit before you go for a solar orbit. Maybe energy-only, maybe some smaller habitats first before you go full O'Neill cylinder. Not sure how deep your pockets are. You might need to build up all the space infrastructure yourself if you want to move fast. There's nothing there yet.

[@drewastolfi6840]

Ha. What's inevitable is global climate change, if our civilization doesn't collapse then we might get there. I got my doubts.

[@unvergebeneid]

@@drewastolfi6840 okay sure but you realise we're talking about this not in the context of our one global civilization and our one species but in the context of the Fermi paradox and galactic timescales? BTW, I find the concept of planetary limits very useful. Look it up if you haven't heard of it. It's like intersectionality but with all our ecological problems. Climate change is but one part of it.

[@ahklys1321]

Sir, please I beg you, take a deep breath, then take 10 slow breaths with your eyes closed. Feel better now right?

[@reynoldsmathey]

I like the idea of a cloud of energy-harvesting structures and habitats better than a solid sphere. It would eliminate a lot of the structural engineering problems and allow for continuous reconfiguration and adjustment. Brilliant video, as always.

[@toddablett4493]

Very cool and well done video again. Thank you. I checked the merch shop, where is my "stay thoughtful, stay curious" t-shirt? 😎

[@CoolWorldsLab]

Working on it!

[@toddablett4493]

@@CoolWorldsLab make sure it comes in black and it will be worn in my robotics lab as soon as I can order one. 😀

[@bigblueshoe777]

Thank you for mentioning Stapledon's "Star Maker!" It's my favorite book!

[@bigblueshoe777]

Oh my god, you showed a Xac video too! They deserve more subscribers!

[@invader_jim2837]

I've always wondered; if a civilisation is already advanced enough to make a "proper" dyson sphere, do they even need one at that point?

[@NuclearWinter7693]

We have the technology to make a proper nuclear/natural gas/coal power plant, do we need them?

[@invader_jim2837]

@@NuclearWinter7693 No.

[@NuclearWinter7693]

@@invader_jim2837 when you ride a horse over here and hand deliver a letter written on papyrus, I’ll believe you mean it. Otherwise, I assume you agree that a functioning economy and society by the rules we understand today requires continually expanding energy sources.

[@invader_jim2837]

@@NuclearWinter7693 Nup

[@GerdRiechers]

Tops! This is absolutly one of the best ever. No hockus pokus but clear science at its best. Thank you for your brilliant work. Interesting and fascinating.

[@emzywillrich7243]

Dr. Kipping, you are maintaining your Superstar status! Great video!!

[@NeWx89]

I'm glad seeing Stapledon be mentioned. Last and First Men and Star Maker are some of the most extraordinary works of fiction ever written.

[@bodrujzaman3854]

Scotty was living on that dysonsphere his own damn self. What a king!

[@Libertaro-i2u]

It is possible to build two kinds of Dyson sphere, the Dyson swarm and a version I'll describe below. A Dyson swarm is a hypothetical collection of spacestead habitats and solar satellites around a star that forms a "cage" or "screen" around it. The orbits would have to be maintained artificially such that the satellites can orbit in really close proximity without collisions. The second Dyson sphere type would have actual rings, the route taken could be the Niven style ringworlds with one continuous ring taking up an entire orbit. Alternatively, chains of bishop rings could be built. A bishop ring is a spacestead concept that would be a scaled up version of the Stanford torus (several hundred or thousand km wide vs under 100km wide), so big that it wouldn't need a roof to immure an atmosphere, and large enough to contain several continents worth of habitable land, and while bishop rings would rotate to get artificial gravity, they wouldn't have spokes like Stanford toruses would. Thousands or millions of these bishop rings could be built such that they link together like a chain. The resulting chain would be hundreds, thousands, even a few million times bigger than Earth in terms of habitable surface area. Multiple such chains could be built at different angles to form the sphere, the rest of the sphere could consist of solar strips.

[@PinataOblongata]

Damn, Prof has put on some stellar mass. Star lifting? More like bar lifting! I'm impressed anyone with the amount of academic work Kipping would be doing during a week can still find the time to consistently get in the gym. 💪

[@ivoryas1696]

@PinataOblongata Huh... Good point! 👏🏾

[@luiousy7329]

He is hot

[@Delibro]

@@luiousy7329 I wonder to don't see more such comments. While being hetero, he sure is hot.

[@UteChewb]

Great to see Olaf Stapledon's "Star Maker" get some recognition. A truly amazing book going way beyond things like Dyson spheres. Despite being almost 90 years, at times it still reads like an inspired vision of the future. Probably my favourite science fiction work, in its own category above all other novels. Also the issue of instability of a solid sphere. When Larry Niven wrote Ringworld, about a ring equivalent to a Dyson Sphere, fans realised the ring was unstable and MIT students told him about it publicly, he then went and wrote The Ringworld Engineers, about how you would solve that.

[@haroldfloyd5518]

I think something like Larry Niven’s Ringworld is more likely, and the reason for building it is obvious: room! A ring half as wide as earth extending the entire orbit of earth would have thousands, maybe millions of times as much surface area, all pointing sunward every hour of every “day”.

[@bricefleckenstein9666]

A Ringworld needs a material (the scrith) that is still a couple orders of magnitude stronger than ANYTHING we can make today. There's also some question if we'll EVER be able to make anything as strong as needed. A ring swarm though MIGHT be possible.

[@360AnimeList]

Can you also make a video on how can we preserve our planet! How long can humanity live on Earth? Before touching the star, let's see the Earth first.

[@NewMessage]

"It's a sphere, Jim... but not as we know it."

[@annoyed707]

With Klingons off its starboard hemisphere...

[@patricksweeney1924]

Dammit, Jim! I’m a DOCTOR…not an orbital physicist/engineer/stellar OR materials scientist! 😅

[@RobertSmith-wj7zf]

"I'm a doctor Jim, not an actor!"

[@TheTraya]

I just found your podcast with Lex. Yesterday, what a great addition to continue the fun!

[@eddieanarchy]

If you have the tech to build a Dyson Sphere, you don't need to build a Dyson Sphere, unless you're bored.

[@thelaughinghyenas8465]

I could see a Dyson swarm being very useful in mining.

[@stephenlavelle5369]

Maybe a suitably advanced civ thinks in the extreme long term which would entail being very economical with matter and energy?

[@AbeDillon]

I absolutely hate this quote. First: I don't know where people get the idea that Dyson swarms require super advanced tech. They're actually quite simple. We have the tech to build a Dyson swarm today. It's concievable that we could build a Dyson swarm within about 1 century. (If you want, I can show you some back-of-the-napkin math) Second: What does it even mean to "need" a Dyson swarm? How long do we "need" to survive into the heatdeath of the universe? How many brain-hours are we going to "need"? How many entities do we "need" to sustain? Interstellar travel and space mining both become much easier with Dyson swarms. It's actually harder to imagine how we would manage interstellar travel without a Dyson swarm.

[@JonnoPlays]

Exactly. Unless you plan to live on it then maybe.

[@bobbybrown1258]

​@JonnoPlays exactly? Justify? Why would the most efficient way of generating power ever be superfluous? With our current understanding of physics it is the best possible way of generating power. Unless we discover some form of exotic matter some from of Dyson sphere will be the best form of power generation

[@raymondcarter1137]

Short answer is no….it’s literally impossible to make a Dyson. Unless you can create material from nothing then no it’s not possible or even desirable.

[@micdavey]

Aside from technological capability, host species lifespan is probably the most prevalent reason artificial habitation spaces wouldn't get built, especially if we assume that evolutionary theory applies universally. I mean, it would take thousands of years just to built an orbital ring that's even a mere million kilometers in diameter, let alone one big enough to encircle a star, and that's to say nothing of a swarm or complete sphere. The time frames for any conceivable biological species to build one are just too long to hold robust consideration of actual construction.

[@NickyBlue99]

💯

[@MyNameIsSalo]

That's assuming we don't extend our bodies to live forever. It's actually pretty easy to do and we are moving towards it very quickly. Make a digital copy of your brain, save that brain on a central server, then download it to whatever electronic body you want. Once that digital copy of the brain is made, you live forever. Data can be backed up and duplicated infinitely. Runs into some ..ethical concerns. But that's the price of immortality.

[@chrisrendon461]

@@MyNameIsSalothe what if game lol

[@patrav2394]

Thank you for posting a great video as always. Dyson spheres/swarms I think are likely to be the ultimate method of power generation for an interstellar / intergalactic civilization. Stars are numerous, and they are practically just free fusion reactors for the taking. I agree with your line of thinking that the universe is basically an infinite sandbox. Perhaps as soon as humanity discovered science, we were doomed to conquer the stars.

[@illogicmath]

In my humble opinion a solid Dyson Sphere is simply impossible even for a very advanced civilization. It's better to have a swarm of solar panels in orbit around the star to collect the maximum possible amount of energy and transmit it to their planet or planets

[@derekflegg2510]

Build one around the event horizon of a singularity #DysonsHole #thinkbig

[@scottbullock3045]

That was my question. A solar flare or prominence would vaporize that part of the dyson sphere, wouldn't it?🤔

[@cabanford]

These are my favorite types of Cool Worlds content. Please more (along with the rest 😉)

[@warriorpitbull1170]

Best YT channel, by far. Thanks again Dr. Kipping. I never tire of your content. It's always fascinating and thought provoking.

[@sanzyboy3952]

You can just use self replicating nanomachines similar to dna to build a complex structure like this

[@yatharthpandey2701]

"The physics may be theoretical but the fun is real" one of the hardest lines dropped by a physicist 🔥

[@jimmyzhao2673]

*Wow* That intro gave me chills !

[@Valandar2]

One of the creepiest ideas related to Dyson Spheres is the idea that the Bootes Void, a massive, nearly spherical region of space with few to no visible galaxies, might be a trans-Kardashev 3 civilization expanding, and encasing entire galaxies in countless Dyson Spheres. It would explain the absolute lack of visible stars present in the region, as well as its nearly perfectly spherical shape - this hypothetical K3 civilization expanded outward, and "Dyson-ized" everything as they expand.

[@jedi9577]

Active support allows for the construction of a sphere with a much thicker shell by removing the compressive strength limit.

[@skynet5828]

Someone has been watching Isaac Arthur.

[@feynstein1004]

@@skynet5828 Haha my thoughts exactly

[@AbeDillon]

One could argue that a swarm is a form of "active support". The destinction really is a subjective matter. You might consider building a ring around Earth at much lower than geosyncronous orbit and actively supporting that ring with an magnetically confined inner ring that spins fast enough that it pushes on the outer ring to suspend it. You could then tether the outer ring to the earth and build an actively supported space elevator. Only, you don't need the outer ring to be a full ring, do you? You can remove the parts of the outer ring so that all that's left is where the space elevator "spokes" need to be supported. And you don't actually need a full inner ring, do you? You can chop it up into chunks so that each spoke station gets its support by just redirecting a stream of massive chunks to eachother. In fact, you could possibly replace the whole inner ring with a particle beam, though that gets much more tricky because charged particles like to push away from eachother, so it'd be difficult keeping the beam focused unless you used some sort of reletivistic ion beam.

[@shantiescovedo4361]

@@AbeDillonYou are my new favorite commenter on Cool Worlds videos.

[@erichtomanek4739]

To build a Stapledon Sphere is easy as. As for a sun, well, don't have a natural star but an artificial fusion star. It doesn't need to be as large as a pesky natural star. To keep it in place, build 6 towers, at right angles to each other, that meet in the centre of the sphere and incidentally, the centre of the artificial star. The thickness of the sphere, or shell, say 10 kilometer thick. This means you can pack in dense material to create a gravity of any value you desire. I personally like Terra's.

[@pbinnj3250]

I’m missing something. 1. How do we get energy from it? 2. Since we don’t have stars volunteering for entombment, or even close enough to use, shouldn’t the engineering question of “what are we really talking about here?” be part of the can we build discussion?

[@massimocole9689]

You can beam the energy via microwaves or lasers. And in the case of swarms of habitats or computers the energy is used on location, so you don't need to transport it. As for which star to use, these are mostly plans for what we would do with the sun. A swarm of solar sail power collectors hovering over the poles on radiation pressure would leave the equator clear for light to still reach earth. Or a more distant swarm of cold computers wouldn't effect light levels on earth cause they would be farther out than earth.

[@pbinnj3250]

@@massimocole9689 cool. Thanks.

[@MadScientist267]

It's one of those utter wastes of time, energy, and thought rabbit holes. File it with warp drive, teleporters, time travel, and overunity, among others.

[@TylerTheTiler]

Einstein once thought that harnessing the energy within the atom would impossible.​@@MadScientist267

[@pbinnj3250]

@@MadScientist267 I feel more charitable. It’s a thought experiment about what it would take to do something, even if not practical. Yes, it did strike me as just silly speculation at first, but it does enable scientists to walk through technical aspects of the idea to see which parts could work with the science we have. They say up front it’s inspired by science fiction, similar perhaps to the communicator in Star Trek inspiring the cell phone. So yes, it’s a flight of fancy, but working out impractical problems can lead to interesting results. (One example might be materials science resulting from working out the physics of tensile strength needed for large spheres in space.)

[@beskamir5977]

That transition at the start of the video was epic! Nicely done. Finally watching this video and I saw your community post about these latest videos not doing well enough. I think that's partly because a lot of us are nerds and know these topics already, I'll be playing this in the background while doing something else since I doubt I'll see anything new in it. Edit: Okay, that had a bunch of info I hadn't come across before.

[@DæmonV86]

0:20 - Riker missed a great opportunity for a 'yo momma' quip there.

[@cmdrTremyss]

Mr Dyson was such a humble gentleman. RIP Legend.

[@DustinTuberville-n3s]

That's cool stooped ppl

[@Sunnanandi]

Trust me, a Dyson Sphere will never enclose our Sun. Even a Dyson Ring will never happen either (a Dyson Ring is a vertical band of real estate encircling the Sun like a wall, whereas Saturn's rings are very thin radial planes). Simply put, there is insuffucient spare building material in the entire Solar System to create such fantastic structures. The material that makes up Saturn's rings all together would only amount to the volume of a few small moons, so what do you propose to use to build Ringworld, a continuous ring with a mean diameter of 300 MILLION KILOMETRES? Suppose the sectional area of the ring is a mere 200 km wide by 10 km thick. Now multiply that by Pi (Pi = approx. 3) times the diameter = 200 x 10 x 3 x 300 MILLION = 1800 BILLION CUBIC KILOMETRES. A cubic metre of concrete weighs at least 2000kg and a cubic kilometre of concrete contains a BILLION cubic metres and weighs 2 TRILLION kg, so the entire ring would weigh 2 TRILLIONkg x 1800 BILLION = 3,600,000,000,000,000,000,000,000 Kg, which is more than half the estimated total weight of Planet Earth.

[@tealkerberus748]

So you're saying that just by using earth, without harvesting the moon or any other planets, we could make two of these? Sounds cool.

[@kaufmanat1]

so we could use venus?sounds good to me.

[@IrishRhapsody]

Actually, Mercury would be the most suitable candidate for use. Abundant in iron, big-ass core, probably just enough for a sizeable swarm.

[@prjndigo]

Short answer: no. Long answer: no. Involved answer: no, kaboom. Highly detailed answer: Its an exceptionally stupid idea... like trying to run an experiment to see if blowing up your tank makes it immune to explosives. Due to the way space time works its only possible if you don't build it around a star because the star's existence will push the star to one side of the sphere no matter what you do. Exceptionally precise answer: stars won't let you put them in boxes, they're actually proton induction motors.

[@ZlothZloth]

Well, not according to the video. It might be right, too. If the star is somehow exactly at the center, everything cancels out. Move the sphere a little bit 'down', though, and the pull between the bottom part of the sphere and the star will be stronger than the pull between the top and the star. However, because the star isn't centered any more, some of the sphere that is in the bottom half is now above where the star is, so that part is now pulling upward instead of downward. According to the video, the two factors cancel each other.

[@feynstein1004]

I find the Dyson sphere thought experiment to be quite interesting. In particular, if you had a perfect Dyson sphere that could reflect all of the energy of the star, you're basically cut off from the rest of the universe and you stop interacting with it, meaning eventually, your local patch of spacetime will reach thermal equilibrium (way earlier than the rest of the universe) and every point inside it will be the same temperature. At first I thought this would be the same temperature as the star but I think it'd be slightly lower because the star's energy is now spread out over a larger area. TLDR: A perfect Dyson sphere is a fun way to experience heat death 😅

[@tealkerberus748]

If the total energy output of the star is not released as heat through the surface of the sphere, it's going to heat up inside until everything melts and it explodes. They're not using up the energy of the star, they're just using the conversion of high-value energy to low-value heat.

[@feynstein1004]

@@tealkerberus748 I don't think so. The star is at an equilibrium between pressure and outward expansion due to fusion. If the energy were unable to escape, this would lead to an increase of outward pressure, which would then cause the star to expand and fusion to stop.

[@MyNameIsSalo]

@@tealkerberus748 No, this was discussed in the video. The dyson sphere can be fully reflective (other than absorbing what energy it needs for consumption), and that reflected energy back to the star causes it to turn redder and grow in size eventually reaching some equilibrium point with the dyson sphere. The dyson sphere can completely black-out everything outside of it.

[@theograice8080]

That was an AMAZING opening transition!

[@Kombrig_2]

I always new that Dyson Sphere is physical absurd. You should to mention, David, that there is simply not enough matter -- to build even a ring around a star 1 m wide and 10 sm thick. Even if you deconstruct all the planets & asteroids.

[@CoolWorldsLab]

This isn’t true, we give the required mass values in the video

[@tedigrizli]

Wow the closer / outro was magnificent! Thanks for that, subscribed!

[@charlesmaurer6214]

You should incorporate a photo of yourself into your logo. Most AI or cloned channels use two tone or b&w logos like yours leading many to hit the do not show tab, including myself. The topic was just enough to get me to take a single look as I almost lumped you into the clickbait trash bin. Simon and Degrass are two that do get that trash bin often as does a few I even follow if it is off the main site. Any fox news post not from fox news direct gets trashed too. Not a bad presentation and not much new I haven't heard before as I do follow the topic since youth. Just think you want to avoid being tossed into the AI trash bin.

[@Jason-gq8fo]

Ngl I never thought that it would mean a solid sphere. Seems so much more impractical despite being possible as you say today

[@scottyk1763]

Never have clicked on a video so fast

[@Facts_vs_Opinion]

Haaaaaa - same!

[@feynthefallen]

The idea of a gossamer thin Dyson sphere is so ingrained in my brain I actually had great trouble comprehending what you meant by "solid Dyson sphere"

[@alsecen5674]

The materials and manufacturing required would be insane. Ican't see why any civilization that could mine away an entire planet and produce the material for a sphere would ever need it.

[@AbeDillon]

It's just a bunch of sattelites. We already have a rudimentary Dyson swarm simply by putting satellites in orbit around the sun. What part of it would require insane materials or manufacturing? You also don't have to mine an entire planet. You could use Von Neumann probes to mine the asteroid belt and get enough material to build a swarm that captures somewhere between 0.01% and 1% of the sun's output depending on several factors. With that amount of power things like interstellar travel at reletavistic speed become possible. Also, once you've "primed the pump" by building a swarm large enough to capture 0.01% of the sun's output, dismantling something the size of mercury becomes trivial, then you have 100x more material than you got from the entire asteroid belt. It forms a feedback loop where it gets easier and easier to build a more "complete" swarm as you build the swarm. I put the word "complete" in scare quotes because you can never capture 100% of the sun's output. The best you can do is build a swarm that effectively captures all of a star's photon flux, but that swarm will heat up and release black body radiation of its own, so you can build another swarm around it to capture that black body radiatioin and so on. That's called a "Matryoshka brane" because it's like a Russian nesting doll. As for why any civilization would "need" so much power. I never understood that point. What does a civilization "need". What does that even mean? Do we really "need" billions of people? Do we "need" to expore the universe? How long into the heatdeath of the universe does a civilization "need" to survive? I mean, did you hear the part about the Landauer limit? We're pretty close to unlocking the potential of synthetic biology which is really just a bootstrapping step to generalized codified molecular self-assembly. At that point, it would be trivial to make a Von Neumann probe the size of an acorn that could mine the entire asteroid belt in a hand-full of decades. Like, this could be a reality IN OUR LIFETIME, then the question goes from "why?" to "you mean I launch this acorn to the nearest asteroid, wait three to four decades for it to do its thing, then I have a Dyson swarm? why the heck not?!"

[@peterd9698]

Exponential growth? It fills basically anything. If FTL were possible humans could populate the observable universe and beyond in just several tens of thousands of years. For sure, more advanced races may possess wisdom that current life has never demonstrated, and every single one might choose not to do that. Who can say.

[@Napoleonic_S]

beings like us would just try that for the novelty and the LOLs, just like someone like us, if not one of us in the future, will actually jump into a black hole for the LOLs.

[@bastiaan7777777]

@@peterd9698 If were possible. There you go. If. May. They may have the wisdom that there is no use to travel. What is in the void?

[@MrCmon113]

Why would you piss away nearly 100% of the available energy?

[@lonemaus562]

In reality you would need a Dyson sphere to create a Dyson sphere. It requires to many resources and energy to make you would need a class 2 type of civilization

[@daverudd-zt3ob]

Believe that is what he is alluding to. A point for an advanced us where the earth is no longer even a factor.

[@robsquared2]

Then some company started making vacuums and ruined it.

[@alexstewart9747]

Fools don’t realise how big a star actually is. There wouldn’t be enough metal or similar material. That’s why it’s science fiction.

[@spw947]

I’ve said the exact thing.

[@Chris.Davies]

The Dyson Sphere rule always applies: IF YOU CAN BUILD A DYSON SPHERE, YOU DON'T NEED A DYSON SPHERE! It is the single dumbest space-idea of all time. For a plethora of reasons.

[@zacharythomas8617]

Negative, it. Will happen.

[@greggbenson8880]

I wish you would elaborate on that idea.

[@RMadmarksman]

Elaborate on those reasons please, cause ur statement is null and void without them. You can't just state "for a plethora of reasons" and not even give at least three or even one. So yeah, I'll wait.

[@desperado3236]

Maybe as a solid sphere (but even then it's still worth it, we get more energy out of it then we put in and extend star life) However, who says it has to be completely solid? We can do it in a form of a swarm of solar panel satellites or some sort of O'Neil cylinder rotating contraption with gaps. (I forgot what they're called) Hell, we have the tech to do swarms now. Just not tech to bring the energy back efficiently.

[@impreza0109]

"If you can build a plane, you don't need a plane." See how stupid that sounds?

[@chrislong3938]

6:30 - It's all Greek to me!

[@XL-5117]

1. How would you make one? 2. Where would you get the material from? 3. What would be the motivation be? 4. What kind of intelligence/ civilisation would do this? 5. Why 6. Why 7. Why………..

[@archimedesnation]

Yeah, it's a nice thought experiment but no more than this. If you have the tech for a DS then terraforming, generation ships, orbital habitats and such would be far more cost effective.

[@bastiaan7777777]

@@archimedesnation Why even bother travelling to some distant galaxy where there is nothing?

[@archimedesnation]

@@bastiaan7777777 Ehm, I didn't write anything about travelling to other galaxies but... how do you know "there is nothing"?

[@bastiaan7777777]

@@archimedesnation Ok, so travel to where...? Just look at what we humans have observed out there; what is worth going to? And why?

[@MrCmon113]

​@@archimedesnationYou're talking pure nonsense. Effective at what? You're pissing away nearly all available energy. After "terraforming", you're still pissing away nearly all available energy. Also to do such a vanity project would be much easier if you had more energy... It's like saying "instead of going to work, it's much more effective to buy a villa".

[@KingsMom831]

This is one of my favorite astronomy channels! Thank you Professor Kipping & your team!😊

[@shantiescovedo4361]

What are your others? I enjoy Anton Petrov mostly, but Cool Worlds is my favorite.

[@KingsMom831]

@@shantiescovedo4361 Me too! Melody Sheep, Damon Scotting, Astrum…. Some of my favorites.

[@shantiescovedo4361]

@@KingsMom831 I watch Astrum, but I don’t know the others. I am excited to look them up.

[@KingsMom831]

@@shantiescovedo4361 Awesome!! Lmk what you think!

[@Penguin5z]

I'm pretty sure my friends girlfriend believes dyson spheres are real and are actually biblically accurate angels in space. lol smh

[@Andromedon777]

I guarantee she doesn't believe that and you're making it up for the likes.

[@tamaragriesel4783]

The big question with the solid Dyson sphere is why bother? If a Dyson swarm will give you the same advantages with fewer disadvantages, why not just do that instead?

[@adammanneh4692]

I wonder what humanity could achieve, assuming we last even a 1000 years from now...

[@micahlovejoy81]

We could achieve a lot now if we put our petty differences aside. Humanity’s worst enemy is itself

[@adammanneh4692]

@@micahlovejoy81 couldn't agree more!

[@m.pearce3273]

Humans in 1000 years at a biological bottleneck as less than 200000 indigenous is all that's left

[@MofoMan2000]

We are the stewards of our own future. In a few thousand years we could begin to colonize the galaxy. The problem is we have to avoid killing ourselves (or our progress) in the meantime. Even if our societies don't collapse on their own, we only have so many resources on this one tiny, insignificant planet. You and I won't live to see it, neither will our children or grandchildren. But if we succeed, we'll finally leave this miserable rock.

[@FieelFlying]

​@@MofoMan2000miserable rock?? Wtf? We literally live on the best, most beautiful and fitting planet for our species and you refer to it as miserable rock?

[@seanspartan2023]

I imagine a Dyson Swarm of self-repairing robots each capable of collecting the sun's energy and beaming it to depositories in orbit around the planets. Mercury could be a factory and materials site. The whole process could be automated and collect a high percentage of the sun's total output. Combine that with fusion reactors and energy would be nearly inexhaustable.

[@NickyBlue99]

Sounds like magic

[@johnlord8337]

Dyson spheres while conceptual are infinitely impossible. Encapturing the entire sun and solar system inside it - requires the entire natural resources of all planets, moons, asteroids, and meteors inside the solar system be converted into the sphere shield. Otherwise, if you put up a smaller sphere, with outside orbitting planets and moons (which is not a pure Dyson sphere we are told to think about with an entire solar system encapsulated). If one made a Dyson sphere around the M zone (habitable zone of Earth), one would STILL have to convert, rape, destroy, and make the sphere from all the inside planets and moons, the asteroid zone, even the Moon (!), and take Mars, Phobos, Daimon, ... and many of the moons of Jupiter and its orbital belt making the sphere. So there is no rational reason for making a Dyson sphere, even putting solar cells on the sphere inside, or a mylar reflective coating for even further solar albedo light bouncing is also quite insane. So nope, nope - say no to dope !!!

[@johnlord8337]

And all those coronal mass ejections happening and flaring out and slamming into outer planets, moons, and the eventual sphere surface ... all this would be destroyed, let alone daily irradiation of thermal, radioactive, and radiowave broadcasting that would degrade the very essence of a Dyson sphere surface.

[@firedragon77777]

No, just no. For starters you'd only need maybe half the mass of mercury to make a standard dyson habitat swarm of mostly o'neil cylinders. The obvious benefit is the sheer population numbers you could sustain, literally quintillions. For a mere power collector swarm of mostly mirrors and a few solar panels you'd only need a large asteroid's mass.

[@firedragon77777]

​@@johnlord8337Solar flairs are of minimal concern, we cam already shield against that.

[@gravoc857]

You only need part of Mercury.

[@skynet5828]

For a dyson bubble around Mercury's orbit you would only need 10^20 kilograms. So you only require a large asteroid's worth of material in order to build a bare minimum dyson sphere.

[@NikolaosSkordilis]

That was a more fascinating video than your usual ones, due to its positivity. I was almost certain you were going to exclude the possibility of Dyson/Stapledon Spheres, like you did with FTL travel and time travel. Yet you didn't. Not even their solid variant. Thanks for keeping the stellar dream alive 🙏🏽

[@mglmouser]

Considering there's not even enough material in our own solar system to even make a Dyson ring, it's highly unbelievable to envision making one, less even a Dyson Sphere unless you pull in material from some nebula or even other star systems.

[@fn0rd-f5o]

Someone able to do that likely can "print" matter. I don't really know how to make Hydrogen atoms from scratch but I could imagine that they do.

[@mglmouser]

@@fn0rd-f5o if you can materialize atoms from scratch in such quantity as to make a Dyson-something, you probably dont need to make a Dyson-something for your energy and material needs. I find the Dyson concept a bit farcical. Other than vacuums.

[@Arvandor81]

Starlifting would provide all the material we need.

[@adamwu4565]

There's plenty of material, actually. At the thickness needed as described in this video, a full Dyson Sphere with a 1AU radius would only need about 0.5 Mercury mass worth of some reflective metal like iron. Which Mercury basically already has in its over-sized metallic core. You need a bit more if you want to add some thicker installations on or around the sphere for things like habitats and such, to make use of the captured energy, but if you're using the Sphere as a computation device, as suggested in this article, you don't really need a lot of those, as your computational hubs can be heavily miniaturized too. It's only if you want to make the entire inner surface habitable to 70kg meat-bag humans that you run into the exorbitant material requirements. (Even then, you can get enough by starlifting heavy metals out of the sun itself, though this would take you some time). If the majority of your surface area is thin reflective light collectors and sails, the material requirements aren't onerous, at least relative to the total resource availability of a Solar System. It's still ridiculously hard for someone at a similar level as we puny 21st Century Earth humans, of course.

[@feynstein1004]

@@mglmouser Bro just casually violated mass and energy conservation to make a Dyson sphere, not realizing that the entire point of the sphere is to overcome the energy scarcity caused by mass and energy conservation 😂😂😂

[@davidtatro7457]

I think this might be the most fascinating video you have ever produced thus far. It's not your most beautiful, relevant, or poetic video. But it might be your most mindbending. Thank you so much for all of your wonderful content.

[@shantiescovedo4361]

I especially like the Bayesian statistics videos on the likelihood of complex life, but this one was very good.

[@beanwithbaconmegarocket]

Physics homeboy here has definitely been testing the effect of gravitational forces on large circular objects. Specifically how those impact the body's ability to get yoked.

[@aracoixo3288]

Phazer

[@FirestormX9]

Love the video, Professor! Infact i got some more CW vids in my playlist right now haha but starting with this. However, it'd be just wildly awesome if there were some way to help understand the formulae faster through that segment of the video itself! Already understand the insane oversimplification this might require considering there could be a multitude of parameters going into the construction a formula. Really glad this topic was covered by CW!

[@Ralph_Cornell]

One of the biggest problems in constructing a Dyson sphere is the question: where to get the material from? The amount required exceeds the material available on all the planets in a solar system. What would be possible instead: constructing a ring world as devised by Larry Niven.

[@quentinreid3111]

A couple things you mentioned, particularly extracting material from the star to manipulate its behavior, and smaller cooler stars requiring smaller less resource intensive structures, brings some ideas to mind. Rather than harvest local planets for materials, or maybe in addition to, we could harvest material from the star itself to build out a Dyson structure. This reduction in star mass would cause it to shrink while the structure built around the star would reflect energy back and partially counteract that effect. It may theoretically be possible to make the star smaller, cooler, longer living and easier to build a structure around, all while contributing to the building of said structure(s). This idea also partially comes to mind from a description given in a sequel novel written for The Time Machine titled The Time Ships. In it, the future descendents of humanity constructed massive ships with magnets that circled the sun. They used a magnetic field to siphone material from the sun and used said material to construct a shell around the star.

[@MyNameIsSalo]

Don't really know how you plan on harnessing material from a star. They're a bit fucking hot and devices we could make would burn

[@stephanieparker1250]

Thank you for another fantastic video.. so grateful you are on KZbin!

[@stevec7923]

Technical point. If you need to gently tug the sphere to keep it centered around the Sun, there's no need to use laser light. You simply slightly modify the opacity/reflectance of the material on one side, allowing the Sun's photons to be the ones to escape asymmetrically. Net photon pressure within the sphere is thus biased to one side, pushing the sphere away from the sun's approach. Much easier than lasers, and uses far more widely dispersed and gentler force.

[@KingBritish]

Good evening David. I've decided you ARE the best space channel on KZbin despite how good some of the others are!.

[@JohnDerhammer]

The key to maximizing reflectivity is in the alloying process. Silvering glass isn't just a hodgepodge curiosity. It a painstakingly tedious process involving countless hours of selecting the correct silicon dioxide with which to process into reflectors.

[@dr.zoidberg8666]

I think a more provocative & perhaps more realistic imagining of the future comes from a different interpretation of the present. The common way of seeing things is that humanity long languished in stagnation, but once we unlocked the steam engine & later electricity we've begun our inexorable rise to infinity. That we've finally begun to grow & will continue to do so for millenia. A different way of looking at it is that we are currently in a transitional period going from one stable state (pre-industry) to another stable state (post industry) & that all of this rapid growth is only a symptom of that transition & may only last a little while longer. Demographers have long expected population growth to end this century. Wealthy nations ran out of room four natural economic growth in the '70s & '80s (we now simulate it with financialization, debt proliferation, planned obsolescence, just-in-time logistics, etc.) Even technology such as AI is running out of runway, with AI companies finding that there is not enough content on the entire internet to improve their algorithms. So, what if instead of a bright future where we keep consuming more & more & more, we actually have a bright future of equilibrium. Where everyone can live a comfortable enough life that we need no longer to sacrifice to the god of growth. Maybe we don't see any Dyson spheres because nobody needs them.

[@MrCmon113]

That's nonsense and would be deeply dystopian. Do you think the best possible world contains only 10 people, who live lives that are barely worth living? That's basically what you're idealizing. Tons of problems aren't solved and unimaginable amounts of amazing lives not lived when there is no "growth". Being against "growth" is just like being for the destruction of nearly everything that is. Imagine a galaxy of a sextillion unimaginably happy entities. And you come in and murder nearly all of them and make the lives of the rest worse.

[@sjzara]

What a wonderfully optimistic video.

[@adamwu4565]

When it comes to the engineering challenges of something like this, there are both known unknowns and unknown unknowns, any one of which could turn out to be an absolute showstopper. On the other hand, there could be unknown unknowns that actually end up making the project EASIER to accomplish too, that turn engineering problems which we currently think are very hard into something much easier.

[@QuantumMechanicYT]

@@adamwu4565 The "funny" thing is that the video discusses the (very) speculative option of an ultra-thin Dyson sphere, which requires disassembling Mercury for materials and clearing out the whole solar system in order to have a hope of it being gravitationally stable, while there are already better options (e.g. Dyson swarm) available.

[@Hakaze]

Regarding temperature and reflecting photons, remember that the point of the object is to harvest energy. It might through tech unthought of, absorb everything the star puts out, and be super cold, even if closer to the star

[@justincosta89]

I enjoy every video you put out. I appreciate the time you and your team put into these explanations. Hopefully your videos are played in classrooms similar to how Bill Nye videos were used to encourage learning science in the 90’s.

[@sliverfoxer]

Thanks for the great video! I think the main problem with dyson's sphere is why would anyone build it. The energy argument to me sounds similar when pre-car era people were asked about the future of human transportation and they replied "faster horses". If a civilization is advanced enough to even consider building a dyson's sphere, they are not in the need of solar panels. Even us humans are (hopefully) a few decades away from fusion energy which would essentially bring the star to us and then we wouldn't need solar panels either. I think it is quite silly to argue that civilization hundreds or thousands of years ahead of us in technological development would do it for the solar energy. They will produce their energy in ways we cannot even imagine and the argument for solar energy as the motivation for dyson's sphere is just "faster horses".

[@sjzara]

They would build it because the energy can be used for grand projects, such as launching missions to nearby stars.

[@mojojoko]

Solar panels are fusion energy. Building stars is way harder than using the one you already have.