What it Takes to Build a Dyson Sphere - Ask a Spaceman!
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- เผยแพร่เมื่อ 19 ต.ค. 2024
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What are Dyson spheres? What would be involved in building one? How much energy would it cost, and could we ever pay it back? I discuss these questions and more in today’s Ask a Spaceman!
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Keep those questions about space, science, astronomy, astrophysics, and cosmology coming to #AskASpaceman for COMPLETE KNOWLEDGE OF TIME AND SPACE! Music by Jason Grady and Nick Bain.
Completely unrelated topic...Larry Niven wrote a book called Ring World in which a civilization built a ring around its star and moved everything off planet and was able to capture a sizable portion of the star's energy.
I read the book many years ago and some of the details are fuzzy to me now, but I remember that he went into some of issues and problems that went along with the project.
I do remember that it was an interesting read in my younger years.
Anyway, it's just a thought
Yeah, I was stunned after reading that. I lent my copy to a friend who was a physics teacher. He basically sat for three days, not moving, mouth open, just staring and probably thinking.
It is my firm belief that by the time humanity would be capable of building a Dyson Sphere there would be far more efficient ways available to produce energy.
Agreed- or perhaps rather than making more room, we shrink humanity and create avatars or some other computer generated way of life. Its interesting to see that in 60 years, the ideas went 180 degrees from massive mega living structures to theorizing about people being created as computer simulations.
That's nonsense. How can letting light escaped be more "efficient" than using it?
Maybe a more interesting question is: how energy feasible is it to make a single "panel" of a Dyson swarm? If the *that* isn't too bad, then we could build them slowly at first, but as they start to pay off feed that energy back into construction. Build rate goes up exponentially as energy production goes up. Very simplified view of course, there's still the whole engineering and logistics challenges involved. But purely on an energy argument I'd be curious to see if that makes it more possible.
Yes, all that matters is whether or not you can build and launch one solar collector that pays back energy in a reasonable amount of time. If you can do that, then you can build a dyson swarm. The only question is how much time and effort you want to put in to doing it.
But that's not to say it's easy, it takes a lot of energy to build and launch anything into space, much less something that needs to last for thousands of years.
What I know about the Dyson Sphere, I learned on Star Trek TNG. My one question was, wouldn’t the captive energy given off by the star accumulate and eventually overwhelm the civilization inside?
Dyson Sphere's necessarily radiate in the infra red anyways.
Dyson orbitals ( Mini Moons hollowed out ) would be more feasible and economic .. they would protect you from stellar and interstellar radiation .. Set them up in LaGrange points and they could move if Sun acts up .. also use them for interstellar travel also
Paul, you are my hero. Many thanks for all the good brain food over the years.
I have to agree that the idea of a Dyson Sphere, while interesting, is simply not the direction any advanced civilization would go. It would be more feasible to build O'Neill cylinder space colonies.
I'm sure you are familiar with the concept, but for others reading the comment, I'll include this expanded description, courtesy Wikipedia:
An O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicist Gerard K. O'Neill in his 1976 book The High Frontier: Human Colonies in Space. O'Neill proposed the colonization of space for the 21st century, using materials extracted from the Moon and later from asteroids.
An O'Neill cylinder would consist of two counter-rotating cylinders. The cylinders would rotate in opposite directions to cancel any gyroscopic effects that would otherwise make it difficult to keep them aimed toward the Sun. Each would be 5 miles (8.0 km) in diameter and 20 miles (32 km) long, connected at each end by a rod via a bearing system. Their rotation would provide artificial gravity.
In his 1976 book O'Neill described three reference designs, nicknamed "islands":
Island One is a rotating sphere measuring one mile (1.6 km) in circumference (1,681 feet (512 m) in diameter), with people living on the equatorial region (see Bernal sphere). A later NASA/Ames study at Stanford University developed an alternative version of Island One: the Stanford torus, a toroidal shape 1,600 feet (490 m) in diameter.
Island Two is spherical in design, 5,200 feet (1,600 m) in diameter.
The Island Three design, better known as the O'Neill cylinder, consists of two counter-rotating cylinders. They are five miles (8.0 km) in diameter and are capable of being scaled up to twenty miles (32 km) long. Each cylinder has six equal-area stripes that run the length of the cylinder; three are transparent windows, three are habitable "land" surfaces. Furthermore, an outer agricultural ring, twenty miles (32 km) in diameter, rotates at a different speed to support farming. The habitat's industrial manufacturing block is located in the middle, to allow for minimized gravity for some manufacturing processes.
To save the immense cost of rocketing the materials from Earth, these habitats would be built with materials launched into space from the Moon with a magnetic mass driver.
The "space" of outer space is not empty. This space is full of balanced forces. Finding a way to utilize these forces could power the planet for eons ❤❤❤.
well, capitalism lol.
Skepticism is always beneficial. There are no situation where you should have "just believed". Nobody is beyond scrutiny.
Knooooo kno kno, kno it is a good idea Paul!
I hope you don't debunk star-lifting next, since that's an alternative answer to the question of how to use the Sun's fuel efficiently
A ringworld would be more feasible ( more feasible being just a step above impossible), just ask a puppeteer.
Orbital Dynamics Video. I’m feeling free to ask.
Every discussion about Dyson swarms I've seen (this one included) makes tons of terrible assumptions that drive me up a wall.
It really should be possible to create a Dyson swarm in a matter of decades with tech not much more advanced than our own.
First: Living space is almost definitely NOT the main concern. It's all about energy capture. I can provide a million reasons why, but for brevity, I'll continue.
The average size of each satellite would be absolutely dominated by a vast array of solar cells. That means the average thickness is about the thickness of a solar cell: ~100 um NOT 1-10 kM 😂.
I don't know why we would assume 10% efficiency when modern cells can be up to 47% efficient.
Most of all, I don't know why we would start with material in deep gravity wells when we have a whole belt of asteroids to bootstrap from with very low binding energy.
If we were to develop a "DNA-synthesase" protein complex based on DNA-polymerase except instead of reading a template strand and building the complement, it reads a signal and builds a corresponding DNA strand in-vivo, then we would unlock the killer app of biology: codified molecular self-assembly.
We would put the tools of synthetic biology in the domain of synthetic biology which would close a feedback loop triggering exponential progress. We could apply everything we've learned about managing complexity and build out layers of abstraction (probably using machine learning extensively). We could engineer living organisms that can have their genome reprogrammed on the fly.
We could expand the codon table to include non-organic molecular building blocks to reach a more generalized form of codified molecular self assembly (although, carbon is clearly quite flexible if you consider all that biological life is capable of and the many carbon nano-materials developed in labs that could possibly be produced through synthetic biology).
Synthetic biologists have already demonstrated the ability to grow solar cells and batteries in petri-dishes. We could go on to develop 3D FPGA logic cells used for a compute substrate.
A von Neumann probe needs to be able to mine, refine, and manufacture its own components so it can reproduce and grow exponentially. With conventional manufacturing tech, that prospect seems like it would require thousands of not millions of tons of equipment, but a single cell bacteria is capable of mining, refining, and replicating.
Let's say a von Neumann probe has a mass of Mp. It mines and refines the material from an asteroid with mass Ma and converts that material to new probes with an average material efficiency of E% and an average reproduction period of P years. That means it mines the entire asteroid when E*Ma = Mp*2^(t/P)
In other words, the time it takes to mine Ma is
t = P*ln(E*Ma/Mp)/ln(2)
You can play around with those numbers and get different values, but it's well within the realm of possibility to imagine a Von Neumann probe built with synthetic biology being able to mine the entire asteroid belt in a matter of decades. Let's plug in Mp = 1 kg (about the size of a small rabbit), P = 0.25 years (about the reproductive doubling rate of a small rabbit), E = 10%, and Ma = 2.39x10^21 kg (the mass of the asteroid belt).
That's 17 years to mine the entire asteroid belt and accumulate 2.39*10^20 kg of material to form a Dyson swarm. Assuming a density of 2390 kg/m3 (similar to crystalline Si and simplifies calculations), an average thickness of 1 mm, and an orbit roughly that of Mercury (47x10^9 m), the probes could reconfigure themselves into a Dyson swarm that covers roughly 0.36% of the sun. That is enough energy to bootstrap dismantling of other bodies like moons, then small planets, then whatever.
You can imagine a probe that has a production center out of which vast, ribon-like solar arrays sprout like the petals of a flower. But the petals loop back to the back of the probe where they are slowly consumed. Their material degraded by solar radiation, is broken down and recycled into new cells on the front of the probe.
It is very telling of your position towards Dyson Spheres that you never once mention Mercury or Statites. Choose a construction site already close to the sun and make your panels only a fraction of millimeters thick and a Dyson Sphere will appear far more plausible.
With an advance in technology, couldn't a Dyson Sphere be built out of very light-weight reflective materials that could be placed in orbit by utilizing a minimum of propulsion (energy).?
What is the gravity on the inside of a Dyson shell? It is not going to be 1G like on Earth. If anything, you will just fly off the surface straight into the Sun, since the surface gravity is going to be so small. Is there going to be an earth-like atmosphere on this sphere? There isn't going to be enough gravity to hold onto an atmosphere or have ozone to absorb harmful solar radiation. How does the sphere stay in orbit around the Sun? It needs to spin at the right speed to stay in orbit. I don't think that would even work since it would all be attached. It will just crash down into the Sun. Then, what is the gravitational forced between the various parts of the shell. It will just collapse into a solid sphere. Same issues exist for a swarm. How do you stay on a swarm part since the gravity will be so small - no 1G's just 0.0000000000001G's. You can't stand on an asteroid. One movement and you just go flying off. How do you mine an asteroid. You can't really even land on it, everything you mine just flies away etc.
I wonder how the beard is doing.
Yess ,...for a mice colony perhaps 😊
No for humans
Wouldn’t the inside of a Sphere be unlivable because it being in freefall? Newtons Shell Theorem iirc? So you would have to put any settlements on the outside - and use artificial light and put a dome over them for the atmosphere?
Well, we better should go and learn how to build ONeill cylinders and hack true fusion, if we want to go out there… and build a few solar collector satellites, which may be a hood alternative if you live close to Sol…
Why "unlivable"? Are people supposed to live on or in a Dyson Sphere ?
Lol. Why not more "solar collectors"?
If you want an honest answer about whether Man could build a Dyson Sphere in the future, then you need to ask a Caveman,
After taking him for a ride in your autopiloting smart car, and showing him a video on your smartphone of an f-22 raptor going full after- burner as well as the bombs dropping on Hiroshima and Nagasaki, while you guys enjoy a fully catered meal on demand by McDonald's. Then take him home and introduce him to your wife, right after you show him to indoor plumbing and a shower. After that, invite him to watch another video about Saturn V rockets, the "trip" to the moon, and the space program. You will get an honest answer.
So I am hearing we need to pull Venus apart 🤔😁😎.
But more seriously, you wouldn't need to have the solar panels and the living space the same thickness.
If you had solar panels a metre thick, but the space for living a kilometre thick, then you can greatly expand the area of eblnergy collection and still have multiple hundreds of Earth's surface for living.
Yes it would be a compormise, but you get the benefit of a faster energy return and still have a vast living space.
And, if you use Venus, then you also have the closer proximity to the sun to your advantage already. Not quite as good as the 1/10 used in the video, but if you want that, the closer proximity of venus reduces the energy of that too.
So, when do we pull venus apart 😁😎
Would not such a device double the sun photons slamming into earth, heating this place up to undesirable levels
When we create a functional nanobot ecosystem that can self produce and incorporate all the functions of AI. We can theoretically build a Dyson sphere before the end of this century. Energy manipulation and control ultimately allows our civilization to advance and evolve into what our races destiny has in store for us.. Hopefully this happens in my lifetime..
Paul--put your face behind your thoughts.
...or before your words.
Paul, the new format of the videos sucks. Please turn back to the old ones, where you're explains, showing your face. I'll upvote anyway...
OMG- LEBENSRAUM????? He actually said that in an academic paper???? YIKESSSSSS Massive cancel in todays world.....I love theoretical/ hypothetical ideas because I think we as humans see the bigger picture and some of us start to see the baby steps that are needed to make the bigger picture a reality and something(s) new and amazing is created because of it....like Patreon!
thanks Paul !
No is the answer. No will always be the answer. There, saved you 37 minutes.
Its not about the answer, its about why is the answer.
@@otaviogabrielli7700 No.
but it would be cool.
IMO,, this Dyson sphere is describing the sun, in biblical writings the path of light leads to the sun where a home is created for us. This sphere could also describe our universe and from our expansion, rotation and the energy expelled per geometric configuration forms what looks like a blazing shell.
Before I watch. No, probably not. Not with any conceivable technology for the next several tens of thousands of years. Even with AI in the drivers seat.
I think that Dyson spheres are total BS.
Dyson spheres and dyson rings are not even good science fiction. Imagine taking all the planets, all the asteroids and even the dust in our solar system. You would not have nearly enough matter to build anything like this. Not even close.
Yes, you would easily.
And you can use mass from the sun as well.
And it's not an on-off thing but more or less coverage.
It's not even scientific fiction, it's trivial that we'll do it.
Wouldn't it be artificial gravity we'd be living under? Isn't that incompatible to human life?
But they found Dyson sphere. Tabby star. cant be explained off by anything else. Im not saying its aliens but its aliens. Michio Kakus type 2 civ.