How to Build a Dyson Sphere

[James Brown]

[YOUTUBE]https://youtu.be/pP44EPBMb8A[/YOUTUBE]

Presented by Kurzgesagt in a Nutshell, one of my favorite YT channels.

 

[steve_bank]

If even a small percentage of the star's energy was absorbed by the sphere the temperature would rise until the sphere was destroyed. The only way the sphere can rid of heat is by radiation.

Earth receives a tiny fraction of the Sun's output, and expose to direct sunlight can kill.

 

[Angry Floof]

That's a new one from Kurzgezagt. Yay!

Why wouldn't a civilization use a Dyson swarm instead? Cheaper and easier than a complete enclosure.

Of course much of the energy would pass by the swarm elements and be lost, but what would such an advanced civilization want with 100% of the power of a star anyway?

 

[James Brown]

If even a small percentage of the star's energy was absorbed by the sphere the temperature would rise until the sphere was destroyed. The only way the sphere can rid of heat is by radiation.

For an enclosed sphere, yes. For the sphere espoused in the video, no.

But I'm glad you enjoyed watching the video.

 

[steve_bank]

Ok point taken, I leapt before looking.

Babylon 5 is probably a good insight into how a large scale space culture would function and the reality of humans living in such a way.

Transplant humans to a Dyson sphere and you still have the same old humans. We are not wired for large scale cooperation.

I'd want to see the calculations on total energy absorbed by the sphere and total radiated energy, the energy balance. You still have exposure problems. Solar events are a threat to the ISS and anyone in orbit. Yes you can live on the oputer surface.

These days I am thinking we need to forget Mars, the moon, and a Dyson sphere until we are stable here on Earth.

 

[Angry Floof]

We may not be wired for large-scale cooperation, but we are re-wireable. We are nothing if not adaptable. We are right now, in fact, adapting to a tribe of seven billion. We might kill ourselves off before we're done, but there is no doubt we are in that process adapting. Brains are plastic. There is no way of knowing how large a cooperative group of humans can be.

 

[steve_bank]

An interesting thought experiment, but given the experience of building the ISS and servicing the Hubble such a construction would not seem to be workable.

Tunneling into the moon would be achievable. Some gravity, protection from radiation, and if deep enough protection from small impacts. Plenty of solar energy.

 

[Angry Floof]

given the experience of building the ISS and servicing the Hubble such a construction would not seem to be workable.

Technology advances. It doesn't just stop at whatever we can do now. I see no reason to think that nanobots won't be able to construct massive things in space in the future. The only questions are when, and will there still be any intelligent life forms around to develop the technology.

 

[steve_bank]

given the experience of building the ISS and servicing the Hubble such a construction would not seem to be workable.

Technology advances. It doesn't just stop at whatever we can do now. I see no reason to think that nanobots won't be able to construct massive things in space in the future. The only questions are when, and will there still be any intelligent life forms around to develop the technology.

What is the mass of all the raw materials to be lifted off the Earth? To populate it would require building an industrial infrastructure from scratch.

Something like Babylon 5 would be more doable. There is also the issue of water and air recycling. It would seem entropy would say air and water despite recycling would need periodic replenishment.

The Biodome experiment was a failure in two ways. The O2 levels dropped due to micro organisms in soil as I recall. They also had a serious social breakdown. I think there may have been violence.

 

[James Brown]

In the first BioDome, the O2 levels dropped due to the wrong kind of concrete.

The respiration rate was faster than the photosynthesis (possibly in part due to relatively low light penetration through the glazed structure and the fact that Biosphere 2 started with a small but rapidly increasing plant biomass) resulting in a slow decrease of oxygen. A mystery accompanied the oxygen decline: the corresponding increase in carbon dioxide did not appear. This concealed the underlying process until an investigation by Jeff Severinghaus and Wallace Broecker of Columbia University's Lamont Doherty Earth Observatory using isotopic analysis showed that carbon dioxide was reacting with exposed concrete inside Biosphere 2 to form calcium carbonate, thereby sequestering both carbon and oxygen.^[63]

So we tried something and learned from it. Most people see that as a good thing.

Although I'm not sure what the BioDomes have to do with building a Dyson sphere.

 

[steve_bank]

In the first BioDome, the O2 levels dropped due to the wrong kind of concrete.

The respiration rate was faster than the photosynthesis (possibly in part due to relatively low light penetration through the glazed structure and the fact that Biosphere 2 started with a small but rapidly increasing plant biomass) resulting in a slow decrease of oxygen. A mystery accompanied the oxygen decline: the corresponding increase in carbon dioxide did not appear. This concealed the underlying process until an investigation by Jeff Severinghaus and Wallace Broecker of Columbia University's Lamont Doherty Earth Observatory using isotopic analysis showed that carbon dioxide was reacting with exposed concrete inside Biosphere 2 to form calcium carbonate, thereby sequestering both carbon and oxygen.^[63]

So we tried something and learned from it. Most people see that as a good thing.

Although I'm not sure what the BioDomes have to do with building a Dyson sphere.

I remember as rerlated to micro organisms upsettingnthe O2 balance, but that does not matter.

Creating a Dtson sphere is experiment. The odds against jumping toa sucees is low.

I read a NASA analysis that predicted the first manned Mars mission will result in a death.

The reliability studies for the space shuttle predicted catastrophic failures.

It took It took some 80 years of cayastophies to reach the commercial aviation safety of today, and catastphic failures still occur.

One issue I see is resonance and propagation o mechanical disturbance of the sphere. A small impact by an asteroid could induce catastrophic vibrations.

What is the gravity in gs at the proposed distance from the sun, and what is the compressive forces on the sphere due to gravity? What metals would be used and what is the long term effect of solar radiation? What is the total mass of the sphere and what dos it do to Earth resources to manufacture it?
For me the biggest argument against ET is economics. Even if an Egyptian like ET civilization with a leader with absolute power ordering a fleet of starships, the economic burden would be enormous.

If you want to go into space the first step is to demonist an isolated self sustain system on the moon supporting a small population. Air, water, and food. Without that we go nowhere, IMO.

And so on. The Dyson sphere is an interesting thought experiment. A STNG episode used one for a plot device.

 

[Elixir]

These days I am thinking we need to forget Mars, the moon, and a Dyson sphere until we are stable here on Earth.

IMHO, undertaking a huge problem (even developing the Moon) would serve to unify the human species and contribute significantly to terrestrial stability. In fact, it might be the only way to develop a unified purpose that involves the entire human race. If we wait around for such stability to emerge before taking the first steps, it's never going to happen.

 

[steve_bank]

These days I am thinking we need to forget Mars, the moon, and a Dyson sphere until we are stable here on Earth.

IMHO, undertaking a huge problem (even developing the Moon) would serve to unify the human species and contribute significantly to terrestrial stability. In fact, it might be the only way to develop a unified purpose that involves the entire human race. If we wait around for such stability to emerge before taking the first steps, it's never going to happen.

Sorry to be conical. The ISS should have been that and it wasn't. China and Russia want an independent identity as space faring nations. When I first saw the Earth rise picture from lunar orbit I briefly thought it might have a global effect.

We may be 1000s of years or more away from any chance of global unity. It has been 2000 years since the Roman Emoire and the era of Jesus and we are at conflict as humans on many fronts.

 

[Elixir]

These days I am thinking we need to forget Mars, the moon, and a Dyson sphere until we are stable here on Earth.

IMHO, undertaking a huge problem (even developing the Moon) would serve to unify the human species and contribute significantly to terrestrial stability. In fact, it might be the only way to develop a unified purpose that involves the entire human race. If we wait around for such stability to emerge before taking the first steps, it's never going to happen.

Sorry to be conical. The ISS should have been that and it wasn't. China and Russia want an independent identity as space faring nations. When I first saw the Earth rise picture from lunar orbit I briefly thought it might have a global effect.

We may be 1000s of years or more away from any chance of global unity. It has been 2000 years since the Roman Emoire and the era of Jesus and we are at conflict as humans on many fronts.

Agreed. It would be difficult to know whether things on earth would be even a little bit different absent the ISS, but I suspect they would. Conflicts won't be going away any time real soon, but I'd surmise that the number of warring entities 2000 years ago worldwide, would outnumber today's count even if many more individuals are involved (we have a lot more individuals now...). Maybe the pressures of an ever more crowded earth will someday force the existence of some unifying vision upon us, but I'd expect a population crash (natural or manmade) before that.

 

[steve_bank]

What is the mass od such a stricture compared to the Earth? You have steel-iron and aluminum. Aside from the mass, how much energy would it take to process all the materials to be used?

The sun along with its motion around the galactic center naves around the center of mass of the solar system. How much energy would it take to position the sphere? In scifi space propulsion is by lights on the back of a spaceship.

A better approach would be a rotating colander like Babylon 5 with a large nearby flat solar collector plate.

 

[Kharakov]

Christians and all law (Allah) worshippers:

Jesus (or lala) left us the asteroid belt so that we'd be able to begin construction of the sphere before we have to crash mars into the moon (sacrificing Earth, which will be recreated in a simulation powered by the sphere) to create more non gravitationally bound ore to expand the swarm.

Beings will take turns living in the simulation, and maintaining the swarm.

 

[steve_bank]

If you are gaping to do heavy industry in space processing asteroids into metals and fabricating structures assuming you have an energy source there is a problem getting rid of heat in a vacuum.

The space shuttle even with a relative small heat load could not stay up if the radiators inside the cargo doors were not exposed to space.

Same issue with the ISS.