this post was submitted on 17 Feb 2025
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Today I Learned

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A Dyson sphere is a hypothetical megastructure that encompasses a star and captures a large percentage of its power output. The concept is a thought experiment that attempts to imagine how a spacefaring civilization would meet its energy requirements once those requirements exceed what can be generated from the home planet's resources alone. Because only a tiny fraction of a star's energy emissions reaches the surface of any orbiting planet, building structures encircling a star would enable a civilization to harvest far more energy.

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[–] [email protected] 6 points 4 days ago (1 children)

Maybe make it a dyson fan since the sphere would only work during the daytime. In polar areas that means half a year without any energy production!

Whereas there is always solar wind.

[–] [email protected] 3 points 4 days ago

wHaT aBoUt wHen iTs NoT WinDy!!??!?!?

[–] [email protected] 4 points 4 days ago

Kind of looks like an atom

[–] [email protected] 4 points 4 days ago (3 children)

Is dark matter just Dyson sphered stars?

[–] [email protected] 1 points 2 days ago (1 children)

While the idea is charming, a Dyson sphere itself would still consist of matter and as such it would emit radiation according to its temperature (https://en.m.wikipedia.org/wiki/Thermal_radiation). And since it surrounds a star it is heated from the inside and would definitely emit radiation that can be detected. Dark Matter is missing this radiation part and is only observed by its gravitation.

So the answer is no, unfortunately.

[–] [email protected] 1 points 1 day ago* (last edited 1 day ago) (1 children)

Edit to add disclaimer: this is shitpost level math here guys, I'm just spitballing.

It would definitely emit thermal radiation. if it was 99% efficient and the size of pluto's orbit, around a star like the sun, and the energy was used to create matter, I think it would radiate the remaining energy as 0.009 W/m2 with a peak emission wavelength of 150micrometers. The James Webb telescope has infrared capabilities that max out at 28.5 micrometers so def not detectable.

But probably a dyson sphere would be smaller than pluto's orbit, which would greatly increase the apparent power, and shorten the wavelength. idk it's all imaginary.

I won't subject you to my hand writing but I did (power of sun × 0.01)/(surface area of sphere with Pluto's orbital radius) to get radiation intensity (0.009 W/m2). Then rearranged Stefan-Boltzmann law to solve for temperature (19.8K). Then used Wien's Displacement Law to calculate the peak wavelength (1.5×10^-4^ m).

Maybe I'll run the numbers again with a martian orbit radius, and 50% efficiency.

[–] [email protected] 1 points 1 day ago

Okay I did the same calculation but with Martian orbit as dyson sphere size, and 50% efficiency I got a wavelength of 3.4um so nicely in the infrared range of JWST.

I think the sphere would need to be like 99.95% efficient to be undetectable by JWST at Martian orbit radius.

[–] [email protected] 4 points 4 days ago* (last edited 4 days ago) (1 children)

My initial reaction: "What? No."

After thinking a little bit: "hmm I guess you could say that..."

[–] [email protected] 1 points 3 days ago* (last edited 3 days ago)

Like I'm sure it's not but I don't know if it's a worse explanation than any of the other ideas being considered. But I don't know enough to even know how wrong I am.

[–] [email protected] 4 points 4 days ago

Start with a dyson ring or swarm

[–] [email protected] 1 points 4 days ago (1 children)

Would recommend Orion's Arm for "theoretical" but fiction takes on structures like this:

https://www.orionsarm.com/eg-article/5067d430e6021

That article is not comprehensive either, their universe is quite expansive.

Two of my favorites may be "W-brains," computing structures with very carefully arranged wormhole pairs serving as data buses to overcome the latency of communicating at such scale, and "neural stars," another take which is a computational structure inside a neutron star sized volume/mass (again, to overcome latency issues).

There are much smaller megastructures too, depending on where in the timeline you are looking.

[–] [email protected] 2 points 4 days ago (1 children)

Is this like the SCP foundation stories but for space opera science fiction?

[–] [email protected] 1 points 4 days ago

Precisely.

And it's a "hard" sci fi universe rooted in theoretically possible physics. No FTL or causality violations.

[–] [email protected] 1 points 4 days ago (1 children)

Or the slightly more achievable version - Ringworld.

[–] [email protected] 1 points 4 days ago

Depends on what you mean by ringworld. The thing I think of is orders of magnitude more impossible than a Dyson sphere, which is already pretty impossible.

[–] [email protected] 1 points 4 days ago

We will be lucky to have Dyson vacuums at the end of this century

[–] [email protected] 2 points 4 days ago

You might like this video: https://www.youtube.com/watch?v=pP44EPBMb8A about how to build one from Earth.

[–] [email protected] 9 points 4 days ago (1 children)
[–] [email protected] 6 points 4 days ago (1 children)

That's crazy that they made this hypothesis based on a steam game

[–] [email protected] 1 points 4 days ago

I think freeman Dyson beat em to the punch by several decades :)

The game is truly great though.

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