I need help Veeky Forums...

Some sort of nanocarbon unobtanium alloy.

Right up there with the thing that'll cause lukewarm fusion, room temperature super conductors, and competent, honest politicians.

Scrith

Oh, Dyson Spheres are super plausible (aside from the immense material costs), because the actual design doesn't have them be solid in the first place. Dyson's actual idea was to have a cloud of satellites orbiting a star to absorb as much light as possible, they're not joined together. The structural stresses that would cause it to fly apart aren't present because it's already flown apart, so to speak.

only one megastructure construction at once is a shit rule.

If this is something for a story or some sort? Cause if so, I'd say do something that makes the way the metal behaves a theme of your world. Like for something like 40k, where everything is terrible, make the material a metal that become more rigid and constricts in intense light or heat, as in, near a star. Heck, it is not so hard to believe that it would be less expensive building the sphere with less space between it's surface and the sun than between the sun and Mercury, never mind building a Dyson Sphere that extends all the way to the Goldilocks Zone. Then the sphere would be subjected to the heat necessary to make it impossibly strong, and all the wretches on it would have to live inside prebuilt hab bubbles on the outer surface, in the solar-powered air conditioning, never glimpsing at the sun that they have harnessed because they honestly could not figure out how to make transparent materials that could survive being so close to a star. The way the material grows more rigid in light could represent how the ruthless rule of the Imperium makes it strong enough to withstand anything, but unable to yield to any sort of benefit for it's people for fear of toppling this house of cards if you pull out one of them. the metal should be more than cool, I think, poetic most likely.

Superthornium-fart gas alloy. Or just go "its ancient mysterious" route.

Remember that Earth will bully its colonies with Nicoll-Dyson Beams.

If we knew we'd be working on orbital elevators right now. What the fuck did you expect?

Try a topopolis instead.

So, fitting for a shit game.

How big a ring-world? You could make a halo out of steel.

Mundane real-life material? Absolutely nothing. Have some form of scifi gravitational fuckery or similar, else the ring would tear itself into a million pieces
Mods, unless you're cheevo hunting. Arent achievements fucked atm anyway?

>Scrith

>The tensile strength of scrith is theorized to be similar to the Strong nuclear force, with the Ringworld foundation only measuring about 30m (100 ft) thick.

en.wikipedia.org/wiki/Strong_interaction

Say what you like about Halo, but living on an artificial planet would be awesome.

Anything really. It's in space. Zero gravity. All the ring's gravity would be artificial and any force it'd go under would be to prevent it from pulling apart. Any thing that would make it bend would just push the fucker.

The ring spins to provide centripetal force as a gravity analogue on the inner surface. Given the stats in Larry Niven's book Ringworld, where its diameter is roughly that of Earth's orbit, around a similar star, it has to spin at about seven hundred and seventy meters per second. The tensile strength required to hold together under the forces this would exert on the ring is on the order of the strong nuclear force. No material holds together that well, so Niven had to make one up, Scrith, or Ringworld Floor Material.

Any ring that spins to provide gravity will run into this issue, though as the ring gets smaller, this is less of a problem. A ring half the size around a star that puts out half as much light might be possible with conventional materials. A ring the size of the Halo rings that appear in said games could be built out of steel.

>All the ring's gravity would be artificial
Side note: While the Known Space universe does have generated gravity, the Ringworld's creators didn't have it when they built it.

It might work if only the inner surface is spinning and the outer layer supports it on a stationary track.

It's called Scrith, and it's basically spun like thread.

If you'd read past the first book, you'd know that...

Living Metal, obviously

With Magmatter( ): orionsarm.com/eg-article/48630634d2591

About Ringworlds
orionsarm.com/eg-article/5151b9b79834e

If you want to built in a lesser scale: orionsarm.com/eg-article/4845ef5c4ca7c

Or if you want to built a one with already existing materials:
orionsarm.com/eg-article/460db7f55a8d3

A fun alternative:
orionsarm.com/eg-article/48473a892041c

I can probably work with that to get the material strength to create my ringworld, that's actually really helpful. Thank you!

Living metal.

The paradox with a Dyson Sphere is that the amount energy needed to create a Dyson sphere would require for you to already have a Dyson sphere.

Mega structures are mostly for ascendant races to dick wave. They don't care about costs because they don't matter all they have to worry about is whether or not they want one.