Cylinders

explain to me how an inertial force acting on you at 9.8m/s is in any way different from gravity. Similarly, if you're capable of building one O'Neill cylinder, you've solved the issue of large scale space construction and you're probably capable of building many more. Each cylinder is 5 miles across and 20 miles long, and you can have whole cylinders set up as nature preserves. Connect cylinders at one pole in a huge cluster, open to enable microbes and flying life to circulate so things don't get ecologically stagnant.

If you have fusion available, you can have cylinders filled with farming powered by efficient red and blue growing lights instead of sunlight, and you'll be swimming in grain to feed meat production. Insect protein is fine for everyday nutrition, but people would certainly be able to have a steak or some omelettes if they wanted. Educate your population on what's acceptable behavior, so you don't get greedy fuckers trying to steal all the cows or something. And if they do get shitty, just chuck em back to Earth on the next flight, and you're better off.

>Spin gravity isn't as good as the real thing.
Why's that?

Way too fragile and way too expensive

>explain to me how an inertial force acting on you at 9.8m/s is in any way different from gravity.

You won't be spinning that fast, because doing so would fuck you up.

Spinning gravity doesn't really force you down, it forces you sideways which in a spinning circle is almost the same as down.

Even ignoring the fact that this means the entire colony is based around a specific center of mass, and if you gather too many people in one place (say, at a sports stadium) you will make the station wobble in its rotation and start tossing everything around like rocks in a tumbler? The fluids in your body will be biased in a direction based on spin.

What this means is that you are walking down main street. You remember you forgot your phone at home and turn around... immediately falling to the ground and vomiting from extreme vertigo and nausea as all of the fluid in your inner ear just reversed direction with the full force of the spin in the time it took you to turn around.

The only way to avoid these problems is to spin slower. That means lower gravity. That means health problems in the long term.

Ah, that makes sense. Thanks for that. I'm curious why it's not brought up more. I would think that a large habitat would negate the worst of the effects of spinning, since I think O'Neill's designs spin at 28 rotations an hour? That's not too much, and you'd just have to screen out people who are super sensitive to motion sickness.

Even with nanotubes it's really hard to achieve reasonable levels of it without material stress getting to dangerous levels.

It isn’t brought up more because it isn’t true. I don’t know why that guy thinks it is, but he’s flat out wrong if he’s being serious.

The centrifugal pseudo force acts on you like gravity does, except when you’re close to the centre of the rotation. With a large enough radius the behaviour of objects at the edge of the cylinder is almost identical to what it would be on earth. The only difference is how things in free fall behave- due to not actually being affected by gravity, they have a slightly curved path from the perspective of someone rotating with the habitat. But this decreases as the object gets further from the centre of the cylinder, and most suggestions for proper O’Neill cylinders are miles across, which is more than big enough. claims that turning around would result in your inner ear fluid changing direction, but that’s not supported or suggested by the physics, and it’s unclear what he even means by it - your inner ear fluid is stationary, not moving, and there’s no reason that changing your orientation would cause it to move.

You have the right idea, but you're thinking too small.

It's all cylinders and spheres with these kids, gotta be all "oh look at me I made a big ol' space station", in my day we shoved a planet with about the right mass into the right orbit, then terraformed the shit out of it.
None of this "centrifugal gravity" shit, just millions of tons of stone and metal pulling you down and then seeding the bastard with life.
Now it was slow, and expensive. But it built character!

Lies, everyone knows our souls are weighed down by gravity.

That ring is absolutely tiny, like fractions of the size of earth. You could probably walk around it in a few days.

>space colonies are tremendously fragile
At the tech level where space colonies would be possible, planets are pretty damn fragile too. At least with a multitude of space habitats you aren't putting all your eggs in one basket.

>millions of Cylinders
where does the mass come from to build cylinders? p.much all the mass in a solar system gathers in gravity wells. Sure there's equilibrium places like Lagrange points, but that's only for matter that floats in and manages not to drift out... which means there's not much mass there.

> but muh post-scarcity economy
if you have infinite resources, then build a ringworld, or a dyson sphere, why settle for less?

Why not just build planets at that point?

>he hasn't heard of harvesting mass from suns

YouTube Isaac arthur

Mostly because a torus is a more efficient shape.

Planets are a very inefficient. There would be vastly more area on the inside of a ring shaped habitat than the surface area of a planet the same mass.

Harvest mass from your star, and build millions of cylinders around it to harvest the energy it puts out.

Congrats you're building a dyson swarm, the actual definition of a dyson sphere.

Technically what he said was true, he just got the scale wrong.

His stuff applies in the context of rotating drums on STARSHIPS and other small structures, where the smaller drum size requires a higher rotation speed. For something the size of an O'neil cylinder, the effect is largely reduced.

Strip Mine Mercury down to dust.

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Wrong. Gravity weighs down your soul, feddie scum.

Isaac Arthur is literally a supervillain. That antebellum slave master accent is just too much.

Not true at all, Magical fields are generated by a planet's ecosystem, and on a planet, the noosphere is spread thin by the fact that planets are huge and only have life on a thin layer above and below the surface, while the rest of it is made of mostly iron, the least magical element. Even the under-dark doesn't go down deep enough. Most of the planet is a molten ball of iron (Cold iron is a figure of speech, any sufficiently large quantity of iron will have minor anti-magic effects) blocking out all the manna that you could be getting from the other side of the planet.

In a space colony you can have a much stronger manna field with a much smaller ecosystem, because manna will be radiating in in all directions. You can even design the outer wall as an orgone chamber so that any magical energy is reflected back into the center, where you can place the most powerful magical artifacts in zero gravity.

All things considered, It's only natural that fey and magic users would want to migrate to space and leave stupid martial classes to die on earth.

As for Ringworlds?

A much more feasible idea would be an equivalent mass of bernal spheres spread across a star's habitable zone in the same orbit that the ringworld would occupy.

It would have a similar habitable area, could be built with non impossible technology, and isn't an all or nothing thing. You just build them until you run out of things to take apart, and at that point you'll be able to house 30 quadrillion humanoids in post scarcity conditions.

Also, the combined light reflecting off of all the solar panels and mirrors of all the colonies would cause the entire formation to look like a solid golden ring, An angel's halo. Only distinguishable as a massive "choir" of individual habitats when you got closer. From the outside of the formation, it would look like a black line across the star, unless you were high enough above the ecliptic, in which case it would look like half a halo.

Compared to a ringworld which requires literal unobtanium to build, and rips itself apart as soon as it's damaged, It would also be more resistant to attack because you'd have to destroy the colonies one at a time. They would all be orbiting in the same direction and spread far out enough that Cosmic scale Kessler syndrome would be very difficult to achieve unless you've already destroyed most of the colonies individually. Sure it sucks if your colony is destroyed, but you can just evacuate to the next colony, and then rebuild it latter. You can't do that with a Ringworld. Up to 30 quadrillion sentient lifeforms killed by a single sufficiently powerful super-weapon that doesn't even have to crack the ring, just make it weak enough to tear itself apart. Ever hear of not putting all your eggs in one basket?

And yes, this can be combined with a dyson swarm if the swarm shards remember to reflect some of the light at he Halo. Best of both worlds if you have the mass to spare.

Post Apocalyptic Dyson Swarm setting:

Humanity and AI is building the Dyson Swarm, all of the solar system has been processed and is moving into place.

Kessler Syndrome begins as a result of human error, AI is unable to correct it. Everything is ruined, AI goes insane trying to correct the swarm.

Ten thousand years later, things have calmed down enough for the AI to make headway and for humans to start returning. The only survivors of the Kessler Syndrome were in tough massy bodies, or on long trajectories through the outer system, or were out system.

And of course synthetics and organics blame each other for the disaster?
It was a human error, but it was technology that facilitated humanity's arrogance

I had an idea for an accidental mega(-scaled lack-of-)structure that results from planetary destruction or failed mega-engineering attempts. It's a proto-planetary disk infested by pirates and competing strains of von-newman probes. Some of them came to the disk to try mining it, but they got attacked by pirates, and then the pirates got attacked by other pirates, ect ect. Eventually things stabilize as some strains of organic and machine-life decide it's safer to trade with space pirates, and a bunch of small pirate havens, free marketplaces, virtual reality taverns, and the space robot equivalent of cleaner shrimp. From a distance it's kind of like a stellar scale coral reef. From the inside it's a giant fucking debris field filled with thick dust clouds that means an ambush could be coming from anywhere, and stealth does in fact exist in this part of space.

Intelligent Machines find this "Ouroboros Reef" to be particularly horrifying, because while they normally take the position that planets are a waste of time and that it's better to just mine space rocks to build megastructures, a solar system sized debris field reduces machine efficiency to a parody of organic chaos. Just machines consuming other machines and fighting over resources that would otherwise be more than enough for everyone.

Humans on the other hand find it fascinating, if a bit dangerous. Something to be admired from a distance, but only visited if you are very brave or very foolish. Things that go into it don't always come back. The ones that do come back with artifacts from long lost civilizations.

That's a fantastic idea. You should write for OA ;-)

Because you could get the same surface area for a fraction of the matter building cylinders.

Micro ring worlds might be a lot easier to build and in larger numbers. They could be built with materials weaker than atomic forces.
You wouldn't need to dismantle the whole star system to build it, neither would you need an inner ring of sun-blocking plates to simulate night.
Just angle half of the inside towards the sun and make sure the spin is fast enough to simulate gravity while providing an acceptable night and day cycle.
Also multiple rings would help mitigate losses in case a ring gets damaged or contaminated by a hostile species.

>Micro ring worlds
Orbitals, friend.

Or halos if you want to upset the halo fans who'll tell you that ACTUALLY they're halo RINGS

soul-damage schmoul-damage, I'm doing just fine.

Because the phosphorous bottleneck is a bitch.

Neat
Sauce?

Gundam Unicorn

While you make a good argument with the fragile thing since it is certainly harder to break a planet than it is to break a space colony, the gravity thing you're a bit wrong about. Spin Gravity for anything you'd call a colony will be just as good as planetary gravity. It's perfectly fine to actually live on a space colony. Though a planet is certainly more defensible.

A rock a few kilometers across has negligible gravity and enough mass to carve up, refine, and rebuild into thousands of cylinders. You don't need infinite resources to explain why it's better to just build a bunch of cylinders. But you do need to break the laws of physics to explain the material Niven's Ringworld is made of.

OA started using magic and breaking the laws of physics almost as soon as someone declared it to be Hard Science. Being an open group collaboration with no actual standards it soon became more about how far you could push pop-sci misunderstandings of the word quantum, nano, and singularity, rather than adhering to any real physics. AI are also Physical Gods and have more in common with D&D domain holding physics breaking superman than merely dynamic computers. Because in the world of Orion's Arm all you have to do is shove in enough RAM cards and you have a physics breaking god that can craft pocket universes for you out of sheer willpower because of course computers can.

Banks came up with the term first, but I think halo should be used to describe a ring-world sized formation of orbital habitats (which might be rings, cylinders, or spheres)

If they all point their mirrors in the same direction, they will look like a ring of light around a star. Perhaps even outshining it if they focus this light on a specific point. The next best thing to a Dyson swarm, and much more AESTHETIC. Built by races that are too advanced to give a fuck about anything else, and inhabited by races who enjoy post scarcity lifestyles but still want to live in the physical world.

I honestly wouldn't mind that as much if it was something type III or IVs could do. Apparently a type II has enough energy to cause a vacuum meta-stability event if they chose to do so, and only type IIIs or IVs could prevent that by reversing causality and preventing it from ever happening

That however means that most civilizations will be messily type Is who will be retroactively erased from existence if they even consider becoming type II without first removing all desire to fuck with the observed laws of reality. The existence of type IIIs and IVs will be nothing more than something type IIs imply might exist, but that meat brains could never comprehend. The old fashioned kind of god that you can't prove exists, but can't disprove either. If they do exist, they are outside of our visible/simulated universe and any kind of discussion about them is probably a waste of entropy. A matter of Theo-philosophy rather than empirical science. The only beings capable of testing these hypothesis are beings which are unwilling to do so for reasons they are unable to explain to impatient mortals with rotting meat for brains. Entropy built both of us for reasons, don't waste my CUP cycles.

At any rate, I stay mostly away from OA because I don't like how their website is formatted. I only sometimes glance at it and find a few ideas interesting. If I spent too much time there however It would probably be counter productive for my own imagination.

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A project like OA needs uniform standards, not mob rule.

>triple eights confirms
These massive cities in space would travel between earth and her colonies, loitering at each long enough to unload their wares and take on new cargoes in an endless interplanetary flow of commerce, ensuring a peaceful future of interconnected markets.

That picture's fucked up perspective and scale makes me want to barf.

It takes a lot of double standards to try and portray the Federation in UC as evil, when the only reason the last 5 UC shows happened is because the Feddies chose NOT to bring an absolute iron fist against the faction that started a war of supremacy that killed more than half the human race, committed multiple war crimes, and then lost.

Like, holy shit. Maybe Earth would be more okay with Spacenoids governing themselves if the spacenoids stopped GASSING THEIR OWN CITIZENS TO DEATH AND THROWING THEIR HOUSES AT EARTH AS WMDS. The fact that this is something that has happened multiple times in Gundam is fucking insane.

>If they all point their mirrors in the same direction, they will look like a ring of light around a star. Perhaps even outshining it if they focus this light on a specific point.
Reminds me of this: antipope.org/charlie/blog-static/2015/04/on-the-great-filter-existentia.html

>Griefers: suppose some first-mover in the interstellar travel stakes decides to take out the opposition before they become a threat. What is the cheapest, most cost-effective way to do this?

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>A Dyson sphere or Matrioshka Brain collects most or all of the radiated energy of a star using photovoltaic collectors on the free-flying elements of the Dyson swarm. Assuming they're equipped with lasers for direct line-of-sight communication with one another isn't much of a reach. Building bigger lasers, able to re-radiate all the usable power they're taking in, isn't much more of one. A Nicoll-Dyson beam is what you get when the entire emitted energy of a star is used to pump a myriad of high powered lasers, all pointing in the same direction. You could use it to boost a light sail with a large payload up to a very significant fraction of light-speed in a short time ... and you could use it to vapourize an Earth-mass planet in under an hour, at a range of hundreds of light years.

>Here's the point: all it takes is one civilization of alien ass-hat griefers who send out just one Von Neumann Probe programmed to replicate, build N-D lasers, and zap any planet showing signs of technological civilization, and the result is a galaxy sterile of interplanetary civilizations until the end of the stelliferous era (at which point, stars able to power an N-D laser will presumably become rare).

>We have plenty of griefers who like destroying things, even things they've never seen and can't see the point of. I think the N-D laser/Von Neumann Probe option is a worryingly plausible solution to the identity of a near-future Great Filter: it only has to happen once, and it fucks everybody.

A dumb idea. By the time a griefer notices you, and by the time it's laser reaches you, you could have an interstellar civilization capable of surviving the beam, figuring out where the beam came from and getting revenge.

In any galaxy where the first civilization is a griefer, the second civilization will be a strain of self replicating von-newman machines broadcasting the griefer's location to everyone, and offering to immortalize any civilization that destroys it as the heroes of the galaxy.

These kinds on scenarios only really work for two power scenarios like the cold war, and even then forget that the speed of light means you don't even know if your first shot will prevent the enemy from responding. RKVs and ND lasers are only useful against planet sized targets. It is not useful against another Dyson swarm, nor is it useful against smaller self replicating spacecraft that can quickly expand across the galaxy warning everyone of the griefer.

Moreover, a ND laser can be destroyed by a type III civilization, multiple Dyson swarms either focusing their light on the griefer star until everything orbiting it is ash, or using some even more exotic weapon to cause the star to go nova or just violate causality to remove it from existence.

The cosmic zoo hypothesis is the most likely explanation for an apparently quiet galaxy. Also the fact that we haven't been looking very hard and the inverse square law is a bitch. Aliens can't watch our TV unless they have probes in our solar system. They probably also use point to point communications to talk to each other because it's more efficient.

But yeah, every solar civilization can be used as a super-weapon if they have a good reason. It's much more likely that such advanced civilizations will have lived through an era where it was easier to kill themselves than not kill themselves. That's the filter right there. It won't select for people who destroy for no reason, it will in fact select against them.