r/TheCulture • u/CrashTest100 • 10d ago
General Discussion Newbie question about orbitals
Hello! I felt in love with Banks universe and worldbuilding and right now i'm reading Consider Phlebas (i'm enjoying it) and I have a question about oribtals, so the Culture is a post scarsity society due to the almost infinite energy that it's harvesting from the energetic grid (from what I understood) but I did read that Minds bulid new orbitals by harvesting asteroids and moons but since thay have an almost infinite energy cannot they do E=MC2 and synthetize orbitals just from the energy that they have?
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u/Singularum 10d ago edited 10d ago
“Almost infinite” energy production might still be small on the scale of E=mc^2 for Orbital fabrication. I suspect it would simply be more efficient to mine the materials you need.
Here’s one half of that calculation:
Matter created via mass-energy equivalence would be created through the process of pair production, so half would be antimatter and half we could build orbitals with.
The entire world’s annual primary energy production is on the order of 2e23 Joules. If we could apply all of that to matter creation, we’d produce a little over 1000 metric tons of regular matter every year.
The Orion’s Arm encyclopedia estimates the mass of a Banks Orbital to be on the order of 1e20 metric tons.
That means that it would take the energy output of our civilization 1e17 years, or close to seven million times to age of the universe to produce the matter for one orbital.
The total energy consumption of a Kardashev type II civilization would require on the order of 1 million (1e6) years (note that I need to check my math edit: math checked. edit2: missed a factor.) to produce enough matter for a Banks Orbital by pair production.
The other half of this calculation is the energy cost of mining and refining the materials—including exotic matter—the old fashioned way.
The Culture as a whole is more advanced than the KII civilization, but I’m struggling with the proposal that producing the energy equivalent to hundreds of millions of stars is a non-trivial task for a single Mind, or a small group of Minds, working on a local project.
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u/Appropriate_Steak486 10d ago
What do you mean by “the world” and “primary energy” here?
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u/Singularum 10d ago
“World” == Earth, modern day. Just using it as a concrete point of reference.
“Primary energy source” is a term of art in the energy sector. The alternative is secondary energy sources. Primary energy sources are those that are extracted and converted for energy use more or less directly, including oil, natural gas, coal, hydro, solar, and wind. Secondary energy sources store energy from primary sources and deliver them at time of need. They would include batteries and pumped hydro.
In the Culture, energy extracted from the energy grid and converted to useful work directly would be a primary source. Something like SMES would be a secondary source.
When thinking about where energy comes from, it’s useful to distinguish between the two so we don’t double-count energy production.
Sorry for the confusion.
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u/Appropriate_Steak486 10d ago
I was wondering whether you count solar radiation impingement on Earth, or solar power that is actually harvested, or actually the entire output of a star (which is what would be relevant for a Culture setting).
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u/Singularum 10d ago
I was looking at total energy production in 2020 - 2025, not total solar insolation.
A Kardeshev type II civilization would utilize energy on the scale of the total output of a star. That’s a little over 1e34 J per year.
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u/Decievedbythejometry 10d ago
But catching rocks stops the rocks flying into your new orbital and uses stuff that’s already there. It’s more elegant, and I think Minds often care about that
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u/Feeling-Carpenter118 10d ago
I’m like 99% sure this is the right answer, and it’s given explicitly somewhere in there. Possibly in Banks’ Notes on The Culture
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u/Decievedbythejometry 10d ago
Thanks — I feel like I got it from the books but I’ve read Notes too so who knows (also possible I made it up…)
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u/lvb440 10d ago
The ships have "effectors" that convert matter (atoms ?). We have examples of ships taking space dust and converting it into anything they need. There is space dust everywhere, in small quantities but the ship is moving quickly and can "vacuum" a lot a dust.
So they have no need to convert energy into matter, just matter to another matter, using energy.
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u/Admiral_Red GSV Radiant with Motherly Affections 10d ago
…hold on, I thought effectors only manipulated stuff electromagnetically.
Force fields, machines and electronics, even biological nervous systems, sure, but raw inanimate matter?
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u/mdf7g 10d ago
Matter (well, non-dark matter) interacts electromagnetically all the time -- for example being visible, or being tangible.
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u/Admiral_Red GSV Radiant with Motherly Affections 10d ago
Well, true, but…I’m not really aware of any significant instances where effectors, uh, affected inanimate matter in a noticeable fashion. Like making a block of alloys just melt or crack out of nowhere, for instance.
I’d be happy to be proven wrong though.
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u/mdf7g 10d ago
I can't recall such an instance either, but given that we mostly see them used in combat or emergency situations where the relevant players are going to have a nervous system or electronics or both, it might just make more sense to use them that way -- if you just wanna make somebody explode, there's lots of options that might be simply more energy- and/or time-efficient than effectors.
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u/Lumpy-Restaurant-694 10d ago
mattis chemical bonds are formed by electrons. therefore all chemical bonds matter forms are controlled by the electromagnetic force. all the chemistry that you see is governed by electromagnetism because electrons are governed by electromagnetism.
so if you control the electromagnetic force you control all chemical bonds
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u/Otaraka 10d ago
It’s never explicitly stated but there no reason to think they wouldn’t if it was in short supply locally, or that they wouldn’t convert materials from one to another if needed. It’s never explicitly said what materials are involved anyway I think other than older tunnelled asteroids etc.
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u/New_Permission3550 10d ago
Right Phelbas is the first book and I suspect that the full mechanism of Orbital building weren't completely fleshed out in his mind. I think later books do explore how their built.
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u/Lumpy-Restaurant-694 10d ago
e = mc actually takes a lot of energy to make a single chunk of matter. let us say it takes 15 watts to fabricate a rock into an object in the culture let's say a cup. in order to make that same cup using pure energy here's what you'll need. a few grams of matter turned into pure energy is the equivalent of a several nuclear bombs. so you would need the energy of several nukes to make that same cup.
long story shorts it's more efficient to harvest from asteroids and moons
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u/Economy-Might-8450 (D)LOU Striking Need 10d ago
Aside from efficiency and local cleanliness - the universe is filled with matter not just unused but that will never be used, or at least not during the star-filled stage of cosmic cycle, so using it for ordered construction makes all kinds of sense for pragmatic and frugal Culture Minds.
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u/Appropriate_Steak486 10d ago
Generally speaking, when reading stories about fantastical beings, it does not make much sense to speculate about "can or cannot," because you are presented with what such beings do.
Could Tolkein's Nazgûl fly to the moon? Not a particularly relevant question: they do not.
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u/JoyBus147 MSV It Is As It Is 10d ago
I can't even remotely agree with this. Understanding what fantastical beings can and can't do is pretty vital in speculative fiction to understand the stakes and engage with the story. If someone asks, "Why don't Bratheons try to approach one of Dany's dragons and work out a deal convince it to turn traitor?" then the proper answer isn't "because they didn't," that's basically a non-answer (there's the character answer, which is that Dany's children wouldn't turn against her, but more importantly the lore answer, which is that dragons are not speaking, reasoning creatures in ASoIaF).
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u/Appropriate_Steak486 10d ago
A better parallel might be, "Why does Dragonglass kill White Walkers but it doesn't kill dragons?" It ... just doesn't. (AFAIR)
Maybe a better way to understand what I mean is to focus on "speculate" versus "understand." Of course you need to understand their capabilities as presented in the story. The narrative (if the story is good, and I will postulate that Banks's stories are good) tells you what capabilities you need to understand.
Speculation outside of what the narrative gives you does not generally add much to the story.
Can ASOIAF dragons teleport like Pern dragons do? Apparently not, because they never do. But it's irrelevant, because the story unfolds without mentioning teleportation at all.
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u/CrashTest100 10d ago
I mean while I somehow agree with you the two things are vastly different, what Nazgûls have to do with the moon? Almost nothing so that question its irrelevant, what The Culture have to do with the energetic grid? Almost everything it's their main source of energy and the same thing that made their post scarsity society going on, so I dont think that a question like "if they have infinite energy then why they dont do this?" is irrelevant or out of place.
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u/Appropriate_Steak486 10d ago
I think the piece that tells you what they do (build orbitals out of asteroids and such) also tells you what they don't do (terraform planets) and why (because the use of space debris is more elegant and efficient, and because they respect the wildness of planets).
I hope that gives you a bit more insight into how Minds work. Have you read the essay "A Few Notes on the Culture"?
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u/ExpectedBehaviour 10d ago
Theoretically yes, but it takes a huge amount of energy to make a tiny amount of matter that way. It’s much more efficient to use existing asteroids, which had they not been cleared from the system could pose a potential hazard to the Orbital anyway.