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Yes, yes dated meme aside I have in my eternal ignorance found about a month ago of the theory of the Dyson Sphere.


And I was hanging with my friend today and a thought hit me, Y there be no Dyson Spheres in Warhammer 40k? Meta explanation is the writers didn't know about them but within the fluff? There's very little reason why there shouldn't be, we had The Old Ones, The Necrontyr, then the Eldar and numerous other alien races, then Humanity in the golden age before the fall. The billions of years, surely one of those advanced intergalactic civilisations would've built them? They aren't even shown during the Great Crusade. I suppose they could be destroyed when found by the Space Marines or whatnot, but the galaxy is unimaginably vast so there are likely more that have been found or yet to be found.

I'm tempted to have my Explorers find a Dyson Sphere made by the Yu'vath or ancient humanity or ancient Eldar in my Rogue Trader campaign, that'd be interesting. But what theories can you guys think of as to why there aren't Dyson Spheres in the fluff. Or maybe there have been in a codex or a BL novel and I've just missed it, if so, please inform me!

Thanks!

In the old Necron fluff, the C'tan known as the Outsider lived inside one out on the Eastern Fringe.

Dyson spheres/swarms don't make a lot of sense when you have FTL travel and can find millions of systems with habitable or terraformable worlds. Though I agree that with the abundance of alien life forms in the 40k universe there should be some critters that didn't figure out any means of FTL and decide to build one.

I’m sure that Dyson spheres could exist in the 40k universe, but if no one knows that they exist how would they find them? One of the major ways we currently discover soloar systems has to do with radiation or light emitted from a Star. Wouldn’t a completed Dyson sphere completely cut off said emissions and basically render its system undiscoverable Save by accident or esoteric means?

 Duskweaver wrote:
In the old Necron fluff, the C'tan known as the Outsider lived inside one out on the Eastern Fringe.

Oh? That's cool. I'll look him up! Thanks.


Automatically Appended Next Post:

 agurus1 wrote:
I’m sure that Dyson spheres could exist in the 40k universe, but if no one knows that they exist how would they find them? One of the major ways we currently discover soloar systems has to do with radiation or light emitted from a Star. Wouldn’t a completed Dyson sphere completely cut off said emissions and basically render its system undiscoverable Save by accident or esoteric means?

That's true, but there will be Dyson Spheres which don't cover the entire sun (they aren't exactly spheres, but still lol) And exploration of the Milky Way could likely allow discovery first hand, too.


Automatically Appended Next Post:

 John Prins wrote:
Dyson spheres/swarms don't make a lot of sense when you have FTL travel and can find millions of systems with habitable or terraformable worlds. Though I agree that with the abundance of alien life forms in the 40k universe there should be some critters that didn't figure out any means of FTL and decide to build one.

The Tau could make them then? That could be a super interesting story and maybe the Imperium might find out and be like, oooh what's that? They might have FTL, but not as fast as the Imperium and a lot less territory.

 agurus1 wrote:
Wouldn’t a completed Dyson sphere completely cut off said emissions and basically render its system undiscoverable Save by accident or esoteric means?

A Dyson sphere would need to radiate the energy from the central star otherwise its interior would heat up continually and cook the contents. A dyson sphere should radiate in the infra-red part of the spectrum.

From a practical POV, a Dyson ring would be a lot easier since it could rotate to simulate gravity on the inner surface. A sphere would need true artificial gravity (probably not a problem if you have the tech to build one in the first place and the energy of an entire sun to power it.

 Adrassil wrote:
Oh? That's cool. I'll look him up! Thanks.

Note that the Lexicanum article wrongly describes the sphere as "a hollow planet". But the 4th edition Necron codex shows it as 1.04 AU in diameter, which is larger than the distance between the Sun and the Earth, so obviously several orders of magnitude too large for a planet, but a suitable size for a Dyson sphere.

 Adrassil wrote:

 Duskweaver wrote:
In the old Necron fluff, the C'tan known as the Outsider lived inside one out on the Eastern Fringe.

Oh? That's cool. I'll look him up! Thanks.

The original fluff about the Dyson Sphere was in the 3rd edition Necron codex. It is a report from a Tech Priest of some sort who was taken there but allowed to leave. Basically the inside of the sphere is full of machines that harvest the star at its centre to feed the Outsider.

(Page 58 https://cdn.preterhuman.net/texts/gaming_and_diversion/Warhammer_40K_Collection/Warhammer%2040k%20-%20Codex%20-%20Necrons.pdf)

WD 273 expanded this somewhat. The Outsider was tricked into feeding on other C'tan by the Eldar God Cegorach (the Laughing God of the Harlequins). However fragments of the consumed C'tan's minds and personalities remained and infected the Outsider, driving it mad. It eventually fled back to its Dyson Sphere and locked itself inside with some Harlequins keeping watch.

Except there is. Solemnace (Trazyn's museum) is a Dyson Sphere. There is a trapped C'tan at the centre of it powering it.

 Grimtuff wrote:
Except there is. Solemnace (Trazyn's museum) is a Dyson Sphere. There is a trapped C'tan at the centre of it powering it.

Sweet, there is. But why aren't there so many more, or at least more Dyson Rings? Humanity would've likely made some perhaps, during the Age of Strife.

 Adrassil wrote:

 Grimtuff wrote:
Except there is. Solemnace (Trazyn's museum) is a Dyson Sphere. There is a trapped C'tan at the centre of it powering it.

Sweet, there is. But why aren't there so many more, or at least more Dyson Rings? Humanity would've likely made some perhaps, during the Age of Strife.

Possibly destroyed. The Men of Iron did a number on the galaxy.

It is probable that the aforementioned Outsider one and Solemnace are now one and the same via retcon. They are in the same area of space on the Eastern Fringes. The final chapter of the 2nd Fabius Bile book go into details about Solemnace. The outer surface of it is made from Necron nanomachines, so small in fact that they appear to be grains of sand and they consume the radiation (and other things, like layers of power armour) of the C'tan at the very centre of it.

 Grimtuff wrote:

 Adrassil wrote:

 Grimtuff wrote:
Except there is. Solemnace (Trazyn's museum) is a Dyson Sphere. There is a trapped C'tan at the centre of it powering it.

Sweet, there is. But why aren't there so many more, or at least more Dyson Rings? Humanity would've likely made some perhaps, during the Age of Strife.

Possibly destroyed. The Men of Iron did a number on the galaxy.

It is probable that the aforementioned Outsider one and Solemnace are now one and the same via retcon. They are in the same area of space on the Eastern Fringes. The final chapter of the 2nd Fabius Bile book go into details about Solemnace. The outer surface of it is made from Necron nanomachines, so small in fact that they appear to be grains of sand and they consume the radiation (and other things, like layers of power armour) of the C'tan at the very centre of it.

Could be the case. I have my doubts but in 40k such destruction is within its reality, so you could be correct lol

Commorragh has the Illmaea, the "captive" suns. If the Eldar had the technology to basically put a sun in a cage and drag that cage inside the webway, I'm sure they could build Dyson spheres.

Maybe they did build some but those were destroyed during the fall, or maybe they just liked terraforming planets better.

You probably need a lot of mass to build a Dyson sphere. I wonder what the minimum size of solar system is required to actually enable one to be build without importing mass from elsewhere.

It's important to note that the resources necessary to create a Dyson Sphere are, literally, astronomical. For example, you could convert literally every object in our solar system into material and we still wouldn't have enough for a complete sphere (at least one that would be far enough away from the sun not to just melt, but close enough to actually perform its function). And in the 40k universe, they've already developed "cold fusion" technology. In other words, the pay off for a Sphere isn't worth the investment for any of these races.

 Tiennos wrote:
Commorragh has the Illmaea, the "captive" suns. If the Eldar had the technology to basically put a sun in a cage and drag that cage inside the webway, I'm sure they could build Dyson spheres.

Maybe they did build some but those were destroyed during the fall, or maybe they just liked terraforming planets better.

Of all the races I think Eldar would be most likely as they can literally summon wraithbone from the air as well as the Craftworlds and before the fall it's likely they could've made one out of boredom or fun or just to see if they could.


Automatically Appended Next Post:

 flandarz wrote:
It's important to note that the resources necessary to create a Dyson Sphere are, literally, astronomical. For example, you could convert literally every object in our solar system into material and we still wouldn't have enough for a complete sphere (at least one that would be far enough away from the sun not to just melt, but close enough to actually perform its function). And in the 40k universe, they've already developed "cold fusion" technology. In other words, the pay off for a Sphere isn't worth the investment for any of these races.

I'm thinking in the past, with so many civilisations throughout the galaxy, including the lesser-known ones like the Slaught there would surely be a few.

 John Prins wrote:
Dyson spheres/swarms don't make a lot of sense when you have FTL travel

Actually that's the only time it makes sense, tbh. The poitn of a dyson sphere is to capture all of the energy output of a star, you don't do that on a habitable system.

 Melissia wrote:

 John Prins wrote:
Dyson spheres/swarms don't make a lot of sense when you have FTL travel

Actually that's the only time it makes sense, tbh. The poitn of a dyson sphere is to capture all of the energy output of a star, you don't do that on a habitable system.

Unless you hate the people living there. But then I'm sure there are less expensive ways to ruin a planet for someone.

Probably some in the Eye of Terror - made of ice cream or screaming souls or both

 Flinty wrote:
You probably need a lot of mass to build a Dyson sphere. I wonder what the minimum size of solar system is required to actually enable one to be build without importing mass from elsewhere.

This really. Dyson spheres are nice in theory but where the feth are you going to get the required materials from?

Of course the internet has answered this... quote from wikipedia.

Also if assuming a radius of one AU, then there may not be sufficient building material in the Solar System to construct a Dyson shell. Anders Sandberg estimates that there is 1.82×1026kg of easily usable building material in the Solar System, enough for a 1-AU shell with a mass of 600 kg/m2—about 8–20 cm thick on average, depending on the density of the material. This includes the hard-to-access cores of the gas giants; the inner planets alone provide only 11.79×1024 kg, enough for a 1-AU shell with a mass of just 42 kg/m2.[14]

 Mr Morden wrote:
Probably some in the Eye of Terror - made of ice cream or screaming souls or both

Yeah very likely, I think full to the brim with trillions of Neverborn, could be a good story about a Chaos Space Marine trying to move the Dyson Sphere into the warp proper and send it into the heart of the Imperium.


Automatically Appended Next Post:

 Flinty wrote:
Of course the internet has answered this... quote from wikipedia.

Also if assuming a radius of one AU, then there may not be sufficient building material in the Solar System to construct a Dyson shell. Anders Sandberg estimates that there is 1.82×1026kg of easily usable building material in the Solar System, enough for a 1-AU shell with a mass of 600 kg/m2—about 8–20 cm thick on average, depending on the density of the material. This includes the hard-to-access cores of the gas giants; the inner planets alone provide only 11.79×1024 kg, enough for a 1-AU shell with a mass of just 42 kg/m2.[14]

The limits of that won't matter to an interstellar empire, and especially not the Eldar due to their Wraithbone abilities.

Nor the Imperium, because it's fething huge. The Imperium just doesn't have the imagination to do it.

Teqnically DE have dysonspheres as they hauled a lot of suns and dark suns (?) into their realm.

^^ Not the same thing, Nilai.
The technology needed to Capture suns and stuff them into a hyperspace pocket is likely far beyond the petty skills needed to build a shell of 1AU diameter around a sun. If you can do the former, then the latter is no longer relevant. When you can build a way to travel through the null-space realms, why build a sailboat?

The 40k writers SHOULD have been aware of them.
Freeman Dyson (actual IRL physicist, look him up) came up with the concept long before 40k was a thing.

Larry Niven borrowed on the idea for his "Ring world" novels - first published in the late 60s - and since these novels were around when the 40k writers were borrowing concepts from Foundation and Dune and Starship Troopers as well as Judge Dredd, they would have been aware of them (and the halo artifacts from those computer games are likewise borrowed from the concepts).

Chromedog, we've got...Two? Or maybe one due to a retcon...maybe? The video I linked here Isaac Arthur says very few sci-fi books have delved into the Dyson Sphere besides the Ring World novel you mentioned he thinks they're far too huge to write, understandable, but if that's the case isn't it even more 40k? As it's well known to be over the top awesome.

The issue with Dyson spheres is that:
- If you want to build a Dyson sphere, you need a large fraction of the material from multiple star systems.
- If you have access to FTL, the simpler way to get more power is to go to a second star system, rather than try to capture a larger percentage of the power of one system.

So you'd need a cultural or religious imperative of some sort, to tilt the decision tree to the point where "We should build a sphere around that sun" becomes a reasonable conclusion to make. In a big galaxy, it's reasonable that there would be cultures that would go "We want to build a sphere around our sun", but if there's enough competition for resources (like you'd expect, if there are enough cultures around to ensure that there are some wanna-be-sphere-builders), you just end up with frustrated wanna-be-sphere-builders.

"The Also People" by Ban Aaronovitch features an advanced multi-species alien civilisation living in a Dyson sphere. When one of the sentient machines inhabiting the sphere is murdered, The Doctor and his companions are called in to investigate.

https://en.wikipedia.org/wiki/The_Also_People

Ah, of course, Doctor Who would have one lol. I think there could've been another Dyson Sphere or swarm in the Rogue Trader scenario I ran about a month ago or so, Dark Frontier, where the Explorers get trapped in a small system which has a 'Black Star' that makes it that any ships larger than Guncutters unable to move and the PCs eventually have to land on its many 'islands' to place an explosive to disrupt its power network. It's obviously a Yu'vath invention so that could be a Dyson Sphere.

Edit: Just looked over the scenario and no, it's the size of a 'medium-sized planet' so too small, unless it's a tiny star...

 chromedog wrote:
^^ Not the same thing, Nilai.
The technology needed to Capture suns and stuff them into a hyperspace pocket is likely far beyond the petty skills needed to build a shell of 1AU diameter around a sun. If you can do the former, then the latter is no longer relevant. When you can build a way to travel through the null-space realms, why build a sailboat?

The 40k writers SHOULD have been aware of them.
Freeman Dyson (actual IRL physicist, look him up) came up with the concept long before 40k was a thing.

Larry Niven borrowed on the idea for his "Ring world" novels - first published in the late 60s - and since these novels were around when the 40k writers were borrowing concepts from Foundation and Dune and Starship Troopers as well as Judge Dredd, they would have been aware of them (and the halo artifacts from those computer games are likewise borrowed from the concepts).

I disagree. Here is from the quote i posted earlier: "[...these celestial phenomena provide a near-endless supply of energy to the Dark City."

On the Kardashev scale a level 2 civelization are able to use all the energy of a sun. Spesefying a dyson sphere among the posabilaties. While the dark eldar has not lined their captured suns with a solar panel all of that energy has nowhere to go except directly into the dark city.

"In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. This law means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another."

The DE has lined their suns with civelization. Weather that energy is just used for heating and lighting it falls within the defenition of a dysons sphere.

https://en.m.wikipedia.org/wiki/Kardashev_scale

https://en.m.wikipedia.org/wiki/Dyson_sphere

https://en.m.wikipedia.org/wiki/Conservation_of_energy