Creating a Galaxy

[Darth Ruinus]

Inspired by those threads about creating stars and keeping stars alive. I have been kicking around an idea in my head for a civilization that has ships that are able to create galaxies in empty areas of space, but I have absolutely no clue how they would go about this.

So, what would it take for the creation of a galaxy? Or what civilizations in Sci-Fi can do such a thing?

[Covenant]

Whuh?

I'd say that you'd need a vessel approximately the energy content of a galaxy.

But seriously, you're asking for some absurd "rabbit out of the hat" schenanigans when you want to create an entire galaxy out of empty space. You need to take a massive dump on science in general to even invent a sci-fi theme where such a thing is possible, so the kind of vessel used at such a point is mostly irrelevent. You might as well just say that the ship is a normal vessel, but that it uses a special bomb with a core of Transphased Temporal Locked Omni Particles to create the effect. Or that the ship is an ancient relic of The Prefounderians and only a 14 year old human girl from Japan can activate the device.

You need to make energy out of nothing, which everything says is impossible. You could instead just ferry the necessary elements to the appropriate region of space and start pumping them out, but honestly, space isn't like a vast empty field. The Universe is a bubble defined by the gravity of the objects inside of it, mostly, so adding a galaxy to a region is just likely to get the galaxy to start drifting off into one of the large superclusters, where it might be torn apart.

If you're looking for a civ that wants to make a tailor-made galaxy to live in and not be bothered, it's much more feasible and reasonable to have them cherry-pick stars out of other galaxies and fly them off to the right places. All you need for that is a starship capable of dragging a star to the right area, or somehow teleporting it there. It's an absurd amount of power to do that, but many Sci-Fi settings include megascale equipment capable of moving planets and occasionally starsystems without getting to the kind of beyond-Skylark level insane nonsensicalness you were first proposing.

[Darth Ruinus]

I never mentioned anything about them making a galaxy out of nothing...

[Covenant]

Creating a galaxy from an empty area of space is essentially like making it from nothing.

What else could you do? Construct it from gas? Drag over a few billion stars worth of hydrogen and let it work itself out? The problem then is not only a matter of energy, since the energy to MOVE that amount of mass is pretty absurd, let along storage... but also efficency. The only place you'll find that amount of mass is, probably, in another galaxy. So you'd basically have to disassemble a galaxy to reassemble it in a different form somewhere else. That's a lot of work, and it's basically just silly.

You'd be better off constructing it from pieces that are fully assembled, like grabbing entire starsystems and so forth. In any case, you wouldn't have a ship capable of creating a galaxy. That's madness. You'd want to have lots and lots of smaller ships capable of moving stars and planets, and together start assembling a galaxy.

But even so, most if not all galaxies seem to have a massive black hole at the center, which presents it's own problems. Are you going to agree to sacrifice a good amount of your hard-moved material to one of those cosmic gluttons? Or are you going to try to steal one and move it to your intended destination? Dragging a black hole... that's pretty wonky. They'll mass in at millions of stellar masses, which means anything used to transport one would have to be absolutely absurd, or it would have to be absolutely absurdly well organized efforts of smaller ships, or some kind of deus ex machina that can teleport a supermassive black hole across vast regions of space. Don't even bother thinking about the military applications of such a maneuver.

And if you don't get one, your galaxy will quickly collapse inwards and create one anyway, so you'd need to replace the thing with some sort of immense repulsor equipment, or have the entire galaxy rigged up with gravitational tractors that conspire to keep it rotating without the massy center.

The type of galaxy you'd probably end up making would be a spherical shape instead of the vortex-like spirals, with some kind of Big Dumb Object in the center of the star shell. The kind of equipment you'd need to make this is so immensely advanced that I can only imagine it as being an Endgame civilization that's basically got no reason to even exist biologically except amusement factor, or is creating the galaxy for some other, unknown purpose.

Anyone else, who needed real estate, would more easily be able to invade and clean-out another galaxy in short order. The power levels here are really up there. It's not impossible to imagine a civilization with that kind of power, it's just hard to imagine that it would be done for any reason other than vanity.

[Darth Ruinus]

Creating a galaxy from an empty area of space is essentially like making it from nothing.

that are able to create galaxies in empty areas of space.

Anyways, yeah, it is pretty wonky, far fetched, and downright silly, which is one of the reasons I like the idea so much. The idea I had in my head was giant jelly-fish shaped ships, and I mean giant, able to carry around all the mass necessary to make a galaxy (or just a galaxy already made, and simply plucked from somewhere) that would, together with millions of other such ships, enter areas of space that are almost empty, and "lay" stellar eggs which hatch into galaxies, or simply go around plunking down galaxies and seeding them with life.


So anyways, it sounds like it would just be easier for them to simply move galaxies rather than make them on the spot. Ok.

What if the ships just carried dark matter and gases, and simply let the galaxy occur naturally?

[Darth Raptor]

Ironically, and with that kind of wanktastic magitech, it's probably easier to make an entire universe ex nihilo with quantum weirdness than it is to make a single galaxy through "conventional" physics. You'd need enough time (an eternity) and REALLY empty space (more like a non-dimensional void of actual nothingness, which is distinct from vacuum) for quantum weirdness to matter. You'd have a Big Bang on your hands though, and your fried egg needs to cool before you can use it. So you'd actually get trillions of galaxies, but in practice it would be more like an inhabitable pocket dimension than some kind of obvious monument.

[Covenant]

The important word is empty. Assembling a galaxy requires materials, so doing it in empty space is impossible. The only way to do it is by making the area non-empty, which to me defied the purpose of creating it in an empty area. And as I'll say below, there's no way of making that amount of matter 'travel ready' so your options are a lot slimmer.

The idea I had in my head was giant jelly-fish shaped ships, and I mean giant, able to carry around all the mass necessary to make a galaxy (or just a galaxy already made, and simply plucked from somewhere) that would, together with millions of other such ships, enter areas of space that are almost empty, and "lay" stellar eggs which hatch into galaxies, or simply go around plunking down galaxies and seeding them with life.

Not millions, billions. There are billions of stars in a galaxy such as ours, and even one half the size you're looking at possibly lugging around 10 billion stars, and that's not even counting the mass in Dark Matter and general detris, and things like planets, Oort clouds, Black holes, etc. So if you had a fleet of a trillion starships, each one capable of relocating a star, you're looking at the right scale to do something like this effectively.

The idea of a steller egg is just idiotic though, so I'd recommend ditching it or re-explaining it. If you took all that matter and put it nice and close, all you'd get is a big angry supermassive black hole. The density of your material MUST be very low or else it will collapse, so you're either ferrying it in small loads on many, many ships or bringing over a ship that's actually the same size as the galaxy--and probably masses several times one. A question is, then, why the ship itself would not collapse inwards on it's own weight.

By and large, the best idea is to simply move a galaxy instead of make a new one, and your 'ship' would just be some sort of engine designed to relocate the supermassive black hole at the galaxy's center. If you can shove that big boy somewhere else, the galaxy will drag along with it. Viola! Galaxies as ammunition.

So anyways, it sounds like it would just be easier for them to simply move galaxies rather than make them on the spot. Ok.

Yes, but I just want you to understand the immense volume of material you're talking about here. Lugging around something the size of a star is not a simple task, and even if you're physically capable of doing it, there's a lot of possible problems. The star could collapse and go nova, it could break apart, and a million other things. If you were somehow able ot transport it without shaking it up too much then we're talking about some really insane technology levels. Even if the ship isn't insanely huge (which I would assume it would be in order to posess the energy capable of doing this task) it would have a ridiculous amount of power.

Not that I mind, I just want you to understand the implications of such power. Your Jellyfish and egg idea isn't really feasible, but there's ways to get it closer, if that's what you've got a hardon for.

What if the ships just carried dark matter and gases, and simply let the galaxy occur naturally?

Then you're still talking about millions of years of time to wait while the gasses slowly pull together, and there's really no reason to do it either. What's the purpose? If they're doing it out of vanity, nostalgia, or some kind of unreasonable reason (like religious edicts and such) then it is certainly EASIER to let nature take it's course, but it won't be quick. This is a civ that'd definately want to go into cold storage for the duration.

[Zablorg]

The important word is empty. Assembling a galaxy requires materials, so doing it in empty space is impossible. The only way to do it is by making the area non-empty, which to me defied the purpose of creating it in an empty area.

I think the point is that the galaxy-creator ship goes to an empty area of space and makes a galaxy there. That's all. The "empty space" bit doesn't hold any special relevance in the idea save the fact that it's empty enough to make a galaxy in.

[NoXion]

Not millions, billions. There are billions of stars in a galaxy such as ours, and even one half the size you're looking at possibly lugging around 10 billion stars, and that's not even counting the mass in Dark Matter and general detris, and things like planets, Oort clouds, Black holes, etc. So if you had a fleet of a trillion starships, each one capable of relocating a star, you're looking at the right scale to do something like this effectively.

Couldn't a ludicrously advanced civilisation use a loop of cosmic string as a "gravity tug" to move galaxies wholesale? I've read about using cosmic strings as time machines, which involves moving them about, so surely a civilisation capable of doing that would be able to use cosmic strings in such a manner...

Of course, even if you could get the galaxy moving at significant fractions of the speed of light, it would take aaaaaaaaaaaaaaages to move the galaxy to any cosmologically significant distance. So as well as having god-like technology, the civilisation in question would need all-surpassing patience.

But hey, the Photino Birds managed to do it, and the Xeelee have demonstrated the ability to manipulate cosmic strings (or do they naturally occur in loops, and the Xeelee simply put one they found to use?).

The idea of a steller egg is just idiotic though, so I'd recommend ditching it or re-explaining it. If you took all that matter and put it nice and close, all you'd get is a big angry supermassive black hole. The density of your material MUST be very low or else it will collapse, so you're either ferrying it in small loads on many, many ships or bringing over a ship that's actually the same size as the galaxy--and probably masses several times one. A question is, then, why the ship itself would not collapse inwards on it's own weight.

An idea occurs:

Think in terms of a seed rather than an egg. Pluck a supermassive black whole from somewhere, and surround it with matter-energy conversion machinery that converts Hawking Radiation and any infalling energy and matter into starstuff. Again, I'd guess this method would take a very long time, but since photons don't decay (as far as I know) I'm guessing one could continue making stars in this manner until at least the early stages of the heat death of the universe.

I very much suspect that creating an entire universe would actually be easier, especially as you can tailor the initial conditions to one's requirements.

Perhaps instead of creating galaxies, Darth Ruinus could have his cosmic jellyfish be universe creators rather than galaxy seed carriers. If I remember correctly, it's conjectured that one could create a universe by compressing a large but finite amount of matter using a large but finite amount of energy. Certain black hole "metrics" seem to be traversable, so it might be possible that after the matter compression one could end up with a black hole leading to a baby universe "budded" off the original one. So not only have these cosmic jellyfish created a universe, but you can enter it too.

Of course, all of this is extremely speculative and most likely horribly wrong, but it sounds good.

[Covenant]

I think the point is that the galaxy-creator ship goes to an empty area of space and makes a galaxy there. That's all. The "empty space" bit doesn't hold any special relevance in the idea save the fact that it's empty enough to make a galaxy in.

Which is the problem that I keep talking about--you either need a mechanism to create mass out of nowhere, or you need to transport all that mass with you. This is a set of impossibilities.

It's obvious why creating matter from nothing is impossible. But transporting that mass in a brick of matter is impossible since it would just collapse into a black hole, and that kinda ruins your plan for galactic creation right there, unless you're telling me you're going to pop the a black hole with possibly a hundred billion stellar masses somehow, and cause it to inflate fast enough not to re-collapse, but slow enough not to simply expand out into other galaxies and be absorbed.

A galaxy exists not in the void, but in large clusters of other galaxies, like the Local Group that we belong to. Your galaxy, even in an empty area, is going to be tugged into orbit with one of these groups.

You need a third option. You can either move the galactic materials in a low-density form (such as galaxy) or you can move it in small parts or you can just move a galaxy to an empty region of space. Either way, all of those third options aren't making a galaxy so much as reorganizing one or transporting one. That's a matter of semantics, but I think his own comments confirm that he wanted to create a galaxy fresh from some other starting form, such as an egg of the appropriately-massed materials that he mentioned.

Couldn't a ludicrously advanced civilisation use a loop of cosmic string as a "gravity tug" to move galaxies wholesale?

You don't need to invoke something as obscure as a cosmic string, the gravity tug is already there. Nearly every galaxy we can see, and quite likely all galaxies anywhere, have a supermassive black hole at their center. They all essentially rotate around their shared center of mass, and the black hole is a big part of that network. Galaxies are always in motion anyway. We are currently moving at approximately 500 kilometers per second as a galactic mass ourselves. So shoving a galaxy somewhere isn't out of conception, as it's happening at the moment. The only question is how long are you willing to take and how much energy do you have available.

Do you want to do the calculations to figure out how much energy it would take to slow down and then reverse the speed of the milky way? I'm not sure you do! Any engine capable of doing this would use so much energy up that it would probably need to burn the mass of another galaxy just to pay for it. But if you had enough energy, yes, a gravitational tractor works fine. You just need the energy to keep reorienting the tractor, in this case, the black hole.

Think in terms of a seed rather than an egg. Pluck a supermassive black whole from somewhere, and surround it with matter-energy conversion machinery that converts Hawking Radiation and any infalling energy and matter into starstuff. Again, I'd guess this method would take a very long time, but since photons don't decay (as far as I know) I'm guessing one could continue making stars in this manner until at least the early stages of the heat death of the universe.

Well, regardless of the universe-creation stuff of which I know too little to comment, yes, you could essentially create your own galaxy by spinning a web around a center mass. What you want to avoid, though, is allowing the mass to simply be drawn into the black hole and swallowed up--you're going to want to make sure that the orbit you kick the stuff into will be appropriate. Assuming that you could extract the energy from the hawking radiation to run your machine, and your stuff wouldn't die, I suppose an ultramassive black hole in the process of slow evaporation could be a useful power source, and it allows you to circumvent the issue of "oh noes i can has nothing but black hole" that presents itself whenever you slam a few billion stellar masses together.

However, if you're willing to build a galaxy the slow way, by spinning it together from threads, you have an immensely vast range of ways to do that. It's basically night and day--vomping a galaxy into being in a dramatic "in the beginning" moment is very nearly impossible. But being a galactic spider is possible. A single ship with a single small cargo hold, enough time and enough energy could conceptually do the job. You only need huge numbers of ships, or immense vessels the size of Andromeda, if you want to do it fast.

Your situation about avoiding heat-death seems the most reasonable, as is your solution to it. Essentially mining a black hole for the energy to create matter that will be used to create stars could be the most time-intensive and pointlessly inefficent process ever, but if it's a choice between that and the cold blackness of neverending space, I think your theoretical uberciv could be convinced to invest in the galaxy-builder plan.

[Darth Ruinus]

it's conjectured that one could create a universe by compressing a large but finite amount of matter using a large but finite amount of energy.

I think thats in M-Theory isn't it? Pumping that mass and energy into a string or whatever and you end up with a small mini Universe within that one.

[Teleros]

So, what would it take for the creation of a galaxy?

1. Time. Unless you're able to shove ready-made stars through wormholes and the like, it'll take a long time to move everything into position.
2. Silly amounts of mass. Mostly hydrogen gas of course, but you need the raw materials somehow.
3. Silly amounts of energy. Either to move the raw materials or use some sort energy-to-matter converter.
4. Forward planning. As said, galaxies tend to appear within clusters and the like, but even if you build one in the middle of nowhere, it will affect other galaxies and get moved around.
5. Transportation. Unless you can generate all the raw materials on the spot or use wormholes etc, you have to transport a hell of a lot of stuff from A to B, whilst presumably avoiding turning the cargo holds of your ships into black holes . Oh, and whatever you're making your ship out of probably violates everything we know about tensile strength and all that too .

By and large, the best idea is to simply move a galaxy instead of make a new one, and your 'ship' would just be some sort of engine designed to relocate the supermassive black hole at the galaxy's center. If you can shove that big boy somewhere else, the galaxy will drag along with it. Viola! Galaxies as ammunition.

I'm reminded of the Xeelee Ring & the photino birds hurling galaxies at it in Stephen Baxter's books...

Think in terms of a seed rather than an egg. Pluck a supermassive black whole from somewhere, and surround it with matter-energy conversion machinery that converts Hawking Radiation and any infalling energy and matter into starstuff. Again, I'd guess this method would take a very long time, but since photons don't decay (as far as I know) I'm guessing one could continue making stars in this manner until at least the early stages of the heat death of the universe.

You have to make sure that all the hydrogen gas (or whatever) created is sent a long way out from the black hole though: you don't want it falling back in, and presumably you'll want a decent sized galaxy as well - spreading out all that gas across 100,000LY will mean both a long time and lots of energy.

Personally, I'd go for some combination of energy to matter conversion, von Neumann machines, and a convenient source of (practically) unlimited energy (let's say your von Neumann machines can tap hyperspace for energy or have Plot Device batteries or something). It will still take ages even if you've near-instant FTL, wormholes and all that to help, but assuming you can do it it would probably be the most efficient and relatively quick way. Compared to transporting all the materials required it'd be dirt cheap, and runaway star-building replicators aside, probably a lot safer too.

The other thing I'm wondering about though is why someone would want to do this. Unless you can make it from nothing (or my hyperspace tapping replicators or something), you're really just shifting a lot of mass around, which just looks impressive - there are more efficient ways to establish new habitats for example - look at Dyson spheres and all that.
One possibility I have thought of though is if the expansion of the universe is eventually going to overwhelm gravity etc and rip everything apart (or a similar non-Big Crunch end to the universe). Creating new galaxies might be a way of slowing down the expansion of the universe, and thus let your civilisation continue either indefinitely or at least for a lot longer. I've no idea if this would actually work, and for all I know you'd need so much new mass you'd have galaxies colliding left right and centre, but perhaps with a little tweaking of physics it could work.