How to make the universe last forever?

Just now, I had this idea. Suppose a race capable of manipulating absolutely everything there is to manipulate, including the laws of physics, decides to avert the heat death of the universe. How could they go about it?

After consulting Wikipedia's timeline, I think two changes need to be made:

• 1. Dispose of enough dark matter that the acceleration of the universe's expansion is stopped. If this isn't done, the universe will grow so large that all matter will be too far away for any kind of physical interaction. If too much dark matter is removed, gravity will cause the universe to collapse back into a Big Crunch. But the combination of dark matter repulsion and gravity attraction, if precisely balanced, could make the universe's size eventually ending up asymptotically converging on a certain, static size.
• 2. Give every chemical element heavier than hydrogen a half-life, maybe in the quadrillion year range. Given enough time, all matter would spontaneously decay back into hydrogen, ensuring an endless fuel supply for stellar formation. If not done, all matter will eventually end up in black holes.

Is this enough? If not, what else is needed?

The heat death cannot be averted for one simple reason : the Second Law of Thermodynamics. Entropy always increases, and this can only be reversed by an outside energy source... but there is no such thing as outside the universe.

Also, regarding your second idea : if every element decay spontaneously back to hydrogen (which probably requires altering physical constants), then nuclear fusion is no longer possible — or rather, it has a negative energy balance. Otherwise, the First Law of Thermodynamics would be violated : it would be like CO 2 and H20 spontaneously condensing back into gas and oxygen, ready to be burned again.

edited 9th Jun '15 4:35:05 PM by Aetol

Worldbuilding is fun, writing is a chore

^ That we're aware of.

"Allah may guide their bullets, but Jesus helps those who aim down the sights."

Your second option doesn't make much sense to me. They wouldn't decay back to hydrogen. They would just decay as energy.

As for your question, you are aware that there is no level of technology that will ever be able to do that, right? You need magic to do all that. And if you are able to do everything, you don't need to save all of the universe. You could just keep supplying matter to your star and live in your paradise system. If you need to keep all of the universe alive, just do that for every star. Or if you let stars die just add a clause that new stars will always be created by magic.

As for the expansion of the universe and stuff being too far away from each other, my first question would be "So what? You can travel much faster than light, so the distances are not important. But since you asked, you could just play around with the gravitational constant, until you achieved an equilibrium.

By definition, if we can interact with it, it's in the universe. Maybe there are other universes that could be said to be outside our own, but since they're separate universes we can't extract energy from them.

And anyway, no matter what you can add to the universe, you're only delaying the inevitable. The only solution I see would be to have a truly infinite universe, containing an infinite amount of energy ; and be the only one to actually use that energy, which means somehow extinguishing all the stars we're not using. Only then, if we have an infinite supply of energy used at a finite rate, the global entropy would stop increasing.

Except extinguishing an infinity of stars (and destroying any civilizations you might encounter, too) is impossible. It would take a literal eternity, and past a certain time the rest of the universe will have reached heat death. So you're stuck with whatever finite amount of energy you could salvage in the meantime, and it won't last forever.

edited 9th Jun '15 4:47:34 PM by Aetol

Worldbuilding is fun, writing is a chore

If one universe won't do, exploit others. There ought to be an infinite number of them out there, and nobody's going to miss the vast majority of them.

Reality is for those who lack imagination.

Yes, but they probably have stars too, so they're using up their own energy and approaching their heat death by themselves. As I said above : at some point in the future, everything that we haven't reached yet will be at maximal entropy, and therefore unusable.

(Also as I said : are they really different universes if we can exploit them ?)

Worldbuilding is fun, writing is a chore

What about that Isaac Asimov story where a computer spends billions of years figuring out how to fix the universe ending, even existing outside of reality by the end of it, and then it figures out how to fix the lack of a universe and brings everything back.

If They are that powerful, then kick 2nd Thermodynamic Law's asses. Problem solved.

...Although eternal universe also has it's own share of problems.

I beg to differ. No amount of technological advance can bypass a physical law.

Worldbuilding is fun, writing is a chore

Well, according to opening post, They can manipulate any physics law. I'm sure if you can manipulate element deconstruction, then you can pretty much manipulate everything.

But no physical law is assured to be absolute.

We could be totally wrong. It's astronomically unlikely, since there's so much to support them and we'd have to rethink almost everything we know if they're wrong, but that's science for you.

Science never says that they're 100% right since there's always the possibility of being utterly and hilariously wrong.

Of course, what we're talking about doing is so hilariously huge that it defies all scales.

Like, let's say the planetary authority gets together and starts building huge solar-panel satellites with the intent that they all, put together, will occlude and capture all of the suns light. This is a work the likes of which make all earlier architectural achievements of human seem like sandcastles. This is something of such scale that they will probably have to deconstruct some of the inner planets and scoop up most of the asteroid belt just to provide the raw materials and room for this. This is something that will require entirely new branches of architecture, engineering and mathematics to be invented just to describe and work with this swarm of satellites. When it's finished it will be something so vast that even in the deep future, when the earth has been devoured by the expanding sun, this monument will leave traces that can be read by creatures of the far flung future, in a time when the stars themselves start to die. When it's finished it will probably outmass our entire planet, and the energy derived in a single second would have been able to support 20 century earth's power consumption for several thousand years.

And if you asked these people, these demigods what they thought of this plan to reverse entropy?

They'd laugh in your face at the sheer ridiculous scale of it. That is something that is further away from their capabilities than building a dyson swarm around every star in the Milky Way is to us. It's crazy.

But hey, science fiction man.

edited 10th Jun '15 6:05:00 AM by Matues

You can't break a physical law. They get bypassed all the goddamn time, usually by way of another one.

Reality is for those who lack imagination.

Broken? No, but they can be discovered to be incomplete or otherwise inaccurate.

I mean, we've gone from Things Fall Because They Want To Be On the Ground to Here's How Things Move (Dunno Why) to Space Is Bendy And That's Why Things Fall to GRAVITONS!

So I think absolute statements should be avoided, because fuck if I know what our technology and discoveries will uncover in a millennium.

Absolute statements trap you in the possibility of being wrong.

We could not be totally wrong. Even when a theory replaces another, the new theory must still give the same results as the old one in all the situations where the old theory had been verified. For example, even though Galileo's findings where supplanted by Newton's theory, then Einstein's, Galileo's findings are still verified on Earth's surface, even when accounting for general relativity.

The Second Law is a bit different though, because in essence it is a statistical principle. And while changing physical properties of the universe is at least conceivable, changing mathematical properties is another kind of impossible altogether.

Worldbuilding is fun, writing is a chore

This is what I get for making absolute statements.

So, yes, we can't be totally wrong unless we find out we've been missing some underpinning law of realty that invalidates everything we know, but that's not really something you can really assume exists. It'd be kind of obvious.

At any rate, People with the level of control and power over the universe that the OP describes would basically be capable of laughing at anything resembling a the laws of reality.

At that point you've got the power to play origami with space-time as an amusing party trick. They could stop the heat-death of the universe just by saying that it no longer applied. It's not like their authority is circumvented by distance or any sort of energy expenditure.

As others have mentioned, aside from dark energy and the expansion of space, the second law of thermodynamics is the main obstacle to overcome. It applies to all baryonic matter in the form of proton decay, and it applies to black holes in the form of Hawking radiation. Essentially, what you want is an 'eternal power box', a device that violates the 2LTD by constantly producing new useful energy and is efficient enough to sustain its own integrity against proton decay and the like while still giving you a significant amount of surplus of power to work with.

The most obvious way of going about this, given what we currently know, is probably to make use of zero point energy. Quantum physics states that all force fields, while appearing flat on a macroscopic scale in the absence of appropriate influences such as a massive object (for gravity) or a magnet (for electromagnetism), must actually be constantly undergoing random fluctuations on a very small scale. This effect doesn't seem to show up much in nature (aside from dark energy, which may derive from it in some way), but can be measured in the laboratory with the right sort of apparatus. So far nobody has proposed any physically feasible way of building an eternal power box that can extract useful energy from this effect forever, but it at least seems less blatantly impossible than traditional perpetual motion.

Another alternative is the EMdrive. If it works as claimed, it would potentially violate conservation of energy by way of violating conservation of momentum as commonly understood. You could release the machine in one place and have it accelerate across a long distance of space, hitting the other end at a very high speed and carrying a large amount of kinetic energy derived seemingly from nowhere. With the drive in its current state of development this would probably require interstellar distances in order to be useful, but if it can be made far smaller and more efficient, there seems to be no inherent reason you couldn't build an eternal power box on a relatively small scale. Moreover, this may turn out to be just another way of harvesting zero point energy, depending on exactly how the drive works, assuming it does work.

Until further notice, both of these should be regarded as long shots in the real world. But they're believable enough for sci-fi.

I wouldn't call it 'astronomically unlikely'. Historically speaking, whenever there was an economically worthwhile reason to violate the then-understood laws of physics, somebody usually did it sooner or later. We've only known about the 2LTD for less than 200 years, and we have billions of years in which to break or circumvent it. Never underestimate the power of intelligent beings who really want something.

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You're confusing technological limitations and scientific impossibilities. One can be overcome with enough R&D and economic incentive, the other needs ground-breaking scientific discoveries. Not quite the same thing.

On the EmDrive : while it does violate conservation of momentum (on paper, that is) it cannot bypass conservation of energy. You still need to power the damn thing.

edited 10th Jun '15 4:35:49 PM by Aetol

Worldbuilding is fun, writing is a chore

Nuclear reactions do. Matter-antimatter annihilation, nuclear fission and nuclear fusion routinely break the Law of Conservation of Mass. Nuclear reactions and matter-antimatter annihilation destroy mass and convert them to energy.

Similarly, a massless ray of energy if applied sufficiently close to an atomic nuclei splits into subatomic particles with mass. Matter created thus violating the First Law of Thermodynamics albeit in extremely small scale.

Granted, these violations are minor and tie into other things that don't mean the failure of causality or special relativity or what have you.

"Allah may guide their bullets, but Jesus helps those who aim down the sights."

Nuclear reactions don't exactly break the law, they sidestep it via the law of matter/energy equivalence.

Which was my point earlier. Even unbreakable laws can be bypassed.

Reality is for those who lack imagination.

Not really. I'm implying that we think is impossible at any one time has a tendency to turn out somewhat more possible after we've worked on the problem for a while, especially when somebody has a big incentive to solve it. Anytime a claim is made that something is impossible, it frequently ends up being scientific hubris sooner or later, and sometimes a lot sooner than anyone expected.

I'm not the first to observe this pattern. Clarke's First Law makes a very similar statement.

Violating conservation of momentum basically permits violation of conservation of energy by default. If the EMdrive can maintain a constant (relativistic) acceleration given a constant level of power, you can load a certain finite amount of energy into it, set it off, and eventually have it accelerating fast enough that it's adding more kinetic energy per second, relative to your frame of reference, than the power drain it incurs to its energy stock, from its frame of reference. At least, that's my understanding.

No. The energy released by the reactions has the same mass as the matter (and/or antimatter) that you originally put into them. Indeed, physicists often regard mass as simply 'a measure of the net energy of a system'.

edited 10th Jun '15 5:35:11 PM by Meklar

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As far as I know, proton decay is just a hypothesis.

Last I heard, it's considered pretty solid. Like, roughly on the level of 'we haven't actually observed this, but if it doesn't happen we'd have to rethink basically everything we know about quantum physics'.

EDIT: Checked Wikipedia, sounds like it may be a little more tentative than I'd thought.

edited 10th Jun '15 7:22:14 PM by Meklar

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Well, I have a setting with a group of "gods" who draw large amounts of heat out of various areas, including the universe as we know it, in order to accomplish great tasks and it slowly radiates out of them as they work.

With a conscious effort they could send heat by to higher concentration areas indefinitely but they don't. A point of the story is that they are functionally immortal but their bodies are not eternal. They are constantly changing in uncontrollable, unpredictable ways in the same way the surface of the Earth is constantly changing. They by and large don't want to make the universe last forever because the universe has and will last forever, it just hasn't and will not last forever as currently known. The thought of preserving the universe how it is wouldn't even occur to most of them(and hadn't occurred to me), though they by and large react with hostility to attempts to direct the changing of the universe to the detriment of others, especially if they think it will effect how their bodies change.(this gives them a loose allegiance humanity, as they are convinced most organic life is in fact a part of their bodies, they used to be called gods because humans are a species that once worshiped the sun)

I suppose you could do something similar, just make your group more focused on keeping things they way they are right now through the redirection of heat transfer on a molecular level. As said though, you'd be getting into the level where technology looks more like magicdivine power. Maybe taking away the functional immortality would help diminish that element? Since they would be trying to preserve something, death gives them a way to fail, they have a motivation to have babies, ect.

edited 13th Jun '15 3:28:49 PM by IndirectActiveTransport

That's why he wants you to have the money. Not so you can buy 14 Cadillacs but so you can help build up the wastes

I don't see how anything that can manipulate the molecular motion (apparently without using energy to do so) on that scale would be susceptible to aging. They could just arrange for whatever deterioration they undergo as result of time not happening.