Consequences of violating conservation of energy

[JCarter426]

Lately, I've been trying to reconcile the laws of the supernatural with the laws of physics. I'm more of a science fiction than fantasy fan, so I don't like writing anything off as just because a wizard did it. I like stories that are grounded in science, or at least in some logical system. They may stretch the rules a bit, take liberties with the science, but I appreciate when the idea is there. But there are many fantastical elements in those stories that are hard to explain, as well. The fundamental problem with nearly all of them is that they rely on energy coming from nothing. Even assuming you had the ability to extend your mind outside your body to manipulate things beyond your reach - matter, or heat, or magnetism, whatever - you couldn't do anything without the energy to power it. Without the energy you couldn't lift a paper clip, let alone the Golden Gate Bridge. Sometimes there's a cursory explanation, like the sun or the motion of tectonic plates, but for the most part the laws of thermodynamics are damned.

So let's assume there is some method, beyond our understanding of science, of creating energy. I've been trying to examine the consequences that would have on our understanding of entropy and causality.

My first concern was all the waste heat generated by magic. If you have all these people in the world moving bridges and creating fire with their minds, we're going to run into another problem with thermodynamics. I haven't done the math to find out how bad it would be, but I suspect not good, so I've tried to think of ways to rectify this. Maybe you allow for the destruction of energy as well - cold rays that actually remove temperature, disintegration that actually erases matter, and the like. Maybe in the long run it'll even out.

Another possibility I considered is that perhaps the energy only exists for a short time before dissipating, like it's willed into existence but the universe pushes it back out of existence. If you conjure a sword or cast a fireball, they only exist for as long as the spell duration. That would potentially have the benefit of brushing the issue aside; energy isn't really created in the long run, so it can't be too bad. And it has narrative benefits as well; it fits with spells as they're described, and adds a potential layer of depth with regard to spell strength vs spell duration. But I realized this too is problematic. Even if the mass of the sword goes away, it has still cut through things. Whatever the fire burns may cool down, but it is still burnt. The energy has been used to do work. Clearly some of the energy continues to exist in some form, and that raises the questions of what energy remains, how much, and why that energy but not the rest. It seems the idea that energy can be created merely temporarily is as ludicrous as the notion that it can be created at all.

These issues arise in time travel as well. If you go backwards in time, that means you've added energy to the universe at that given point. Though there are some theories that allow for it, closed time-like curves that allow a particle to reach a point earlier along its worldline. The math says that's ok. Perhaps a positron is merely an electron going backwards through time. Perhaps there is only one electron, with a massively complex worldline. The math suggests some crazy things.

But there is the issue of the grandfather paradox. No, not the paradox itself. My problem is with the mysterious force that's supposed to erase a person from existence. Marty McFly begins to fade after interfering with his parents' meeting; again, that's destroying energy. The problem with the paradox too is that, logically, he should have always existed or never existed. It seems that conservation of energy is truly a constant. Everything that exists has always existed and will always exist, in whatever form it may take.

And I've heard theories that suggest the creation of energy, or more precisely information, can have even more troubling repercussions on causality. So my question is... is there a way? Is there a way to imagine energy is created or destroyed without having to throw out all the laws of physics and allow for anything to be possible?

[factotum]

Well, no...conservation of energy is about as fundamental a property in physics as you can get, if you break that, the whole structure collapses. However, I'm not sure that generating energy from nothing on the surface of the Earth would actually cause too much of a problem, because the excess will get radiated into space? If you think about it we've been burning fossil fuels for centuries now, and that hasn't directly warmed the planet--global warming is caused by CO2 buildup in the atmosphere, not the heat from our fires.

[Chen]

Just assume all the energy that is created by magic or the like comes in from some other, alternate universe or something. Same with all the waste heat or whatnot that would result of doing what people do.

[Kato]

Ignoring conservation of energy on a large scale, yes, would mean the whole universe would break down.
However, such minor events as casting a fireball, even if one in ten people did it regularly, would hardly if even measurably affect Earth's energy balance. We produce a ludicrous amount of waste heat as it is, with all kinds of devices and machines and body heat, etc.
Making more matter might be slightly weirder but still, you really need to try hard to make a dent on a planetary, let alone a stellar scale.


The idea with "borrowing" energy (or matter) for the duration of the spell is actually pretty useful and solves many problems. A cut from a magic sword doesn't have any "more" energy, and a piece of burnt flesh on the whole has less energy, so it's not a problem if the energy disperses. Only if you want to, say, cook water purely with a fireball, the water would cool down. But you could set a forest on fire, because once the spark has done its work, the forest will continue to burn on its own.
As long as you don't want to conserve energy, or keep matter, the borrowing idea is fine for a work of fiction. Also, better mages being able to lend more energy/longer is a good explanation for different skill levels.

Something I like to do if I feel the need to justify magic is turn mages into gluttons, as in they need to provide the energy their spells use with their own caloric intake. Of course that is not something one should run the numbers on, but still :smalltongue:

[Yora]

Doesn't even need to be from another dimension. The great thing about mass and energy is that you theoretically can have any form change into any other. (Entropy and waste heat being the notable limitation, but still conforming to that.)

You don't have to create energy when you can tap into some form of energy that is already present but not actively doing anything that people perceive directly. Vacuum energy, cosmic background radiation, or just sunlight or potential energy from gravity. If the source of the energy is massive, which for any cosmic or interstellar phenomenon would be the case, the amount needed to make even powerful magic work would by insignificant on the larger scale of things.

Thermondynamically speaking, magic doesn't have to be any different than mechanical work, it just relies on fictional mechanisms.

[Fri]

In Culture series, how they seemingly power all their massive sci-fi technologies and whatever is that they use another dimension, subspace, or whatever. The animorphs store their extra masses in a subspace as well. Primitive civilizations like us might see them as creating energy out of nowhere, but they do have source of energy and venting it somewhere.

[Flickerdart]

What if magic uses dark energy and transforms it into regular energy?

[Lord Torath]

Well, no...conservation of energy is about as fundamental a property in physics as you can get, if you break that, the whole structure collapses. However, I'm not sure that generating energy from nothing on the surface of the Earth would actually cause too much of a problem, because the excess will get radiated into space? If you think about it we've been burning fossil fuels for centuries now, and that hasn't directly warmed the planet--global warming is caused by CO2 buildup in the atmosphere, not the heat from our fires.CO2 traps heat. So if your new energy source results in an increase in waste heat, it will also contribute to a warming globe. Not by increasing the insulation around the earth (CO2 concentration), but by increasing the amount of heat generated on the earth, which then has to get past the insulation to escape.

For an example of adding heat without changing the insulation: http://https://what-if.xkcd.com/35/. Just how much it will change the temperature depends on its effects on CO2 levels (probably will decrease levels if we can use it instead of fossil fuels) and how much waste heat it generates. If suddenly we have access to "free" clean power, I suspect we'll start generating a lot more waste heat than before.

[wumpus]

If your world has magic, then there is no known [a priori] relationship between magic and energy. Increasing the amount of energy may well reduce the amount of magic (and considering the relationship between mass and energy, don't be too surprised if you lose a *lot* of magic for a little energy).

It can make a handy bit of handwavium for moving a plot in the direction you want it to go.

[JCarter426]

Thanks for the replies, everyone.

With regards to energy coming from another universe, or another dimension, or subspace, or the vacuum, or whatever... yeah, I know that's a possibility, but I have a few issues with it. First, it sounds just a little closer to the sci-fi end of the spectrum than I'd like. And despite that, it's still essentially the same as saying a wizard did it. Furthermore, there's the danger of falling into god of the gaps scenario, if it relies on as yet unexplored science. It might follow the rules of thermodynamics as we know it, but a year from now someone could crack dark energy and establish other rules that would disprove the entire mechanism of the story. That's one reason I'm ok with it being closer to the fantasy end of the spectrum; you can't discredit the idea that people can create energy with their minds any more than you already have. That's one simple concept to deal with, so if you can get past that then the suspension of disbelief threshold is low.


The idea with "borrowing" energy (or matter) for the duration of the spell is actually pretty useful and solves many problems. A cut from a magic sword doesn't have any "more" energy, and a piece of burnt flesh on the whole has less energy, so it's not a problem if the energy disperses. Only if you want to, say, cook water purely with a fireball, the water would cool down. But you could set a forest on fire, because once the spark has done its work, the forest will continue to burn on its own.
As long as you don't want to conserve energy, or keep matter, the borrowing idea is fine for a work of fiction. Also, better mages being able to lend more energy/longer is a good explanation for different skill levels.
Yeah, those are the benefits I was thinking about. But even if the magically created energy dissipates, and a cut from a magic sword or a burn from fireball don't appear to have more energy than they started with, the level of entropy has changed. It would take more energy to restore things to the way they were before the magic, which is problematic to the laws of thermodynamics.

I've also been scratching my head trying to figure out how the energy disperses. Putting aside the requirement for some mechanism that magically destroys energy, how do you pinpoint what energy is "new" energy, created by magic? With a sword it's fairly easy: the sword vanishes. But if you're talking about a fireball, well, everything in the area has been heated up, so you'd have to figure out the rules governing that, whether it's an issue of distance, and that's linear or inverse square or whatever... and then there's the air pressure, and the actual chemical reaction that is fire. I guess it's more a question of difficulty in describing it, rather than a hindrance to its possibility.

It becomes further complicated when you try to address magic with permanent effects, because you have to explain why the energy doesn't dissipate.


Something I like to do if I feel the need to justify magic is turn mages into gluttons, as in they need to provide the energy their spells use with their own caloric intake. Of course that is not something one should run the numbers on, but still :smalltongue:
I forgot to mention this one. This is the exact mechanism for spellcasting in Slayers, and I've also seen it used to explain speedsters and other things of that nature. As you said, though, the numbers are... questionable. It wouldn't hold up for larger scale magic, unless you're talking about direct matter to energy conversion... in which case you wouldn't have to eat a lot in the first place, because E=mc2.


CO2 traps heat. So if your new energy source results in an increase in waste heat, it will also contribute to a warming globe. Not by increasing the insulation around the earth (CO2 concentration), but by increasing the amount of heat generated on the earth, which then has to get past the insulation to escape.
Yeah, that's my concern over this. Even if it's not a large amount, it's still adding to an existing problem, one that is causing our scientists a little trouble. And if the amount isn't negligible - and we're talking about the use of magic across thousands of years of history here, so it may well add up - then the greenhouse effect would've set in place ages ago. Again, that depends on how much heat magic would generate and whether that would have a significant impact on a planetary scale, but the underlying issue is there, so I'd prefer a solution that avoids it.


If your world has magic, then there is no known [a priori] relationship between magic and energy. Increasing the amount of energy may well reduce the amount of magic (and considering the relationship between mass and energy, don't be too surprised if you lose a *lot* of magic for a little energy).
The problem with this, though, is that if you assume magic can be converted into energy and energy into magic, that's basically a perpetual motion device.

[Misery Esquire]

Dear Sir,

We have recently noted that you have the ability to add energy to the universe.

Please find a way to cause this ability to be used autonomously of yourself and, if possible, to create additional sources of itself, thereby staving off the heat death of the universe.

Thank you kindly,
The Management

More seriously, I believe it would depend on what kind of energy you have created. Your created energy will still have normal waste, presumably, such as light and heat, but where does it go when you are directing the Golden Gate Bridge to rise with your mind? Discworld-ean where you can only lift as strong as your brain is, else it comes out your ears (Your brain, that is)? Or is it why alien tractor beams in movies always have the light show and eerie sound effect?

Aside from which fireball is downright dismissible compared to a (Dungeons and Dragons) wizard creating a ten foot block of steel. That is a lot of power.

Edit ::

The consequences of being able to create energy rather than simply transferring it from one form to another... I suppose you wouldn't actually have any input waste, your output waste would be... Strange, though. It can still dissipate as normal energies, unless you are creating, er, Temporary Energy? In which case you are also breaking it, by removing energy from the system.

[Closet_Skeleton]

What if magic uses dark energy and transforms it into regular energy?

...

That's nonsense.

There's no such thing as 'regular energy', just various types of energy (none of which are substances). Dark energy would be just another kind of energy, not something opposed to 'non-dark energy'. (since its sort of just another name for the cosmological constant it might not be energy at all). You could turn dark energy into other kinds of energy fine, but there's not a lot of it around in the local area and it would create entropy just like other kinds of energy transformation.

Did you mean 'turn quantum vacuum energy into real energy' because while that's completely different its closer to what you probably meant. It could also potentially make energy appear without violating conservation of energy.

[factotum]

With regards to energy coming from another universe, or another dimension, or subspace, or the vacuum, or whatever... yeah, I know that's a possibility, but I have a few issues with it.

Does the same apply to simply being able to convert matter into energy? There's a huge amount of energy locked up in even a small piece of matter, as the famous equation E = mc ^ 2 shows; it's fundamentally where nuclear reactors and stars both get their power. (The Sun outputs so much energy that it loses four million tonnes in weight every second, for example). You can put a fantasy slant on it by saying that's what the material component of the spell is--it's the item which is consumed to power the effect.

[NichG]

One thing to keep in mind is, whatever you want to introduce, it will almost certainly be going on at a base level as a natural phenomenon in the universe. For biological organisms to evolve to take advantage of it as a built-in ability, it would have to be easy enough that an un-tuned population of organisms could notice small changes ability as the species got closer to the correct way to tap it. Alternately, it has to be discovered by a process of intelligences studying the natural world - that is to say, there still has to be some observable natural phenomenon for human scholars to have studied it enough to figure out how to tap it.

The consequence of this is that if you've got a way to violate conservation of energy, it will be going on all the time everywhere in the universe. It won't just be the mages doing it, and odds are that mages will be a negligible contributor to the overall violation of energy conservation. For example, humans have studied nuclear fusion sufficiently to be able to create it artificially, but think of the ratio between e.g. a fusion bomb and the sun. So imagine whatever your mages are doing, and scale it up like that - odds are that something roughly like that will be out there, all over the place, in space.

Now as to the consequences, the main thing that conservation of energy 'means' for the laws of physics is that the laws of physics do not change over time (that is, time-translation invariance is the symmetry that produces energy conservation). So you could have things like the speed of light gradually drifting to a different value as the process proceeds. The weird thing is that this change has to be somehow not encoded by structures that are embedded in time (otherwise, you could just say 'oh, well there's some other set of laws of physics more fundamental that are constant, and which explain the drift in the speed of light'). So there's a pretty problematic logical closure issue there - you're almost certainly going to end up with a necessary consequence that there is some exterior 'universe' which is uni-directionally influencing the universe in which energy conservation is being violated, without being influenced in return (if you want the energy-conservation-violating process to be intrinsic, rather than only occurring at a boundary between universes, that is).

Another consequence is that the equations of physics become fundamentally unstable. Energy conservation excludes exponentially growing and shrinking solutions. If the mechanism for de-conservation is not just stochastic (the energy randomly fluctuations) but is directable - which you need it to be in order to have the supernatural be controllable at all - then you'll tend to get exponentially increasing or decreasing amounts of energy in the universe. That means that the universe will likely be very, very young compared to ours, and will have a window of time in which human-like life can survive that only lasts centuries or millennia.

[Swordsmith]

So you are suggesting that we could end up with a universe with vast amounts of matter and very little antimatter? Yeah, that would be Weird.

Or how about one where Dark Matter (the Ashes of magic) vastly outmasses "regular matter"?

Hard to imagine what that would be like.

Forget String Theory, I propose Wand Theory!

[NichG]

So you are suggesting that we could end up with a universe with vast amounts of matter and very little antimatter? Yeah, that would be Weird.

That particular feature is thought to possibly be the consequence of parity violation, actually.

[shawnhcorey]

The fundamental problem with nearly all of them is that they rely on energy coming from nothing.

Nope. Almost all magic system tell you that magic comes from Mana. Sometimes the Mana comes from the world, sometimes it's from the character's body. You seems to be complaining that Mana is ill-defined. Agreed. Mana has yet to have it Newton yet.

[factotum]

Nope. Almost all magic system tell you that magic comes from Mana.

Larry Niven (best known for his fairly hard SF novels) actually wrote some really rather good stories and books set in an ancient Earth where magic is real, but mana is a limited resource that is gradually running out. In those stories, Atlantis is tectonically unstable, and only the spells of the sorcerer-kings keep it afloat--when the mana runs out, the island sinks under the waves, never to be seen again.

[Closet_Skeleton]

Nope. Almost all magic system tell you that magic comes from Mana.

Not really.

Vancian magic: no mana

Plenty of mana/spell point systems don't actually have a in character explanation of it and just treat it as an abstract mechanic.

Mana as a concept was basically invented after 1891 and is completely absent from most folk concepts of magic (including the polynesian ones the word was lifted from).

[shawnhcorey]

Not really.

Vancian magic: no mana

Plenty of mana/spell point systems don't actually have a in character explanation of it and just treat it as an abstract mechanic.

None is needed.


Mana as a concept was basically invented after 1891 and is completely absent from most folk concepts of magic (including the polynesian ones the word was lifted from).

Yeah, someone was trying to reconcile magic without physics. It doesn't matter what it's called. All that matters is that it is a resource with limited access. A magician can somehow overcome this limited access and manifest mana as matter and energy. Conversation of energy is preserved because it comes from mana.

[Fiery Diamond]

None is needed.



Yeah, someone was trying to reconcile magic without physics. It doesn't matter what it's called. All that matters is that it is a resource with limited access. A magician can somehow overcome this limited access and manifest mana as matter and energy. Conversation of energy is preserved because it comes from mana.

Basically this. Most modern depictions of magic have it, or its source, be a limited resource that may or may not be renewable. Whether they explicitly call it out as mana or not is pretty irrelevant. While folk and historical depictions of magic often don't, this is, as shawhcorey said, because they weren't messing around with trying to reconcile magic and physics due to either a) not knowing or b) not caring, depending who and when we're talking about.

"Magical energy (which may be called Mana) is a (potentially renewable) resource used to power acts of magic (which may be called spells)" is fairly universal in modern fantasy, and it neatly gets rid of the problem of creating energy by saying that there is something, whatever this thing is, that exists that powers magic. Some stories and systems call it out more explicitly, telling us it's generated by a human organ (Trion from World Trigger; Mana from Tales of Xillia) or by the world tree (Tales of Symphonia, others) or something else. Others don't bother, but that doesn't mean you can't easily implant specifics to explain what's there.

For example, here's a stab at using this to explain Vancian magic in 3.5: Mana is an unseen, mostly undetectable substance that permeates the world. Spellcasting races have the innate ability to use their brains to tap into mana and manipulate it to use its energy for desired effects. Doing so is difficult and causes mental strain. Due to this, the brain compartmentalizes its use and limits itself to avoid overexertion. This is why you have a limited number of spell slots per day. Resting sufficiently restores the mind and resets your limits. With enough training and practice, you can expand your limits (increase spell slots per day) and expand your capacity for wielding mana at once (increase highest spell level you have a spell slot for). Why are limits dependent on spell level? Because using a higher spell level isn't just manipulating more mana, but manipulating mana in a different way. Your brain imposes limits on how much manipulation in a particular category of manipulation you can do, just like it imposes limits on your use of different muscles differently. Core Classes: Sorcerers and bards come upon this ability naturally (high talent). Wizards study to discover it and do it (high discipline). Divine casters meditate and either come across this talent by connecting with gods or the natural world's rhythms. And so on. Foci assist in channeling mana, material components have their energy released to magnify the effects of the mana, etc. Wild magic zones have fluctuating mana, dead zones lack it entirely, etc.

Vancian casting isn't inherently based on mana, but it is easy to see that it is a renewable resource, and not necessarily creating energy.

[weaseldust]

The weird thing is that this change has to be somehow not encoded by structures that are embedded in time (otherwise, you could just say 'oh, well there's some other set of laws of physics more fundamental that are constant, and which explain the drift in the speed of light'). So there's a pretty problematic logical closure issue there - you're almost certainly going to end up with a necessary consequence that there is some exterior 'universe' which is uni-directionally influencing the universe in which energy conservation is being violated, without being influenced in return (if you want the energy-conservation-violating process to be intrinsic, rather than only occurring at a boundary between universes, that is).

I don't understand this part. Suppose the speed of light gradually increases with the age of the universe, and therefore so does the charge of electrons. E.g. in the right units the energy of an electron in a static electric potential might just be 0.5mv^2 + tE, where t is the age of the universe in billions of years and E is the potential. (Obviously relativity complicates this, but the DnD universe might be galilean.) We'd see electromagnetic interactions become more energetic relative to other forces, we'd see electron orbits in atoms change (I think?), we'd see more and/or higher-energy photons buzzing around. Why does there have to be some hidden lawful structure or process explaining this change? Why can't it just be the nature of electromagnetism? (I agree that if there were a deeper explanation, it would have to be external on pain of regress.)


Another consequence is that the equations of physics become fundamentally unstable. Energy conservation excludes exponentially growing and shrinking solutions. If the mechanism for de-conservation is not just stochastic (the energy randomly fluctuations) but is directable - which you need it to be in order to have the supernatural be controllable at all - then you'll tend to get exponentially increasing or decreasing amounts of energy in the universe. That means that the universe will likely be very, very young compared to ours, and will have a window of time in which human-like life can survive that only lasts centuries or millennia.

I get the point, but perhaps the universe could alternate smoothly between periods in which the de-conservation mechanism adds energy and periods in which it removes energy? DnD wizards could just live in an era in which energy is being pumped in rather than sucked out.


In general, though, I agree with the suggestions above that magic might just spring from a natural but 'hidden' form of energy, one that can be turned into useful work only in very specific circumstances. Wizards would just be those people who found out how to replicate those specific circumstances.

[NichG]

I don't understand this part. Suppose the speed of light gradually increases with the age of the universe, and therefore so does the charge of electrons. E.g. in the right units the energy of an electron in a static electric potential might just be 0.5mv^2 + tE, where t is the age of the universe in billions of years and E is the potential. (Obviously relativity complicates this, but the DnD universe might be galilean.) We'd see electromagnetic interactions become more energetic relative to other forces, we'd see electron orbits in atoms change (I think?), we'd see more and/or higher-energy photons buzzing around. Why does there have to be some hidden lawful structure or process explaining this change? Why can't it just be the nature of electromagnetism? (I agree that if there were a deeper explanation, it would have to be external on pain of regress.)


The question is 'where is the information about the charge of electrons stored?'. Think about something like temperature - the temperature of an object is stored in the velocity fluctuations of its component particles. That's a local property, embedded in time and space. If that information is just a number 'about' the universe that changes according to its own special rule based on the universe's age, then thats what I mean by it being external. You basically have a whole separate universe (a boring one, since it only contains one thing - the structure deciding the charge of an electron in someone else's universe) whose laws of physics are just how that structure changes, and therefore generates the dynamics that you can see in the other universe but not influence.



I get the point, but perhaps the universe could alternate smoothly between periods in which the de-conservation mechanism adds energy and periods in which it removes energy? DnD wizards could just live in an era in which energy is being pumped in rather than sucked out.


The instability arises if the degree to which energy is pumped in or removed depends on the state of the universe into which the energy is being pumped/removed. That is to say, if a D&D wizard doing magic changes the amount of energy that ends up being pumped in, whatever natural processes that the D&D wizard is using to do that are enough on their own to give you the instability.

If the amount of pumping is not dependent on the state of the universe, then you actually do still have something with the same mathematical structure as conservation of energy because you can know exactly how much energy there will be in total at any point in time without knowing anything else about the universe. So in such a case, the wizards would have no way to innately access that new energy which is becoming available - that is to say, it would have to take the form of a concrete and localized 'resource' like mana or whatever, rather than just be something the wizard can pull out of the vacuum.

[JCarter426]

Dear Sir,

We have recently noted that you have the ability to add energy to the universe.

Please find a way to cause this ability to be used autonomously of yourself and, if possible, to create additional sources of itself, thereby staving off the heat death of the universe.

Thank you kindly,
The Management
Fortunately, I've established that this phenomenon isn't reproduceable through any autonomous means, and I believe the energy output per person is too minimal to end up with a Superman on a treadmill scenario either. Or maybe the combined energy output of all magic, everywhere, is enough... and that's actually a good thing?


Does the same apply to simply being able to convert matter into energy? There's a huge amount of energy locked up in even a small piece of matter, as the famous equation E = mc ^ 2 shows; it's fundamentally where nuclear reactors and stars both get their power. (The Sun outputs so much energy that it loses four million tonnes in weight every second, for example). You can put a fantasy slant on it by saying that's what the material component of the spell is--it's the item which is consumed to power the effect.
Well, let's look at the math here. One banana contains about 125 grams of mass, or .125 kilograms. So, going by E=mc2, we calculate E=.125*299,792,4582 and get roughly 1016 joules (rounded down). On the list of things with less energy: a lightning bolt, the largest superconducting magnet in the world, yearly use of a refrigerator, yearly use of a car, fuel capacity of a jet, orbital kinetic energy of the International Space Station, Little Boy, a megaton of TNT (it's actually more than 2.5 megatons), and the yearly electricity consumption of some small countries.

The problem is it's far too much energy locked in that matter. If we were to assume matter is our energy source (and I really don't like the idea of material components, but putting that issue aside...) then either:

a) We would never actually see this, because the amount of matter required to power a spell would be trivial. Maybe that's why D&D wizards prepare their spells in the morning; breakfast is the most important meal of the day....

or b) We'd have to tone this down and account for energy loss through some inefficiency in the conversion process. But in that case, there is the question of where all that energy is going. If it's anything like a matter/antimatter reaction, then we'd be getting a deadly gamma ray burst with each spell.


Nope. Almost all magic system tell you that magic comes from Mana. Sometimes the Mana comes from the world, sometimes it's from the character's body. You seems to be complaining that Mana is ill-defined. Agreed. Mana has yet to have it Newton yet.
See: "cursory explanation". Also, I was talking about sci-fi abilities there, not magic. Magneto doesn't use mana. :smalltongue:

But with regards to mana... yes, ill defined, but there's still a problem here. And you can apply this to dark energy or whatever you want, too. Even supposing all that energy is out there, as a natural phenomenon, and malleable in some manner... as NichG said, if that's possible, then it will already be happening. But as far as we can tell, it's not. And second, he issue of waste heat and thermondynamic violations and all that, they still apply. Because that stuff isn't happening, but you're asking that it suddenly does start happening, bringing the impossibly efficient conversion process and waste heat that comes with it. It's like if we magically found an infinite supply of oil and coal and whatever we want. Yeah, that solves our energy problem, but you have to explain where that came from, and then we're adding more waste heat and CO2 and so on, on top of what's already there.

And regarding that matter, generally... the idea that wizards are people who discovered mana and learned how to convert it into energy... that's just science flavored as magic. It's been done a thousand times, few times particularly well, and in those instances by writers more with more experience than I have.


One thing to keep in mind is, whatever you want to introduce, it will almost certainly be going on at a base level as a natural phenomenon in the universe. For biological organisms to evolve to take advantage of it as a built-in ability, it would have to be easy enough that an un-tuned population of organisms could notice small changes ability as the species got closer to the correct way to tap it. Alternately, it has to be discovered by a process of intelligences studying the natural world - that is to say, there still has to be some observable natural phenomenon for human scholars to have studied it enough to figure out how to tap it.

The consequence of this is that if you've got a way to violate conservation of energy, it will be going on all the time everywhere in the universe. It won't just be the mages doing it, and odds are that mages will be a negligible contributor to the overall violation of energy conservation. For example, humans have studied nuclear fusion sufficiently to be able to create it artificially, but think of the ratio between e.g. a fusion bomb and the sun. So imagine whatever your mages are doing, and scale it up like that - odds are that something roughly like that will be out there, all over the place, in space.
I've established that is not, in fact, a natural phenomenon. It's not an ability produced by evolution, nor is it a science learned through the study. So the only conservation violators we're dealing with are magic users, fortunately.


Now as to the consequences, the main thing that conservation of energy 'means' for the laws of physics is that the laws of physics do not change over time (that is, time-translation invariance is the symmetry that produces energy conservation). So you could have things like the speed of light gradually drifting to a different value as the process proceeds. The weird thing is that this change has to be somehow not encoded by structures that are embedded in time (otherwise, you could just say 'oh, well there's some other set of laws of physics more fundamental that are constant, and which explain the drift in the speed of light'). So there's a pretty problematic logical closure issue there - you're almost certainly going to end up with a necessary consequence that there is some exterior 'universe' which is uni-directionally influencing the universe in which energy conservation is being violated, without being influenced in return (if you want the energy-conservation-violating process to be intrinsic, rather than only occurring at a boundary between universes, that is).

The question is 'where is the information about the charge of electrons stored?'. Think about something like temperature - the temperature of an object is stored in the velocity fluctuations of its component particles. That's a local property, embedded in time and space. If that information is just a number 'about' the universe that changes according to its own special rule based on the universe's age, then thats what I mean by it being external. You basically have a whole separate universe (a boring one, since it only contains one thing - the structure deciding the charge of an electron in someone else's universe) whose laws of physics are just how that structure changes, and therefore generates the dynamics that you can see in the other universe but not influence.
Yeah, these are the more worrying consequences I was talking about before. Now, changing the laws of physics... not a huge problem. But the issue is that they will change over time on their own, if conservation of energy is allowed to be violated at all, yes? And we need a contrivance outside the established laws of physics and the known universe to account for the lack of change in the areas we want to remain normal. That's not too problematic, though.

There are a couple possibilities. First, there may be some container for our set of immutable laws of physics. We usually call this the universe, but in this case, it's a universe or set of universes outside the universe in which the story is told. Call it the astral plane or axis mundi or Yggdrasil or the Akashic records or whatever you want. There's some stabilizing presence upon the laws of physics that govern how and under what circumstances they may be changed, which is not subject to the same malleability.

Another thought occurs to me. Assume, for the moment, that the human mind exists outside the universe. I mean within the story; I'm not talking metaphysics here. This has been my working theory on the grounds that for someone to be able to alter the laws of the universe, part of them must exist outside of the universe in order to do it. The idea here is that if a person's mind exists outside the universe, it may follow whatever laws it wants, and some individuals possess the ability to exert the laws of their universe upon the common universe. So I'm wondering if it's enough for this external contrivance to simply be other people. If a magic user wills their spells into existence, everyone else in the universe disbelieves them back into oblivion. Sometimes this may be particularly strong, in the case of an antimagic spell, but in general there's an omnipresent "no, you can't do that" notion shared by all life which causes any spell to dissipate to some degree.

A third possibility is that a magic user must preserve the laws of physics within their own mind while casting a spell, lest it tumble out of control.


Another consequence is that the equations of physics become fundamentally unstable. Energy conservation excludes exponentially growing and shrinking solutions. If the mechanism for de-conservation is not just stochastic (the energy randomly fluctuations) but is directable - which you need it to be in order to have the supernatural be controllable at all - then you'll tend to get exponentially increasing or decreasing amounts of energy in the universe. That means that the universe will likely be very, very young compared to ours, and will have a window of time in which human-like life can survive that only lasts centuries or millennia.
Is that why it's always the middle ages? :smalltongue:


The instability arises if the degree to which energy is pumped in or removed depends on the state of the universe into which the energy is being pumped/removed. That is to say, if a D&D wizard doing magic changes the amount of energy that ends up being pumped in, whatever natural processes that the D&D wizard is using to do that are enough on their own to give you the instability.

If the amount of pumping is not dependent on the state of the universe, then you actually do still have something with the same mathematical structure as conservation of energy because you can know exactly how much energy there will be in total at any point in time without knowing anything else about the universe. So in such a case, the wizards would have no way to innately access that new energy which is becoming available - that is to say, it would have to take the form of a concrete and localized 'resource' like mana or whatever, rather than just be something the wizard can pull out of the vacuum.
So if there's a constant flow of "new" energy that nothing within the universe can affect, a mathematically predictable flow, then the universe can behave as ours with conservation of energy... the model is different, but still stable. But to what degree must that be constant or predictable?

For example, could we imagine a scenario in which every magic user is born with a specific, knowable power level (spells per day or mana pool or whatever) so they aren't pulling energy out of the vacuuum, but merely accessing their predetermined amount of energy? Is that sufficient?

[NichG]

I've established that is not, in fact, a natural phenomenon. It's not an ability produced by evolution, nor is it a science learned through the study. So the only conservation violators we're dealing with are magic users, fortunately.

In this case, you can probably ignore the rest of the details of things like changing the laws of physics, because all of that assumes that we're working within a causal structure. If magic is implemented by an extra-universal agent picking and choosing to make changes to the structure of the universe at their whim, but in a way purely governed by their dynamics and not at all governed by the physics of our universe, then we don't have to worry about instability, drift in the laws of physics, etc. Those are all consequences of the conservation-violating mechanism being part of the laws of physics themselves.

Essentially, there are two ways to change the energy of any system. One way is that the system's dynamics inherently just change its energy (e.g. its laws do not conserve energy). Another is that the system has a boundary to an 'outside', and energy can cross that boundary. In the former case, the necessary consequence of laws of physics that change the energy over time is that those laws of physics cannot be independent of an absolute time coordinate. But in the latter case, in which there's a boundary, its pretty much anything goes.

Generally in physics, the point is that you can always dissolve the boundary by just treating a bigger system that includes both sides. That bigger system now has its own laws of physics, (and maybe its own boundaries). Keep repeating until there are no boundaries left, and the results from a closed system follow.

But if you specify that the thing is not a natural phenomenon, you're (essentially) saying that you can't dissolve the boundary. The behavior of the system on the other side is just inherently un-knowable (or, at the very least, it doesn't fit into the same coordinate system as the inner universe, so things like time translation invariance symmetry don't have meaning across the boundary). So in that case, you just have an open system, and there aren't that many predictions you can make on its behavior aside from that the only way the system's energy will change is when energy flows across that boundary.

The more you allow causation to flow in both directions, the harder it will be to prevent the phenomenon from occurring autonomously (and thus dissolving the boundary in practice, and inducing the structures of one universe to apply to the other or to form some joint coordinate system with the product of their symmetries or something like that). Essentially, you have to rule out the possibility of the exterior universe being 'tricked' somehow by the natural dynamics of the interior one into thinking 'oh, there's a mage here casting a spell'. That's probably going to require an active, intelligent agent or system actually performing the check, because you're going to want to integrate information over a wide nonlocal area to provide robustness and redundancy. E.g. you need something that can look at a mess of particles doing stuff and say 'that particular mess of particles is/is not a mage' - that pretty much requires intelligence.

[JCarter426]

In this case, you can probably ignore the rest of the details of things like changing the laws of physics, because all of that assumes that we're working within a causal structure. If magic is implemented by an extra-universal agent picking and choosing to make changes to the structure of the universe at their whim, but in a way purely governed by their dynamics and not at all governed by the physics of our universe, then we don't have to worry about instability, drift in the laws of physics, etc. Those are all consequences of the conservation-violating mechanism being part of the laws of physics themselves.

Essentially, there are two ways to change the energy of any system. One way is that the system's dynamics inherently just change its energy (e.g. its laws do not conserve energy). Another is that the system has a boundary to an 'outside', and energy can cross that boundary. In the former case, the necessary consequence of laws of physics that change the energy over time is that those laws of physics cannot be independent of an absolute time coordinate. But in the latter case, in which there's a boundary, its pretty much anything goes.

Generally in physics, the point is that you can always dissolve the boundary by just treating a bigger system that includes both sides. That bigger system now has its own laws of physics, (and maybe its own boundaries). Keep repeating until there are no boundaries left, and the results from a closed system follow.
So, we can think of the universe as an isolated system, with its energy level constant, but there's nothing stopping us from imagining any number of other systems, and energy can be shared between them without violating the laws of thermodynamics we know. I wasn't certain you could do that on a universal scale. But wouldn't that imply, supposing other universes do exist, that anything could pop into our universe at any time? That's a little ominous. I've heard of traveling to other universes through a black hole, sure, and the reverse may be true for someone coming out of a white hole in our universe, supposing white holes exist... but I hadn't even thought about the consequence of that, that theoretically anything could pop into our universe at any time and cast meteor swarm, and that would be consistent with our laws of physics. But that's good for the story, I guess.


But if you specify that the thing is not a natural phenomenon, you're (essentially) saying that you can't dissolve the boundary. The behavior of the system on the other side is just inherently un-knowable (or, at the very least, it doesn't fit into the same coordinate system as the inner universe, so things like time translation invariance symmetry don't have meaning across the boundary). So in that case, you just have an open system, and there aren't that many predictions you can make on its behavior aside from that the only way the system's energy will change is when energy flows across that boundary.
Yes, that all sounds consistent with what I'm suggesting.


The more you allow causation to flow in both directions, the harder it will be to prevent the phenomenon from occurring autonomously (and thus dissolving the boundary in practice, and inducing the structures of one universe to apply to the other or to form some joint coordinate system with the product of their symmetries or something like that). Essentially, you have to rule out the possibility of the exterior universe being 'tricked' somehow by the natural dynamics of the interior one into thinking 'oh, there's a mage here casting a spell'. That's probably going to require an active, intelligent agent or system actually performing the check, because you're going to want to integrate information over a wide nonlocal area to provide robustness and redundancy. E.g. you need something that can look at a mess of particles doing stuff and say 'that particular mess of particles is/is not a mage' - that pretty much requires intelligence.
It sounds like you're implying that a fantasy setting requires the existence of some sort of divinity in order for its magic system to function. That's an intriguing consequence.

But what do you mean causation flowing in both directions? So far it seems entirely one sided. How could the exterior universe be tricked, as you say?

[NichG]

So, we can think of the universe as an isolated system, with its energy level constant, but there's nothing stopping us from imagining any number of other systems, and energy can be shared between them without violating the laws of thermodynamics we know. I wasn't certain you could do that on a universal scale. But wouldn't that imply, supposing other universes do exist, that anything could pop into our universe at any time? That's a little ominous. I've heard of traveling to other universes through a black hole, sure, and the reverse may be true for someone coming out of a white hole in our universe, supposing white holes exist... but I hadn't even thought about the consequence of that, that theoretically anything could pop into our universe at any time and cast meteor swarm, and that would be consistent with our laws of physics. But that's good for the story, I guess.

I would say that it's more like, the fact that we don't observe energy being de-conserved suggests that if there are other universes, there's no mechanism for material access from one to the other that operates at the energy scales that exist nowadays in the universe. Though the actual measurement on a cosmic scale is a little tricky, I think you'd see it as an anomaly in the cosmic microwave background. Alternately, if you measured the cosmological constant separately at different distances away, you'd see it change depending on when you measured it from.


It sounds like you're implying that a fantasy setting requires the existence of some sort of divinity in order for its magic system to function. That's an intriguing consequence.

But what do you mean causation flowing in both directions? So far it seems entirely one sided. How could the exterior universe be tricked, as you say?

In general the really problematic thing about magic is that it cares about things humans care about, rather than things that e.g. atoms care about. Magic recognizes 'a living target', things like that. Those ideas only exist in the minds of people, there's no life particles or vital energy or anything that can be easily read out to determine 'this target is alive'. Healing wounds, for example, involves an extremely specific and very difficult microscopic rearrangement of complex matter. It would be beyond any human intelligence, and certainly beyond any purely passive process.

Anyhow, as to tricking it, it has to decide whether or not to transmit. Presumably, that decision must be based on some kind of measurement of the matter of the universe they're transmitting to, which means interaction. And even if it doesn't, its an incredibly difficult problem. Imagine that I just gave you the coordinates of every atomic nucleus in an 80kg object. Could you tell in real time whether it was a living body or a pile of finely ground minerals with the same composition as a human and cast into a mold in a human shape?

[JCarter426]

I would say that it's more like, the fact that we don't observe energy being de-conserved suggests that if there are other universes, there's no mechanism for material access from one to the other that operates at the energy scales that exist nowadays in the universe. Though the actual measurement on a cosmic scale is a little tricky, I think you'd see it as an anomaly in the cosmic microwave background. Alternately, if you measured the cosmological constant separately at different distances away, you'd see it change depending on when you measured it from.
So, I'm safe from Xykon for now. That's nice. :smallsmile:

In general the really problematic thing about magic is that it cares about things humans care about, rather than things that e.g. atoms care about. Magic recognizes 'a living target', things like that. Those ideas only exist in the minds of people, there's no life particles or vital energy or anything that can be easily read out to determine 'this target is alive'. Healing wounds, for example, involves an extremely specific and very difficult microscopic rearrangement of complex matter. It would be beyond any human intelligence, and certainly beyond any purely passive process.
Yeah, the crux of the matter is that magic is the manipulation of information far beyond a human being's capacity to process that information. Healing is a problem if you go beyond speeding up the body's own capabilities, as are shapeshifting, conjuring, teleportation, and any number of staple powers. And that's sort of why I'm resorting to the idea that the laws physics just get temporarily rewritten, and it's never going to make sense.

Anyhow, as to tricking it, it has to decide whether or not to transmit. Presumably, that decision must be based on some kind of measurement of the matter of the universe they're transmitting to, which means interaction. And even if it doesn't, its an incredibly difficult problem. Imagine that I just gave you the coordinates of every atomic nucleus in an 80kg object. Could you tell in real time whether it was a living body or a pile of finely ground minerals with the same composition as a human and cast into a mold in a human shape?
I see, so the issue is the process by which energy is created or destroyed exactly when and where the magic user wants it. If there were no such system, it would pop up at random places of universe, to say nothing of the time factor. That's an issue that will require some thinking on my part, but at least so far it sounds like no part of this system is completely absurd. Obviously this is not how our universe works, but suspension of disbelief is at a level with which I'm comfortable.

[The Great Wyrm]

Imagine that I just gave you the coordinates of every atomic nucleus in an 80kg object. Could you tell in real time whether it was a living body or a pile of finely ground minerals with the same composition as a human and cast into a mold in a human shape?

Yes. That's basically what MRI does with protons in water. Getting the precise (to within quantum uncertainty) coordinates of every nucleus, not just protons, would make it even easier than MRI.

[LibraryOgre]

What if magic uses dark energy and transforms it into regular energy?

Some sort of, say, Mass Effect?

[NichG]

Yes. That's basically what MRI does with protons in water. Getting the precise (to within quantum uncertainty) coordinates of every nucleus, not just protons, would make it even easier than MRI.

I'm not saying its difficult to get the coordinates. I'm saying its difficult to interpret them.

Open up a random section of your computer's RAM and tell me what that section is doing, just based on the byte values. That's a much easier problem than getting a list of 10^23 coordinates and telling me what it is

[ace rooster]

To the initial question, I would guess at a Nobel prize and every phyisict both loving and hating you in equal measure. Other than that probably very limited large scale effects though you may get some cool pieces of kit that exploit it.

With regards to putting magic coherently into a setting, energy is not the limiting factor. As has been pointed out, there is enough energy in a banana for an thermonuclear bomb, and we can invoke magic to get access to some of that energy (probably not a lot, or there would be bad consequeces for our wizard). The difficulty is processing the information, but that can also be solved by magic. If we assume that magic is in some sense "programmable", then you need very little in the way of basic manipulation to create complicated spells.

If we further assume that magic is throughout the setting working in the mechanics of everything, things like healing become possible because you augment magic that is already there. Material components can be crucial for spells because of some magic process that occurs within it that is used as a "subroutine". In particular filtering magic through a mind could be used for constructs and summons*, because intelligence is simply much easier done that way than programming AI from scratch.

*if 'summons' are temporary effigies created on the spot rather than brought in from elsewhere. I prefer this thinking because it avoids ethical concerns.