A question regarding the physics of the sun

[Quickshot0]

Lets add yet more science in to this, I should have looked here earlier. What people are saying about compression increasing reaction rate is entirely correct. Though compressing the sun much with a magnetic field would require incredibly powerful fields, I don't expect that to happen really.

Also important to realize is, is that heat and light exert a pressure out away from the core, this creates an automatic balance as it will reduce the heat and pressure on the core. Thus the core will only increase reaction rates till it balances out the new pressure. This also means no cascade effects etc, fusion doesn't work like that, fusion rates are directly related to how close you can push atomic cores together, which is only accomplished with heat or pressure. (So no feedback loops, instead dynamic balancing. Also the only part of the Sun really having any reactions is the core, the rest is just a puffed up ball of plasma. And the transfer time of heat from the core to the edge I believe was measured in years, if not decades or centuries...)

Anyway, what this all comes down to is, is that the suns are ridiculously stable and the amount of energy to really take it is astronomical. Or to put it another way, it's probably just easier to blow up our entire planet, then to seriously mess up the sun. For instance, it would be easier to throw up a dust cloud between the Sun and Earth and thus deprive Earth of much light. If one wants, you could speculate I suppose on some ways to change the suns out out, or cause gigantic solar flares that do a hell lot more damage then the cute mild versions our sun only produces. Examples of such solar flares recorded around other stars, which if I remember correctly were more then potent enough to roast our planet crispy. Inducing these would be massively much easier then doing serious damage to a star and you could even try to partially work the Suns energies in this case atleast, so this is one possibility that has some real potential I guess.

Another option kind of mentioned here, was to change the suns output. Even a few percent change in the suns output is enough to throw us in to an ice age of Epic proportions, or make current global temperature increases look like a cute joke. So you could try that, though trying to even change core pressures of a sun a bit would be as noted before, require titanic amounts of energy. So overall it would probably still just be easier to blast Earth to debris then.


What this all comes down to is, is that you want to do anything with the Sun to seriously harm Earth, you really need to find ways to make its energy work for you. On that note, I once calculated with someone how long it would take to vaporize the entire planet, if all its solar power was directed at it. If I remember correctly it was something like a second or two. (And that was for complete vaporization and putting enough energy in to it that it wouldn't even stay together) That's really the scale of difference of things, use even a small portion of that energy for something and you could create serious serious trouble.


PS, the Earths magnetic field is no where as uniform as you might think. Nor does it always give excellent protection against the sun, in certain orientations it lets rather much pass, typically those are the days when things like Radio have the most interference.

[Crescent Pulsar R]

Hmmmm... Okay, how about this. Let's say there's a force, shaped like a sphere, that's being pressed against (and through) the sun's magnetic field. We'll just say that it's half the size of the sun. Let's also say that the magnetic field can't pass through it or act upon it. Would such a thing eventually cause the sun to jet/explode out in the direction of its approach?

[Knight of L-sama]

Also important to realize is, is that heat and light exert a pressure out away from the core, this creates an automatic balance as it will reduce the heat and pressure on the core. Thus the core will only increase reaction rates till it balances out the new pressure. This also means no cascade effects etc, fusion doesn't work like that, fusion rates are directly related to how close you can push atomic cores together, which is only accomplished with heat or pressure. (So no feedback loops, instead dynamic balancing.

That's not quite right. Its true that hydrogen fusion, at least in a stellar context won't cause a run away reaction. Helium fusion is another story entirely. It is ridiculously temperature sensitive and since by the time it starts the core is degenerate there's excellent heat conduction. As a result you do get a runaway reaction known as a Helium Flash where a star burns all the helium in the core in the space of minutes.

[Quickshot0]

Hmmm, I researched it a bit on Wikipedia and seemingly what is happening atleast in part is that magnetic fields are digging deep in to the sun, connecting far deeper layers with the surface layers, this makes me speculate that we're pumping energy from closer to the core straight up to the surface. So basically these form the sun spots we see on the surface and it seems, that what happens is that around the edges the magnetic fields will violently reconnect with the upper atmosphere (Magnetic Reconnection example, as you can see it can dramatically change flow directions, with in certain cases epic energy releases.). So basically you are in a way I suspect cycling energy far quicker from the core to the surface, so by creating more tunnels to the energy near the core to the surface and grouping them in hazardous ways, could lead to a cataclysmic burst. You could consider it a way to concentrate more solar energy on one section of the solar surface and if you just engineer it neatly, it'll explode very violently and when you want it to.

Basically I don't think that just pressing a sphere in would do it thus, but with a bit more sophistication it seems like a feasible method, perhaps multiple toroid like structures, that push magnetic fields through the stellar surface deep in to the core? I'm not an astrophysicist, so you've hit my limit of speculative knowledge here, I suspect for story purposes that the only thing that matters is, is that some how they managed to do that then. On a last note, you probably can't maintain such a tube against the rotation of the sun, as that would require stupendous power I suspect, sure that would probably release a huge flare, but I also suspect your energy investment to return would be lousy. So it is probably easier to just time the flare to erupt when the sun is facing Earth. (Around the equator the Sun spins once ever 25 days about)

That's not quite right. Its true that hydrogen fusion, at least in a stellar context won't cause a run away reaction. Helium fusion is another story entirely. It is ridiculously temperature sensitive and since by the time it starts the core is degenerate there's excellent heat conduction. As a result you do get a runaway reaction known as a Helium Flash where a star burns all the helium in the core in the space of minutes.

I looked that up, because I didn't know that specific case. What you are talking about here only happens in stars more then 2.25 times heavier then our sun. Basically what happens is that the core of the star collapses so violently after it runs out of Hydrogen, that it does temporarily enter degenerate matter phase (The stuff neutron stars are made of I believe) before Helium fusion can ramp up enough. Due to the nature of degenerate matter, fusion occurs much easier in it, combined with massive pressure and heat spike that you get from a core collapse and inevitably your Helium fusion goes crazy. It should be noted though that this only lasts a few seconds, till the heat becomes so intense that the degenerate matter is ripped apart. This is despite its excellent heat conduction ability, basically the fusion rates just keep climbing till it can't keep up anymore and starts falling apart. After that the Sun shifts in to normal Helium burning mode, which is the same as hydrogen fusion and just as resistant to change.
as hydrogen burning is really.

So in fact, not all the Helium is used up, not in a long shot. And the reaction isn't actually a runaway reaction, it's just a temporary burst in reaction due to the core developing degenerate matter temporarily after it runs out of hydrogen. It basically quickly reasserts balance and things go on as usual afterwards. I think it actually underlines what I said, that stars are ridiculously stable, no matter virtually what you do to them. The only real exception I know to that is in that case of 100 Solar Mass or heavier stars, composed of almost entirely Hydrogen. Current stars pretty much are all to light or have to many non hydrogen impurities. In any case, with such a star, you get actual short lived antimatter production in the core, leading up to a catastrophic core collapse and rebound, resulting in the entire star including the core exploding like a huge fusion bomb. Really really scary events which makes Supernovas look pedestrian and weak, also incredibly rare, we've only seen one or two up till now, as far as I know.

[Quickshot0]

Though now I'm wondering... if you could some how form a seed of stable degenerate matter and chuck it in to a star, would it have a temporary run away effect? I think I'd have to actually ask an astrophysicist to know for sure... I'll see if I can find some one I guess...

[Spokavriel]

Increased gravity was the stated cause. 2.25 times heavier could presumably be reached in that situation. The keys are temperature and pressure on the Helium.

But really the talk of any field half the size of the sun. If it is made by a creature of human scale then somehow this being managed to be an every day army ant that somehow make a Mokotakabisha the size of Jupiter. Have you looked at any scale models of our solar system?

[Crescent Pulsar R]

Well, it's not a field in that sense, and it's generated by the enemy, so it should be possible. If I saw a problem on that end I would have asked more than just stuff regarding the sun's reaction to various outside influences. Speaking of which: if said outside influence just got in the way, and prevented the usual behavior of the sun's magnetic field, would it cause more magnetic reconnections (and thus more sunspots)?

[Quickshot0]

Hmmm, can't find an astrophysicist right away. Though I did find some one with a bit of a clue. Throwing some how stabilized degenerate matter in to a stellar core, would either a cause something like a helium flash, though maybe a bit slower. Which would cause the star to massively expand briefly once the energy pushes itself far enough up through the stars atmospheric layers, briefly in stellar terms that is. Earth would probably end up a charred rock after some decades, or however long it would take for the effects to present themselves. Alternatively.... it might be possible the star will just explode... I suspect this isn't likely though, considering it doesn't happen with the Helium Flash either and our Sun in particular is a bit on the low end to tend to quite such a violent death.

Increased gravity was the stated cause. 2.25 times heavier could presumably be reached in that situation. The keys are temperature and pressure on the Helium.

But really the talk of any field half the size of the sun. If it is made by a creature of human scale then somehow this being managed to be an every day army ant that somehow make a Mokotakabisha the size of Jupiter. Have you looked at any scale models of our solar system?

Degenerate matter is extremely compact, basically packing far more mass in to a ridiculously small area (neutron stars can pack about a solar mass away in an object of I believe about 10 km diameter, so far small then Earth even), of course the local gravitational field will increase massively.

As for electromagnetic fields, making those large is much much much easier then things like gravity. Electromagnetism is a far more powerful force. To give a comparison, the entire Earths magnetic field requires a power output around 1 to 10 terawatt. We actually produce more then that already ourselves.(So we are quite able to create an artificial magnetosphere around a planet) This means the energies involved aren't unfeasibly huge and can be managed. And there we would be assuming an alien threat, some what more ability may by safely assumed one would think. Of course the Suns magnetic field is far more powerful yet, but the idea would be to make local alterations, nudge it in the direction you want, not battle the entire thing.

[Quickshot0]

Well, it's not a field in that sense, and it's generated by the enemy, so it should be possible. If I saw a problem on that end I would have asked more than just stuff regarding the sun's reaction to various outside influences. Speaking of which: if said outside influence just got in the way, and prevented the usual behavior of the sun's magnetic field, would it cause more magnetic reconnections (and thus more sunspots)?

Oops, you caught me out while I was busy editing my own reply through various permutations.

And it would definitely be possible in theory to cause massive increases in sun spots, yes. In what way or why exactly that happens in Sailor Moon, I don't know. But it is definitely possible, yes. The Magnetic reconnection are caused by sun spots though, but that doesn't really matter further, aside of keeping cause and causation in the correct order.

[Crescent Pulsar R]

Well, I figured that some of the effect should include sunspots, since Metallia was able to effect the sun in that way (I'm assuming) in the manga, when she arrived. (By a coronal mass ejection, or a solar flare, I can't be certain. I just know that the sun was very "active" and a sunspot was shown before it happened.)

[Quickshot0]

Well Metallia is very powerful, so at a glance there is no reason not to assume that she could greatly influence the magnetic fields in the sun and cause an eruption. At a glance I would say this should be well within her energy range.

[Knight of L-sama]

I looked that up, because I didn't know that specific case. What you are talking about here only happens in stars more then 2.25 times heavier then our sun.

Not according to Wikipedia. It's stare of less than 2.25 solar masses that undergo Helium Flash.

Stars with greater than about 2.25 solar masses start to burn helium before their core becomes degenerate and so do not exhibit this type of helium flash.

Emphasis added

that it does temporarily enter degenerate matter phase (The stuff neutron stars are made of I believe).

Yes and no. Neutron stars are a form of degenerate matter but they're held up by neutron degeneracy. White dwarfs, helium cores and the like are held up by electron degeneracy pressure and are considerably less dense. Inserting electron degenerate material into a G2V star (read that as sun-like) probably isn't going to do all that much. It's just going to heat up and reach equilibrium with the stuff around it. And if you can make neutron degenerate matter that's stable outside the immense gravitational fields of a neutron star... what the hell are you doing trying to be subtle? Any society with the technology to manipulate stars is more than capable of wiping out humanity at their leisure.

They're obviously not interested in the real estate since messing with Sol is going to have serious, long term consequences on the Earth so why not just send a couple of asteroids screaming in at relativistic velocities, shatter the planet and be done with it?

[Quickshot0]

Not according to Wikipedia. It's stare of less than 2.25 solar masses that undergo Helium Flash.

Ah, that is my mistake, I misread the larger and smaller there, thanks.

Yes and no. Neutron stars are a form of degenerate matter but they're held up by neutron degeneracy. White dwarfs, helium cores and the like are held up by electron degeneracy pressure and are considerably less dense. Inserting electron degenerate material into a G2V star (read that as sun-like) probably isn't going to do all that much. It's just going to heat up and reach equilibrium with the stuff around it. And if you can make neutron degenerate matter that's stable outside the immense gravitational fields of a neutron star... what the hell are you doing trying to be subtle? Any society with the technology to manipulate stars is more than capable of wiping out humanity at their leisure.

They're obviously not interested in the real estate since messing with Sol is going to have serious, long term consequences on the Earth so why not just send a couple of asteroids screaming in at relativistic velocities, shatter the planet and be done with it?

I've been thinking about this awhile and I'm not really sure if even adding neutron degeneracy will do all that much, most likely the rest of the core would just compensate by heating up a bit. It's not like everything is set up neatly at that moment to precipitate a core collapse after all.

In any case pretty much any messing with the sun, compared to just directly attacking the Earth tends to be rather wasteful. Though one might speculate that once you've perfected such a technology, that it might not be expensive at all any more. (Of course, good luck achieving that kind of mastery.) But even if you had that kind of mastery, then you probably still had a thousand cheap ways of eliminating any threat from Earth in a more direct fashion, rather then trying to make stars go boom. So yeah, I guess the only reason you'd target the star would be if you just wanted to see fireworks.

[Spokavriel]

Just thinking about your theory that the increase heat would increase the size of the photosphere or the gravity would balance out. For all the proposals we really don't have enough information for that.

Technically this whole proposal is adding mass without additional matter. So it would have an increase of compression but we have no materials that can measure any parts of the inner layers of the sun. All we know are theoretical based on fluid dynamic studies of the photosphere.

We could even find that Helium with sufficient pressure can achieve a crystalline state. Its unlikely as hell given the instability of the atom but we are already dealing with an improbability that would take God to properly achieve for beings of sufficient power in theologies.

[Quickshot0]

Just thinking about your theory that the increase heat would increase the size of the photosphere or the gravity would balance out. For all the proposals we really don't have enough information for that.

Technically this whole proposal is adding mass without additional matter. So it would have an increase of compression but we have no materials that can measure any parts of the inner layers of the sun. All we know are theoretical based on fluid dynamic studies of the photosphere.

We could even find that Helium with sufficient pressure can achieve a crystalline state. Its unlikely as hell given the instability of the atom but we are already dealing with an improbability that would take God to properly achieve for beings of sufficient power in theologies.

Well we do have some objects to study where materials are under truly beyond Earth achievable extreme pressure, namely White Dwarf Stars and Neutron Stars. Also we have been studying other stars for some time now, seeing what happens with them, if for instance they consume another star over time. Another method is to watch a supernova and watch what comes out of those, if your models are right you should be able to properly predict what is made under the extreme pressures of a supernova after all. As such I would say while our data is pretty sparse, it isn't entirely based only models or some theory.


So any way, when you mentioned crystalline Helium my first thought was that it might be possible in the right circumstances and maybe wasn't entirely unplausible.
Which brought me to you know, google it, which led me to this article and this one, which casually talks about researching certain properties of crystalline helium and that we can make it.... Based on this revelation I put forward that we are God, we just you know... missed the fact we were.

On a side note, for a truly extreme phenomenon, it is known that a Magnetar has such an extremely powerful magnetic field, that it should actually be able to polarize the vacuum of space and act like a calcite crystal. I'm not entirely sure they've actually managed to observe some of those effects, but it's possible they might have. In any case, think about it, you can polarize empty space in to something which has properties of a crystal, this is what you would call truly crazy.