The Supernova Method

Destroying the Earth by means of a supernova is a geocide method which comes in two broad varieties. In one of them, we move the Earth to the vicinity of a star which is about to go supernova and wait. Transit time is a factor, and then we have to consider just how long we wish to wait. Imminently collapsing stars are not easily come by in space. All in all, such a proposal is thoroughly tedious and mundane. Somehow, it smacks of effort and laziness. It lacks panache.

The other option we have is to leave the planet where it is and induce the Sun to go supernova manually, and this is the task I want to consider today.

What causes a supernova, anyway?

The Sun, like all stars, is a vast mass of hydrogen gas which collapsed under its own gravity. As more hydrogen gathered around the central point, the heat at the core of the ball of gas rose to the point where nuclear fusion began to occur spontaneously. Each time hydrogen nuclei (protons) fuse into heavier nuclei, a little energy is released, raising the temperature nearby and enabling further fusion to occur. Thus, the fusion process is self-sustaining for as long as there is enough hydrogen fuel.

Stars are generally in hydrostatic equilibrium. This means that the radiation pressure of energy trying to escape from the core (where it was produced by fusion) is equal to the gravitational force pulling the star together. When, after millions or billions of years, the hydrogen fuel begins to run out, fusion slows down and the radiation pressure decreases. Gravity takes over and pulls the star into a smaller ball. This increases the pressure and temperature at the core, to the point where helium can now fuse into carbon. The star finds a new hydrostatic equilibrium at a smaller, more svelte diameter, with helium fusion at its core, and the remaining hydrogen continuing to fuse in a shell around the core, heated from within by helium fusion.

As time passes, even the helium begins to run out. Two more facts come into play now. Firstly: the heavier the element, the more energy it takes to cause it to fuse. The energy in the core of a star is a function of temperature which is a function of pressure which is a function of its mass. Thus, the more massive the star, the more elements it could theoretically fuse. (Balls of gas which do not have enough mass to even fuse hydrogen do not start shining at all and don't become stars.) The majority of stars aren't massive enough to get far past helium. So far so good.

But in the case of truly gigantic stars, above eight solar masses, the second fact arises: the heavier the element, the less energy you get back from fusing it. We end up with descending layers of fusing elements, like an onion: hydrogen fusing into helium in the outer layer, helium fusing into carbon in the next layer, then carbon fusing into neon, neon fusing into oxygen, oxygen fusing into silicon and finally silicon fusing into nickel. Once you get to nickel (which in this case undergoes radioactive decay into iron), fusion doesn't generate any energy at all. Beyond the iron point, it actually requires a net energy input to fuse anything. Thus, the very bottom layer in the onion does not fuse or generate any energy. It does not support itself with radiation pressure. It just sits there and accumulates.

The iron core is a different thing entirely. This is not just a lump of metal. It is under such intense pressure that it becomes something called electron-degenerate matter which is an extremely dense phase of matter in which the iron nuclei are kept separate from one another only by the Pauli Exclusion Principle.

Electron-degenerate matter is completely awesome. Because the individual iron nuclei are packed so closely together, so are their surrounding electrons. Because the electrons' positions are so constrained, the uncertainty in their position is very low. Thanks to the Heisenberg Uncertainty Principle, this means that the uncertainty in the electrons' momentum is very high which means the electrons move at very high, relativistic speeds. This creates an outward pressure. If, as here, the pressure due to fast-moving electrons exceeds the pressure due to thermal motion in the matter, the matter is called degenerate. Oh, and, paradoxically, adding more iron to this core causes its pressure to increase and its volume to contract further.

Even now, it is still possible for a star to run out of fuel. You would simply get a white dwarf, with some layers of fusing material above a tiny electron-degenerate iron core. But if the star started out with nine or more solar masses, a point is reached where even the Pauli Exclusion Principle isn't strong enough to prevent the core from collapsing. The system breaks down, the core collapses still further forming a neutron star. A neutron star is just a few tens of kilometres in diameter but has about the same density as an atomic nucleus. The rest of the star - suddenly having no supporting bottom layer - implodes in on the core at relativistic speeds, the majority of its remaining fusable material fuses all at once, and more energy is released in a few days than the Sun will release in its entire ten-billion-year lifetime. The rest is history. Literally.

Basically the crux of this method of geocide is this: create a large, momentary "power vacuum", or rather, a literal vacuum, in the core of the Sun. Do this by removing something that was already there. The Sun will instantly collapse into the space, and the sudden increase in pressure and temperature will liberate orders of magnitude more energy than the Sun typically puts out, incinerating the Earth and most of the Solar System besides.

*

The reason why we can't do it is this.

At 1.45 solar masses, a lump of iron is massive enough that it will actually implode in the manner described enough. We need a hair less than 1.45 solar masses of iron. We then need to fire that iron bullet into the core of the Sun, and then have the Sun manufacture enough additional iron to put it over the Chandrasekhar limit and cause it to implode.

Even combining all the physical objects (planets and miscellaneous) in the solar system, we only have 0.14 solar masses of material, almost none of which is iron. We would have to ship the iron in from another star system entirely.

The Sun is not massive enough to manufacture iron, period. It doesn't have eight solar masses. It has 1.00 solar masses. Any amount of iron in the Sun's core is either 1) never going to collapse or 2) already collapsed. There is no middle ground and unfortunately the additional weight of the Sun's upper layers cannot be used as the tipping point; the electron degeneracy pressure inside the electron-degenerate iron is a purely quantum-mechanical effect which is not increased by whatever is sitting on top.

*

We could ship in the equivalent of eight other Suns' worth of hydrogen, raise the Sun's mass to 9 solar masses and then wait for nature to take its course. But that's stupid. Could it be possible to open a bubble inside the Sun using titanic electromagnetic fields? Perhaps these electromagnets could be solar-powered? But what shape would they form? What current would be required? Could we remove the Sun's core using teleportation? We're verging on fantasy.

What we wanted was a magic bullet. We wanted to take Venus or Mercury or something equally small and conveniently-placed and poison the Sun with it-- a low-effort solution. Unfortunately it seems like this would not give the desired effect.

There is no feasibility rating today. But we haven't failed; we've successfully eliminated a possibility.

Back to Blog
Back to Things Of Interest

Facebook Twitter Reddit Email Hacker News StumbleUpon

Discussion (29)

2010-06-22 02:44:38 by Thrack:

Basically you want to turn off the Sun. The same proposal you made for solving global warming, right? But extended long enough for the Sun to collapse. Reminds me of the proposal of turning the Sun into a black hole someone made but was rejected.
If you could keep the hydrogen from fusing for long enough for the sun to collapse, or siphon out its energy somehow, would it be able to go supernova afterward?

2010-06-22 03:29:51 by YarKramer:

I'd just like to point out that this is the first time I've ever seen the word "svelte" used to describe stellar masses.

2010-06-22 04:44:16 by jnnnnn:

In fiction: I believe Larry Niven's Protector novel had a "fusion-suppression field" that was used to prevent thermonuclear war.

Also, it might be theoretically possible to compress a star with carefully focused gravitational waves? That would likely involve a lot more effort than just adding another 8 solar masses.

2010-06-22 08:20:33 by jonas:

To jnnnnn: I thought that happened in a Heinlein novel, but I haven't read that novel and so I'm not sure. Maybe both?

2010-06-22 11:19:39 by Jonas:

What about placing a sub-critical iron core in the centre of the sun, then shooting a smaller bullet of iron into it, causing it to go critical? They do it with nukes, why don't do it with stellar bodies?

2010-06-22 13:46:08 by Thrack:

Presumably it can be done with nuclear weapons because the uranium is unstable to begin with, it just needs a push so it will decay all at once. I am unsure how it would be done with a hyper dense iron core. If it's possible at all.

2010-06-22 14:47:37 by lolwat:

Thrack,

You're confusion Fission and Fusion.

2010-06-22 15:37:29 by Ross:

The beginning of the novel "Iron Sunrise" by Charles Stross: http://3.ly/ANc9- (Google Books)

Basically, the core of a normal star is, um, twisted out to another universe, where it is allowed to sit for several trillion years until it has all turned to iron. ("Fusion didn’t stop but ran incredibly slowly, mediated by quantum tunneling under conditions of extreme cold.... Mass migrated until, by the end of the process, a billion trillion years down the line, the [core of the] star was a single crystal of iron crushed down into a sphere a few thousand kilometers in diameter, spinning slowly in a cold vacuum only trillionths of a degree above absolute zero."

Then it's brought back to our universe, right where it came from in the center of the original star, but about 30 seconds after it left. For 30 seconds there's been a vacuum at the core of the star, and it started to collapse; then suddenly there's this iron in the way. Boom.



(WTF? "Names can consist only of letters"?? I suggest you read http://3.ly/RNBp- ("Falsehoods Programmers believe about names"))

2010-06-22 15:43:42 by Cory:

Jonas, he mentioned that idea. The problem is, the amount of available iron is significantly less than that required to trigger collapse. We'd need to ship it in from another star system.

Maybe we can analyze teh tape Sam was given (http://qntm.org/reading), and see how the alien race caused the supernova? ;)

Also, the captcha nearly caught me... I didn't noticed it had changed to the stupid notation for sqrt(-1). [Please don't hate me, engineers...]

2010-06-22 16:14:55 by Sam:

Ross: maybe in reality people have all kinds of weird names (or not). This, however, is my website! Names here are different. For one thing, you have to have one, and for another, it can't be "Sam".

2010-06-22 17:37:22 by Thrack:

lolwat, I was responding to Jonas' post just above mine. I know what fusion and fission is. Fusion is the bonding of atomic nuclei by overcoming the strong electromagnetic repulsive forces until the strong force binds them as happens in the sun's core. Fission is the separation of generally unstable atomic nucleons as is done in modern atomic weapons. Hmnn... I imagine adding electrons to Uranium's electron shell would promote decay due to attracting the nucleons.
I've been doing a lot of Chemistry reading lately.

2010-06-23 05:25:22 by Daniel:

You could move the Earth to another star and then induce a supernova in it as a comprise.

You could also switch it. Leave the planet where it is and wait for its sun to go supernova. I don't think that really counts, but you did have a couple things like that in your "How to destroy the Earth" thing.

Also, could you make the sun go regular nova? How about red giant? I admit you'd still probably have to wait a really long time.

2010-06-23 10:04:11 by Sam:

Moving the Earth to another star and then inducing it to go supernova is the worst of both worlds!

And the Sun won't go supernova left to its own devices.

2010-06-23 11:49:23 by Pete:

@Thrack

Quote:"I imagine adding electrons to Uranium's electron shell would promote decay due to attracting the nucleons."

In reality? Sorry, nope.
Generally, the nuclear and electronic environments are pretty seperate, there arn't many things in either that can affect the other.

The uranium electron cloud is HUGE, the other shell (where your electrons will go) is [figuratively] miles away from the nucleus and is shielded by all the other electrons in between. I have not heard of any process involving the electron cloud "attracting the nucleons" from the nucleus.

There is the process of electron capture, which is a machanism for decay, but adding/subtracting electrons or and bonding, will only have a significant effect on much smaller radioactive atoms as their inner shells will be affected.

Induced Gamma Emmision might be more what you need - although this appears a little (probably a lot) "wishy-washy" at the current state of hypothesis, but Im gonna run with it.
-Whack a chunk of something suitably fissile into the core of the sun (ooh, I dunno, lets transmute mars into a solid lump of just-what-we-need-ium) and zap it witha a specific spectrum of gamma rays. This induces a huge release of yet more gamma rays, causing a whole bunch of as-yet unfused material to fuse.

= Supernova.

2010-06-23 16:12:50 by Thrack:

Perhaps isotope 3hydrogen would have been a better choice, uranium just happened to be the only radioactive element I could remember off the top of my head. And anyway, I didn't say adding valence electrons were going to make the uranium *significantly* more unstable, though I probably should have mentioned its effect would be an insignificantly tiny amount. I just happened to delve into nuclear physics a bit while reading on chemistry and read that the nucleus of a radioactive element is weakly bound so it seemed logical that adding to the electron shells would weaken it further by whatever tiny amount it ended up being.

2010-06-24 13:34:53 by Pete:

True, the electronic configuration can have a small effect on the decay of a nucleus *in a very few specific circumstances* involving light nuclei.

It is not a matter of a negative charge cloud causing the nucleus to become more and more “weakly bound” until it flies apart. This is not an effect. I just wanted to clear that up.

Generally, it is impossible to change the rate of decay of a given bundle of nucleons, without directly futzing with the nucleus itself (which the above examples involving lighter nuclei do – the rate of capture of inner electrons by the nucleus is affected).

2010-06-24 16:17:46 by Thrack:

Oh, of course the electrons aren't going to be able to cause an element to decay all on their own. I figured it would just reduce the half life by a tiny amount. Now, after having given it more thought I guess the half life of 3Hydrogen (12.32 years) would be reduced by less than a fraction of a second. Wouldn't this be right? Useless for any practical purpose though and probably not even measurable.
Of course I guess there's not much point to saying what effects such a thing would have since the effects are tiny enough to be safely ignored. Unless you're studying the physics behind it and can detect it of course.

2010-06-24 18:12:03 by Dentin:

I seem to recall that there's a major problem with this: the material the sun is composed of pretty much won't detonate regardless of temperature. The proton-proton fusion process is moderated by the weak force, happens very slowly, and is the limiting factor.

I had asked this question several years ago and that's the answer I got back; someone with a more thorough understanding may be able to clarify (or disqualify) it.

For helium and higher though, the situation is markedly different. I've always wondered what a small nuclear detonation would do if it happened in the core of a helium or carbon star.

2010-06-25 09:37:39 by Pete:

...

2010-06-25 09:45:52 by Pete:

@Dentin

Yeah, I've wondered about that too, or what about at the centre of Jupiter? Its not going to turn into a sun but something interesting might happen - a short lived fusion wavefront? Is that a thing? Like a detonation wave in high explosive.

Its one of those giantsuperexperiments that I wish we could just do.

2010-06-25 12:11:22 by Snowyowl:

How about shooting a black hole into the core of the sun? That would certainly cause a collapse, and solves the problem of finding 1.45 solar masses from somewhere - even a black hole weighing 16 micrograms will take a good 5 minutes to evaporate from Hawking radiation, and solar radiation alone will probably be enough to extend its lifespan considerably. If the black hole is that small, you won't need to overcome the inertia of a Jupiter-sized lump of iron either, and making a black hole from scratch isn't all that far-fetched (keeping it stable until you can feed it a microgram of fuel is a problem, however, but I'm sure we can figure it out). As for pushing it into the sun - park a large spaceship nearby, and use your gravitational field to slow it down and spiral it into the Sun. You'll need a lot of spaceship fuel, but nothing that can't be solved with a large enough solar panel.

Any comments? (The scientists at CERN must be fuming; they've only just reassured people that black holes won't destroy the Earth.)

2010-06-29 05:25:17 by Mick:

Alas, any technology powerful enough to force the Sun to go supernova could also easily destroy the Earth without the intermediate.

It would, however, look really cool.

2010-06-29 11:46:15 by KingBob:

If the technology existed to manufacture a black hole, then conceivably we'd have the technology to create an Einstein-Rosen bridge (wormhole).
If you could target both ends of the bridge in space (spatial coordinates), you could position one at the centre of the sun, and the other in the depths of space or near a black hole, thus creating the required vacuum to collapse the sun. Or you could point the other end of the wormhole at the earth, basically frying us with a solar scale flamethrower, then cooking us with a supernova!

Or, perhaps use the bridge to connect the core of our sun, with another star. Wonder what would happen if you suddenly bridged our sun with a red giant, or a neutron star?

2010-07-05 01:42:35 by Snowyowl:

I don't think black holes and wormholes are on the same level. Making a small black hole is, with our current technology level, above all an engineering feat. You need to concentrate a few million laser beams onto a single point - and if that's not possible, we know there are naturally occurring black holes out there, so we might be able to use one of those.
Einstein-Rosen bridges require large amounts of "negative matter" to make (I'm talking about a weight comparable to Jupiter), and we don't even know whether it exists, let alone how to synthesise it. On the other hand, bridging the Sun's core with the Earth's atmosphere would be just too awesome for words.

(My knowledge of General Relativity isn't quite up to scratch, but I'm pretty sure trying to bridge the Sun with a black hole or a neutron star would just collapse the wormhole.)

2010-08-19 17:36:05 by Aegeus:

Considering that some of your methods include moving black holes or planet-sized chunks of antimatter, I don't think it's fair to throw out this method just because it involves moving 8 suns worth of hydrogen around.

Also, once you've made the sun massive enough to make iron, couldn't you then start "poisoning" it with big chunks of iron like you originally planned?

2010-12-12 22:29:42 by M:

What about opening a Jupiter sized wormhole connecting the core of the sun to deep space momentaeily?

2011-07-30 01:16:56 by Molikai:

hmm. A sphere of satellites around the star, capable of generating our (Hypothetical - if you can figure out a way to do this, you win many fun prizes. like the Nobel.) Gravity waves, intersecting at the core of the star in such a fashion so as to constructively interfere, and dial up the effective gravityarional pull of the centre - turning solar energy into more mass, effectively. now the thought that always comes to my mind is this: should i set this up, then the rate of fussion, the expansive force, will increase to match the compressive force of the new gravitational pull. And once it is balanced..
I turn the satellites off.
The expansive force is now much higher than the compressive force. Hilarity ensues.
Get a big /enough/ differential, you shhould get a nice explosion with all sorts of fun fusion byproducts. Bonus points if the satellites can then deploy a 'net' of millions of strong point sources by the same method of constructive interference, to 'catch' the cast-off material so you can make stuff with it. I suspect the amount of energy you'd need to do this would be ever so slightly astronomical, though. But I like the idea of mining stars, don't you?

2011-09-11 10:20:23 by Jason:

Why not just break the universe?
What I mean, is have a wormhole near a neutron star connect to one near the Earth. Then send a photon through the wormhole. Due to time dilation, the wormhole near the neutron star will be in the past at the time of your connection, but in the future if you look at it. Anyone who understands that sort of stuff, correct me. What will then happen will be one of two things:
a) The universe will break, because a non-virtual photon travelled back in time.
b) The universe will not break, and you have just invented time travel.

2011-11-12 00:08:31 by TW:

I think type 1a supernovas "come to the rescue" here. They're caused when a white dwarf accreting matter from a companion star passes the critical mass, which is about 1.4 solar masses.

There are two basic ways to go about it. You can move a white dwarf from somewhere into a close orbit around the Sun, thereby triggering a supernova in the solar system, but technically it's the white dwarf not the Sun that goes supernova. That's a big thing to move, but it's a smaller than the nine solar masses quoted above. Or you can move Earth to a normal star-white dwarf system, then move the white dwarf in said system closer to its parent star. That way the big thing doesn't have to be moved as far.

And we don't have to go off to the other side of the galaxy either. The Sirius system is under nine light-years away, there's our white dwarf, with its companion for the second method of moving Earth into its system. (Admittedly, Sirius B will need about half a solar mass more to go supernova; I don't know how long it would take to accrete that.