We all hear what a perfect world it’d be if we could perfect cold fusion, a process only stars can achieve at ridiculous temps. But, stars die in volatile manners. Some become neuton stars - rather uneventful, as I recall.
So, what about fusion reactors? Supernova and black hole? Boy, would that raise some zoning issues! - Jinx
Supernovas occur, in general, because the depletion of nuclear fuel in the core results in a drop in the star’s core pressure which is no longer sufficient to prevent gravitational collapse. This collapse of the star under its own weight triggers a massive outburst of heavy-element fusion which blows the star apart.
Earthbound fusion reactors, whenever they manage to be built, will not have this issue.
Not enough mass. To form a black hole, a star must have a minimum mass, ISTR 2-3 solar masses. Unless that is some really big fusion reactor, it can’t happen.
Why, I’ve got half a solar mass in my pocket.
and, ads for cold fusion for students and cold fusion hosting. wonder what that’s about.
A star has to have that mass, other things don’t. You can create a black hole with less mass, but then it’s probably not going to be a big deal. Take a look at any of the recent particle accelerator threads.
Isn’t there a thought that the really small ones evaporate almost immediately?
In a star, all the fuel it’s ever going to have is already inside it.
In a reactor, it’s fed in through a fuel line of sorts. (some kind of magnetic channel)
If containment of the reaction is lost there will be a burst of heat that would destroy the reactor, (and possibly some of the surroundings) but the nuclear fusion will stop immediately because it needs that containment to achieve the pressure needed for fusion in the first place.
A star is massive enough for it’s own gravity to provide that pressure.
Hawking has a theory that black holes radiate energy at the event horizon. The smaller the black hole, the theory says, the more radiation it gives off. Since radiation causes a loss in mass, eventually black holes essentially evaporate, and the smaller they are to begin with, the quicker they will disappear.
As well, it has been proposed that cosmic rays may cause eensy-teensy-tiny black holes in the upper atmosphere, because of the immense energy they have.
I thought it was a hadron. :eek:
I have a feeling if we keep up this line of puns, the Mods. will apply the Paoli Exclusion Principle. 
If it were inappropriate, the Mods woulda lepton it already, you boson.
That’s this ColdFusion, not this one…
Damn you, Turek!
A fusion reactor will be intrinsically safe because, unlike fission, fusion is not a chain reaction. A fusion reaction actually tends to inhibit further fusion in the area by creating heat (which pushes the potentially fusing atoms apart) and daughter elements which are usually much harder to fuse than the fuel elements and therefore dilute and poison the fuel. Unlike a fission reactor, which becomes spontaneously self-supporting once a critical mass is achieved, a fusion reactor has to work very hard constantly to maintain the conditions required to sustain fusion. If anything goes even a little bit wrong, fusion ceases instantly. At worst you’ll damage the reactor, and even that will be mostly due to release of energy stored in superconducting coils, capacitors, and similar reactor components rather than energy generated directly by the fusing plasma.
Stars can only manage stable fusion due to the staggeringly huge amount of mass they contain, which creates huge pressure in their core. The fusion that takes place in a star’s core actually opposes that pressure, preventing further collapse. A supernova is what happens when the star runs out of fuel, and fusion in the core is no longer able to fight gravitational collapse. This can’t happen in a fusion reactor, since everything in the reactor has to be working perfectly for the fusion to happen at all.
We have already achieved fusion, the hydrogen bomb. Yes it makes a mess. No it doesn’t blow the solar system apart.
Well, yes. But to start fusion we actually need to detonate a fission device first - not exactly a feasible way of achieving fusion for use in any future fusion reactor.
About as likely as a fission reactor starting a chain reaction that leads to the Earth blowing up like planet Krypton. :rolleyes: