Canadian Researchers Create Supernova In-lab

Erebus42 writes "Canada has done something neat. Apparently researchers at the University of British Columbia have created supernova in their ISAC (Isotope Seperator and Accelerator), transmuting sodium 21 into magnesium 22. Spiffy."

Comments

Article is misleading

[LMCBoy]

It's a huge stretch to say this is the first man-made supernova. Maybe it's the first man-made r-process nuclear reaction, but that's a far cry from a supernova. The reaction they've reproduced involves trace elements, not the iron/nickel that are really important in a SN.

Basically, a SN happens when a massive star has converted all of its core fuel into iron by nuclear fusion. The star's gravity compresses and heats the iron until it can fuse also. However, iron is the most tightly bound element, so fusing iron nuclei doesn't release heat energy, it removes it. The thermal pressure that was holding up the star's core disappears in a fraction of a second, and the whole thing comes crashing down in a huge implosion. The implosion causes the core material to form a neutron star or a black hole, and the rebounding shock wave blows the rest of the star apart.

Doesn't sound much like what they did. I don't mean to downplay their achievement; it's still very impressive. I'm just lamenting the sorry state of most science reporting...

Re:Black Holes?

[Bonker]

but aren't supernovas the cause of black holes?

Not necessarily. The immense amount of forces that are involved in a supernova create conditions that allow black holes to form. All you really need for a black hole is enough heavy matter in small enough space.

It's like this... When planets and even small stars form, the electromagnetic force is enough to keep individual atoms from crushing each other. You can't push electrons any closer.

Stars who die without becoming any bigger become white, and eventually black dwarfs.

In larger stars, after they ignite, the nuclear force-- the constant fusion reaction-- is enough to do the same thing. Once that fusion reaction shuts down, however, the atoms begin to collapse, increasing density and pressure until the heavier atoms are able to fuse.

If a star this size goes nova, the electrons and protons collapse, leaving neutrons. The neutron matter will hold up to a certain point under the force of gravity. AP's correct me, but I think it's the electroweak force that is responisble for this resistance.

If a star dies at this stage, you get a neutron star.

If a star is very, very massive... Think blue giants... Even the force that keeps the neutrons from crushing eachother is not enough to overcome the force of gravity. The neutrons collapse under their own weight into an infinitly small point and the space around the singularity warps until the escape velocity is greater than the speed of light.

I'm certain what we all know that singularity + event horizon = black hole.

Despite the fact that the researchers were creating the same kinds of reaction that occurs in the latter period of the death of a star, they simply weren't dealing with the kind of mass necessarly to create a black hole. Even if scientists *did* manage to create enough pressure to force matter to collapse into a singularity, it would evaporate away into Hawking radiation almost instantly. You don't just need the singularity to keep a black hole, you need to have it be massive and keep feeding it to keep it alive.