Boffins: Antimatter comes from black holes, neutron stars
'No one could have expected so much unexpectedness'
Topflight astrophysics boffins believe they may have cracked the tricky problem of how to make antimatter, which would be useful for many purposes: for instance powering relatively practical starships, or - of course - blowing up an entire planet in one go. However, it appears that making antimatter requires the possession of a black hole or a neutron star, so it won't be happening any time soon.
For those few readers who don't know, antimatter is like normal matter but with properties reversed. Thus a normal electron of the type used to publish this article has a negative charge*, but an anti-electron (aka positron) is positive.
The clever thing about antimatter is that when it bumps into normal matter the two annihilate each other completely, converting entirely into energy according to Einstein's famous formula E=mc2. This is the most powerful fuel-to-energy generation process possible - it makes an H-bomb look like a cap pistol. Some form of antimatter-powered drive might actually allow humans to travel between the stars within their own lifetimes under Einsteinian physics.
The energy created when electrons and positrons meet is emitted in the form of gamma rays. Back in the 1970s the existence of antimatter in the universe was verified in the obvious way - by sending gamma-ray detectors into the upper atmosphere on balloons.
According to the balloon detectors, there seems to be a large cloud of positrons throughout the centre of our galaxy, about 10,000 lightyears across and giving off the energy of 10,000 suns from constant antimatter annihilation as it reacts with ordinary electrons. But nobody knew why or how the antimatter was being created in the first place.
Now, however, that conundrum seems to have been solved.
"I think I can hear a collective sigh of relief," said Marvin Leventhal, a noted brainbox active in the field.
It seems that an international team of astrophysicists boiled down four years' worth of data from the European Space Agency (ESA) satellite INTEGRAL (INTErnational Gamma Ray Astrophysics Laboratory). They noted that the glowing gamma-ray positron cloud bulged significantly in the direction of Galactic west.
The positron cloud bulge coincided with a region in which there are believed to be a lot of binary star systems containing neutron stars or the even more outrageous black holes. These star systems are known as "hard low-mass X-ray binaries".
According to NASA, this strongly suggests that "these binaries are churning out at least half of the antimatter, and perhaps all of it."
Rival boffins had of late been suggesting that the antimatter was actually created by some process involving dark matter, but NASA's Gerry Skinner pooh-poohed such notions.
"The INTEGRAL results seem to rule out dark matter," he said.
"Simple estimates suggest that about half and possibly all the antimatter is coming from X-ray binaries," added his colleague Georg Weidenspointer of Germany's Max Planck Institute for Extraterrestrial Physics.
Weidenspointer, Skinner and Leventhal published their findings in the current issue of Nature.
Nobody knows exactly how black holes and neutron stars make antimatter, however. Nor is it clear how the antimatter gets away from such massive gravity fields, to drift about the Galactic core getting annihilated.
"We expected something unexpected, but we did not expect this," said Skinner, rather splendidly, suggesting that nobody could have expected so much unexpectedness.
NASA presumes to trump INTEGRAL by launching GLAST, the Gamma-ray Large Area Space Telescope, this year. The space agency says its new satellite "may help clarify" the business of antimatter production; also that it might allow the detection of other, larger antiparticles rather than just positrons. ®
*Possibly explains a lot from a literary viewpoint.
Occam's razor - the new Grail?
If you have a fiction called Perseus, it needs a horse to ride. Hence, you invent a fiction called Pegasus. But what's a hero without a maiden. So, you invent another fiction called Andromeda. Hero and maiden, how to get them together? To fix that problem you have a "thought experiment" - what if maiden needs to be rescued (from terrorists is good)? Great idea, really "works". And so, another fiction called Medusa. E cosi' via.
The more you invent, the better it all looks. The more fictions you have, the easier it is to juggle them together. The easier it is to "modify the behaviour" of your fictions on an ad hoc basis if your audience starts picking holes in your story. The more time you invest in all this, the more reluctant you are to give up your fictions. Especially if someone keeps throwing a lot of money your way to keep inventing them.
Things used to be so different when scientists paid for their own researches. For one, there was no incentive to cheat yourself out of the truth.
Black holes have long been thought to be a source of antimatter in the form of Hawking Radiation. The theory goes that empty space is fizzing with pairs of virtual particles that ordinarily pop into existence and subsequently vanish again after a fleeting instant. If such a pair span a black hole's event horizon, however, one of the virtual particles will be gobbled up by the immense gravity. The other is at liberty to be whisked away by a magnetic field, and there's a pretty good chance that it will be an anti-particle.
If you really want to give a physicist a headache, ask him why our universe is overwhelmingly dominated by matter rather than by anti-matter. On a related note, a spinning cobalt nucleus will spontaneously spit out an electron (beta decay), but it's always in the same direction with respect to the spin. Spooky. God definitely favours one hand over the other in our universe, but how does he know which one is which? After all, there's no external reference. Definitely spooky.
ow! ow! ow!
"DOCTOR!!! My brain hurts..."
Is it just me or does it seem like the whole "dark matter" biz was dreamed up because no "reputable scientist" wanted to admit they hadn't a clue?
And as for black holes, I thought that NOTHING, not even LIGHT, could escape a black hole. Did science change when I wasn't looking? It is commonly accepted that there is a "supermassive" black hole (roughly several million times Solar mass) at the center of our galaxy and that the ludicrous gravitational pull from same is largely what holds the galaxy together as a spinning mass.
Further out on the tangent: how many gazillions of years before the black holes gobble up all matter in the universe? And is that where my keys went?