Meanwhile, physicists have found other practical applications for the antimatter produced in the laboratory. Positron emission tomography (PET), for example, made it possible to look into the thinking brain for the first time. Using hamster cells, scientists at CERN are currently testing the efficacy of antiproton radiation in destroying tumors. Positronium containing antimatter, on the other hand, could be used to detect tiny hairline cracks in turbines.
The Very Small and the Very Large
But the real fascination with antimatter is not a technical but of a philosophical nature. It played a key role in modern physics' spectacular attempt to bridge the gap between the microcosm and the macrocosm.
In the 1960s, scientists became aware of how closely particle physics and cosmology -- the sciences of the very small and the very large -- are interconnected. The deeper physicists penetrated into the subatomic world, the more they learned about the early days of the cosmos. It was there, in the delivery room of the universe, that the symmetry between matter and antimatter, which makes all material existence possible, must have come about.
The decisive connection was established by a physicist who ultimately won the Nobel Prize, albeit not for his research into physics but for his contribution to world peace. At about the same time at which he was gradually becoming a dissident, Andrei Sakharov, one of the fathers of the Soviet hydrogen bomb, also became interested in questions of cosmology.
Cut off from his Western colleagues, he mulled over the question of how matter could have achieved its victory over antimatter -- and formulated conditions under which this could have been possible.
It must have happened in the middle of the birth pangs of the universe, only fractions of a second after the beginning of time. Just as ice changes all of its properties when it turns into water, the entire, seething and bubbling universe must have undergone a transformation -- a "hiccup," as CERN theoretician John Ellis puts it. And there was something else, too. Sakharov theorized that somewhere deep within its laws, nature treats the seemingly identical twins of matter and antimatter differently.
What Sakharov had postulated seemed bold and speculative, and yet nature seemed to want to prove him right. A sensational discovery had just shaken the world of particle physics. So-called kaons, extremely short-lived and otherwise not particularly remarkable residents of the particle zoo, apparently decayed in a different manner than their counterparts, the anti-kaons.
The difference is admittedly tiny -- far too small, in fact, to satisfactorily explain the quantity of matter in the universe. Nevertheless, a dam had been breached, now that someone had proven that antimatter is not the exact counterpart of matter. There are differences. Particle physicists, seeking to gain a better understanding of what those differences are, embarked on a global hunt for other asymmetries. The most determined among them are the scientists at CERN.
'The First Truly Exciting Result'
There, beneath the peaks of the Jura Mountains, about 10,000 scientists have made it their mission to make protons crash into each other with the greatest possible force. Bundles of particles, accelerated by giant magnets, speed around a 27-kilometer circular tunnel. They rush from Switzerland to France and back again, 11,200 times per second, until they eventually crash and explode.