Trapped antihydrogen (click here)
...Under a theory expounded in 1931 by the eccentric British physicist Paul Dirac, when energy transforms into matter, it produces a particle and its mirror image — called an anti-particle — which holds the opposite electrical charge.
When particles and anti-particles collide, they annihilate each other in a small flash of energy. Until now, experiments have produced anti-atoms, namely of hydrogen, but only in a free state. That means they instantly collide with ordinary matter and get annihilated, making it impossible to measure them or study their structure.
In a paper published on Wednesday by the British journal Nature, a team at the European Organisation for Nuclear Research (CERN) in Geneva explain a method of snaring these so-called anti-hydrogen atoms....