Why the Universe is Made of Matter: CERN Exploring to Answer?
November 18, 2010 Leave a comment
Scientists at CERN said they’ve trapped dozens of anti-hydrogen atoms, a technical breakthrough that will allow them to explore why the universe is made of matter. 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. Since then, physicists have wondered why the universe seems to be dominated by matter and not antimatter. If everything were equal at the birth of the cosmos, matter and anti-matter would have existed in the same quantities. The observable universe would have had no chance of coming into being, as these opposing particles would have wiped each other out.
Trapping anti atoms Technical Feat
Understanding why there is this huge imbalance presents a daunting technical challenge. 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 in the British journal Nature, a team at the European Organisation for Nuclear Research (CERN) in Geneva explain a method of snaring these so-called antihydrogen atoms.
Experiments conducted in its ALPHA laboratory found a way of using strong, complex magnetic fields and a vacuum to capture and hold the mirror-image particles apart from ordinary matter. Thousands of antihydrogen atoms have been made in the lab, but in the most successful experiment so far, 38 have been trapped long enough – one tenth of a second – for them to be studied.
For reasons that no-one yet understands, nature ruled out antimatter. It is thus very rewarding, and a bit overwhelming, to look at the ALPHA device and know that it contains stable, neutral atoms of antimatter. This inspires us to work that much harder to see if antimatter holds some secret.