Project at Daya Bay nuclear plant tries to unlock key to origin of the universe

Scientists at the Daya Bay nuclear power plant - about 50 kilometres from Hong Kong - say new results they have recorded about ghostly particles called neutrinos may be a step towards solving some of the biggest mysteries of the universe.

The importance attached to the Daya Bay Reactor Neutrino Experiment, as the multinational physics project is called, can be gauged by the fact that the results were named among the top 10 science breakthroughs last year by Science Magazine.

Neutrinos are among the most abundant yet least understood fundamental particles in the universe. Scientists believe a knowledge of them is key to understanding the origin and history of the universe.

Finding them is not easy. They are similar to electrons, but are tiny, as their name implies, and lack an electrical charge. They have mass, but it is miniscule even compared with other subatomic particles.

Scientists say that to understand how they work, they must establish their mass - in other words, weigh them. This has never been done accurately.

Neutrinos are hard to find because of the very small chance they have of interacting with regular matter. For example, they can pass right through the earth without touching any other particles. Because they have no charge, they are unaffected by electromagnetic force. Detectors built to find them see only flashes of 10 to 15 a year.

The sun produces lots of neutrinos, but it is far away. While commercial nuclear reactors such as Daya Bay allow scientists to study these particles at close hand, it is still not an easy job.