Å®ÉúСÊÓƵ

THE world’s largest neutrino detector—a tank in an abandoned mine
holding 50 000 tonnes of pure water—began operations in Japan last week.
Neutrinos that pass through the 1-kilometre layer of rock above the tank should
leave telltale tracks in the water. Å®ÉúСÊÓƵs from Japan, the US and Poland
will study the neutrinos as they pass through to see if they change into other
particles.

The tank cost £63 million to build. Astronomers hope that within two
years the detector will answer questions about the inside workings of the
Sun.