LONDON: Physicists have unveiled a raft of new findings about neutrinos bombarding the Earth from above, below and within.
An experiment built in a vast slab of Antarctic ice has doubled its count of “cosmic neutrinos” from outer space, by searching for arrivals passing through the planet from the north.
The same team this week announced the highest-energy neutrino ever detected.
Meanwhile, a detector in Italy reported the first firm evidence for neutrinos produced beneath the Earth’s crust.
These “geo-neutrinos” carry much less energy but can inform scientists about the radioactive processes generating heat deep within our planet.
The fast-moving neutrinos from space, by contrast, offer clues about mysterious, violent sources of radiation beyond our own galaxy.
Neutrinos are subatomic particles with no charge and almost no mass, which very rarely interact with anything. This means they can practically cross the Universe in a straight line, passing through entire planets undeflected – and undetected.
But the IceCube collaboration has laced a cubic kilometre of ice beneath the South Pole with light sensors, to record the flashes created when a neutrino very occasionally bumps into an atom.
