'Ghost particles' ARE coming from the centre of the Earth
25.08.2015 20:30
For decades scientists have worked to pinpoint where mysterious 'ghost particles' called neutrinos come from.
Now they have collected the first firm evidence that the barely-there neutral subatomic particles are produced beneath the Earth’s crust, using an underground laboratory in Italy.
The research could help to reveal what radioactive elements lie within the Earth and the radioactive processes generating heat inside our planet.
Neutrinos are generated by nuclear reactions involving the decay of unstable atoms and are often described as ghostly because they are so tiny - 500,000 times lighter than the electron, LiveScience reported.
Because they don’t have a charge and rarely interact with other particles, they rarely strike atoms.
But when they do, a flash of light is created, which has previously been recorded by scientists as proof of their existence.
Neutrinos have now been detected coming from the Earth’s interior and these ‘geoneutrinos’ give physicists a glimpse inside our planet’s centre.
Experts can pinpoint individual radioactive isotopes in the Earth’s interior and work out how their heat affects geological activity such as volcanoes and earthquakes.
The Earth’s interior generates 20 times as much heat as all of its power stations, the BBC reported.
While most of its heat is left over from its creation, some of it comes from the decay of radioactive elements.
Until now, no-one could even hazard a guess about how much.
Scientists at Gran Sasso National Laboratory in Italy, which is located one mile (1.5km) below the Apennine Mountains, used the Borexino neutrino detector to study the ghost particles.
The instrument uses 2,200 sensors to spot rare flashes of light emitted when neutrinos interact with 200 tonnes of a special oil housed in a sphere.
They pinpointed 24 geoneutrinos within 2,056 days of data from the detector to find that 11 came from the Earth’s mantle and 13 from its crust.
These geoneutrinos suggest that around 70 per cent of the heat inside the Earth is created by radioactivity, but the number is uncertain.
The results are reported in the journal Physical Review D.
‘It's at 98 per cent the confidence level, which means there is still a small probability that there is no signal from the mantle,’ Aldo Ianni, an experimental particle physicist at the laboratory told the BBC.
That two per cent chance of a mistake is too large for the research to be defined as a ‘discovery’ under the rules of particle physics.
‘It's small, but in terms of physics it should be much smaller,’ he said.
In order to get a more precise number, the international team will need to gather data for around 17 years, Dt Ianni said.
In the future, experts may install more geoneutrino detectors in different locations around the world to see how the radioactive elements spread though our planet’s interior.
(dailymail.co.uk)
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