Scientists have used a laser to create magnetic fields similar to those thought to be involved in the formation of the first galaxies; findings that could help to solve the riddle of how the Universe got its magnetism.
Magnetic fields exist throughout galactic and intergalactic space, what is puzzling is how they were originally created and how they became so strong.
A team, led by Oxford University physicists, used a high-power laser to explode a rod of carbon, similar to pencil lead, in helium gas. The explosion was designed to mimic the cauldron of plasma — an ionized gas containing free electrons and positive ions — out of which the first galaxies formed.
The team found that within a microsecond of the explosion strong electron currents and magnetic fields formed around a shock wave. Astrophysicists took these results and scaled them through 22 orders-of-magnitude to find that their measurements matched the ‘magnetic seeds’ predicted by theoretical studies of galaxy formation.
‘Our experiment recreates what was happening in the early Universe and shows how galactic magnetic fields might have first appeared,’ said Dr Gianluca Gregori of Oxford University’s Department of Physics, who led the work at Oxford. ‘It opens up the exciting prospect that we will be able to explore the physics of the cosmos, stretching back billions of years, in a laser laboratory here on Earth.’