Tuesday, March 27, 2012
How universe got its magnetism?
http://timesofindia.indiatimes.com/home/science/How-universe-got-its-magnetism-Physicists-attempt-to-solve-it/articleshow/12414302.cms
Physicists attempt to solve it
PTI | Mar 26, 2012, 03.33PM IST
For long, it has been a mystery. Now, physicists claim to have attempted to solve it by using laser to create magnetic fields similar to those involved in formation of the first galaxies.
Magnetic fields exist throughout galactic and intergalactic space, what is puzzling is how they were created originally and how they became so strong.
A team, led by Oxford University, used a high-power laser to explode a rod of carbon, similar to pencil lead, in helium gas. The explosion was designed to mimic cauldron of plasma -- an ionised gas containing free electrons and positive ions -- out of which the first galaxies formed.
The physicists found that within a microsecond of the explosion strong electron currents and magnetic fields formed around a shock wave.
They 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, the 'Nature' journal reported.
"Our experiment recreates what was happening in the early Universe and shows how galactic magnetic fields might have first appeared. 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," said Dr Gianluca Gregori, who led the team.
The results closely match theories which predict that tiny magnetic fields -- "magnetic seeds" -- precede the formation of galaxies. These fields can be amplified by turbulent motions and can strongly affect the evolution of the galactic medium from its early stages.
Dr Gregori said in a release: "In the future, we plan to use the largest lasers in the world, such as the National Ignition Facility in California, to study the evolution of cosmic plasma."
Physicists attempt to solve it
PTI | Mar 26, 2012, 03.33PM IST
For long, it has been a mystery. Now, physicists claim to have attempted to solve it by using laser to create magnetic fields similar to those involved in formation of the first galaxies.
Magnetic fields exist throughout galactic and intergalactic space, what is puzzling is how they were created originally and how they became so strong.
A team, led by Oxford University, used a high-power laser to explode a rod of carbon, similar to pencil lead, in helium gas. The explosion was designed to mimic cauldron of plasma -- an ionised gas containing free electrons and positive ions -- out of which the first galaxies formed.
The physicists found that within a microsecond of the explosion strong electron currents and magnetic fields formed around a shock wave.
They 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, the 'Nature' journal reported.
"Our experiment recreates what was happening in the early Universe and shows how galactic magnetic fields might have first appeared. 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," said Dr Gianluca Gregori, who led the team.
The results closely match theories which predict that tiny magnetic fields -- "magnetic seeds" -- precede the formation of galaxies. These fields can be amplified by turbulent motions and can strongly affect the evolution of the galactic medium from its early stages.
Dr Gregori said in a release: "In the future, we plan to use the largest lasers in the world, such as the National Ignition Facility in California, to study the evolution of cosmic plasma."
Labels: galaxies, laser, magnetic fields, magnetism, universe
Subscribe to Posts [Atom]