The universe is strangely magnetic – and a process of runaway expansion at its birth is to blame. New calculations shore up the idea that cosmic inflation stretched out tiny magnetic fields in the infant universe, leading to the magnetism that now surrounds galaxies, galactic clusters and giant voids in space.
To create a magnetic field in stars or a planet, the spins of individual electrons in a magnetic material, such as iron, line up in the same direction. If these then rotate, like liquid iron in Earth's outer core, it creates a geodynamo, which produces an electric current and in turn a magnetic field.
But the alignment of interstellar dust grains and measurements from radiotelescopes reveal that primordial magnetic fields surround galaxies, galaxy clusters and even cosmic voids – and these cannot be caused by geodynamos. This magnetic fields are much weaker than Earth's, measuring at most 10-6 gauss, although if you add up all the ones across the universe, it amounts to a lot of energy, says astrophysicist Gianluca Gregori of the University of Oxford.
This magnetic fields are much weaker than Earth's, measuring at most 10-6 gauss, although if you add up all the ones across the universe, it amounts to a lot of energy, says astrophysicist Gianluca Gregori of the University of Oxford. (...) Read original article in full here