The universe is 2.5 billion times less magnetic than a fridge magnet

https://www.newscientist.com/article/2202343-the-universe-is-2-5-billion-times-less-magnetic-than-a-fridge-magnet/

Night sky

Magnetism, how does it work?

Giulio Ercolani / Alamy Stock Photo

The magnetism of the entire universe is 2.5 billion times weaker than a fridge magnet, according to a new analysis.

“The magnetic field is weak by that standard, but it’s a lot of energy. There’s as much energy in the Milky Way in magnetism as there is in starlight,” says Bryan Gaensler at the University of Toronto in Canada.

As light passes through a magnetic field, the Faraday effect causes the light’s orientation, or polarisation, to rotate. Gaensler and his colleagues used this …