For a variety of obvious reasons, it’s impossible to reproduce the exact environment in which galaxies form. The lack of direct experimental tests for the models astrophysicists use creates a disconnect between what astronomers observe and theoretical work. However, that barrier is being broken down by a combination of high-powered lasers and a new understanding of how lab-scale experiments can be related to vastly larger systems such as galaxies.

Researchers at the Laboratoire pour l’Utilisation de Lasers Intenses (LULI), along with colleagues at various universities, have successfully simulated the magnetic fields that form in early galaxies. Naively, there seems to be no correspondence between the experiment and the real astrophysical system. The lab set-up is very small, works on a very short time frame, and uses carbon rods and lasers; the real environment for galaxy formation is clouds of gas and dark matter, and the time-scale is hundreds of millions of years. Nevertheless, a magnetic field strength (along with other effects) has been observed in the lab that corresponds to that experienced by early protogalaxies.

(via Bringing galaxy-scale magnetic fields down to size in the lab)