Hunting for the Primordial Magnetism

The universe is structured around a colossal skeleton known as the "cosmic web," a vast lattice of wispy filaments made of galaxies and gas that stretch across hundreds of millions of light-years. While these filaments were once thought to be empty spaces held together solely by gravity, astronomers are now discovering that they are threaded by a hidden force: magnetism. Recent breakthroughs have identified magnetic field lines spanning 50 million light-years between galaxy clusters, as well as radio ridges of magnetic fields and relativistic particles connecting clusters across 10 million light-years of space. These findings raise a fundamental question: are these intergalactic fields the overgrown offshoots of stars and galaxies, or are they primordial fossils dating back to the Big Bang?