Both teams took advantage of a phenomenon called the Sunyaev-Zel’dovich effect that occurs when light left over from the big bang passes through hot gas. As the light travels, some of it scatters off the electrons in the gas, leaving a dim patch in the cosmic microwave background – our snapshot of the remnants from the birth of the cosmos.

Holy moly this is badass.

But I don't understand how gas 'tendrils' between galaxies accounts for half of the matter in the universe.

posted by ooli: 469 days ago