Astronomers measure ripples in cosmic web for first time

US-based astronomers have made the first measurements of small-scale ripples in the 'cosmic web', hydrogen gas leftover from the Big Bang. They identified exceedingly rare pairs of quasars, celestial objects containing supermassive black holes emitting energy. Astronomers then measured subtle differences in the absorption of intergalactic materials in the two quasars to measure the ripples.