* Astronomy

Ripples in Cosmic Web Measured Using Rare Double Quasars

The most barren regions of the Universe are the far-flung corners of intergalactic space. In these vast expanses between the galaxies there are only a few atoms per cubic meter - a diffuse haze of hydrogen gas left over from the Big Bang. Viewed on the largest scales, this diffuse material nevertheless accounts for the majority of atoms in the Universe, and fills the cosmic web, its tangled strands spanning billions of light years.
Now a team of astronomers including Alberto Rorai and Girish Kulkarni, post-doctoral researchers at the Kavli Institute for Cosmology, University of Cambridge, have made the first measurements of small scale ripples in this primeval hydrogen gas. Although the regions of cosmic web they studied lie nearly 11 billion light years away, they were able to measure variations in its structure on scales a hundred thousand times smaller, comparable to the size of a single galaxy.
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