The warm-hot intergalactic medium (WHIM) has been seen before, along incredibly overdense regions, like the Sculptor wall, illustrated above. But it’s conceivable that there are still surprises out there in the Universe, and our current understanding will once again be subject to a revolution. (Spectrum: NASA/CXC/Univ. of California Irvine/T. Fang. Illustration: CXC/M. Weiss)

We Just Found The Missing Matter In The Universe, And Still Need Dark Matter

Many hoped we could do without dark matter. On cosmic scales, the evidence has finally spoken.

Ethan Siegel
Jul 2, 2018 · 3 min read

For over 40 years, scientists have argued over dark matter’s existence.