THE TNG COLLABORATION20 DISCOVERMAGAZINE.COMExperts have known for a while that gas and dark matter — the theoretical counterpart to regular matter — sprawl through
the cosmos. These so-called cosmic webs account for the bulk of the matter in the great unknown. Generally, where there’s
plenty of gas, there are also plenty of galaxies, which give off ultraviolet (UV) light). Today, that UV light keeps most of that
gas transparent, and galaxies shine through. But in our universe’s youth — around 12.5 billion years ago — it was pretty
opaque. And that opacity varied wildly throughout the universe.
A recent paper in Astrophysical Journal found out why: These once-opaque patches didn’t have many galaxies within
them, and thus not enough UV light to make gas transparent; it’s the opposite of what we see today, depicted below. In this
simulation of today’s universe, a dense gaseous void in the upper left appears empty, in contrast to bright galaxies in orange
and white. But back in the day, that void would have looked as impenetrable as a dense fog bank.“We can do a couple things geochemically with amber.
It’s pretty easy to detect fakes. It’s resin, a sap that
catches and traps gas bubbles, and we can use them
to chart it geographically and temporally.”
— University of Alberta paleontologist Michael Caldwell, on how researchers know
a series of spectacular fossil finds in Burmese amber are the real thingStaring Into the Abyss
THE CRUX