Slash Boxes

SoylentNews is people

Submission Preview

Link to Story

Half the Matter in the Universe Was Missing—We Found It Hiding in the Cosmos

Accepted submission by Phoenix666 at 2020-05-28 14:48:15

ScienceX []:

In the late 1990s, cosmologists made a prediction about how much ordinary matter there should be in the universe. About 5%, they estimated, should be regular stuff with the rest a mixture of dark matter and dark energy. But when cosmologists counted up everything they could see or measure at the time, they came up short. By a lot.

The sum of all the ordinary matter that cosmologists measured only added up to about half of the 5% what was supposed to be in the universe.

This is known as the "missing baryon problem" and for over 20 years, cosmologists [] like us [] looked hard for this matter without success.

It took the discovery of a new celestial phenomenon and entirely new telescope technology, but earlier this year, our team finally found the missing matter [].
But when radio waves pass through matter, they are briefly slowed down. The longer the wavelength, the more a radio wave "feels" the matter. Think of it like wind resistance. A bigger car feels more wind resistance than a smaller car.

The "wind resistance" effect on radio waves is incredibly small, but space is big. By the time an FRB ["Fast Radio Burst"] has traveled millions or billions of light-years to reach Earth, dispersion has slowed the longer wavelengths so much that they arrive nearly a second later than the shorter wavelengths.
We were overcome by both amazement and reassurance the moment we saw the data fall right on the curve predicted by the 5% estimate []. We had detected the missing baryons in full, solving this cosmological riddle and putting to rest two decades of searching.

The initial results are based on six data points, FRBs; the researchers will continue to look for others.

Original Submission