Did Scientists Just Find a Missing Piece of The Universe?



Given how small the Earth is compared to the vastness of the cosmos, it would be silly to think we completely understand our universe. Baryons or the ordinary matter, make up all physical objects in existence, from stars to the cores of black holes. Until now, astrophysicists had only been able to locate about two-thirds of the matter that theorists predict was created by the Big Bang.

As far as humans can tell, the universe is composed mostly of some mysterious, unexplained energy called dark energy that pushes it apart. Only 4% is the is the regular matter that we can see: stars, planets, and interstellar and intergalactic gas. But the observed amount of this regular matter still falls perhaps a third short of the amount of stuff.

In a new study, an international team pinned down the missing third, finding it in the space between galaxies. That lost matter exists as filaments of oxygen gas at temperatures of around 1 million degrees Celsius. The finding is a major step for astrophysics. Specifically, scientists are looking for baryons, particles made from quarks that make up the nuclei inside of atoms.

The team really did was observe the light coming from one very bright source several billion light-years away. As this light approaches Earth, it stretches due to the expanding universe, therefore longer wavelengths indicate older light. At two distances, they observed what looked like a filter made of positively-charged oxygen atoms that absorbed the light. 

Researchers have a good idea of where to find most of the ordinary matter in the universe, not to be confused with dark matter. About 10% sits in galaxies, and close to 60% is in the diffuse clouds of gas that lie between galaxies. In 2012, the team predicted that the missing 30 percent of baryons were likely in a web-like pattern in space called the warm-hot intergalactic medium (WHIM).

Co-author of the study, Michael Shull said, “This is one of the key pillars of testing the Big Bang theory: figuring out the baryon census of hydrogen and helium and everything else in the periodic table.

The research study which concludes that the missing  baryons have been found was published in the journal Nature with the title “Observations of the missing baryons in the warmhot intergalactic medium”.