Washington: A team of American astrophysicists has made the most accurate measurement of the total amount of matter in the universe ever. This is a long-term mystery of the universe.
The answer was published in the Astrophysical Journal on Monday, that is, matter accounts for 31.5% of the total matter and energy that make up the universe, or 1.3%.
The remaining 68.5% is dark energy, which is a mysterious force that accelerates the expansion of the universe over time. It was first determined by observations of distant supernovae in the late 1990s.
In other words, this means that the total amount of matter in the observable universe is 66 billion billion times the mass of the sun. Mohamed Abdullah, an astrophysicist at the University of California, Riverside, told AFP.
Most of it (80%) is called dark matter. Its nature is unclear, but it may be composed of some subatomic particles that have not yet been discovered.
The latest measurements correspond well with values previously found by other teams using different cosmological techniques, such as measuring temperature fluctuations in the low-energy radiation left over from the Big Bang.
“This has been a long process over the course of 100 years where we’re gradually getting more and more precise,” Gillian Wilson, the study’s co-author and a professor at UCR told AFP.
“It’s just kind of cool to be able to make such a fundamental measurement about the Universe without leaving planet Earth,” she added.
So, how do you accurately measure the universe?
The team honed a 90-year-old technique that involves observing how galaxies rotate inside galaxy clusters (large systems containing thousands of galaxies).
These observations tell them how strong the gravity of each galaxy cluster is, and then they can calculate its total mass.
-The fate of the universe-
Wilson explained that, in fact, their technology was originally developed by the pioneering astronomer Fritz Zwicky, who was the first person in the 1930s to suspect dark matter in galaxy clusters.
He noticed that the total gravitational mass of the galaxies he observed in the nearby comatose galaxy cluster was not enough to prevent these galaxies from flying away from each other, and realized that there must be some other invisible matter.
The UCR team’s research received funding from the National Science Foundation and NASA. They perfected Zwicky’s technology and developed a tool called GalWeight, which can more accurately determine which galaxies belong to a given galaxy and which ones are not. Belong to a given galaxy.
They applied the tool to the Sloan Digital Sky Survey, the most detailed three-dimensional map of the universe currently available, used to measure the mass of 1,800 galaxy clusters and create a catalog.
Finally, they compared the number of star clusters observed per unit volume in their catalog with a series of computer simulations, each of which assigned a different value to the universe as a whole.
There are too few simulated clusters with less material, and too many simulated clusters with more material.
They found that “Goldilocks” were just right.
Wilson explained that a more precise measurement of the total amount of matter in the universe might bring us closer to understanding the properties of dark matter, because scientists “we know how much matter to look for” when conducting particle research. Experiments, such as the Large Hadron Collider.
She added: “In addition, “the total amount of dark matter and dark energy tells us the fate of the universe.” The current scientific consensus is that we are moving towards the “great freezing point” and the distance between galaxies is getting farther and farther. The stars in the galaxy eventually ran out of fuel.
