On October 14, Beijing time, according to foreign media reports, one of the ultimate goals of cosmology is to accurately measure the total amount of matter in the universe. Even the most mathematical people will find this task extremely arduous. But a team of scientists at the University of California, riverside, has done it. According to their paper in the Journal of astrophysics, the team determined that matter accounts for 31% of the total matter and energy in the universe, and the rest consists of dark energy. < / P > < p > Muhammad Abdallah, the first author of the paper and a graduate of physics and astronomy at the University of California, riverside, said: “if all matter is evenly distributed throughout space, then its average mass density would be equivalent to only six hydrogen protons per cubic meter. However, since we know that 80% of matter is actually dark matter, in fact, most matter is not made up of hydrogen atoms, but of a matter that cosmologists have not yet understood. ” < / P > < p > the research team determined that matter accounts for 31% of the total amount of matter and energy in the universe. Cosmologists believe that about 20% of matter is made up of regular or “baryonic” matter, including stars, galaxies, atoms and life, while the remaining 80% is made up of dark matter. So far, no one knows the mysterious properties of sub dark matter. < / P > < p > Abdallah explained that a mature method to determine the total amount of matter in the universe is to compare the observed number and mass of galaxy clusters per unit volume with the predicted results of numerical simulation. Because today’s galaxy clusters are made up of matter that collapsed in the past billions of years under its own gravity, the number of galaxy clusters observed today is very sensitive to cosmological conditions, especially the total amount of matter. < / P > < p > “a higher proportion of matter will lead to more clusters,” said Abdallah. “The challenge for our team is to measure the number of clusters and then determine which answer is” more correct. “. But it’s hard to measure the mass of any cluster precisely because most of the matter is dark and we can’t see it with a telescope < / P > < p > to overcome this difficulty, astronomers led by the University of California Riverside team first invented “galweight” – a cosmological tool that uses the orbits of member galaxies to measure the mass of the cluster. The researchers then applied their tools to observations at the Sloan Digital Survey Center to create “galwcat19,” a publicly available catalog of galaxy clusters. Finally, they compared the number of clusters in the new catalog with the simulation results to determine the total amount of matter in the universe. < / P > < p > “we have successfully completed the most accurate measurement ever using galaxy cluster technology,” said Gillian Wilson, a co-author and professor of physics and astronomy at the University of California, riverside. The values obtained by this technique are consistent with those obtained by using non cluster techniques such as cosmic microwave background anisotropy, baryon acoustic oscillations, type Ia supernovae or gravitational lenses. ” < / P > < p > “the great advantage of using galweight orbital technology is that our team can determine the mass of each cluster independently without relying on indirect statistical methods,” said Antory kriping, the third author of the paper. < / P > < p > by comparing their measurements with those of the team using other measurements, the UC Riverside team was able to determine the best combination and conclude that matter accounts for 31.5 ± 1.3% of the total matter and energy in the universe. It is said that “gta5” will be launched on Google cloud game platform stadia

By ibmwl