The largest galaxy survey ever conducted suggests that our universe is not as clumsy as envisioned.Lack of clumsiness can mean that there is a discrepancy with Einstein General theory of relativityUsed by scientists to understand how the structure of our universe has evolved over 13 billion years.
“If this gap is true, Einstein might have been wrong,” said Niall Jeffrey, one of the co-leaders of The Dark Energy Survey (DES) and a cosmologist at the Ecole Normale Superiore in Paris. It was. Told BBC News
The DES team has cataloged hundreds of millions of galaxies and used small distortions in the shape of those galaxies to measure cosmic vital statistics.We have confirmed that almost all of these measurements are general big Bang Model Cosmology, All cosmic problems have grown from surprisingly hot and incredibly small points.
However, one of those measurements, the mass of matter, was slightly off. If the universe is smoother than you think, it means that our understanding of how structures evolve in the universe, based on Einstein’s general theory of relativity, is wrong.
Some news headlines have already declared that Einstein is wrong and physicists need to modify the model, but the reality is much more subtle. This is because the discrepancy is not yet a statistical slam dunk.
Best survey ever
More than 400 scientists from 25 institutions in seven countries are working on DES, one of the largest astronomical collaborations in history. The team used a 4-meter (13.1 ft) Victor M Blanco telescope at the Serotrollo Intercontinental Observatory in Chile to gaze at one-eighth of the entire night sky during 758 night observations.
The observation project started in 2013 and ended in 2019. However, the observation was an easy part. The DES collaboration took two years to release the latest results, considering only the data from the first three years of observation.
And that’s great.
Described in the avalanche of 29 scientific papers, this release contains detailed observations of 226 million galaxies, making it the largest and most detailed galaxy survey in history.
This huge catalog still represents less than a tenth percent of all galaxies in the observable universe, but that’s the beginning.
Measure the universe
DES has used a treasure trove of galaxies to study two key features of our universe. One is called the Space Web. It turns out that galaxies are not randomly scattered in the universe, but are organized in the largest pattern found in nature. On a very large scale, astronomers find huge clusters of galaxies called clusters of galaxies, long filaments of galaxies, wide walls, and vast empty cosmic cavities.
The cosmic web is a dynamic object that has evolved into its present state over billions of years. Astrophysicists believe that long ago, matter in the universe was much more evenly distributed. By studying the evolution of the universe’s web, DES scientists can understand what the universe is made of and how it behaves. That is because the contents of the universe determine how it evolves. Just changing the ingredients to your favorite cake recipe will change the way you get out of the oven.
DES also uses what is called the weak gravitational lens effect.From Einstein’s general theory of relativity, an object is gravity You can bend the path of light. The most famous example of this comes from the cluster of galaxies. Their incredible mass can greatly distort the light from the background galaxies, so they appear to the observer to be very stretched.
DES employs a much more subtle version of this lens effect. It looks for small changes in galaxy shape as light from the galaxy passes through billions of light-years of space. By comparing the shapes of these galaxies with what we know from a survey of nearby universes, DES astronomers can plan the distribution of matter in the universe. ..
Something is off
The DES collaborative study compared the results of other major studies, such as the Cosmic Microwave Background Planck study. The echo of the Big Bang was revealed by the faint glow of radiation spreading in space. Their results are almost in line with existing observations and general cosmology.We live in an expanding universe about 13.7 billion years ago, and its mass energy is composed of about one-third of matter (most of it). Dark matter), The rest is made of Dark energy..
But one measurement stood out. It is a parameter called S8 that characterizes the amount of cosmic mass. The higher the S8 value, the tighter the substance will aggregate. The new DES results support the S8 value of 0.776, while the old Planck results show a slightly higher value of 0.832.
Planck results come from early cosmic measurements, while DES results come from later cosmic measurements. These two numbers should match, and if they are actually different, how a giant structure grows and evolves over time, based on Einstein’s understanding of gravity by the general theory of relativity. Our understanding of the universe may be wrong. No one expected to find this discrepancy, so astrophysicists have not investigated exactly what part of the theory of relativity is flawed.
Queue headlines praising the results of DES as a major rift in the foundations of modern cosmology. “I spent my life working on this theory [of structure formation] Carlos Frenk, a cosmologist at Durham University in the United Kingdom, who has nothing to do with DES, told the BBC News. “But my brain has taught me that the measurements are correct, and we have to see new physics possibilities.”
However, it is uncertain that those headlines (and articles) neglect to mention. All measurements are uncertain. Scientists can only do it very accurately given the amount of data available. DES and Planck results generally overlap with each other if they contain statistical uncertainties. Not so many — the difference is worth digging deeper — but not enough to ring the alarm. In the language of statistics, the two measurements are only 2.3 standard deviations off. In other words, there is no actual difference in the value of S8, and if the observation is repeated 100 times, it will be the same (or more). ) 98 times difference. This is well below the five standard deviations normally required to signal new discoveries.
Let’s see what the data for three more years will bring.
Originally published in Live Science.
Did the discovery of dark energy just prove that Einstein was wrong? Not perfect.
https://www.space.com/dark-energy-survey-einstein Did the discovery of dark energy just prove that Einstein was wrong? Not perfect.