The new discovery exposes a major misunderstanding of dark energy

This month, astronomers are doing what they describe as… The largest survey in the history of the universe They announced that they could have discovered A A major flaw in understanding dark energy, The force that accelerates the expansion of the universe. Dark energy was supposed to be a constant force. But new data suggest they may be more likely to change, strengthen or weaken over time, reverse or even fade away.

“This may be the first real evidence we've had in 25 years about the nature of dark energy,” said Adam Rees, an astronomer at Johns Hopkins University and the Space Telescope Science Institute in Baltimore, Maryland, who shared the prize. He won the Nobel Prize in Physics in 2011 along with two others for his discovery of dark energy, but he was not involved in this new study.

If the discovery is confirmed, it could free astronomers from a long-held bleak prediction about the ultimate fate of the universe. If the action of dark energy were constant, over time it would push all the stars and galaxies so far apart that even atoms could tear apart, extinguishing all life, light and energy in the universe. This result has a 1 in 400 chance of being just a statistical fluke.

The news appears in the first progress report of a collaboration called the Dark Energy Analysis Instrument, or DESI. The group has just begun a five-year effort to create a 3D map of the positions and velocities of 40 million galaxies over 11 billion years of cosmic time. Their initial map, based on the first year of observations, includes only 6 million galaxies.

“So far we are seeing a fundamental match with our best model of the universe, but we are also seeing some interesting differences that could indicate that dark energy is evolving over time,” Michael Levy, director of the DESI Institute, said in a released statement. By Lawrence Berkeley National Laboratory in California, which manages the project.

In 1998, two competing groups of astronomers discovered that the expansion of the universe was accelerating rather than slowing down, as most astronomers had expected. This seemed to indicate that this dark energy was behaving like the famous cosmological constant (denoted by the Greek letter Lambda) that Einstein introduced into his equations to explain it. Why didn't the universe collapse due to its own gravity? As Einstein formulated it, lambda was a property of space itself: as space increased as the universe expanded, dark energy increased, pushing harder and harder and eventually leading to an unruly, lightless future.

The DESI project is designed to test the stability of dark energy by measuring the speed at which the universe expanded at different times in the past. To do this, scientists equipped a telescope at Kitt Peak National Observatory in Arizona with 5,000 fiber-optic detectors that can perform spectroscopic analysis on as many galaxies at once and detect how fast they are moving away from Earth.

Scientists have divided the last 11 billion years of cosmic history into seven time periods. For each of them, they measured the speed at which the galaxies in them were moving away from us and from each other. They found that galaxies from the last three epochs appeared closer than they should.Which suggests that dark energy could evolve.

Michael Turner, a scientist at the University of California, San Francisco, said: “Although collecting data sets is complex, and these are the first results from DESI, the potential evidence that dark energy is not constant is the best news I have heard since acceleration was established.” “The universe has been strong for more than 20 years.” Professor Emeritus at the University of Chicago who coined the term “dark energy.”