Is The Universes Endless Expansion In Doubt? Changing Dark Energy Sparks Fresh Cosmic Debate

Scientists are debating new evidence that suggests the Universe may not expand forever as once believed. Recent research points to the possibility that dark energy, a mysterious force that controls how the Universe grows, may be changing over time. If this is true, it could completely alter how scientists understand space, time, and the future of everything around us, reported BBC.

For a long time, astronomers believed that the universe originated from the Big Bang about 13.8 billion years ago and has been continuously expanding ever since. Initially, scientists thought that gravity, which pulls everything towards everything else, would slow down this expansion over time.

But this thinking changed in 1998 with the discovery of dark energy. This was considered a mysterious force that was pushing galaxies away from each other at an ever-increasing rate. Studies of extremely bright stellar explosions called supernovae revealed that distant galaxies were not slowing down, but instead accelerating away from each other.

This led to several theories suggesting that the expansion of the universe would never stop. Some more radical ideas even proposed the possibility of a future "Big Rip," in which stars, planets, and even atoms could be torn apart. Another theory suggested that at some point, gravity might prevail, and the entire universe could collapse back on itself, a scenario known as the "Big Crunch."

The current debate began in March when the Dark Energy Spectroscopic Instrument (DESI) produced surprising results. This instrument is mounted on a telescope in the Arizona desert and is designed to study dark energy in detail.

DESI tracked the movement of millions of galaxies. The data indicated that the rate of the universe's expansion has changed over time. Professor Ofer Lahav of University College London, who is involved in the project, said that these results do not fit with the currently accepted understanding. According to him, if dark energy increases and then decreases over time, it would require a new explanation that could challenge fundamental principles of physics. 

In November, the Royal Astronomical Society published a study by a South Korean research team led by Professor Young-Wook Lee of Yonsei University in Seoul. This team re-examined the supernova data that led to the identification of dark energy 27 years ago.

Instead of assuming all supernovae have the same intrinsic brightness, the team analysed the data taking into account the age of the galaxies where these explosions occurred. This new analysis suggested that dark energy has changed over time and that the expansion of the universe is now slowing down.

According to Professor Lee, if these results are confirmed, it could completely change our understanding of the universe's future. He stated that if dark energy is not constant and is gradually weakening, it would fundamentally alter the foundations of modern cosmology.

Professor Lee's findings suggest that if dark energy weakens sufficiently, gravity could once again pull galaxies towards each other. This would raise the possibility of a Big Crunch instead of a Big Rip.