New findings released on Wednesday by the Dark Energy Spectroscopic Instrument (DESI), a scientific research instrument which measures the effect of dark energy on the expansion of the universe, revealed that dark energy appears to be changing over the past 4.5 billion years. 

Advertisment

Dark energy is the mysterious force that makes galaxies accelerate away from each other. Despite making up about 68% of the universe's total energy density, the nature of dark energy remains unknown.  

Also read: Mars 1,000,000 BC: 'Mind-reading spy' claims he saw people 'dying' on the red planet

Last year in April, the effect was first reported. However, the latest results were presented on March 10 by DESI collaboration at a meeting of the American Physical Society in Anaheim, California. 

Advertisment

"Now I’m really sitting up and paying attention," said Catherine Heymans, an astronomer at the University of Edinburgh, UK, and the Astronomer Royal for Scotland as quoted by Nature. 

Also read: Are there really 8.2 billion people on Earth? Study suggests there is a huge miscalculation

The results are based on three years' worth of data-taking, versus one year for the results announced in 2024. However, the scientists behind the research emphasise there is not yet definitive proof. This would rule out that dark energy is a cosmological constant if the theory turns out to be true. 

Advertisment

"What we are seeing is deeply intriguing," said Alexie Leauthaud-Harnett, a spokesperson for the DESI collaboration which brings together 70 institutions across the world. 

Also read: What’s next for Sunita Williams on Earth after nine-month stay in Space?

"It is exciting to think that we may be on the cusp of a major discovery about dark energy and the fundamental nature of our universe," she said in a statement. 

Joshua Frieman, a theoretical astrophysicist at the University of Chicago, told AFP, "It could not be "the energy of empty space -- because empty space doesn't change."

It would likely require the existence of some incredibly light, as-yet-unknown particle, for dark matter to change. 

Another possibility is that there is something wrong with our calculations -- or our understanding of gravity." 

Also read: Not just solid, liquid and gas: Scientists discover fourth form of water that might be on alien planets

What is dark energy? 

If we say dark energy makes up roughly 70 per cent of the universe and there is around 25 per cent of mysterious dark matter, it just leaves five per cent for everything that we can see and touch -- matter made up of atoms. 

However, there are some recent cosmic clues which are linked to this phenomenon, and this could eventually mean humanity will have to rethink our understanding of the universe. 

Now scientists hope to find answers with several new telescopes aiming at the problem. 

(With inputs from agencies)