Medical and Hospital News
STELLAR CHEMISTRY
Dark energy seems to be changing, rattling our view of universe
Dark energy seems to be changing, rattling our view of universe
By B�n�dicte Rey and Daniel Lawler
Paris (AFP) Mar 19, 2025

Dark energy, the mysterious force thought to be driving the ever-faster expansion of the universe, appears to be changing over time, according to new observations released Wednesday.

If dark energy is in fact weakening, it would likely mean that science's understanding of how the universe works will need to be rewritten.

The new findings come from the Dark Energy Spectroscopic Instrument (DESI), which sits on a telescope at the Kitt Peak National Observatory in the US state of Arizona.

"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.

"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.

The DESI instrument's thin optical fibres can simultaneously observe 5,000 galaxies or quasars -- blazing monsters with a black hole at their heart -- for 20 minutes.

This allows scientists to calculate the age and distance of these objects, and create a map of the universe so they can detect patterns and trace its history.

- 'Tensions' emerging -

Scientists have known for a century that the universe is expanding, because massive clusters of galaxies have been observed moving away from each other.

In the late 1990s, scientists shocked the field by discovering that the universe's expansion has been speeding up over time.

The name dark energy was given to the phenomenon driving this acceleration, the effects of which seem to be partially offset by ordinary matter -- and an also unknown thing called dark matter.

The universe is thought to be made of 70 percent dark energy, 25 percent dark matter -- and just five percent normal matter.

Science's best understanding of how the universe works, which is called the standard cosmological model, refers to dark energy as being constant -- meaning it does not change.

The idea was first introduced by Albert Einstein in his theory of relativity.

Arnaud de Mattia, a French physicist involved in analysing the DESI data, told AFP that the standard model is "satisfactory" but some "tensions" are emerging between observations.

There are several different ways of measuring the expansion of the universe, including looking at the lingering radiation from after the Big Bang, exploding stars called supernovae and how gravity distorts the light of galaxies.

When the DESI team combined their new data with other measurements, they found "signs that the impact of dark energy may be weakening over time", according to a statement.

"When we combine all the cosmological data, it favours that the universe's expansion was accelerating at a slightly higher rate around seven billion years ago," de Mattia said.

But for the moment there is "absolutely not certainty" about this, he added.

- 'Inflection point' -

French physicist Etienne Burtin was confident that "we should have a clearer picture within five years".

This is because there is loads of new data expected from DESI, Europe's Euclid space telescope, NASA's upcoming Nancy Grace Roman space telescope and the Vera Rubin Observatory in Chile.

"This new generation of surveys -- in the next few years -- will nail this," Joshua Frieman, a theoretical astrophysicist at the University of Chicago, told AFP.

But for now, "we're at this interesting inflection point", added Frieman, a dark energy expert and former DESI member.

Burtin said confirming the "evolving dark energy" theory would be a "revolution on the level of the discovery of accelerated expansion", which itself was the subject of a physics Nobel.

"The standard cosmological model would have to be different," he added.

The DESI research, which involved three years' worth of observations of 15 million galaxies and quasars, was presented at a conference of the American Physical Society in California.

Related Links
Stellar Chemistry, The Universe And All Within It

Subscribe Free To Our Daily Newsletters
Tweet

RELATED CONTENT
The following news reports may link to other Space Media Network websites.
STELLAR CHEMISTRY
'Dark universe detective' telescope releases first data
Paris (AFP) Mar 19, 2025
Europe's Euclid space telescope, which is on a mission to shed light on the mysteries of dark matter and dark energy, released its first data Wednesday with a little help from volunteers and artificial intelligence. The telescope launched in 2023, aiming to chart one third of the sky - encompassing 1.5 billion galaxies - to create what has been billed as humanity's most accurate 3D map of the universe. Euclid, which is now hovering 1.5 million kilometres (932,0000 miles) from Earth, has previ ... read more

STELLAR CHEMISTRY
Indonesia passes bill allowing military in more govt roles

Milei pledges funds for deluge-stricken Argentine city

UK makes manslaughter arrest of ship captain over North Sea crash

US to deploy 600 additional troops to southern border

STELLAR CHEMISTRY
ESA's Mobile Navigation Lab Tackles Arctic Interference Testing

Chip based microcombs boost gps precision

Unlocking the future of satellite navigation with smart techniques

ESA advances optical technology for next-generation navigation

STELLAR CHEMISTRY
When did human language emerge?

Study reveals how rising temperatures could lead to population crashes

Earliest evidence of human habitation in rainforests uncovered

Pentagon orders removal of pro-diversity online content

STELLAR CHEMISTRY
Monarch butterfly public comment reopened to determine Endangered Species Act listing

Sri Lanka adjusts train timings to tackle elephant deaths

Colombia's 'Lord of the Fruit' fighting for native species

Nepal community efforts revive red panda population

STELLAR CHEMISTRY
Merkel denies covering up report on Covid-19 origins

Sudan cholera outbreak kills 70 in a week: officials

Virus disinformation drives anti-China sentiment, lockdown fears

A new vaccine approach could help combat future coronavirus pandemics

STELLAR CHEMISTRY
China says acted 'in accordance with the law' after 4 Canadians executed

Australia slams reported targeting of citizen by Hong Kong

Tibet lawmakers vow 'high pressure' against alleged separatists

China's goals for 2025: five things to know

STELLAR CHEMISTRY
Colombia warns Trump against drug blacklisting

Peru declares state of emergency in Lima over extortion

Peru declares state of emergency in capital over extortion killings

Philippine police rescue kidnapped teen, hunt ex-gambling site operators

STELLAR CHEMISTRY
Subscribe Free To Our Daily Newsletters




The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.