An international team of about 100 scientists has charted the universe’s gradual decline into darkness in the most comprehensive assessment of its energy output, the GAMA survey.
They studied more than 200,000 galaxies and found the universe generates only half as much energy as it did 2 billion years ago.
This is a bleak outlook, but not a new one – it was first observed in the late 1990s, according to a press release by the researchers.
However, the GAMA survey’s observation that fading is occurring across all wavelengths from the ultraviolet to the far infrared, is a significant new finding.
Simon Driver, the study's lead author and an astronomer at the University of Western Australia, told the Los Angeles Times, "We’d seen this decline in just the ultraviolet light […] We didn’t know whether it was happening at all wavelengths or not."
Astronomer Luke Davies explained all energy originates from the Big Bang, with a significant portion locked up as mass. This is slowly being released as stars fuse elements together and convert this mass into energy, mostly in the form of light at different wavelengths.
What does this all mean?
“The Universe will decline from here on in, sliding gently into old age. The Universe has basically sat down on the sofa, pulled up a blanket and is about to nod off for an eternal doze,” Driver said.
“The universe will convert less and less mass into energy until eventually it becomes a cold and dark desolate place where all of the lights go out,” Davies said.
But death does not mean the universe will cease to exist, CNN notes. It alludes, instead, to a depletion of energy and subsequently, light.
“Universal dimming is driven by a slump in the rate of new star formation, which peaked about eight billion years ago. Stars shine by fusing hydrogen into helium, but as they consume their cosmic fuel supply, the birth rate of new stars falls dramatically," The Guardian reported.
John Beacom, a physicist and astronomer at Ohio State University, told NPR before this study scientists lacked a coherent understanding of how the universe was changing but now “this [research] pretty much closes the case: yes [the universe] is coming to an end.”
But there’s no imminent reason to worry. Although Davies said the universe has left “its active, athletic, partying days” behind, astrophysicists estimate the process will take trillions of years, CNN reported.
However, there may be other cosmic threats to think about.
“I guess we've got worse things to worry about at some level,” Driver told the Los Angeles Times.
“In about 5 billion years, the sun is going to swell up and swallow the Earth; in about 10 billion years it’s going to collide with the nearest [major] galaxy, the Andromeda galaxy; and in about 100 billion years the universe will be so expanded and producing so little light that we basically won’t see anything," he said.