HONOLULU, Aug. 11 (UPI) -- The universe just isn't what it used to be. According to new research, the universe boasts just half the galactic energy it had 2 billion years ago.
Researchers at Australia's International Centre for Radio Astronomy Research (ICRAR) recently used some of the world's most powerful telescopes to survey the spectral output of some 200,000 galaxies -- plotting the barrage of wavelengths from ultraviolet to infrared.
The results allowed scientists to measure the rate of star formation and galactic mergers -- measurements that suggest the universe is slowly dimming.
Researchers have known the universe is dimming since the 1990s, but researchers say the latest effort is the most comprehensive survey yet of the universe's energy output across the electromagnetic spectrum.
"While most of the energy sloshing around was created in the aftermath of the Big Bang, additional energy is constantly being released by stars as they fuse elements like hydrogen and helium together," Simon Driver, an ICRAR professor who presented the new research at this week's International Astronomical Union's General Assembly in Honolulu, said in a press release.
"This newly released energy is either absorbed by dust as it travels through the host galaxy, or escapes into intergalactic space and travels until it hits something such as another star, planet, or very occasionally a telescope mirror," Driver explained.
Researchers say they can't pinpoint when the universe will go dark. A smattering of stars will continue shine on for billions of years.
"The universe is fated to decline from here on in, like an old age that lasts forever," Driver said. "The Universe has basically plonked itself down on the sofa, pulled up a blanket and is about to nod off for an eternal doze."
The works of Driver and his colleagues will soon be published in the Monthly Notices of the Royal Astronomical Society.