Scientists have known for almost 20 years that the universe—everything that exists—is dying. The overall energy is slowly fading to a distant but inevitable conclusion. Now new research supports this theory and takes a closer look at the overall energy decline.
Yesterday an international team of researchers presented findings from the Galaxy And Mass Assembly (GAMA) project at the International Astronomical Union conference, in Hawaii, which show that the current energy output across more than 200,000 galaxies is only about half as strong as it was 2 billion years ago.
According to GAMA principal investigator Simon Driver, of the International Centre for Radio Astronomy Research, the project "used as many space- and ground-based telescopes as we could get our hands on." They measured each of the 200,000 galaxies at 21 wavelengths from the ultraviolet to the far infrared, making this effort the largest multi-wavelength survey ever put together.
The GAMA study sets out to map and model all of the energy generated within a large volume of space today and at different times in the past. What they're actually measuring is the light emitted as stars convert mass back to energy as described by E=mc^2. And that light is dimming because, simply put, the fuel for the stars is running out.
"Once you've burned up all the fuel in the universe, essentially, that's it," Joe Liske of the University of Hamburg, one of the members of the research team, told NPR. "The stars die, like a fire dies, and then you have embers left over that then glow but eventually cool down. And the fire just goes out."
On the human scale, there's no need to panic. Scientists speculate the universe has at least a few billion years left to live. But on the galactic scale, the universe is downright geriatric. "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 in a (kind of depressing) statement.