He said, before this comprehensive study, there was always the possibility that scientists didn’t fully understand how the universe was changing.
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What they’ve found is that the energy output of those galaxies today is “only about half of what it was two billion years ago”, and the fading can be seen in all the studied wavelengths.
Two NASA space telescopes, a space telescope of the European Space Agency (ESA) and the Anglo-Australian Telescope in New South Wales in particular have been involved in this study.
The worldwide team measured the energy output of more than 200,000 galaxies measuring at 21 wavelengths. Such studies are important in understanding how the Universe evolved from an early dark period to one when galaxies began to shine.
A galaxy from the GAMA survey observed at different wavelengths from the far ultraviolet to the far infrared.
This is not exactly unexpected.
Ancient Mayan prophecies predicted that the world will end in 2012 – that’s a bust as three years later we are all still here.
Without applause or encore, the lights are going out across the universe, as old stars die faster than new ones are born to replace them. It has been slowing down ever since.
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.
Now, learning that the universe is slowly dying is nothing new to astronomers.
HOPKINS: We’ve been able to show that the energy production of, say, 3 billion years ago was substantially higher than the energy production in galaxies in much more recent times.
Although this is a frequently detected signature in galaxies close to Earth, the detection of Lyman-alpha emission at such a great distance is unexpected as it is easily absorbed by the numerous hydrogen atoms thought to pervade the space between galaxies at the dawn of the universe. Current theories indicate that the universe will grow cooler and darker and, if there are any humans left at that stage, other galaxies will move too far away to be seen. But, he notes, this process will take a very long time. “It’s about 100 billion years or so until all starlight stops being produced”. Finally, the black holes will evaporate, leaving an endless void.
Researchers working with the survey now want to use a host of new observatories coming online in the next 10 years to figure out how much energy the entire universe is producing and compare that to our part of the cosmos.
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“The universe will decline from here on in, sliding gently into old age”, Driver said.
