Universe dying slowly but surely, scientists say
04:22PM Thu 13 Aug, 2015
We know that our universe has already lived through great number of exciting phases. But new research released overnight shows the universe has long passed its peak and is slowly but surely dying.
The research was presented at the year’s largest gathering of astronomers at the International Astronomical Union’s General Assembly in Hawaii. But before we start writing any obituaries, let’s have a quick recap of the good times.
When the universe was less than a second old and more than a billion degrees Celsius, it was hot enough for exotic particles to freely pop in and out of existence. As the universe expanded, it cooled and was no longer able to produce hugely energetic particles.
After a few seconds, the universe was a sea of protons and neutrons, and after a few minutes it was mostly a dense fog of hydrogen and helium. In terms of building more complex matter, that was pretty much the end of the action for 400,000 years.
Then, quite suddenly, matter and radiation were decoupled and photons of light were able to free-stream across the universe for the first time. This is all very exciting for cosmology, but something important had also happened to the hydrogen and helium: it could now hold onto electrons and create neutral atoms.
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