MELBOURNE (TIP): Astronomers have made the most precise measurement ever of how the universe has cooled down during its 13.77 billion year history just as predicted in Big Bang theory. They studied molecules in clouds of gas in a galaxy 7.2 billion light years away — so far that its light has taken half the age of the universe to reach us. Using the Australia Telescope Compact Array, a team from Sweden, France, Germany and Australia has measured how warm the Universe was when it was half its current age. “This is the most precise measurement ever made of how the Universe has cooled down during its 13.77 billion year history,” said Robert Braun, chief scientist at CSIRO Astronomy and Space Science in a statement.

Because light takes time to travel, when we look out into space we see the Universe as it was in the past — as it was when light left the galaxies we are looking at. So to look back half-way into the Universe’s history, we need to look halfway across the Universe. The astronomers studied gas in an unnamed galaxy 7.2 billion light-years away. The only thing keeping this gas warm is the cosmic background radiation — the glow left over from the Big Bang. By chance, there is another powerful galaxy, a quasar called PKS 1830-211 , lying behind the unnamed galaxy