In February 2010, scientists at Brookhaven National Laboratory's Relativistic Heavy Ion Collider on Long Island, New York, USA, announced that they had smashed together gold ions at nearly the speed of light, briefly forming an exotic state of matter known as a quark-gluon plasma. This substance is believed to have filled the universe just a few microseconds after the Big Bang. During the experiment the plasma reached temperatures of around 4 trillionºC, some 250,000 times hotter than the centre of the Sun.
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