angry tapir writes "An international team of astronomers has used the CSIRO-run Australia Telescope Compact Array to measure the cooling of the universe since the Big Bang. According to the CSIRO, it is the most accurate reading yet of how hot the universe used to be. When the universe was half its current age its temperature was -267.92 degrees Celsius (5.08 Kelvin), the team found, which is warmer than today's universe (270.27 degrees Celsius). (The paper itself is online and not paywalled.)"
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