Asked by: Adam Smith, York
This is one of the biggest mysteries facing 21st-century science. Recent studies of the heat left over from the Big Bang have revealed that conventional matter made from atoms accounts for just a few per cent of the matter in the Universe. Most of it is in the form of so-called cold dark matter (CDM), whose enigmatic name reflects the awkward fact that astronomers don’t know what it is.
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Authors
Robert is a science writer and visiting professor of science at Aston University.
