It's a discovery that could require a complete rethink of how life on Earth began, and how likely life is on other planets. The current consensus is that over millions of years, simple molecules must have formed amino acids, then primitive proteins, before finally forming an organised cell structure. However, physicists recreating the atmosphere of the early Earth have produced blobs of gaseous plasma that fulfil the four criteria used to define living cells: possession of a distinct boundary layer and the ability to replicate, communicate and grow. What's more, such cell-like self-organisation can occur in a few microseconds...