Why a Hint of Life Isn't a Discovery Until the Odds of a Fluke Drop Below 1 in 3.5 Million
When a possible sign of life turns up in an exoplanet's atmosphere, scientists don't celebrate right away. Until the chance of a fluke falls below roughly 1 in 3.5 million — the '5-sigma' threshold — and until they've finished doubting their own wishful thinking, it isn't a 'discovery' yet. SORABUMI explains the yardstick of scientific confidence and why researchers hold their excitement in check.