What is life? This question was already pondered by Erwin Schrödinger. Today, physicists have found an unexpected answer for bacteria. Their DNA works like a culinary recipe passed down from generation to generation in a living 'bakery'. As long as the recipe has no errors, life continues. But once smudges appear, the dish spoils — that is death. Scientists call the recipe's flawless preservation quantum coherence, and its breakdown — quantum decoherence.

Using the core equation of quantum physics and the methods of Heisenberg and Dirac, researchers derived a simple formula: τ = 1/λ, where τ is lifespan and λ is the error accumulation rate. The faster the recipe gets 'smudged', the shorter the life. An unexpected model outcome: two bacteria with the same recipe cannot occupy the same imaginary cell — exactly like two electrons avoid identical states (Pauli principle).

This approach turns death into a measurable loss of quantum information — essentially a quantum collapse. It gives a clear criterion for life, especially valuable for the search for extraterrestrial life. If a probe finds molecules with long-lasting coherence, that will be a biosignature. And on Earth, quantum sensors will help us understand how entanglement within DNA protects health and why we age.