Life Isn't Quantum, but the Math It Uses Looks Like ItBiology Might Not Be Quantum, but Its Math Is Quantumlike

A long-hoped-for piece of evidence for quantum coherence in photosynthesis collapsed under closer scrutiny, and a Princeton chemist now suspects life mimics quantum math with ordinary classical networks instead.

Twenty years ago, scientists thought they were about to explain life with the word 'quantum.'

First, what quantum means: an ordinary thing can only be in one place at a time, but a quantum object spreads out like a water wave, sitting in every possible position at once. Two overlapping waves can reinforce or cancel each other, and that is called coherence. Such states are extremely fragile: a bit of heat or jostling destroys them.

The inside of a living cell is hot, wet and chaotic, so a quantum state there should fall apart almost instantly. That made 'life exploits quantum effects' a bold, slightly reckless claim.

That pretty signal fell apart

In 2007, Graham Fleming at the University of California, Berkeley fired extremely short laser pulses at bacterial photosynthetic pigments and saw a series of synchronized beats. At the time it looked like evidence of quantum coherence: if energy could explore several routes to the exit at once, photosynthesis approaching 100 percent efficiency would make sense. Gregory Scholes, a chemist at Princeton, got similar results.

Looked at more closely, those beats turned out to be a resonance between vibrating chemical bonds, not quantum coherence. Interesting, but short-lived and short-range.

The disappointment was real. Scholes no longer believes life makes use of genuine quantum effects.

Copying the answer, not the mechanism

Late in 2023, after a conference, he went back to his hotel room and wrote down a different idea: maybe life never used quantum mechanics, only imitated it.

Scholes and colleagues showed that many ordinary oscillating parts, wired into a complex network, produce synchronized collective states. These states are not quantum, only quantumlike: the mathematics describing them is the same mathematics that describes the quantum world.

It is a bit like parabolas. A flying baseball and the tip of a cactus spine both trace one, but the forces shaping them are completely different. Mathematical resemblance is not physical sameness.

Some admire the elegance of the framework. Others warn against mistaking a mathematical link for physical evidence: interference is not uniquely quantum, since all waves do it.

But there is a practical question: if nobody can ultimately tell the two apart, then a quantumlike trick assembled over 3.5 billion years of evolution might be far cheaper than building a quantum computer.