A physicist who had never touched a gene explained one anyway
Erwin Schrodinger's 1944 lecture is remembered as a footnote to DNA — it deserves to be read as the argument that got there first.
In February 1943, a Nobel physicist stood up in Dublin and admitted he knew almost nothing about biology. Erwin Schrodinger then spent four lectures explaining, from first principles, what a gene would have to look like if the laws of physics were true.
His answer: not a fluid, not a vague hereditary "substance," but something more like a code — a molecule stable enough to survive for generations yet varied enough to store nearly unlimited information, the way letters do. He called it an aperiodic crystal, ten years before anyone had seen the double helix. James Watson later said reading it was the reason he stopped studying birds.
What's easy to miss is that Schrodinger got the biology wrong in places and never claimed otherwise. He wasn't reporting a discovery. He was showing that a discovery had to be possible — that heredity couldn't be magic, because physics doesn't leave room for magic.
The useful trick isn't his conclusion. It's his method: state plainly what the world would need to contain for your hunch to be true, then go check.