Birthday of Erwin Schrödinger (1887)

Schrödinger gave us the wave equation of quantum mechanics: iℏ ∂ψ/∂t = Ĥψ. His equation, like a wave on a string, describes the probability amplitude ψ. The square |ψ|² is the probability density. He also proposed the famous thought experiment of a cat that is both alive and dead until observed (to illustrate the measurement problem). Schrödinger was a complex character who wrote about biology (What is Life?) and ancient philosophy. His equation is the basis of chemistry, solid‑state physics, and the modern electronics industry.