Science › Quantum world
Erwin Schrödinger
1926· Person
ProvenTested many times; part of working physics.
Austrian physicist (1887–1961) who wrote quantum mechanics' central equation in 1926 and later devised the famous cat thought experiment.
See it on the Science map →How it works
Inspired by de Broglie's matter waves, Schrödinger wrote an equation in 1926 describing how an electron's wave changes over time. It produced Bohr's energy levels naturally, with no add-on rules. He hoped electrons were real smeared-out waves, but Max Born showed the wave instead gives probabilities. Uneasy with that, he posed the cat paradox in 1935. His 1944 book 'What Is Life?' influenced early molecular biologists.
Why it matters
His equation is the everyday workhorse of chemistry, materials science and electronics. Nobel Prize 1933, shared with Dirac.
How the work held up
His equation predicts atomic spectra, chemical bonds and semiconductor behavior. In 1926 it was shown equivalent to Heisenberg's matrix mechanics, so both describe the same physics.
Still a mystery
He never accepted that the wave was only probability and believed quantum theory was incomplete. The question he raised remains open.
Connections (2)
▸Erwin Schrödinger wrote the equation for The wave functionProven
The relationship
Schrödinger wrote an equation that tells how a quantum system's wave function changes over time. Feed in the forces, such as the pull of a nucleus, and it yields the allowed energy levels and how waves spread and interfere. It does for quantum systems what Newton's laws do for planets.
How the link was found
Erwin Schrödinger, in four papers in early 1926, begun over a Christmas 1925 holiday in Arosa in the Swiss Alps, inspired by de Broglie's matter waves.
Why it's proven
It reproduced hydrogen's levels without Bohr's ad hoc rules and predicts chemistry and solid-state physics accurately. Max Born's probability interpretation, the same year, made its meaning testable.
Open questions and mysteries
The equation is smooth and predictable, yet measurements give random single outcomes. How the two fit together is the measurement problem.
▸Erwin Schrödinger proposed Schrödinger's catProven
The relationship
Schrödinger connected a single atom's superposition to a cat's life through a chain of devices. If the quantum rules apply all the way up, the cat ends up in a blend of alive and dead. He meant this as a reductio, a way to show the standard view leads to nonsense.
How the link was found
Schrödinger, in a 1935 paper in Naturwissenschaften, written after exchanging letters with Einstein about EPR.
Why it's proven
The historical link is documented. As a thought experiment it proves nothing about nature, but it pinpoints a real gap in the theory.
Open questions and mysteries
Schrödinger's challenge, where the quantum blend ends and definite outcomes begin, still has no agreed answer.