Quantum Mechanics Contradicts Itself (and He Proved It)

Professor Renato Renner at ETH Zurich proved something that wounded every interpretation of quantum mechanics.

He’s one of the most influential quantum information theorists alive. He reshaped how the field reasons about entropy and cryptographic security. He co-proved (with Colbeck) that quantum randomness is irreducible and the wave function is real. But a few years ago, he showed (together with Daniela Frauchiger) that quantum mechanics when applied to the physicists who use it, leads to flat contradictions.

This is quite an odd result. It’s not the kind of theorem you hear about every day. I wouldn’t even call it a no‑go theorem (though he calls it that). I call it an “inconsistency result.”

Renner went from many-worlds to QBism to what he calls “no man’s land.” Some of his students have refused to work on these problems at all because of the psychological discomfort to their sense of self.

We cover:

• Quantum mechanics, applied consistently to its own users, generates genuine contradic…