On: Richard Feynman's blackboard at the time of his death (1988)

[pdonis]

I'd put Planck, Einstein, Bohr, Pauli, and Dirac ahead of Feynman. I'm not so sure about the others; not that they weren't world class physicists, but so was Feynman.

[cyberax → pdonis]

Planck? His greatest achievements were a bit before the 20-th century.

Feynman also became active in physics right at the end of the heroic era. So he's disadvantaged by it.

[pdonis → cyberax]

If we're limiting to work actually done in the 20th century, yes, I agree Planck might not qualify because of the century boundary. And we also get to split hairs over whether 1900, when Planck published his quantum hypothesis, is in the 20th century or the 19th. :-)

[AnimalMuppet → pdonis]

Einstein for sure. For the rest: I'm not sure that they're clearly ahead of Feynman. I'm not sure they're behind, either. To me, they seem to kind of be in a cluster.

[pessimist → AnimalMuppet]

Apart from Einstein, Heisenberg, Dirac, Pauli, Bohr and Fermi are clearly ahead in depth and breadth of contribution. Post-war it's less clear, but IMO Steven Weinberg and Murray Gell Mann are probably greater.