#7 - **Erwin Schrodinger**

*Schroedinger, Erwin! Professor of physics! Wrote daring equations! Confounded his critics!*

That's the first couple of lines of Cecil Adams' brilliant epic poem about Schrodinger's cat. Why does Schrodinger deserve an epic poem? Because he's the 7th greatest physicist, that's why.

Schrodinger was born in Austria in 1877. Looking back we can see that such a placement is a bit ominous, but war has rarely prevented science from moving forward. Quite the opposite, usually. He achieved his habilitation in 1914, and spent the next four years as an artillary officer. It is unclear to me whether his duties actually involved combat, but in any case he survived the war and in 1922 he returned to university and a few years later he revolutionized the world of physics by ushering in the era of modern quantum mechanics. 1926 found him discovering and publisheing the Schrodinger equation, using it to solve the hydrogen atom, the harmonic oscillator, and several fundmental molecular configurations.

Now this is something first-year graduate students learn to do, but at the time those systems were essentially complete mysteries. Those very systems are absolutely ubiquitous today, and if no one had developed the quantum mechanics describing those systems, physics would be stuck. He also showed that his wave equation method produced the same answers as Heisenberg's matrix method (about whom more later).

His other important work included studies of electrodynamics, statistical mechanics, and optics. Most of this was done before his breakthrough in quantum mechanics. Later in life he also published work on the biology of color vision and a thermodynamic view of the nature of biological life, about which he wrote a well-known and quite accessible popularization.

In 1933 he had enough of the Nazis (whom he loathed) and he left to Austria, picking up a Nobel prize along the way. In 1938 the Nazis invaded Austria, and so he fled the country and ended up in Ireland. There he led a rather unique personal life, with multiple women including students, and he fathered two children.

He's well known in the popular press today for his thought experiment of Schrodinger's Cat, which contemplates what a superposition of quantum states might mean on a macroscopic level. This led to a famous argumentative but friendly correspondence with Einstein about the nature of quantum mechanics. Schrodinger himself was not happy with the seeming counterintuitiveness of the theory he helped create, but the facts are the facts and it's a quantum world we live in, confusing or not.

Like Einstein, he spent the later years of his life working on problems of nearly intractable difficulty including the quest for a unified field theory. Like Einstein he did not even come close to success, but no one yet has made much progress in this area so I don't think that's a fault.

He died in 1961, and was buried in his homeland of Austria.

*The list so far:
10. Pauli
9. Thomson
8. Dirac
7. Schrodinger*

And it's time for another honorable mention: Werner Heisenberg. Heisenberg along with Schrodinger were two of the people who contributed the most to the nascent science of quantum mechanics. Heisenberg's matrix formulation is in fact now considered to be more fundamental in some sense than Schrodinger's wave mechanics. But on balance I rate the sum of Schrodinger's contributions higher than Heisenberg's. And even were they equal, the fact that Heisenberg was actually pretty terrible at practical physics and his involvement with the embryonic Nazi atomic bomb program would make a fairly convincing tiebreaker in Schrodinger's favor.

## Comments

Angliederung(maybe affiliation in English) was a process many Austrians embraced. During the 1930s, Austria had already turned into a nationalist state (though not as radical as Germany), and although the inclusion into the Reich was initiated (and pressed) by the German nationalists, one should not confuse it with a military invasion like the annexation of Czechoslivakia in 1939.Anyway, SchrÃ¶dinger is a great choice. I wish we had such a physicist today, only to change the way in which the public perceived scientists.

Posted by: Odysseus | September 29, 2008 3:31 PM

... I knew the

Umlautwouldn't make it past the preview. Schrodinger is spelled with ö !Posted by: Odysseus | September 29, 2008 3:34 PM

Two ?? that contributed the most? Mysterious equations?

Heisenberg invented Quantum Mechanics the year before Schroedinger's paper, and it is his version that connects clearly to classical mechanics. That alone gives him priority. Schroedinger's second paper closed the theoretical connection by showing that his wave mechanics was the same as Heisenberg's matrix mechanics, hence only indirectly reducing it to classical mechanics.

Then there is that uncertainty principle. Not very important?

Schroedinger lacked the insight to accept Born's interpretation of the wavefunction as a complex probability amplitude, so he rejected what we mainly use his methods for today. Their popularity followed from the fact that all physicists of the day were familiar with wave equations, but few knew squat about matrices.

As for the Hydrogen atom equation itself, those differential equations were all well known and Schroedinger probably learned how to solve them from Sommerfeld's math physics class.

PS - We should not examine his contribution to physics in the light of his utter failure to understand fission any more than we should reject Feynman or Bohr (or many others) for bomb work or Hahn for his work on poison gas - although I hold strong views on the last case. Just be glad that Heisenberg did make mistakes that contributed to the failure of their weapons program.

Posted by: CCPhysicist | September 29, 2008 4:13 PM

I figured my choice of Schrodinger over Heisenberg would be one of the more controversial moments, but all things considered I think Schrodinger edges him out. I'd also say Schrodinger's proof of the equivalence of the approached edges out the undertainty principle in terms of importance, as that principle also naturally follows from the application of Fourier transforms to the wave equation. If you'd rather though, think of Heisenberg's honorable mention as a shared #7.

There's at least two more in the remaining 6 physicists that will probably be similarly debatable, but this is hard stuff ranking the top 10!

Posted by: Matt Springer | September 29, 2008 5:38 PM

Dude, make the list at the end links.

Posted by: Grad | September 29, 2008 9:50 PM

Wikipedia seems to thing he was born in 1887.

http://en.wikipedia.org/wiki/Erwin_Schrodinger

Posted by: Frank | September 29, 2008 10:54 PM

I THINK THIS IS THE MOST BORING STUFF

Posted by: ZAKSTER21828810 | January 8, 2009 11:02 AM