His solution has proved crucial in furthering statistical mechanics, allowing theorists to check all of there approximation schemes against analytical results.
I call his effort a tour de force because it was a huge mathematical exercise, his solution spanning 33 pages. I also call it a 'tour de force' because I have seen it referenced as such in no less than 5 different sources, as well as numerous times in speech. This got me wondering, just how many times is Onsager's solution called a tour de force...
