Remember the post a while back where we tried to come up with a list of the 10 greatest physicists? I’ve been thinking and rearranging and I think I’ve come up with a list I’m reasonably happy with. There are quite a few great physicists I’m not happy at all about having to leave out, but 10 is a small number and no matter which ten are picked there’s at least ten more who have some good cause to feel left out. The criteria is the importance of their contribution to physics, not just their raw brilliance.

To make up for those left out, I’m including a number of unordered Honorable Mentions who at least deserve to be in the top 20 but for one reason or another I decided that the others had a better case. I’m going to start out with two of those today, and the we’ll start the Top 10 list proper later this week. We’ll keep adding honorable mentions as we go, and over the next week or two we’ll count down probably two at a time. Here we go:

Honorable Mention: **Galileo Galilei**

Galileo was at or near the top of numerous submitted lists. Why is he not on mine? If I were making a list of the greatest *scientists* of all time, he would be. He might even be at the top. But it’s a list of greatest physicists, and in the modern sense he wasn’t really one. He was a natural philosopher, largely because the mathematical nature of modern physics did not yet exist. Natural philosophy was the predecessor science to physics, and he brought it to its completion and ushered in the dawn of physics, though sunrise would have to wait until Newton. Galileo helped lay the foundation for physics, and for all of modern science. From an absolute revelation in our knowledge of astronomy to the invention of the telescope to the first tentative steps toward a theory of force and motion, modern science owes almost everything to the revolution he started. For that matter, his early experiments with the speed of light and his concept of Galilean relativity provided the framework that Maxwell, Lorentz, and Einstein corrected and revolutionized centuries later. If this is an honorable mention, it’s about as honorable as it gets.

Honorable Mention: **Emmy Noether**

Emmy Noether is definitely top 10 material, but though it pains me I have to disqualify her on the grounds that she was best known as a mathematician. But her greatest achievement is one in mathematical physics, and it’s about as important as mathematical physics achievements get. In 1915 she wrote down Noether’s Theorem and started a new era in physics – one in which the basic symmetries of nature were intimately and mathematically connected to the very conservation laws which have stood unbroken since our exploration of physics began. Symmetry of the laws of physics with respect to time implies conservation of energy, symmetry with respect to space implies conservation of momentum, and a host of more subtle and profoundly powerful results.

That’s leaving aside entirely the rest of her very substantial pure mathematics accomplishments. Her eponymous theorem by itself is more than enough by itself to ensure her a place with the greatest mathematicians. Einstein and Hilbert both spoke about her work in the highest possible terms, and their opinion counts far more than mine ever could. Like Galileo, “honorable” doesn’t begin to cover it.