The Bohr Identity

I have a favorite physicist. While that puts me in a relatively small subset of the American population, I suspect that among members of that subset my choice is relatively common. After all, few physicists this side of Einstein and Newton are more well known than Niels Bohr, and even fewer of them have had a greater effect on physics.

The title of this blog, Contraria Sunt Complementa, is the motto on Bohr’s coat of arms. It means “opposites are complementary.” As is well documented by, among others, Richard Rhodes (The Making of the Atomic Bomb) and Fritjof Capra (The Tao of Physics), Bohr was fascinated by paradox. Take, for example, the dual nature of light and other electromagnetic radiation. One of the more fascinating mysteries that modern physicists had to sort out is the observation that light behaves sometimes as a wave (it reflects, refracts, interferes, etc.) and sometimes as a particle (it collides, billiard-ball-like, with electrons in a phenomenon known as Compton scattering. Because it obscures imaging and delivers unwanted dose to patients, Compton scattering is the bane of medical physicists everywhere, but it’s OK by me because deriving the formula for its scattering angle helped get me though my modern physics qualifying exam for the doctoral program in the University of Wisconsin-Madison’s Department of Engineering Physics.).

What made Bohr a visionary physicist was his readiness to see this dual nature not as a contradiction but, in the words of one physicist I know, as “two sides of the same coin.” What made him an influential physicist, though (at least in my opinion), were two of his other traits that captured my interest: his insistence that the language with which we describe physics is as important as the physics itself and his warm and collegial relationships with his students, many of whom became great physicists themselves.

This is not a blog about Niels Bohr. In fact, as time passes, I’ll probably talk less and less about him. But I hope his playful, collaborative, often interdisciplinary approach to a range of subjects (physics, writing, philosophy, and world affairs, to name a few) can inspire and serve as a model for much of what goes on here.

I’m not a first-time blogger, but it has been a while since “X-ray”ted Summer, the blog I wrote about my time as an x-ray repair man in New York, came to an end. In the mean time, I’ve read an awful lot of blogs. The most interesting ones, in my opinion, are those that refuse to treat their respective subjects as islands. I think Bohr, who agreed with Schiller that “Nur die Fuelle fuehrt zur Klarheit” (“only wholeness leads to clarity”), would appreciate that sentiment. Thus, with Bohr as my epistemological guide, I’ll be offering up thoughts and analysis on the subjects that make me whole: science, engineering, teaching and tutoring, writing and editing. Maybe a little music and baseball for good measure. I hope you’ll join me.