5. Chemical Physics: The rise of quantum mechanics

In the 1920's, along came an entirely new physics, quantum mechanics. It's clearly not classical and it takes some effort to connect it to thermodynamics. Nevertheless there were chemists who saw the potential of this new physics in describing chemical processes. The trouble was that such papers couldn't be published in the Journal of Physical Chemistry. The editor of the time, Wilder Bancroft, limited physical chemistry to only that which used thermodynamics. This mistake would unfortunately last until roughly 1980. In the meantime, the community found a different solution in the founding of the American Institute of Physics (AIP) Journal of Chemical Physics in 1933. Thus was defined the new interdiscplinary field of chemical physics as that science which utilizes physics—the more rigorously the better—to chemical processes.

So in the mid twentieth century, we had a subtle distinction between physical chemistry and chemical physics. It was made concrete according to which of the two American journals you chose to publish your work. Physical chemists who wanted to go beyond the confines of thermodynamics had to turn to the physics community. The amount of chemistry that physical chemists needed to learn and teach made it difficult for them to fulfill the complete physics undergraduate curriculum or pursue doctoral degrees in physics. So where was a physical chemist/chemical physicist to teach? In practice, the answer was chemistry departments in the States, but often physics departments in Europe or other parts of the world. This gave root to yet another distinction between the names. To put it simply, you did physical chemistry in chemistry departments and chemical physics in physics departments. (Students went to both.) Of course, the distinction was in name only because most of the practitioners could easily transfer their appointments between the respective departments. Indeed, several of the editors of the Journal of Chemical Physics have held appointments in chemistry departments. The irony here is that physical chemistry become a core component of chemistry curricula when the subject is interpreted to have the scope of chemical physics.


(This is the fifth post in a series starting with the first one on interdisciplinary sciences.
Click here for the previous post.)