6. The blurring of physical chemistry and chemical physics

In 1980, Mostafa El-Sayed took over the Journal of Physical Chemistry. Because of the mistakes of his early predecessors in confining the physical chemistry they published to thermodynamics, the Journal of Physical Chemistry had been regulated to a second tier status. Mostafa quickly turned this around by simply asking all his friends to submit articles to the Journal. It helped that he had a lot of smart friends, and that they were spread through the entirety of the interdisciplinary space between chemistry and physics. That is, physical chemistry as codified by the eponymous ACS journal was finally redefined to include all physics, not just thermodynamics. Mostafa's drive to resuscitate the Journal of Physical Chemistry was also helped by the fact that the Journal of Chemical Physics had also ignored a critical part of the field. In the latter's drive to be increasingly rigorous, there was little room for phenomenological papers in which nature was not fully understood. Putting this together over the 24 years that Mostafa was at the helm (which also included his move from UCLA to Georgia Tech!), he succeeded in raising the Journal of Physical Chemistry to the top tier status it enjoys today.

The road between chemistry and physics has two lanes. One of these heads from chemistry to physics. Call it physical chemistry. The other lane heads from physics to chemistry. Call it chemical physics. But the road is the same road. As such, there truly is little difference between the names. However, there is a subtle difference due to the fact that each is pointing in a different direction. Chemistry has historically been an empirical science over which principles are constructed. Physics has historically been driven by axiomatic principles that give rise to the nature that we see. In likewise fashion, the Journal of Physical Chemistry has always tended to publish a slightly greater portion of phenomenonolgical results, that in turn have practical implications in advancing the field. Meanwhile the Journal of Chemical Physics tends to publish a slightly greater proportion of theoretical results and precise measurements, that in turn have implications on advancing fundamental principles. But both are moving towards the middle. As such, even these subtle differences should soon be lost (if they haven't already).

A different journal run by the Royal Society of Chemistry replaced the Faraday Transactions and formalized the blurring between the two names by simply naming itself as Physical Chemistry Chemical Physics (PCCP) in 1999. There is evidently plenty of room for us to publish our work. More importantly, the true meaning of physical chemistry and chemical physics is fundamentally the same and truly lies on a one-lane road between chemistry and physics.


(This is the sixth and last post in a series starting with the first one on interdisciplinary sciences.
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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.
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4. Physical Chemistry: The rise of thermodynamics

It may seem easy (specially in hindsight) to find common ground between chemistry and physics. But not so in the late 1800's when that terrain was barely tread. First, you must determine which physics to use, and how it might have something, anything, to say about the chemistry of your system. This is where thermodynamics comes in. It was a relatively new physics at the time. Gibbs gave it root; Ostwald and van't Hoff used it to make physical chemistry a science.  The success of thermodynamics lies in its ability to describe energy transactions between large bodies. These bodies can consist of a single type of atom or molecule like a pure glass of water or, more likely, it can be a mixture. No question that mixing liquids is fun, but the action lies in having them react. The use of thermodynamics to describe chemical reactions gave rise to what may have been the first significant interdisciplinary application of physics to chemistry. Thus the field of physical chemistry was born.

The power of thermodynamics to describe chemical processes—like reactions and phase transitions—is so great that it still fills much of the material that we teach in general chemistry courses. It's useful to understand that atoms and molecules exist as indivisible objects—up to chemical bonds—which allows us to create balanced reactions that also reflect energy transactions. So what need does a chemist have for any other physics? Sadly, the American Chemical Society (ACS) Journal of Physical Chemistry (founded in 1896) and their editor—Wilder Bancroft—answered this question in the negative well beyond the 1920's. Lest you think that Bancroft was a heretic, it is important to note that he was a graduate student of Ostwald and a postdoc of van't Hoff! Under Bancroft's rule, the Journal defined physical chemistry as only that science which involved the use of thermodynamics to understand chemistry. Pretty powerful, yes, but also limited.


(This is the fourth post in a series starting with the first one on interdisciplinary sciences.
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Drowning in Reviews, Part 2

Should we crowd source the review of research proposals as a way to solve the peer review system? This question may seem absurd. After all how does one even begin to implement such a scheme? The first problem involves the fact that releasing proposals to the commons would kill any protection for the ideas they contain and release them to your competitors. Even if you solve this problem, then you have to identify a mechanism through which the crowd would participate, perhaps motivated to learn about untested hypotheses. Likely what it would mean is that proposals would include even more ready-to-publish material than they do now. Regardless, these obstacles make it seem unlikely that granting agencies are headed down this path soon.

Or are they? Research grants are funded in part according to past accomplishment as measured, for example, by the level of publication of the investigator. Those principal investigators who publish in online journals are building capital through crowd sourcing. Moreover, through citation indexes and other network measures, weights to the impact of the work—whether published through traditional or open access mechanisms—are already being assigned and used by all sorts of parties interested in the so-called impact of their investments. Thus renewal proposals could, in principle, be awarded based on how the crowd has weighed in. Trouble is that the crowd is larger in some fields than others, and such a funding mechanism would tend to make large subfields more crowded. Therein lies the problem with crowdsourcing reviews: whether directly or indirectly, the sparsely populated research areas of today might not receive the attention necessary to remain alive to solve tomorrow's problems.

Drowning in Reviews, Part 1...

During the past few weeks, I've reviewed over twenty grant proposals for three different agencies and several journal articles. It's enough work that it reminds me of Yuan Lee's advice, "you can read articles or you can write them; it's your choice."  The problem is that we're not paid to review articles or grants, but the system of peer review falls if we don't. That is the social contract among scientists rests on all of us volunteering as reviewers. As a rough measure, we should review in proportion to what we submit. Since the reviewing task is not blind to the editors or the grant program officers, we build some kind of social capital that may affect the reviewing process of own submissions. However, the system is presumably "fair" because other reviewers aren't aware of our contributions to the reviewing process. So, as in the tragedy of the commons, not all scientists are motivated to contribute their fair share. This, in turn, has driven journals to create mechanisms of recognition for reviewers—like advisory board memberships or awards. But the scofflaws win because they spend more time writing and publishing.

One solution is to publish nearly everything, just like a blog, and let the crowd decide what's important. That's what the arXiv does. Trouble is that it creates an enormous volume that could lead to everyone drowning in articles all the more. Another solution being taken by many online journals like PLoS ONE is to review articles at a minimal standard such as that it be valid and novel. This still leads to article creep but perhaps not much more than what we are already seeing in standard journals. However, if the validation is crowd sourced without being manicured in some way, there is the danger that it will exacerbate fads, and obscure advances outside of them. So far I have published in traditional journals, and paid my dues by just keeping my nose above the waterline of reviews! But is the grass greener on the other side?