Mentos and Diet Coke Blurs Physics and Chemistry

You know, when it comes down to it Chemistry calls itself "The Central Science" because when you draw all of science as a Venn Diagram it overlaps with more sciences it than any other. For all that Chemistry is the most insecure science as well. Very few universities are creating pure chemistry departments now and are in fact rolling them into other disciplines such as biology and physics.

The line between Chemistry and the other sciences gets blurrier all the time. Take for example this recent publication by the American Journal of Physics ...

LINK TO ARTICLE

This is of course the famous reaction that spawned a 1000 YouTube videos and made these guys famous.

LINK TO EepyBird

The article has even been reviewed by the news magazine for the American Chemical Society [LINK] and it turns out that there are a number of factors that combine to make the Mentos / Diet Coke reaction explosive. It appears that the gum arabic used in the composition of the Mentos make the foam more stable and frothier. A microscopic analysis of the surface of the Mentos reveal that it is covered with gas bubble nucleation sites and that the density of the mint meant that it falls to the bottom of the bottle of pop. All useful insights.

But it is not physics. Indeed what exactly do the authors mean in their title when they say "physical reaction". Now I have a little physics in my background and as I remember my terminology a physical reaction is a response to a force (you know ... Newton's Laws and such). I think they are just trying to avoid the word "Chemical" as if it were a dirty word.

I think chemists need to protect their turf while it is still ours and this is not a physics paper. The problem is how do we protest? I mean, we all know the hierarchy ... if you are not smart enough to do math you do physics, if you are not smart enough to do physics you do chemistry, if you are not smart enough to do chemistry ... well you know how it goes etc. We will need to be careful and bide our time but we can't let them walk over OUR turf and pretend to own our ideas. Wait for the right time and remember the codeword (stoichiometry (it is the only science word that chemistry truely owns)).