Connections in physics, 21st-century style

Spectators of science often miss what working scientists consider "cool", instead being dazzled by counterintuitive results and "gee, they can really do that?"

To physicists, finding relations between quantities previously seen as independent--the canonical example being the relationship between coupling constants and particle masses--being thus able to indirectly measure things of interest, is one of the joys of the field. "Connections in physics"--finding that different phenomena are governed by similar laws--is yet another.

In March's Physical Review E, Northwestern University biophysical theorists Houyin Zhang and John Marko derive analogues of the Maxwell relations familiar to science undergraduates, allowing experimenters to (among other things) find the number of proteins bound to a nucleic acid molecule from force-extension measurements, without a microphysical model for the mechanism of binding.

From the point of view of someone who works daily with optical tweezers: very cool.