The announcement of this year's Ig Nobel Prizes, for “achievements that make people laugh, and then make them think”, included one for physicists Lakshminarayanan Mahadevan of Harvard University and Enrique Cerda Villablanca of the Universidad de Santiago de Chile, who won the award for studying how thin elastic sheets become wrinkled. That doesn't sound strange to a physicist, but presumably it does to the general public. The Ig Nobels amuse because they catch scientists studying what seems to be ridiculous, although it often turns out to be entirely sensible — knowledge or capability in one area of science is almost always important in others, sometimes in the most unexpected ways.

A nice illustration comes from recent experiments on microfractures in crystals, more sensitive than previous ones by several orders of magnitude, and capable of measuring events that release only a few femtojoules — equivalent to the breaking of a few hundred bonds. Naively, one might suppose that such a huge advance resulted from a focused effort on that specific goal, yet the truth is rather different.

Deep within the Gran Sasso underground laboratory in Italy, the European CRESST research team is trying to detect weakly interacting massive particles (WIMPS), which might make up some of the dark matter that numerous cosmological anomalies suggest may exist. This requires extremely sensitive detectors, well isolated from noise and perturbing cosmic rays. The CRESST team uses crystalline detectors, coated with a thin film of tungsten and working near 15 mK, at the boundary between the film's superconducting and normal states. A tiny change in the film's temperature — triggered by energy deposited by an absorbed particle — will cause a much larger change in its resistance, which can be measured using a SQUID.

Knowledge or capability in one area of science is almost always important in others.

In preliminary experiments, researchers found spurious signals, bursts of energy with signatures unlike those expected for WIMPS. However, the researchers realized later that they were seeing traces of microfracture events in sapphire crystals within the bearings supporting the device. They learned how to fix that problem, but also had the good sense to recognize that, almost by accident, they had created an exceptionally powerful tool for studying the fracture dynamics of single crystals. It's as if astronomers had built an immense telescope to glimpse distant galaxies, and then found it to be the world's most sensitive microscope.

Data collected so far reveal striking similarities between the microfracture process in perfect crystals and fracture dynamics in far messier settings such as the Earth's crust (http://arXiv.org/abs/0708.4315v2). For one thing, the distribution of fracture events with energy released follows the Gutenberg–Richter law of earthquake science, with the number of events releasing energy E being closely proportional to 1/E2. The similarity also extends to the time domain: microfractures cluster much as earthquakes do, revealing a power-law distribution of waiting times between events.

These findings aren't especially surprising — more striking is the extension of these dynamical similarities over an impressive thirty orders of magnitude in energy, from crystalline microfractures up to the largest earthquakes. Also not surprising, perhaps, is that the researchers didn't set out specifically to do it, but just tackled one small puzzle after the next.