Nature and mathematics have a long and complex relationship. Is the world around us fundamentally mathematical? Or is the mathematical nature of the laws of physics merely a reflection of our own disposition?

Most physicists would strongly opt for the former explanation, proudly carrying on a tradition that dates back to Pythagoras.

A fascinating, charismatic and provocative individual, Pythagoras is sadly associated today only with a rather uninspiring relationship between the squares of the sides of right angle triangles.

His real legacy was more significant -- elevating mathematics from the lowly realm of mere practical calculation to the necessary ingredient of our understanding of the world around us.

In fact, Pythagoras' belief went even further than this. Upon discovering that harmonic progressions on the strings of lyres were clearly linked to mathematical ratios (i.e. what fraction of the string the musician places his fingers on), he not only concluded that musical harmony was related to mathematics, but he also generalized this to assume that all earthly and heavenly phenomenon were subjected to some over-arching mathematical principle. "All," as he put it, "was number."

The keen mathematical mind, he maintained, could detect these mathematical principles in the movement of the heavenly bodies and would consequently be able to hear "the music of the heavens."

This notion of marrying harmony, beauty and mathematics to describe all universal phenomena within a coherent framework has had both enduring appeal and success.

In many ways, it can be regarded as the progenitor of Newton's laws of motion and his universal law of gravitation, Einstein's theories of special and general relativity, the standard model of particle physics and modern attempts to unify all the forces of nature, such as the superstring theory.

Today, most physicists imbibe this world view early in their university training, often subconsciously: the world is fundamentally mathematical and it is the job of the physicist to discover the deep relationships (or, better yet, single relationship -- the equation to be fit on a T-shirt) that govern physical law.

But physicists are known for their lateral thinking abilities (not to mention obduracy and uniqueness), so it is not surprising that there are a few members of the community who are motivated to turn this mind set on its head.

Michael Berry, the renowned mathematical physicist from the University of Bristol in England, is one of these individuals.

Rather than trying to discover profound mathematical relationships in the physical world, Prof. Berry exhibits a curious tendency to look to the real world for "applications" of mathematical relationships.

While perhaps his most famous venture in this domain has been to explore the Riemann Hypothesis (one of the greatest unsolved conjectures in pure mathematics) within a physical context, he has also had fun looking for physical "demonstrations" of mathematics in rainbows, starlight and other sometimes ordinary phenomena.

Such avenues of inquiry were likely not what Pythagoras had in mind when he founded his cult of numerical brotherhood over 2.5 millennia ago.

But I imagine that he would have found it both intriguing and gratifying to discover that all those years later, we are still busying ourselves with probing the world around us in our search for harmonies.