I enjoy giving presentations about the development of Perimeter Institute and the importance of science in our society.

Apart from the general sense of accomplishment one gains by spreading the gospel of scientific inquiry, there is nothing quite like the satisfaction from stimulating an accountant or lawyer to appreciate the wonders of physics. On my best days, I'm convinced that I can almost get them to reconsider their career choice for a second or two.

But there is always a moment when I lose my audience: when I begin talking about the beauty of physics and the elegance of sophisticated theories.

Physics? Beautiful?

To most people, no two concepts could be further apart. For them, the very word "physics" brings to mind some horrible tortuous experience in high school when a malevolent dictator clad in a white lab coat and black-rimmed glasses subjected them to myriad indignities in an incomprehensible tongue.

But history speaks a different tune. The pursuit of beauty and elegance has always been a driving force in the development of scientific theories. To its most radical proponents, this bias is based on a firm, axiomatic belief that, at its core, nature simply must be beautiful.

In this view, a description of the physical world must be simple and elegant: one unified law, one guiding principle, one overriding approach. If things look messy and incoherent, if a theory can not be completely encapsulated within a clearly delineated framework of a few basic beliefs, it simply must be wrong.

Substantial scientific progress consists of identifying a new framework of beliefs that sheds light on old inconsistencies and incongruities.

There is much to support this view.

The enormous complexities of the old Ptolemaic motion of the planets moving in circular orbits with epicycles, deferents, equant points and so forth were swept clean by the powerful simplicity of Newtonian mechanics, where the planets were shown to simply move in elliptical orbits naturally resulting from his universal law of gravitation between any two bodies.

When James Clerk Maxwell was able to unify the two forces of electricity and magnetism, he set the mathematical stage for the development of all modern communication theory.

And perhaps most spectacularly, Einstein's elegant, axiomatic theory of general relativity redefined our understanding of space, time and matter.

The pursuit of beauty, elegance and simplicity has an impressive track record. But it is hardly flawless

There are many beautiful theories lying on the side of the road of scientific progress, quite perfect except for their alarming lack of experimental relevance.

One of the earliest examples was Kepler's theory of the five Platonic solids. Johannes Kepler was a brilliant and tenacious astronomer who devoted his life to studying the motions of the five known planets. He was the first to recognize that they moved in ellipses rather than circles.

When first embarking on his quest, he had been seduced by a beguiling idea. Centuries ago, it had been proven that there were only five Platonic solids (three dimensional objects with faces of all the same shape), while in Kepler's day only five planets could be seen by the naked eye.

Five planets -- five Platonic solids --they must be related! And so Kepler set to work to develop a theory of how each of the orbits of the planets was somehow related to each of the five Platonic solids, thereby "explaining" why there were only five planets as well as describing their motion.

It was a beautiful and elegant idea - and completely wrong

In scientific parlance, beauty and elegance may be necessary conditions for success, but they are certainly not sufficient.

And then there are those who believe beautiful formalism may not be so important after all.

For the proponents of the so-called anthropic principle, the reason why we find ourselves in our present universe with all its familiar laws is not because of some higher elegant structure at all but because, well, just because.

If something else would have happened giving us different laws, life wouldn't have been possible and we simply wouldn't be asking the question at all. And that's just all we can say.

To some, this is a deeply dispiriting approach - a veritable copout from the glorious scientific tradition of finding deep, beautiful and sophisticated structure.

But to others, this is the inevitable bedrock to our knowledge, a notion that in itself holds a certain intrinsic elegance. For scientists, just like the rest of us, beauty truly is in the eye of the beholder.