Prof. Scott Tremaine will give Perimeter Institute's last public talk of this series, entitled The Stability of the Solar System, this Wednesday.

Tremaine will discuss how our understanding of both the creation and the future of the solar system has evolved over the recent past, owing to a wealth of data, new techniques and concepts and powerful computer simulations.

But what he might not mention is the symbolic significance of this line of scientific inquiry, for questioning the detailed structure of the solar system will be forever associated with the birth of the modern scientific era.

Popular folklore has it that, until Columbus, everyone thought the world was flat. However colourful this notion might be, it is certainly not the case.

Most of the ancient Greek philosophers and mathematicians were well aware that Earth is spherical, and the scholar Eratosthenes even made an impressively accurate calculation of its circumference in the third century BC.

But it is certainly true that for much of human history, there was little doubt that Earth was the centre of the universe, with the sun, moon and planets (literally "wandering star" in Greek) orbiting Earth in a series of circular paths.

But when Copernicus finally published his sun-centred (heliocentric) theory in the 1540s, postulating that Earth and all the planets moved about the sun, he did far more than merely provide an alternative view of describing the motion of the heavenly bodies.

He did nothing less than launch the modern scientific era.

No longer would Earth (and, by extensions, humans) be seen as the literal or metaphorical centre of scientific inquiry. No longer would human ego and sentiment play an unquestioned role in the development of explanatory theories. Copernicus fundamentally altered our perception about the importance of relating natural phenomena to human affairs and inclinations.

To the Catholic Church, the very act of considering Earth to be anywhere other than the natural centre of the heavens was an egregious affront to both God and man. To the Copernicans, on the other hand, it was a natural question to consider in the new spirit of intellectual inquiry -- a spirit that was free to ponder not only how but also why. For if the sun could equally well be at the centre of the heavens, surely there was some way of distinguishing which theory was actually correct.

And from there it was only natural to consider not only which view was right, but why it was so. So from Copernicus, who set the cat among the pigeons, we move to Galileo and Kepler -- who refined the theory and found considerable evidence for it -- and to Newton.

Newton, in perhaps the greatest intellectual accomplishment, singlehandedly unified the entire framework in a systematic accounting of not only what was happening, but why, invoking both his laws of mechanics and the universal law of gravitation.

In less than 150 years, scientific inquiry had moved from a realm deadened by superstition and religious authority to one of free-ranging investigation where anyone could boldly learn the tools to not only predict the return of a comet, but why it was returning at all.

Nowadays, to a scientist, "the heavens" mean something considerably more involved than solely the solar system. The last 100 years have revealed a richness and depth to the universe that is both shockingly predictable (and testable) and profoundly mysterious. We have discovered, through powerful telescopes and indirect techniques, numerous planets not unlike ours orbiting faraway suns. And we have sent countless probes to closely study the planets we once associated with the gods.

But despite all our accomplishments, the solar system is by no means all figured out. A rigorous analytical solution of the trajectories of many gravitationally interacting bodies may be theoretically computable from Newton's basic laws, but the specific details quickly become intractable.

There is much exciting science to be done to give shape to these mysteries hidden in the folds of seemingly untenable complexity.

Understanding the solar system might have given rise to modern science, but there is much in modern science to do there yet.