I remember once watching a presentation of the creation of the universe in a planetarium. It was a fascinating experience: lights flashing, particles appearing to rush by as an explosive roar echoed throughout the planetarium. Then suddenly ... black ness. And after a few seconds ... tiny lights--stars blinking into existence. I tried to imagine myself actually going back to this event. Was this really what it was like? It was an interesting facsimile, but far from what the real thing would have been like. The creation of the universe is an event that is impossible to imagine accurately....

I remember sitting spellbound, watching the movie When Worlds Collide. Two planets hurled through space toward Earth while scientists and engineers frantically raced to complete a rocket ship that would take them to safety. In the final moments the spaceship lifted off as the occupants watched the Earth bulge, crack, then literally explode as one of the planets struck it. As I left the theater I wondered if it was really possible for another world to collide with Earth. Later I learned that while many catastrophic collisions no doubt occurred early in the his tory of the solar system, today...

'he year was 1889. The French physicist-mathematician Henry T Poincare could not believe his eyes. He had worked for months on one of the most famous problems in science-the problem of three bodies moving around one another under mutual gravita- tional attraction-and what he was seeing dismayed and trou- bled him. Since Newton's time it had been assumed that the problem was solvable. All that was needed was a little ingenuity and considerable perseverance, but Poincare saw that this was not the case. Strange, unexplainable things happened when he delved into the problem; it was not solvable...