By Hans Christian von Baeyer I pick up a stone and playfully
fling it into Lake Matoaka. The stone rises gracefully through
the morning air, tips over, and ends its symmetrical trajectory
with a plop. Like countless baseballs, footballs, and
basketballs, like lumps of lava hurled out of bubbling volcanoes
when Earth was young and drops of water splashed up by oceans
till the end of time, my missile traces a mathematical curve
through space. We physicists find beauty in the timeless
perfection of that motion. It represents a rare glimpse of the
absolute in this chaotic world of ours. Galileo first derived
the shape of the trajectory and found it to be the figure that
Appolonius of Perga over two millennia ago called a parabola.
"Ignoring air resistance, cannon balls move along parabolas," we
learn in school. But the truth is more intriguing. Imagine the
stone as a point and the Earth all shriveled up and shrunk down
to another point four thousand miles below your feet. This is
how Newton, who was born the year