Taming the atom Book

The atomic hypothesis - that the universe consists of innumerable tiny particles in ceaseless motion - traces its roots to Greek antiquity, but until recently individual atoms remained theoretical conceptions far removed from the senses. Now technology has reached down into the abstract realm of the atom, and made it accessible to our eyes and fingertips. We have learned to catch, photograph, touch, and even modify atoms one by one. Thus, for the first time since the philosopher Democritus imagined it more than two thousand years ago, the atomic landscape has been revealed in lavish beauty, as in the cover illustration from the scanning tunneling micrograph shown below, which depicts a baker's dozen of iodine atoms bonded together in six-fold symmetry, with a gaping hole glowing yellow where one of their number is missing. This picture represents a completely new perception of physical reality. It is the interface between the familiar macroscopic world and the microworld of elementary particles, where experience and intuition clash with the tantalizing paradoxes of quantum theory, marking the gateway to a mysterious inner territory that is as fascinating as outer space. Today the unsettling contrast between the notion of the atom as an ordinary object that we can see and touch, and as a quantum mechanical specter, has taken on a new urgency. "Nobody understands quantum mechanics," complained the great American physicist Richard Feynman, and he meant to include himself. The quantum theory of matter that predicts the properties of atoms in exquisite detail describes a world where probability replaces certainty, where an object can be in two places at once, and conventional logic fails. This world, once the subject of intense philosophical debate among such scientists as Einstein, Schrodinger, and de Broglie, has finally been unveiled. Experiments that had previously been carried out in a physicist's imagination and associated only with the hidden world of the inf