Information gently but relentlessly drizzles down on us in an invisible, impalpable electric rain.

Time has been called God's way of making sure that everything doesn't happen at once. In the same spirit, noise is Nature's way of making sure that we don't find out everything that happens. Noise, in short, is the protector of information.

Information gently but relentlessly drizzles down on us in an invisible, impalpable electric rain.

To put it one way, a collection of Shakespeare's plays is richer than a phone book that uses the same number of letters; to put it another, the essence of information lies in the relationships among bits, not their sheer number.

Entropy is not about speeds or positions of particles, the way temperature and pressure and volume are, but about our lack of information.

This is not what I thought physics was about when I started out: I learned that the idea is to explain nature in terms of clearly understood mathematical laws; but perhaps comparisons are the best we can hope for.

In order to understand information, we must define it; bit in order to define it, we must first understand it. Where to start?