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.

We don't know what energy is, any more than we know what information is, but as a now robust scientific concept we can describe it in precise mathematical terms, and as a commodity we can measure, market, regulate and tax it.

The switch from 'steam engines' to 'heat engines' signals the transition from engineering practice to theoretical science.

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

If the intensity of the material world is plotted along the horizontal axis, and the response of the human mind is on the vertical, the relation between the two is represented by the logarithmic curve. Could this rule provide a clue to the relationship between the objective measure of information, and our subjective perception of it?

In fact, an information theory that leaves out the issue of noise turns out to have no content.

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.