Seven Brief Lessons on Physics

by Carlo Rovelli

Science begins with a vision. Scientific thought is fed by the capacity to “see” things differently than they have previously been seen.

Here, in the vanguard, beyond the borders of knowledge, science becomes even more beautiful—incandescent in the forge of nascent ideas, of intuitions, of attempts. Of roads taken and then abandoned, of enthusiasms. In the effort to imagine what has not yet been imagined.

Physics opens windows through which we see far into the distance. What we see does not cease to astonish us. We realize that we are full of prejudices and that our intuitive image of the world is partial, parochial, inadequate. Earth is not flat; it is not stationary. The world continues to change before our eyes as we gradually see it more extensively and more clearly. If we try to put together what we have learned in the twentieth century about the physical world, the clues point toward something profoundly different from our instinctive understanding of matter, space, and time. Loop quantum gravity is an attempt to decipher these clues and to look a little farther into the distance.

The fundamental phenomenon that distinguishes the future from the past is the fact that heat passes from things that are hotter to things that are colder. So, again, why, as time goes by, does heat pass from hot things to cold and not the other way around? The reason was discovered by Boltzmann and is surprisingly simple: it is sheer chance.

To trust immediate intuitions rather than collective examination that is rational, careful, and intelligent is not wisdom: it is the presumption of an old man who refuses to believe that the great world outside his village is any different from the one that he has always known.