Seven Brief Lessons On Physics, by Carlo Rovelli (2014)

There are absolute masterpieces which move us intensely: Mozart’s Requiem; Homer’s Odyssey; the Sistine Chapel; King Lear. To fully appreciate their beauty may require a long apprenticeship, but the reward is sheer beauty - and not only this, but the opening of our eyes to a new perspective upon the world.

You would, of course, need to study and digest Riemann’s mathematics in order to master the technique to read and use this equation. It takes a little commitment and effort. But less than is necessary to come to appreciate the rarefied beauty of a late Beethoven string quarter. In both cases the reward is sheer beauty, and new eyes with which to see the world.

When Einstein died, his greatest rival Bohr found for him words of moving admiration. When a few years later Bohr in turn died, someone took a photograph of the blackboard in his study. There’s a drawing on it. A drawing of the ‘light-filled box’ in Einstein’s thought experiment. To the very last, the desire to challenge oneself and understand more. And to the very last: doubt.

For now this is what we know of matter:
A handful of types of elementary particles, which vibrate and fluctuate constantly between existence and non-existence and swarm in space even when it seems that there is nothing there, combine together to infinity like the letters of a cosmic alphabet to tell the immense history of galaxies, of the innumerable stars, of sunlight, of mountains, woods and fields, of grain, of the smiling faces of the young at parties, and of the night sky studded with stars.

When we say that we are free, and it’s true that we can be, this means that how we behave is determined by what happens within us, within the brain, and not by external factors. To be free doesn’t mean that our behaviour is not determined by the laws of nature. It means that it is determined by the laws of nature acting in our brains.

Our moral values, our emotions, our loves are no less real for being part of nature, for being shared with the animal world, or for being determined by the evolution which our species has undergone over millions of years. Rather, they are more valuable as a result of this: they are real.

I believe that our species will not last long. It does not seem to be made of the stuff that has allowed the turtle, for example, to continue to exist more or less unchanged for hundreds of millions of years; for hundreds of times longer, that is, than we have even been in existence. We belong to a short-lived genus of species. All of our cousins are already extinct. What’s more, we do damage.

We are born and die as the stars are born and die, both individually and collectively. This is our reality. Life is precious because it is ephemeral.

But immersed in this nature which made us and which directs us, we are not homeless beings suspended between two worlds, parts of but only partly belonging to nature, with a longing for something else. No: we are home.