Archive | July 2021

Reality is not what it seems

Writing popular science books is hard. Taking very complex topics and making them understandable to a lay person is a special skill.

Carlo Rovelli is the best science writer I have ever read. Reality is not what it seems: the journey to quantum gravity is indeed a joy to read.

Rovelli takes us on a journey from ancient Greek philosophers to today’s edge of theoretical physics. The first half of the book is devoted to telling the story of how our understanding of reality has developed from early Greeks like Democritus and Leucippus through Galileo, Newton and on to Faraday, Einstein and Bohr. It is amazing to me how what we know of the physics of the ancient Greeks is pieced together from tiny fragments of their writing, and what other philosophers said about their ideas. How devastating to understand what we’ve lost, and yet incredible that we know anything at all.

Rovelli builds up a picture of how we have come to understand the world, starting with concepts of atoms and particles, adding waves and fields, and ending with something quite different to what we might have learnt at school. I wonder how different the physics that is taught now is to what I was taught thirty years ago.

The second half of the book gets into what current theoretical physics is thinking about what reality is, with some description of how experimental physics is providing evidence for those theories. It ends with some discussion about the two main theories now competing to draw all this together.

I am obsessed with the idea that the reality of the universe is so completely alien to the human perception of our surroundings. It’s amazing that with such limited brains and ways of experiencing the world that we can even begin to understand what reality is. For me the best bit of this book is that time doesn’t exist independently of humans. There is no objective, separate thing that is time: our sense of time is generated by our existence.

Loved it. Definitely read this.