What would you comment about the mental state of your friend who thinks the outcome of this world cup depends on whether he will watch the final or not. He must be kidding, you will think, or he has lost his mind or he is just plain superstitious.
But that’s exactly what happens in the world of electrons and quarks. The world of fundamental particles. And it is the world on which are our reality is built.
In the subatomic world the things don’t ‘just’ exist. They only exist when someone or something watch them. Their existence manifesting depending on the observer. Until you look at them, you can’t tell whether they exist or not!
As Schrodinger explained in his famous thought experiment.
“The cat is both dead ‘and’ alive inside the box. Only when you open it, the cat’s reality collapses into one of the states.”
Quantum mechanics is like this. Mysterious, baffling, counter-intuitive.
Physics has always worked at the edges of human understanding. Things which seem impossible to us are the everyday thoughts for the scientists. They ponder on exotic theories. Things like quantum entanglement and black holes and the possibility of time travel. Subjects which for most of us are a stuff of sci-fi fiction.
So it isn’t surprising to read about these esoteric subjects with a pinch of salt. Will time travel will ever be possible! Seems far fetched. But isn’t this what we have always done? Doubted the cutting edge Physics? One time not so far back in human history, people had found hard to believe the heliocentric model of the earth. So much that we were ready to kill those who uttered such hearsay. Those are the fact that even children take for granted these days.
This was the reason I couldn’t resist not reading the book “Seven Brief Lessons on Physics.”
It is a short book. Less than hundred pages. Its seven chapters devoted to the seven domain of the physics. These summarise our current understanding of the universe. In a very simple language, the book expands from the microscopic world of quantum particles to the massive black holes in the universe.
Every chapter is a pleasure to read.
Its first chapter is devoted to the General Theory of Relativity. The most beautiful of the theories. One of the most fascinating areas of Physics, it’s a heavy topic, and I have always found the explanations on internet vague for a common reader.
But Carlo Rovelli, the Italian physicist who wrote the book, explains General Theory of Relativity in one single line.
Space curves where matter exists.
This one line is the foundation from which spawns of every other prediction about the universe. From black holes to variability of time all comes out of it. From this single line. And Rovelli explains this in so easy terms that any layman can understand.
This theory unseated Newton’s theory of law of motion as the fundamental theory of Physics.
He writes while explaining gravitation –
That is the reason why you fall towards earth (there are no mysterious forces that pulls you towards it.) The heavy objects curve space around them so that the lighter objects fall towards them. Not pulled by a a mysteries force that we are so used to considering in current domain of physics.
He follows this with a thought experiment which will help any layman to understand this concept –
Imagine a horizontally stretched piece of cloth. Very tightly held from the four corners with many marbles over it. In this configuration, all the marbles will stay as is. Now put a heavy ball in the middle and see it making a depression in the stretched cloth. The marbles now start rolling because of the depression. Not because of any force that pulls them. In our universe, space is this piece of cloth. And the sun is the heavy ball that makes smaller things like planet fall towards it. Isn’t it so simple, yet so fascinating? And that’s all that General Theory of Relativity is – the theory that turned out Physics on its head.
There are many such gems through which Rovelli is able to put everything in context.
In school, we have studied different areas of physics separately. But through this book, I realised everything is connected. From gravitation to electromagnetism and quantum physics. All of these is trying to make heads or tails of this cosmos we inhabit. Insights from one feeding into other. Sometimes to unravel the mystery, and at others to make it more complicated. The way it happened in quantum physics.
The book is a scaffolding over which you can structure all your future readings about the physics.
Rovelli ends the book with apt lines that were implied throughout the book –
Here on the edge we know, in contact with the ocean of unknown, shines the beauty and mystery of the world. And it’s breathtaking.
And that’s what science is all about. To unravel this mystery of the universe we inhabit. A universe which is a mystery to us, and we have barely scratched the surface of this mystery.
Rating – 5/5
Who should read it – Any one who is curious about the cosmos we inhabit. This book, though short, very well ties up disparate areas of physics as a whole.
USP – You’ll be able to appreciate any future readings on Physics better.
Find it here –Link for the book
Also published on Medium.