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The lazy universe : an introduction to the principle of least action

Posted: Mon Jun 25, 2018 5:30 am
by quantropy
Why I looked at this book
Newtonian physics is fairly intuitive: there are forces which cause things to move the way they do. But this behaviour can also be framed in terms of the principle of least action. To me this seems a bit weird: it's as if particles were intentionally trying to economise on the use of certain stuff. Given that it's such a powerful principle should the teaching of physics include it from the start, or should it begin with ideas which are more intuitively grasped? I'm looking to this book to discuss such issues and help me better understand the principle of least action.

Re: The lazy universe : an introduction to the principle of least action

Posted: Wed Jun 27, 2018 7:36 pm
by quantropy
First Impressions
In the first chapter Coopersmith lists the advantages of the principle of least action. One that I find important is the ability to link together different viewpoints. For instance the underlying models in Newtonian gravity and General Relativity look totally different, but in many situations their predictions are very similar. I'm hoping that least action may help to show their similarities.

This book is dedicated to Cornelius Lanczos, and is based on his textbook The Variational Principles of Mechanics, the idea being that Coopersmith offers a more accessible explanation of the concepts. I realised, though, that she is the author of Energy, the subtle concept : the discovery of Feynman's blocks from Leibniz to Einstein, which I found a bit intimidating when I started to read it. This book seems a bit wordy at times, but I'm hoping that it is easier to get into, although I wouldn't say that it was written as a 'popular' book. I'll have to see how it turns out. Maybe I'll look at Lanczos' textbook to check how much this book makes the concepts easier to understand.