I just had a look at whats new on the DEVONthink website and under Searching, Linking and Exploring you are showing a physics book as an example
May I ask for the title and author of the book?
By coincidence I am reading about physics, spacetime and special relativity at the moment and would like to check out this book as well. Thanks.
I took this as a fun little challenge. I thought “Chapter 21 The Harmonic Oscillator” might be unique enough to identify the book with a search query. The top result on DuckDuckGo was this: The Feynman Lectures on Physics Vol. I Ch. 21: The Harmonic Oscillator, and the Table of Contents match perfectly.
I conclude that the answer is: The Feynman Lectures on Physics, Volume I.
I can’t tell you what edition it is, though 
That is a PDF volume of The Feynman Lectures.
I’m on lunch but will look for it when I’m back at my Mac.
Thanks for the help - will look it up.
Yes, that is correct.
Here you can also find recordings of some of the lectures.
