Nothing really matters
(Review of Void, James Weatherall, November 2016)
Most of us grew up learning that outside our atmosphere, there is nothing, a vacuum, a void. But physics disagrees. It also disagrees within itself, and that is the subject of Void.
One of the great things about the mess of quantum theory is that it allows you to approach from a multitude of angles. In this case — nothing, or the lack of it. There are far too many ways of looking at nothing. Weatherall says nothing is not the absence of “stuff”; it is one possible configuration of stuff. And while things like black holes and gravitational waves don’t count as stuff — they’re still there, preventing the void from actually being empty. The electromagnetic field is always present, regardless of whether it is stimulated, distorted or otherwise excited — or not. Then there is the question of light. If light is a significant factor, bent by other forces as it travels, is it non-nothing content? Does a pinpoint of light mean anywhere it can be seen is not empty? Finally, nothing means different things in classic physics, general relativity and quantum field theory. And common English. Which muddies the waters even further. Nothing it seems, is not simple.
My favorite paradox from Weatherall is the case where two waves of exactly the same peaks and troughs are in the same space, essentially canceling each other out. Are there two things in that space, or none?
While most if not all the quantum physics books I have reviewed insist on an 80 page recapitulation of history, from Ptolemy to Copernicus and Galileo, Newton, Brahe, et al., Void does it with panache. Weatherall shows us the reasoning, the faults, and even the very personal attacks, arguments and lawsuits involved as we learned bits and pieces of how the universe works. It is, for the first time in my experience, entertaining as well as illuminating. It is fast and fascinating. And understandable.
With everything there to not to understand in quantum physics, I will never understand how Weatherall could have titled this book Void. He passed on the title Nothng Really Matters, which he says it right up front and which is brilliant, Oh well; nothing ventured, nothing gained.