By Gavin Hesketh
Quercus (1 Sept. 2016)
The first word in Gavin Hesketh’s book The Particle Zoo is “Beauty.” I read the word, closed the book, and didn’t reopen it for several months. Having just myself finished writing a book about the role of beauty in theoretical physics, it was the absolutely last thing I wanted to hear about.
I finally gave Hesketh’s book a second chance and took it along on a recent flight. Turned out once I passed the somewhat nauseating sales pitch in the beginning, the content considerably improved.
Hesketh provides a readable and accessible no-nonsense introduction to the standard model and quantum field theory. He explains everything as well as possible without using equations.
The author is an experimentalist and part of the LHC’s ATLAS collaboration. The Particle Zoo also has a few paragraphs about how it is to work in such large collaborations. Personally, I found this the most interesting part of the book. Hesketh also does a great job to describe how the various types of particle detectors work.
Had the book ended here, it would have been a well-done job. But Hesketh goes on to elaborate on physics beyond the standard model. And there he’s clearly out of his water.
Problems start when he begins laying out the shortcomings of the standard model, leaving the reader with the impression that it’s non-renormalizable. I suspect (or hope) he wasn’t referring to non-renormalizability but maybe Landau poles or the non-convergence of the perturbative expansion, but the explanation is murky.
Murky is bad, but wrong is worse. And wrong follows. Fore example, to generate excitement for new physics, Hesketh writes:
“Some theories suggest that antimatter responds to gravity in a different way: matter and antimatter may repel each other… [W]hile this is a strange idea, so far it is one that we cannot rule out.”I do not know of any consistent theory that suggests antimatter responds differently to gravity than matter, and I say that as one of the three theorists on the planet who have worked on antigravity. I have no idea what Hesketh is referring to in this paragraph.
It does not help that “The Particle Zoo” does not have any references. I understand that a popular science book isn’t a review article, but I would expect that a scientist at least quotes sources for historical facts and quotations, which isn’t the case.
He then confuses a “Theory of Everything” with quantum gravity, and about supersymmetry (SuSy) he writes:
“[I]f SuSy is possible and it makes everything much neater, it really should exist. Otherwise it seems that nature has apparently gone out of its way to avoid it, making the equations uglier at the same time, and we would have to explain why that is.”Which is a statement that should be embarrassing for any scientist to make.
Hesketh’s attitude to supersymmetry is however somewhat schizophrenic because he later writes that:
“[T]his is really why SuSy has lived for so long: whenever an experiment finds no signs of the super-particles, it is possible merely to adjust some of these free parameters so that these super-particles must be just a little bit heavier, just a little bit further out of reach. By never being specific, it is never wrong.”Only to then reassure the reader
“SuSy may end up as another beautiful theory destroyed by an ugly fact, and we should find out in the next years.”I am left to wonder which fact he thinks will destroy a theory that he just told us is never wrong.
Up to this point I might have blamed the inaccuracies on an editor, but then Hesketh goes on to explain the (ADD model of) large extra dimensions and claims that it solves the hierarchy problem. This isn’t so – the model reformulates one hierarchy (the weakness of gravity) as another hierarchy (extra dimensions much larger than the Planck length) and hence doesn’t solve the problem. I am not sure whether he is being intentionally misleading or really didn’t understand this, but either way, it’s wrong.
Hesketh furthermore states that if there were such large extra dimensions the LHC might produce microscopic black holes – but he doesn’t mention with a single word that not the faintest evidence for this has been found.
When it comes to dark matter, he waves away the possibility that the observations are due to a modification of gravity with the magic word “Bullet Cluster” – a distortion of facts about which I have previously complained. I am afraid he actually might not know any better since this myth has been so widely spread, but if he doesn’t care to look at the subject he shouldn’t write a book about it. To round things up, Hesketh misspells “Noether” as “Nöther,” though I am willing to believe that this egg was laid by someone else.
In summary, the first two thirds of the book about the standard model, quantum field theory, and particle detectors are recommendable. But when it comes to new physics the author doesn’t know what he’s talking about.