Not Even Wrong

A review that I wrote of David Kaiser’s How the Hippies Saved Physics is now available at American Scientist. A quick summary is that I think it’s a marvelous book, telling in well-researched and entertaining fashion a story I’ve always wanted to know more about. I’m not convinced though by the main argument of the title, that this group of people “saved physics”, rescuing it from an oppressive “shut up and calculate” ideology by showing the way towards the importance of Bell’s theorem and helping start the field of quantum information theory. Perhaps the author though is just emulating his subjects, known for their playful outlandishness.

There are quite a few interesting things I learned from the book that didn’t make it into the review. One example is the story of Werner (of EST fame) Erhard’s theoretical physics conferences of the late 70s and early 80s, organized in collaboration with Sydney Coleman and Roman Jackiw. Among the factors that brought these events to an end was the advent of string theory: it was felt that no string theory conference without Witten attending would be taken seriously, and by then Witten wanted nothing to do with EST and its founder (although he had attended, with the likes of Feynman and Weinberg, the earliest conference in the series back in 1977).

If you find this subject at all interesting, I highly recommend the book.

For another take on the same subject, from one of its main participants, Jack Sarfatti’s memoir Star Gate is available for free these days in a pre-publication version here.

I’m afraid that my own description of where the physicists described in Kaiser’s book ended up would not be the field of quantum information theory, but the much larger swamp of dubious claims about quantum physics that is still very influential. For example, this week at the AAAS meeting in San Diego there’s a session on Quantum Retrocausation, see this listing from the World of Parapsychology.

Update: I should also mention that Chad Orzel discusses the book here and here.

Jim Baggott’s The Quantum Story: A History in 40 Moments is now out here and I’ve been starting to see it in bookstores. I read most of it a year or two ago when he sent me a draft of the manuscript asking if I’d take a look at it, and very much enjoyed getting the chance to see it then. If you’re looking for an excellent popular level physics book to read, I highly recommend that you consider this one, which should be accessible to just about anyone, no matter what their background.

The topic of the book is the story of quantum physics in general, told historically with a structure of 40 vignettes. The first three chapters cover mainly events of the dramatic period of the mid-1920s to early-1930s during which physicists uncovered the basic structures of quantum theory and struggled to make some sense of them. The next two take on the late-40s to mid-70s during which a long succession of discoveries about elementary particle physics drove theoretical progress on quantum field theory and gauge theory, culminating in the Standard Model falling into place in 1973. The material Baggott works with here has been the topic of many other books, but he does a wonderful job of putting it together in a fast-paced but very clear and entertaining narrative. Along the way, the individual stories he tells often contain fascinating details I’d never heard before, even though I thought this was a subject I knew all too well.

The next to last chapter starts with the 1950s and David Bohm, picking up the thread of later debates and discoveries related to the general problem of the interpretation of quantum mechanics. It brings this story up to date, explaining some of the current questions that are still being debated. The final chapter gives an appropriately short discussion of speculative ideas in quantum gravity and string theory that have dominated theoretical research for the past few decades, making clear that they’re a long ways yet from the solid science that’s the main topic of the book.

The LHC and the search for the Higgs make up a final epilogue or 41st vignette, accurately describing the high expectations and drama that surrounds the final period of the long wait for new data that is finally coming to an end this year. The story of quantum theory is not a finished one, and we all hope that very soon we’ll get some clues as to where it will go next.

Today’s Wall Street Journal has a review I wrote of Sir Roger Penrose’s new book Cycles of Time. The review is aimed at a much wider audience than this blog, and is the product of substantial editing to get its length down and make it as readable as possible for as many people as possible, so here are some supplementary remarks.

I should make it clear that I’m not at all convinced by what Penrose is proposing. He needs the distant future of the universe to be conformally invariant, and this requires all particles to be massless. As far as we know the electron is completely stable, with unchanging mass, and this will always ruin conformal invariance. Penrose himself notes the problem. For this to be overcome, whatever our ultimate understanding is of how particles get mass must change so that these masses go to zero in the future. It’s also seems to me that the conformal anomaly of QCD will always be a problem, with quantization and the renormalization group always breaking conformal invariance and giving a mass scale, indefinitely far into the future.

The other main problem is the one shared by most “pre-big-bang” ideas: how do you ever test them? Penrose and a collaborator last year created a stir by claiming to see in the CMB patterns of the sort he argues might be expected from black hole decays late in an era before the Big Bang, but it’s not clear there’s a real prediction here, and others who have redone this analysis say they see nothing.

Attempts to get a Big Bang in our future as well as our past generally strike me as motivated by a very human desire to see in the global structure of the universe the same cyclic pattern of death and rebirth that govern human existence. To me though, deeper understanding of the universe leads to unexpected structures, fascinating precisely because of how alien they are to human concerns and experience. Just because we might find a cold, empty universe an unappealing future doesn’t mean that that’s not where things are headed.

The book is in many ways an unusual document. It includes an extensive appendix working out some of the details of the mathematics of his proposal. In some sense he has managed to get a trade publisher to put out a highly technical discussion of a speculative idea inside the covers of a popular book, instead of going the usual route of publishing this in a refereed journal. The only references I can find to other places where he has written some of this up are to chapters in this book and this one, as well as this contribution to a conference proceeding. The technical idea behind this, that the hypothesis of the vanishing of the Weyl curvature in the early universe leads to possible cosmological models that can be extended past the Big Bang singularity he attributes to this paper of K.P. Tod. There’s a nice recent exposition of this by Tod here.

So, I’m not convinced by the speculation about the far future, and for an evaluation of the ideas about extending back through the big bang singularity you’ll need someone more expert about cosmology than me. These topics are very clearly labeled in the book as speculative, without support from other physicists or any experimental evidence. The bulk of the book though is other material providing a background and context for the speculation, and it is this which I think makes it most valuable as a popular book. Penrose is a wonderful, elegant and clear writer, and he covers a lot of ground about physics beautifully here. Most remarkable are the illustrations, by far the best visual representations of a range of important ideas that I know of. Physicists and mathematicians work with lots of internal pictures in their minds representing important aspects of the concepts they are investigating, but very rarely do they have the technical skill to grasp some of the essence of these pictures and get them down on paper. Even more rarely do they make it into wide distribution in print, so I’m glad to see that happen here.