Amanda Gefter, a science writer who has often covered theoretical physics topics for New Scientist, has a new book coming out soon, Trespassing on Einstein’s Lawn. On one level it’s a memoir, telling a story that begins with her father getting her interested in fundamental questions about physics. This led to a career interviewing well-known physicists and writing about these topics, and now, a book. Self-reflexivity is a major theme of the book, with one aspect of this the way it tells in detail the story of its own genesis and creation.
In many ways, it’s comparable to last year’s book by Jim Holt, Why Does the World Exist?, with both books motivated by versions of the question “Why is there something rather than nothing?” In both books, there’s a memoir aspect, with the author front and center in a search for answers that involves meetings and discussions with great thinkers. For Holt, these were mostly philosophers with a few physicists thrown in, while for Gefter they’re mostly physicists, with a few philosophers making an appearance. These are lively, entertaining writers with wonderful material about deep questions, and I greatly enjoyed both books. Gefter is the funnier of the two, and I had trouble putting the book down after it arrived in my mail a couple days ago.
For those familiar with the topics she covers, the descriptions of her encounters with famous physicists is what will most likely provide something new. A few examples:
- She somehow managed to get to moderate a private debate between Lenny Susskind and David Gross, mainly on the topic of the multiverse. Much of the result is familiar to anyone following the topic over the last ten years (Gross detests the multiverse, Susskind is madly in love with it), but one interesting aspect is Gross’s comparison of Susskind’s behavior to his own back in 1984-5:
What I’m saying… is that some of the reaction is exactly like the reaction I got for exuberance in 1984, when we believed the answer was around the corner and we got carried away with that position. And, Lenny, you are carried away with this position. The stakes are damn big. So you are open to severe criticism.
So, it seems that Gross is accusing Susskind of engaging in hype deleterious to physics, while acknowledging that he did much the same thing to get string theory unification off the ground and widely accepted.
- Several string theorists pointed out that strings themselves have pretty much disappeared from the story. The emphasis is now on the holographic principle and the hope for some unknown M-theory that embodies it. About M-theory, Polchinski has this to say:
It’s remarkable to know so much about many limits and yet have no good idea of what they are limits of! Holography is clearly part of the answer. The fundamental variables are probably very nonlocal, with local objects emerging dynamically.
Witten tells Gefter that the “M” in “M-theory” really was intended to refer to membranes. He doesn’t see much happening though as far as new ideas about understanding it:
…in the mid-eighties and mid-nineties, before the second revolution happened, there were kind of hints that something was going to happen – I didn’t know what, of course. I don’t have that feeling now, but perhaps other people do… If I had my druthers I’d like to go deeper into what’s behind the dualities, but that’s really hard.
- John Wheeler plays a large role in Gefter’s story, which starts with her asking him a question at this conference in 2002. She has a fascinating description of Wheeler’s journals, which have been preserved in Philadelphia, where she and her father spent quite a lot of time looking through them.
The list of interviewees includes also Kip Thorne, Raphael Bousso, Tom Banks, and Carlo Rovelli.
Gefter makes it clear that she started out with essentially no background in physics or math, other than enthusiasm shared with her father for speculation about “nothingness” and the like. She studied not physics, but philosophy of science at the London School of Economics. Despite this lack of technical training, she does a good job of accurately characterizing what the physicists she talked to had to say. Towards the end the book does suffer a bit as she moves away from reporting what others are telling her to expounding her own interpretation of what it all means.
While I liked the book, at the same time I found the whole project deeply problematic, and would have reservations about recommending it to many people, especially to the impressionable young. The part of physics that fascinates Gefter is the part that has gone way beyond anything bound by the conventional understanding of science. This is really and truly “post-modern physics”, completely unmoored from any connection to experiment (the discovery of the Higgs in the middle of the period she is writing about just gets a short footnote). The questions being discussed and answers proposed are woolly in the extreme, focused on issues at the intersection of cosmology and quantum mechanics, suffering from among other things our lack of a convincing quantum theory of gravity. Gefter seems to be sure that the problem of quantum gravity is an interpretational one of how to talk about a quantum cosmology where observers are part of the system. The very different, much more technical issue of how to consistently quantize metric degrees of freedom in a unified way with the Standard Model fields is ignored, perhaps with the idea that this has been solved by string theory.
Not recognizing that this post-modern way of doing science is deeply problematic and leading the field into serious trouble isn’t so much Gefter’s fault as that of the experts she speaks to (David Gross is an exception). Those taking the field down this path are dominating public coverage of the subject, and often finding themselves richly rewarded for engaging not in sober science but in outrageous hype of dubious and poorly-understood ideas. Only the future will tell whether the significance of this book will end up being that of an entertaining tale of some excesses from a period when fundamental physics temporarily lost its way, or a sad document of how a great science came to an end.