Wednesday, 29 December 2010

The Trouble with Physics

Lee Smolin
 I bought myself a book for Christmas called the “Trouble with Physics” by Lee Smolin. He calls into question the physics research of the last thirty years by taking a layman, like myself, on a tour of the five great unanswered problems in physics (**see below), from its inability so far to unify general relativity and quantum theory, to the need to explain dark matter and dark energy.
In fact he starts by representing the lack of fundamental theoretical breakthroughs in the last thirty years as a failure and goes on to undermine much of the current research in physics by describing it as being based on unsound foundations.  He consequently attracts criticism even "flaming” for his challenging views from certain physicists who, in the direction of their research, are committed to what amounts to the new orthodoxy of String Theory.
Perhaps this extract below concerning supersymmetry will help explain why he is sometimes considered controversial.

"In supersymmetry-theory convention, the superpartners of fermions begin with an “s,” like the selectron, while the superpartners of bosons end in “ino.” .........
First of all a theory cannot be partly supersymmetric. If one particle has a superpartner, they all must. Thus, each quark comes with a bosonic partner, a squark. The photon is partnered with a new fermion, the photino. ..........
Not only are there squarks and sleptons and photinos, there are also sneutrinos to partner the neutrinos, Higgsinos with the Higgs, and gravitinos to go with the gravitons. Two by two, a regular Noah’s ark of particles. Sooner or later, tangled in the web of new snames and naminos, you begin to feel like Sbozo the clown. Or Bozo the clownino, or swhatever."

Within the context of a comprehensive review of recent research, he paints a picture of a large highly cohesive group of earnest string theorists unquestioningly following their leaders and excluding alternative views or fields of research. Whilst doing so they are ignoring the basic requirement of a scientific theory, which is to make predictions that are testable by observation and experiment. (Otherwise it is all just metaphysics - my comment not his!)
Towards the end of the book he comments on the sociological aspects of the organisation of scientific research in physics and finds many elements of the same sort of "groupthink" that has unfortunately been seen in twentieth century politics.  In addition he makes the case that academic recruitment to physics research posts in the USA is structured in such a way that the likelihood of scientific visionary thinkers obtaining a post is extremely limited, whilst those researchers committed to extending the work of more senior scientists in the current orthodoxies are most likely to be appointed or given tenure. He implies that without a change in the support made available to visionary theorists the US physics academy will continue to stagnate in terms of a lack of fundamental and testable theoretical breakthroughs. 
The irony is, as he also points out, that the psychology and sociology of these self sustaining groupthink situations, which undermine performance or lead to disastrous consequences, is well understood, particulary by US academics in other disciplines and even in businesses.

I found it surprisingly soothing over the Christmas and New Year holidays after I had had a wisdom tooth removed and whilst I was surrounded by family chit-chat in French.

Here is Lee in entertain and amaze mode!

**1. Combine general relavity and quantum theory into a single theory that can claim to be the complete theory pf nature.  This is called quantum gravity.
2. Resolve the problems in the foundations of quantum mechanics, either by making sense of the theory as it stands or by inventing a new theory which does makes sense.
3. Determine whether or not the various particles and forces can be unified in a theory that explains them all as manifestations of a single fundamental entity.  The unification of the particles and forces.
4. Explain how the free constants in the standard model of particle physics are chosen in nature.
5. Explain Dark Matter and Dark Energy.  Or if they don't exist determine how and why gravity is modified on large scales.  More generally, explain why the constants of the standard model of cosmology, including the dark energy, have the values they do.  

1 comment:

  1. I sent an email to Lee and he was kind enough to reply as follows:-
    Dear John,

    Thanks very much for the review. It’s very satisfying to me that four + years later that book is still drawing interest. For me it’s a long time ago, although there is very little in the book I would change. I am hoping to do as well in my next book and in the meantime doing a lot of science.

    All best wishes,