Strung out

Here's an interesting letter from the latest Weekly Worker. Over the last year or so I've tried to pursue intermittently the connections between Marxism and chaos theory, but string theory is way over my head. Anyone want to have a go?

String ’em up

Classic Marxism took a keen interest in physical science and its relationship to materialist philosophy, so following the developments in modern physics should be of interest to Marxists. The problem is that, since the early 20th century, what is meant by ‘matter’ has become a far more complicated question than when Engels and Lenin wrote on it. If you’re seriously interested in the debates in modern physics, I wouldn’t rely on Michio Kaku, who is a populariser, not a leading string theorist by any means.

Instead, start off with The emperor’s new mind by Roger Penrose to get a grounding in relativity and quantum theory and then read The elegant universe by Brian Greene, the best popular introduction to string theory. Also, remember that this is a hotly debated field, with recent books by Peter Woit (Not even wrong) and Lee Smolin (The trouble with physics) opposing string theory for lack of testable propositions and stalled progress.

‘M-theory’, originally developed by Ed Witten, is not a particularly new theory, as stated by Alan Conchar (Letters, April 12). It’s been around since the 1990s and it’s unlikely to be “proven” soon, either by satellite evidence in 2012 or any other foreseeable experiment. At best, it’s possible that the proposed LISA satellite or the LIGO experiment may detect gravitational waves, which might offer clues to the existence of gravitons, a requirement of all string theories.

The Large Hadron Collider particle accelerator at CERN in Geneva may soon provide evidence of effects beyond the standard model of quantum chromodynamics (based on quarks). In particular, it may provide evidence of supersymmetric particles, a requirement of string theory, but not a direct proof. However, the scale and energy levels at which strings are supposed to operate is many orders of magnitude beyond the LHC and, indeed, close to the area where direct physical measurements become impossible due to the ‘planckian’ nature of matter.

The real goal is to develop a quantum theory of gravity, which would reconcile general relativity and quantum theory, descriptions of nature which are proven and correct within their own limits, but have mutually contradictory implications at the highest energy levels. A good starting point is the blog run by Sean Carroll and others, which has links to other useful science and physics blogs and resources.

I would also recommend Christoph Schiller’s very stimulating online physics text. This argues for a complete conceptual revolution in looking at the universe, although he won’t provide you with all the answers!

Alex Nichols
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