Science and Global Security (sciencesecurity) wrote,
Science and Global Security
sciencesecurity

How Many p-Branes Can Stand On The End Of A Pin?



The local "news pictorial" The Herald-Sun once carried this picture with the caption "Einstein calculates the density of the Milky Way". This had me wallowing in laughter for like ages...Einstein here is writing down the field equations of General Relativity and that looks awfully like the Riemann curvature tensor...

How many p-branes can stand on the end of a pin?

Generally speaking whenever we see collective irrationality we know that we are going to need the tools of the "sociology of knowledge" in order to discern the hidden institutional and social interests that underlies it. This is not a universal rule. For example, collective irrationality can arise because of mysticism and various crazed cultish forms of belief but for the most part in the modern world irrationality pays, for someone at least.

The key form of irrationality that interests us is the widespread upholding of systems of belief in the intellectual world that completely fly in the face of empirical reality.

The sociology of knowledge has come to be associated with the "strong programme" which asserts that knowledge is a social convention. This is unfortunate because the "strong programme" is a mere collection of poly-syllabic discourse and fashionable nonsense. It is fashionable because its presence is ubiquitous in the social sciences and humanities and nonsense because here the real world, or should we say "real world", is but a trifling which we can safely be ignorant of.

The sociology of knowledge works when we ignore the fashionable nonsense and concentrate on the empirical study of why systems of irrational belief come to be upheld on a collective basis. It is an interesting self-referential paradox for adherents to the "strong programme" and "social constructivism" that their school of thought is a classic case of collective irrationality.

But can collective irrationality also be displayed in the hard sciences? Sure, Isaac Newton spent much of his time on mysticism and alchemy. Albert Einstein spent many years on a futile attempt at "unified field theory" through refined mathematics whilst all around him physicists were working on developing new theoretical insights in conjunction with experiment. We have seen the saga over cold fusion, fraud in nanotechnology research and so on.

But these are not really collective forms of intellectual mania.

Collective irrationality in the sciences is usually seen as a feature of totalitarian regimes. For instance during the Stalin era we had the Lysenko affair in biology, "Aryan physics" in Nazi Germany and mad "Mao Tse Tung Thought" style particle physics during the cultural revolution. Sometimes, funny enough, this type of collective irrationality can work. For instance a group of Japanese physicists, who tried to prove Karl Marx's philosophy of "dialectical materialism", actually made some important discoveries in our understanding of the strong nuclear force in the 1950s but alas they went off the rails thereafter.

But could we be going a through a period of collective irrationality right now in physics, the queen of the sciences? If so, what would that tell us about knowledge and the university?

One of the enduring goals of theoretical physics is the marriage of Einstein's general theory of relativity, a theory of gravity, with quantum mechanics which accounts for the microworld. It is hoped that the consummation of this marriage, quantum gravity, would unify physics and provide us with new insight into the underlying laws of nature. Some even hold out the promise of a "theory of everything" following unification.

But the problem here has been a most calamitous and rocky courtship. Every attempt at unification resulted in ugly mathematics that spewed out nonsense and anomalies including particles that travel faster than light and too many predictions of infinite physical quantities. Even Dexter with his compatibility algorithm in Perfect Match would be struggling.

Without any shadow of a doubt the most popular theory that promises to deliver the unification of physics is what is called "superstring theory". Superstring theory has had a very long and torturous history but essentially the premise is that the physical world, including spacetime, is fundamentally composed of strings and membranes, such as D-branes and p-branes. Those who follow popular science would be familiar with the theory for it is truly remarkable to observe how many books, magazine articles, TV documentaries and Radio shows have been produced that attempt to explain the promise and hidden intricacies of the theory. For a theory still in development this is surely unprecedented and it would be interesting to inquire to what extent public rapture has played in the fortunes of the theory.

To be sure superstring theory is noted for its mathematical elegance and in fact has prompted important new developments in pure mathematics. But it appears that string theorists are collectively making the same mistake as Einstein in his latter years.

It is not the only theory that promises to deliver new theoretical insight. There are others such as twistor theory, loop quantum gravity, canonical quantum gravity and so on. But if we measure the amount of papers that have been written we see that superstring theorists are by far the most productive. That's because there are so many of them. Needless to say at the popular level the alternatives have hardly been given the limelight.

But superstring theory comes at a price. To be mathematically consistent we must assume that spacetime has many dimensions. First it was 26 dimensions. Then mercifully it went down to 10 dimensions. It now stands at 11. The obvious paradox is explained away by simply assuming that all those extra dimensions that we do not perceive are hidden in tiny, tiny topological spaces. The theory in some guises has predicted a kind of "shadow matter" that mirrors the ordinary matter that we are familiar with.

It also has many "solutions". This means that the theory requires more universes than our own. For a theory purporting to be a "theory of everything" we seem to have an embarrassment of riches. The embarrassment is explained by invoking the "anthropic principle". It is asserted that our particular universe takes a physical form consistent with the evolution of observers. Because we are here our universe is a life consistent solution to the theory. This is a sloppy way to do the unification of physics. In essence the theory of everything has become a theory of nothing precisely because there is too much of everything.

Superstring theory, since the 70's!, has made precisely zero verifiable predictions. To be sure it has made a number of "postdictions". For instance in a particularly celebrated result amongst string theorists, the theory was used to derive Stephen Hawking's equation on radiating Black Holes. But alternative conceptions of general relativity from Einstein's can postdict Newton's law of universal gravitation. So what?

What this all means is that progress in superstring theory is being conducted without reference to empirical reality, like "postmodernism" in the humanities. In the 1980s the leading theorist explained this by stating that superstring theorists are doing 21st century physics with 20th century mathematics. But it's 2008 already. It is also argued that the theory operates at energy levels far beyond current experimental technologies. However most of the work in classical general relativity occurred in similar circumstances but this did not prevent progress that was founded on solid ground.

In fact, we know that the expansion of the universe is accelerating. This expansion is consistent with a small but albeit non-zero value for the cosmological constant. This was introduced by Einstein into his field equations of general relativity to preserve a non-expanding universe, the widespread belief at the time, and so is a kind of anti-gravity. Einstein subsequently went on to describe this as the greatest mistake of his life after the static universe was exploded by Edwin Hubble.

Current theory has problems with a small cosmological constant because quantum theory predicts a value for the constant way at odds with observation. Einstein himself famously viewed quantum mechanics with more than a little contempt. It would be ironic if his greatest mistake should be the undoing of quantum theory. Needless to say, string theorists need another "postdiction". In fact the "super" in superstring comes from what is called supersymmetry and the small cosmological constant seems incompatible with supersymmetry.

Richard Feynman is reputed to have remarked of superstring theorists that they "don't make predictions, they make excuses". One excuse for the small cosmological constant involves all those universes. It is said that different universes have different values for the constant and a small one is compatible with life. It thereby follows that we observers must be in a universe where the value for the constant is small. So again we have the anthropic principle. In other words, Feynman was spot on.

Fundamental new science occurs when an experimental anomaly cannot be explained by current theory. This is how the scientific revolution began with Copernicus and quantum physics was ushered in by trying to explain blackbody radiation. The accelerating expansion of the universe appears to be our experimental anomaly perhaps requiring us to have a fundamental re-look at both of our most cherished physical theories. If only the horde of bright theorists were concentrating on this universe instead of all those other universes we might get somewhere.

A small, but growing, number of critics, have made these points in relation to superstring theory. In other words we may very well be witnessing a form of collective irrationality in the most basic and fundamental of the sciences. If so, then the sociology of knowledge would be the appropriate tool to account for this. Such a study has not been attempted but it may tell us a lot about the nature of science and the university system in the context of funding constraints.

It is true that it is easier to get a job or get on the box doing superstring theory than any of the rival approaches. If we look at superstring theory and cults in the humanities it might be appropriate to conclude that it is the university itself with the dual emphasis on quantity of publications and citations combined with the gravitational effect that intellectual celebrity has on university funding levels that is helping to block intellectual progress . In the humanities irrationality has now reached the level of scandal.

Ultimately, the purpose of the university is to advance human knowledge and if current structure is helping to hinder this then reform is needed.
Tags: lofty thoughts
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