The aim of string theory is to seek the unification of quantum mechanics (the mathematical explanation for the behaviour of matter at the atomic and subatomic scales) and the general theory of relativity (the mathematical formulation of gravitation). String theorists say theirs is the best bet to correlate the physics of the very small and the physics of the very big. The quest is for a single formula, like Einstein’s E=mc^2, which is the unification of energy (E) and mass (m), showing they are essentially the same thing and can be converted into each other (c is the speed of light). Such a formula doesn’t exist for quantum mechanics and gravitation.
What feeds physicists’ optimism about arriving at such a formula is experience: Galileo and Newton unified rest and motion (the principle of inertia, or Newton’s first law of motion), Maxwell unified electricity and magnetism (Maxwell’s equations), and Einstein joined rest-and-motion with electricity-and-magnetism into the special theory of relativity.
Physics, in a nutshell, is about four fundamental forces — the strong nuclear force (which holds the nucleus of atoms together), the weak nuclear force (which determines radioactivity) the electromagnetic force (the force between charges and the magnetic force), and gravitation. String theory tries to reconcile gravitation with the other three fundamental forces.
But it does this on the basis of mathematical speculation and the arbitrary use of extra dimensions of space without any support of experiment.
The most common defence string theorists mount in defence of their hypothesis is that since its mathematical formulation is elegant and beautiful, it must be true. But as Smolin points out, the assertions of string theory are hardly testable because they emanate from a theory which comes in an infinite number of versions — all resulting from complex, esoteric maths.
“With such a vast number of theories, there is little hope that we can identify an outcome of an experiment that would not be encompassed by one of them. Thus, no matter what the experiments show, string theory cannot be disproved. But the reverse also holds: No experiment will ever be able to prove it true.”
In other words, string theory is ‘not even wrong’ — the name of Woit’s book and also blog, but originally a phrase coined by the physicist Wolfgang Pauli about scientific arguments which can be neither proved nor disproved by experiment.
Woit says: “In the case of string theory what gets obscured is that choosing an extra six dimensions introduces so much complexity and so many possibilities that the theory becomes useless.”
Science beyond logic
Smolin writes: “If string theorists are wrong... Theirs will be a cautionary tale of how not to do science, how not to let theoretical conjecture get so far beyond the limits of what can rationally be argued that one starts engaging in fantasy.”
An example of such fantasy is the anthropic principle, which says the universe is fine-tuned for the benefit of human life. Its chief proponent is Leonard Susskind, one of the founders of string theory. Susskind is an atheist, but is his theory any different from the theory of intelligent design, which says the universe is too complex to not have been made by a creator? One of the critics of the anthropic principle, the influential American evolutionary biologist, the late Stephen Jay Gould, said the theory seems to reverse known instances of cause-and-effect.
He said the theory is like saying ships were invented to house barnacles. Gould showed through compelling biological evidence that life adapted to the cosmos, to the laws of physics, and not the other way round.
When cricket creeps in
Salmon goes so far as to say that economists, physicists, and academicians from other disciplines wield mathematics inappropriately not just often, but almost always. One may take exception to such an extreme claim, but not if one is a cricket lover. Because whenever maths has been used to tinker with the game, the results have been ridiculous.
Take the Duckworth-Lewis method, for example. It is supposed to be a mathematically perfect way to set the target for the team batting second when a match is interrupted for reasons like inclement weather, but the targets thus set often seem to militate against commonsense.
Last month, two statisticians announced the result of a similar exercise to rank batsmen by factoring in the vagaries of cricketing eras, but it was so bizarre that it challenged sanity. While Donald Bradman emerged on top, Sachin Tendulkar was dumped deep, beyond even the figure that makes up the entire team line-up.
A mortal matter
The question arises, how can maths, the ‘queen of the sciences’ (as the ‘prince of mathematicians’ Carl Friedrich Gauss used to refer to it) get it so wrong sometimes. This cannot be answered unless one is able to understand what maths is. Reuben Hersh, co-author of the landmark book The Mathematical Experience and an emeritus professor at the University of New Mexico, says: “Mathematics is a science, like physics or astronomy; it constitutes a body of established facts, achieved by a reliable method, verified by practice, and agreed on by a consensus of qualified experts.
“But its subject matter is not visible or ponderable, not empirical; its subject matter is ideas, concepts, which exist only in the shared consciousness of human beings. Thus it is both a science and a ‘humanity’. It is about mental objects with reproducible properties.”
In the book, Hersh and co-author Philip J Davis, in answering how maths works and what gives it its power, demonstrate that “mathematical truth, like other kinds of truth, is fallible and corrigible”.
In short, maths is just another human pursuit — with warts and all. Maths, indeed, is much like love.
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