Wikipedia summarises String theory as an active research mathematical framework
in particle physics that attempts to reconcile quantum mechanics and general relativity (GR). It is a contender for the theory of everything (TOE), a manner of describing the known fundamental forces and matter in a mathematically complete system. The theory has yet to make testable experimental predictions, leading some to claim that it cannot be considered a part of science. Critics say string theory is a failure as a theory of everything. Some common criticisms include: ## very high energies needed to test quantum gravity ## lack of uniqueness of predictions due to the large number of solutions ## lack of background independence.
—– Lee Smolin The Trouble with Physics, the Rise of String Theory, the Fall of a Science, and What Comes Next, Houghton Mifflin Harcourt, 2006
“The string theories we know how to study are known to be wrong. Those we can’t study are thought to exist in such vast numbers that no conceivable experiment
could ever disagree with all of them.”
String Theory… rests on several key conjectures, for which there is some evidence but no proof. …worse, we.. do not know whether there is a complete and coherent theory that can even go by the name of ‘string theory’:
… a large collection of approximate calculations (plus) a web of conjectures that if true point to the existence of a theory.
… never written down, we don’t know its fundamental principles, we don’t know what
mathematical language to use.
—– Brian Greene: The Fabric of the Universe 2004; professor and co-director of Columbia’s Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP)
… most string practitioners believe we still don’t have a comprehensive answer to
the rudimentary question: What is string theory?
… most researchers feel that our current formulation of string theory stlll lacks the
kind of core principles we find at the heart of other major advances.
—– Gerard ‘t Hooft (physicist) In Search of the Ultimate Building Blocks Cambridge 2006
“I would not be prepared to call string theory a ‘theory’, rather a ‘model’ or not even that: just a hunch.”
—– Lisa Randall (String physicist, Professor Harvard): Designing Words, 2006, in John Brockman (ed.) Intelligent Thought: Science Versus the Intelligent Design Movement, published by Vintage Books.
defines a theory as: “a definite physical framework embodied in a set of fundamental assumptions about the world – and an economical framework that encompasses a wide variety of phenomena. A theory yields a specific set of equations and predictions that are borne out by successful agreement with experimental results.
—– Peter Woit (former theoretical physicist) 2006. Not Even Wrong: The Failure of String Theory & the Continuing Challenge to Unify the Laws of Physics, Jonathan Cape. Blog – Not Even Wrong http://www.math.columbia.edu/~woit/wordpress/
“…. there is absolutely no evidence whatsoever for this complex and unattractive conjectural theory. There is not even a serious proposal for what the dynamics of
the fundamental ‘M-theory’ is supposed to be or any reason at all to believe that its dynamics would produce a vacuum state with the desired properties. The sole argument generally given…. is that perturbative string theories have a massless spin two mode and thus could provide an explanation of gravity, if one ever managed to find an underlying theory for which perturbative string theory is the perturbative