by Peter Woit
Physics has become obsessed with strings, branes and multiple dimensions, yet the big questions remain fundamentally unanswered. Has the time come to admit these wild conjectures have failed, and move on?
What neither my fellow student nor I would ever have guessed during our graduate student days was that, in our middle age some 25 years later, we'd be no closer to answering any of these questions, and ever more speculative attempts to find such answers would have taken on some of what used to be the characteristics of the fringes of science.
FUNDAMENTAL PHYSICS now finds itself in a
historically unprecedented situation. The multi-decade dominance of
string theory, along with its extremely speculative research into the
implications of exotic scenarios far removed from any hope of
testability, has changed the subject in dramatic and fundamental ways.
What used to be considered part of the dubious fringes of science
has now become institutionalised within the mainstream. In physicist
Lee Smolin's recent book, The Trouble With Physics, he characterises
the current sociology of the field as dominated by 'groupthink', with
too few physicists willing to admit how far off the tracks things have
gone. The nearly infinite complexity of string theory, M-theory,
branes, higher dimensions and the multiverse has led to a vast number
of possible challenging calculations for people to do to keep
themselves busy, all embedded in a mathematical structure far too
poorly understood to ever lead to definitive, falsifiable predictions.
The problems of the Standard Model that faced my colleague and I a
quarter of a century ago continue to inspire new generations of young
theorists to devote their lives to work that might some day lead to
real progress. But these problems remain extremely difficult ones, and
we have little in the way of promising ideas, with far too much effort
going into the evasion of difficulties and the pursuit of the chimera
of unification through ever more complex higher dimensional
constructions inspired by string theory.
The hopes of particle theorists now rest on the efforts of
experimentalists hard at work at the Large Hadron Collider near Geneva.
Perhaps within the next few years they will report new results that
will finally provide the right hints about how to move forward in the
right direction, leading most people to abandon unsuccessful ideas. If
the Standard Model continues to hold, particle physicists will be in a
difficult spot, one that will require them to find ways to both
acknowledge the failure of some well-entrenched speculative research
programs, and encourage ambitious young theorists to take chances and
try to find new, more promising ones.
Whole article: http://www.cosmosmagazine.com/node/1756