Like many a maturing beauty, string theory has gotten rich in relationships, complicated, hard to handle and widely influential. вЂњWeвЂ™ve been trying to aim for the successes of the past where we had a very simple equation that captured everything,вЂќ said Robbert Dijkgraaf, the director of the Institute for Advanced Study in Princeton, New Jersey. Coming off the momentum of completing the solid and powerful вЂњstandard modelвЂќ of particle physics in the 1970s, they hoped the story would repeat - only this time on a mammoth, all-embracing scale. Many, in retrospect, realized they had raised the bar too high. вЂњThe last 20 years have really been a great extension of theoretical tools, but very little progress on understanding whatвЂ™s actually out there.вЂќ вЂњAfter a certain point in the early вЂ™90s, people gave up on trying to connect to the real world,вЂќ Gross said. The complexities of string theory, all the possible permutations, refused to reduce to a single one that described our world. вЂњWe even thought for a while in the mid-вЂ™80s that it was a unique theory.вЂќДЄnd then physicists began to realize that the dream of one singular theory was an illusion. A moment,вЂќ said David Gross, an original player in the so-called Princeton String Quartet, a Nobel Prize winner and permanent member of the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara. No one knew just how the dimensions were compactified - the possibilities for doing so appeared to be endless - but surely some configuration would turn out to be just what was needed to produce familiar forces and particles.ДЇor a time, many physicists believed that string theory would yield a unique way to combine quantum mechanics and gravity. These dimensions were folded in on themselves - or вЂњcompactifiedвЂќ - into complex origami shapes. The strings were too small to be probed by experiment and lived in as many as 11 dimensions of space. To be sure, the theory came with unsettling implications. At last, it seemed, here was a workable theory of quantum gravity.Д®ven more beautiful than the story told in words was the elegance of the math behind it, which had the power to make some physicists ecstatic. For one, quantum uncertainty couldnвЂ™t rip space-time to shreds. Avoiding the infinitely small meant avoiding a variety of catastrophes. The vibrations would sing out quarks, electrons, gluons and photons, as well as their extended families, producing in harmony every ingredient needed to cook up the knowable world. It seemed, to paraphrase Michael Faraday, much too wonderful not to be true: Simply replace infinitely small particles with tiny (but finite) vibrating loops of string. String theory strutted onto the scene some 30 years ago as perfection itself, a promise of elegant simplicity that would solve knotty problems in fundamental physics - including the notoriously intractable mismatch between EinsteinвЂ™s smoothly warped space-time and the inherently jittery, quantized bits of stuff that made up everything in it.

String theory not even wrong