The latest issue of New Scientist has an article entitled Nobel Laureate Admits String Theory is in Trouble. It describes remarks by David Gross at the recent Solvay conference in Brussels, mentioned here earlier.
Gross described the current state of string theory as “We don’t know what we are talking about”, and also admitted:
“Many of us believed that string theory was a very dramatic break with our previous notions of quantum theory,” he said. “But now we learn that string theory, well, is not that much of a break.”
He said the field was in “a period of utter confusion”, and compared the current situation to that at in 1911, at the time of the first Solvay conference, when no one had any idea what was causing radioactivity.
“They were missing something absolutely fundamental,” he said. “We are missing perhaps something as profound as they were back then.”
The same issue of New Scientist also has an editorial on the subject entitled Physics’ greatest endeavour is grinding to a halt, which ends as follows:
For decades, string theorists have been excused from testing their ideas against experimental results. When astronomers discovered the accelerating expansion of the universe, which string theory fails to account for, many string theorists took shelter in a remarkable excuse: that their equations describe all possible universes and should not be tied to matching data in just one of them.
But when the theory does not match the one data set we have, is it science? There is a joke circulating on physics blogs: that we can, after all, call our universe unique. Why? Because it is the only one that string theory cannot describe. Should we laugh or cry?
There is a growing feeling that string theory has run into the sand. Gross thinks we are missing something fundamental. We need a leap in understanding, though where it will come from is not clear. Many of the greatest minds in physics were there at last week’s conference, and none had an answer.
We are approaching the end of Einstein’s centennial year – a celebration of physics. While some lesser-known areas of the subject are flourishing, the search for a theory of everything is in a sorry state. Unless string theory gets a radical shake-up, gifted but frustrated minds will begin to drift into other areas of science. And if that is what makes biology the subject of the century, it will be depressing reason indeed.
Update: Lubos Motl has some comments on this. He compares the current devastation of string theory to the effects of hurricane Katrina and me to an Islamic extremist, while arguing against the terrible danger to physics if all this leads to study of a “diversity of approaches” other than string theory.
Update: Gross now claims his words were misinterpreted.