The debates over string theory represent fundamental differences in how to view science. Many people have proposed ideas about what the goals of science should be. But over the years, science changes as new ideas are introduced, and it’s in trying to understand the nature of these changes where the meaning of science really comes into question.
The methods in which scientists adapt old ideas and adopt new ones can also be viewed in different ways, and string theory is all about adapting old ideas and adopting new ones.
The interplay between experiment and theory is never so obvious as in those realms where they fail to match up. At that point, unless the experiment contained a flaw, scientists have no choice but to adapt the existing theory to fit the new evidence. The old theory must transform into a new theory. The philosopher of science Thomas Kuhn spoke of such transformations as scientific revolutions.
In Kuhn’s model (which not all scientists agree with), science progresses along until it accumulates a number of experimental problems that make scientists redefine the theories that science operates under. These overarching theories are scientific paradigms, and the transition from one paradigm to a new one is a period of upheaval in science.
In this view, string theory would be a new scientific paradigm, and physicists would be in the middle of the scientific revolution where it gains dominance.
A scientific paradigm, as proposed by Kuhn in his 1962 The Structure of Scientific Revolutions, is a period of business as usual for science. A theory explains how nature works, and scientists work within this framework.
Kuhn views the Baconian scientific method — regular puzzle-solving activities — as taking place within an existing scientific paradigm. The scientist gains facts and uses the rules of the scientific paradigm to explain them.
The problem is that there always seems to be a handful of facts that the scientific paradigm can’t explain. A few pieces of data don’t seem to fit. During the periods of normal science, scientists do their best to explain this data, to incorporate it into the existing framework, but they aren’t overly concerned about these occasional anomalies.
That’s fine when there are only a few such problems, but when enough of them pile up, it can pose serious problems for the prevailing theory.
As these abnormalities begin to accumulate, the activity of normal science becomes disrupted and eventually reaches the point where a full scientific revolution takes place. In a scientific revolution, the current scientific paradigm is replaced by a new one that offers a different conceptual model of how nature functions.
At some point, scientists can’t proceed with business as usual; they’re forced to look for new ways to interpret the data. Initially, scientists attempt to do this with minor modifications to the existing theory. They tack on an exception here or a special case there. But if there are enough anomalies, and if these makeshift fixes don’t resolve all the problems, scientists are forced to build a new theoretical framework.
In other words, they are forced not only to amend their theory, but to construct an entirely new paradigm. It isn’t just that some factual details were wrong, but their most basic assumptions were wrong. In a period of scientific revolution, scientists begin to question everything they thought they knew about nature.