"STRING" "THEORY"

String theory, also known by names such as "superstring theory" and sometimes "M-theory", is an idea that has been around for a rather long time, over two decades.

The discovery of string theory as a potential unified theory was something of an accident. In a context unrelated to the unification of forces, researchers in the 1970's wondered what theory one might be able to write down to describe a fundamental quantum string -- an object with a finite spatial extent, which could not be described in terms of deeper constituents. It was certainly an interesting new mathematical problem in a physical context.

Such a string would be described classically by giving the location of an object extended like a (straight or curved) line in space at a given time. The string could be closed, like a loop, or open, with two end points