To get the string of string theory, you have to imagine taking a violi — Paul Townsend

"To get the string of string theory, you have to imagine taking a violin string and just keep pulling on the two ends. Now, if you keep pulling, what happens of course is that the waves on the string move along at a certain speed which depends on the tension with which you pull it. And if you keep pulling on the violin string of course a real one will break. But if you imagine that you keep pulling, then at some point the speed of the waves on the string will increase indefinitely. But not of course indefinitely because theres a fundamental limit which is the speed of light. So when youve reached the point where you pull on your violin strings and youve stretched it to the point where actually the waves on it are now moving at the speed of light, then you have a very strange material and that material is the string of string theory. In a way the branes are essentially the same material but just more extended."