Witten is a professor at the Institute for Advanced Study at Princeton, where Einstein worked from 1933 until his death in 1955. He is the leading exponent of “M theory,” a version of string theory that claims to provide a “unified” account of the fundamental structure of physical reality (or of what Witten calls the “multiverse,” which extends beyond the observable universe). In 2014, physicists Peter Woit and Paul Steinhardt criticised the model as “immune to experimental and observational tests.” Witten hit back, telling Scientific American that string theory remains “on the right track” and that, in any case, “the universe wasn’t made for our convenience.”
Physics Titan Edward Witten Still Thinks String Theory “on the Right Track”
Interview with Witten about his continued support for string theory, by John Horgan.