Edward Witten How Do Scientific Breakthroughs Happen Asymptotic freedom the last big breakthrough was discovered by Gross Wilcheck and Pulitzer just before I started my graduate school It took me a year to understand what was happening in the world of physics The standard model involved new mathematics unfamiliar to both physicists and mathematicians at the time and whose exploration proved to be very rich The standard model is based on a nonlinear version of Maxwell s equations where two waves interact I and scatter each other but cannot be treated classically the way light waves can be treated so it has to be treated quantum mechanically In 1976 right after I finished my graduate school there was a breakthrough in the math of nonbillion gauge theOry applied to these strong interactions In 1982 and 1 983 John Schwartz Michael Green and Lars Brink made enough progress in string theory that I started to take their work seriously though I knew it was a long term proposition In 1984 a colleague who had just returned from Aspen mentioned the development that had been achieved and at that instant I knew I would be working on string theories because it was like magic The breakthroug h of Green and Schwartz in August I 984 made the difficulties in elementary particle physics go away It had a huge impact on me and I was sure that my interest would never be the same again By the mid 1980s I had caught up to where others were As a graduate student I was obsessed with the fact that the equations of the Standard Model are challenging to solve because the quantum effects are significant In 1994 Cyborg and I collaborated on an interesting instance of what people in the physics and mathematics fields call Cyborg written theory The equations of the Standard Model are tough to solve because quantum effects are large and it proved to be particularly captivating The story that I presented in a lecture at USC University of Southern California in 1995 where I sort of unified the string theories really resulted from an attempt to disprove some of them In 1 995 I was successful in doing something similar fOr string theory I tried to somet hing simi ar tor string theory I tried to educe the number at string theories by showing that some were inconsistent