Last century, two great revolutions dominated our thinking about the fundamental nature of the universe: quantum theory and relativity. John Baez : mathematical physicist who introduced the notion of spin foam in loop quantum gravity a term originally introduced by Wheeler. Scientists such as Rana Adhikari, professor of physics at Caltech, think the space we live in may not be perfectly smooth but rather made of incredibly small discrete units. Olga Papadoulaki. Read more. Create new account.