Department of Mathematics, Macquarie University Mathematics Colloquium Lecture Monday 6 February 2012 at 1pm in E7B T2 Speaker: Professor John Baez, University of California, Riverside Title: Probabilities versus Amplitudes Abstract: Some ideas from quantum theory are just beginning to percolate back to classical probability theory. For example, there is a widely used and successful theory of "chemical reaction networks", which describes the interactions of molecules in a stochastic rather than quantum way. If we look at it from the perspective of quantum theory, this turns out to involve creation and annihilation operators, coherent states and other well-known ideas - but with a few big differences. The stochastic analogue of quantum field theory is also used in population biology, and here the connection is well-known. But what does it mean to treat wolves as identical bosons? ============================================================== About the speaker: ============================================================== Amongst other things, Professor John Baez is famous for his ability to explain in an understandable way the latest developments in mathematics and physics. The following background is adapted from the Wikipedia page <http://en.wikipedia.org/wiki/John_C._Baez >. Born in 1961, John Baez is an American mathematical physicist and a professor of mathematics at the University of California, Riverside. He is known for his work on spin foams in loop quantum gravity. More recently, his research has focused on applications of higher categories to physics. On 14 January 2010 Baez announced that he was leaving categorical mathematical physics. He said "I want to shift the focus of my research away from fancy abstract n-categorical math to slightly more practical things. My job at the Centre for Quantum Technologies (National University of Singapore) will give me a chance to explore computer science, microtraps, and quantum optics. What I really want to do is help save our beleaguered planet." Baez is also known to science fans as the author of This Week’s Finds in Mathematical Physics, an irregular column on the internet featuring mathematical exposition and criticism. He started This Week’s Finds in 1993 for the Usenet community, and it now has a worldwide following in its new form, the blog "Azimuth". This Week’s Finds anticipated the concept of a personal weblog. Additionally, Baez is known on the World Wide Web as the author of the crackpot index. Yes, and before you ask, the famous singer and progressive activist Joan Baez is his cousin (her father, physicist Albert Baez, was his uncle). ============================================================== In February, Professor Baez will be visiting the Centre for Australian Category Theory (CoACT) at Macquarie University for research purposes and to treat us to three lectures: 1. Mathematics Colloquium entitled "Probabilities versus Amplitudes", of interest to many people in the Faculty of Science, 1pm Monday 6 February 2012, in E7B T2; 2. Lecture: "Energy, the Environment and What We Can Do", of general interest, 1pm Tuesday 7 February 2012, in E7A T2; 3. Australian Category Seminar: "Symmetric Monoidal Categories in Chemistry and Biology", of more specialized interest, 2pm Wednesday 8 February 2012, in E7A 333.