SEMINAR: The sound of a vase, and the quantum universe

The two deepest theories of nature, quantum theory and general relativity, long considered esoteric, are nowadays at the heart of everyday life, for example in all sorts of electronics and in GPS geo- location.

New areas of applications, such as quantum biology, quantum computing and quantum communication via satellites are on the horizon, and they too have the potential to change our lives.

Not all is well with these two theories, however: While general relativity is great for understanding the universe on big scales, it describes atoms incorrectly. Quantum theory gets atoms right but it cannot correctly describe the expansion of the universe.

Much effort is therefore going into the development of one unifying theory of “quantum gravity” that applies in all circumstances. These studies concern the deepest mysteries of nature. For example, the universe is thought to have arisen from a quantum fluctuation and it is likely that the fabric of spacetime still continually somewhat vibrates due to small quantum vacuum fluctuations.

Along the way, studies into these questions produce surprising mathematical side results. For example, as I will explain, it recently turned out that the mere sound of a vibrating object such as that of a vibrating vase can give away all details of the shape of the vase.

Achim Kempf is a professor in the Departments of Applied Mathematics and Physics at the University of Waterloo (near Toronto) in Canada. He studied physics in Germany, at the Universities of Heidelberg, Karlsruhe and Munich, obtaining his Ph.D. in 1993. From 1993 to 1998 he was a postdoc and a College Research Fellow at the University of Cambridge. He then spent three years as an IFT postdoctoral fellow at the University of Florida until he joined the faculty at the University of Waterloo (UW) in 2001. He is an associate member of the Institute for Quantum Computing at UW and he is an affiliate member of the Perimeter Institute for Theoretical Physics. Since 2004, he has held the Canada Research Chair for the Physics of Information.

Professor Kempf’s main research interest is the study of the interplay of information theory, quantum theory and general relativity. He showed that spacetime could be simultaneously continuous and discrete in the same way that information can be. His research interests also include inflationary cosmology as well as high temperature superconductors. He holds a patent related to data compression and has a patent on radar-related methods pending. He has also published in Mathematical Biology on the use of information theoretic methods in the study of the origin of life.