Physics & Astronomy Colloquium – Steven Carlip

Speaker: Steven Carlip , University of California, Davis

Title: The Small Scale Structure of Spacetime

Abstract: The general theory of relativity tells us that what we call gravity is really a manifestation of the geometry of space and time. The 100-year-old unsolved problem of quantum gravity is to understand the structure of this spacetime at the smallest scales.

Several recent lines of evidence hint that spacetime at very small distances may undergo “spontaneous dimensional reduction,” behaving as if it had only two dimensions rather than four. I will summarize some of the evidence for this strange behavior, complete with a few pictures of quantum fluctuations of spacetime, and talk about what it means for “dimension” to be a physical observable. Although the scales involved are tiny — a billionth of a billionth of the size of a proton — it is conceivable that this effect could be measurable; I’ll talk about that possibility, and what it would mean for physics.

Speaker Biography:

• BA — Harvard College, Cambridge, MA, 1975
• Ph.D., University of Texas, Austin, 1987 (adviser: Bryce DeWitt).
• Postdoctoral Researcher, The Institute for Advanced Study, 1987-1990
• Faculty member, University of California, Davis, 1990-Present
• Research Interests: quantum gravity; classical general relativity; theoretical particle physics; mathematical physics
• Selected honors:
  • Fellow, American Physical Society
  • Fellow, Institute of Physics (UK)
  • Editorial Board member, Proceedings of the Royal Society of London
  • Divisional Associate Editor, Physical Review Letters
  • Advisory Panel member, Classical and Quantum Gravity
  • Kramers Professor, Utrecht University, 2007
  • Member, Nominating Committee, International Society on General Relativity and Gravitation,2004-09
  • Member, Executive Committee, American Physical Society Topical Group in Gravitation, 1998-2001
  • Editorial Board member,Classical and Quantum Gravity, 1995-2004
  • National Science Foundation Young Investigator Award (NYI), 1993
  • Department of Energy Outstanding Junior Investigator Award, 1991
  • Referee for about 35 different physics journals
  • Grant reviewer for national science agencies of nine countries

Department Website on Prof. Carlip

Prof. Carlip’s Personal Website

Video: Prof. Carlip’s Talk on Black Holes and Quantum Gravity at SETI Institute (2013)