Physics Problems for the Next Mi

Physics Problems for the Next Millennium

In 1900 the world-renowned mathematician David Hilbert presented twenty-three
problems at the International Congress of Mathematicians in Paris. These
problems have inspired mathematicians throughout the last century. Indeed,
Hilbert's address has had a profound impact on the direction of mathematics,
reaching far beyond the original twenty-three problems themselves.
As a piece of millennial madness, all participants of the Strings 2000
Conference were invited to help formulate the ten most important unsolved
problems in fundamental physics. Each participant was allowed to submit one
candidate problem for consideration. To qualify, the problem must not only
have been important but also well-defined and stated in a clear way.

The best 10 problems were selected at the end of the conference by a
selection panel consisting of:

Michael Duff (University of Michigan)
David Gross (Institute for Theoretical Physics, Santa Barbara)
Edward Witten (Caltech & Institute for Advanced Studies)

Here are the problems:
Are all the (measurable) dimensionless parameters that characterize the
physical universe calculable in principle or are some merely determined by
historical or quantum mechanical accident and uncalculable?
David Gross, Institute for Theoretical Physics, University of California,
Santa Barbara

How can quantum gravity help explain the origin of the universe?
Edward Witten, California Institute of Technology and Institute for Advanced
Study, Princeton

What is the lifetime of the proton and how do we understand it?
Steve Gubser, Princeton University and California Institute of Technology

Is Nature supersymmetric, and if so, how is supersymmetry broken?
Sergio Ferrara, CERN (European Laboratory of Particle Physics)
Gordon Kane, University of Michigan

Why does the universe appear to have one time and three space dimensions?
Shamit Kachru, University of California, Berkeley
Sunil Mukhi, Tata Institute of Fundamental Research
Hiroshi Ooguri, California Institute of Technology

Why does the cosmological constant have the value that it has, is it zero and
is it really constant?
Andrew Chamblin, Massachusetts Institute of Technology
Renata Kallosh, Stanford University

What are the fundamental degrees of freedom of M-theory (the theory whose low-
energy limit is eleven-dimensional supergravity and which subsumes the five
consistent superstring theories) and does the theory describe Nature?
Louise Dolan, University of North Carolina, Chapel Hill
Annamaria Sinkovics, Spinoza Institute
Billy & Linda Rose, San Antonio College

What is the resolution of the black hole information paradox?
Tibra Ali, Department of Applied Mathematics and Theoretical Physics,
Cambridge
Samir Mathur, Ohio State University

What physics explains the enormous disparity between the gravitational scale
and the typical mass scale of the elementary particles?
Matt Strassler, Institute for Advanced Study, Princeton

Can we quantitatively understand quark and gluon confinement in Quantum
Chromodynamics and the existence of a mass gap?
Igor Klebanov, Princeton University
Oyvind Tafjord, McGill University

These ten questions were presented by David Gross at the closing of the
conference on Saturday July 15, 2000.