Colloquium

Some of the speculations on new physics, beyond what is in the standard model are reviewed. Particular attention is paid to ideas that try to address the hierarchy puzzle, i.e., why is the weak scale so much smaller than the Planck scale. These new theories will be tested at the large hadron collider in the near future.

Experimentalists at the Relativistic Heavy Ion Collider create exploding droplets of quark-gluon plasma, the stuff which filled the universe for the first microseconds after the big bang. I'll give one theorist's perspective on what we are learning about the properties of quark-gluon plasma from these experiments, including the conclusion that it is closer to an ideal liquid than to an ideal gas and the observation that it "quenches" high energy quarks ("jets") trying to plow through it.

With a cosmic flight simulator, we'll take a scenic journey through space and time. After exploring
our local Galactic neighborhood, we'll travel back 13.7 billion years to explore the Big Bang itself and
how state-of-the-art measurements are transforming our understanding of our cosmic origin and ultimate fate.
We then turn to the question of whether this can all be described purely mathematically, and discuss
implications ranging from standard physics topics like symmetries, irreducible representations, units,

If spacetime is "quantized" (discrete), then any equation of motion compatible with the Lorentz transformations is necessarily non-local. I will present evidence that this sort of nonlocality survives on length scales much greater than Planckian, yielding for example a nonlocal effective wave-equation for a scalar field propagating on an underlying causal set. Nonlocality of our effective field theories may thus provide a characteristic signature of quantum gravity.