Colloquia

I describe some of the things we think we know about the physics of a hot quark-gluon plasma and the phase transition between the stuff of the big bang and ordinary hadronic matter. The questions I will pose motivate people to collide heavy ions at relativistic energies. I will give two examples of how we may use measurements made in these experiments to map the QCD phase diagram, and hence to study the condensed matter physics of QCD.