George Ellis at 70
Quantum Field Theory and General Relativity are among the most impressive of human achievements of the 20th century. Within its own domain, each theory has been remarkably successful, with agreement between theoretical predictions and experiments at the one-part-per-billion level in some cases. Yet, even after almost a century and a clear underlying theme - that of a fundamental length scale limiting the resolution of spacetime - a clear unifying theoretical framework within which both theories might be reconciled is still sorely lacking.
While several promising proposals - including String theory and Supergravity,
Loop Quantum Gravity, Causal sets, Regge calculus and Dynamical triangulations
- have emerged with varying degrees of success, none can yet claim to be an unequivocal solution to the problem of quantum gravity complete with experimental predictions. The fundamental principles of the best solution are in dispute, and even the form of quantum theory that should be utilized in this context is not clear. One of the key issues is the foundational nature of space and time; and even here there is no agreement. It is becoming increasingly clear that the fundamental principles and essential progress of each research program are in need of review in a comparative context.
While review meetings in quantum gravity are certainly not new, most are dominated by one specific research direction. This is where this meeting is markedly different. The aim of this week-long workshop is to bring together experts in each of the major representative approaches toward quantizing gravity, to critically and openly discuss the successes and failures of each approach and on that basis to consider pointers towards a satisfactory resolution.