I will give a talk on Monday at Boston University’s Center for Philosophy and History of Science, where we will celebrate the 40th Anniversary of the First Osgood Hill Conference on Quantum Gravity. This will be a fun event, with talks by John Stachel, Roger Penrose, George Ellis, Giovanni Amelino-Camelia, and Tian Yu Cao, among others.
Here is the abstract for my talk, entitled ‘The problem of space in quantum gravity’:
There is, of course, the well-rehearsed problem of time (and change) in canonical theories of quantum gravity. Within the strictures of these approaches, the problem of time states that if we only accept a few seemingly innocuous assumptions, then we are forced into accepting that, fundamentally, there cannot be time, or at least that there cannot be genuine change. In this talk, I will suggest that in some approaches to quantum gravity, an analogous, though perhaps less severe, problem of space arises from similarly defensible assumptions. ‘Space’ in quantum gravity, it turns out, lacks quite a bit of the structure we normally attribute to it. In particular, I will consider two programs in quantum gravity–loop quantum gravity and causal set theory–in order to make this point evident. I do this by showing how what can reasonably be interpreted as that which corresponds to, or gives rise to, ‘space’ lacks several of what are naturally taken to be essential properties of physical space.