John Donoghue: We Have Already Quantized Gravity (And It Works)

John Donoghue· Guest0:00

I think the popular phrasing is totally wrong. Quantum physics and gravity go perfectly well, as well as any other theory that we know about. One of the biases of the field is that things unify, and we don't really have any evidence for that. I'm actually a champion of a crazier theory.

Curt Jaimungal· Host0:17

[upbeat music] You've heard it before, quantum theory and general relativity are fundamentally incompatible. But is that actually true, or is it something we just say so often we start to believe it? Professor John Donoghue thinks this entire framing is misleading. Gravity is a field, the metric, so you quantize it like QCD. In fact, Feynman and DeWitt did exactly that several decades ago. So what's the actual problem? Donoghue argues it's hidden assumptions. Perhaps something like causality, supersymmetry, or grand unification, even so-called naturalists could be a human bias rather than an objective law. Today, we delve into quadratic gravity theory and another more speculative theory called random dynamics. On this channel, my name's Curt Jaimungal, and I interview researchers about their theories of reality, most often in physics, and today's a particularly technical talk, so be prepared. I'm excited because you'll see why John Donoghue is a legend in the subject of gravity and its quantization. We'll delve into effective field theory and learn why this professor's judicious restraint unnerves his colleagues. Professor