Heck, many of the doubts and questions raised there are commonly held among string theorists. (The days of people exclaiming "We're going to unify physics withi

Heck, many of the doubts and questions raised there are commonly held among string theorists. (The days of people exclaiming "We're going to unify physics within a few years!" are at least two decades behind us.) In my experience, string theorists do consider those issues significant, but not problematic enough to make them uneasy about the theory as a whole. As a string theorist, the thing that bugs me about this dialog is mostly that the string theorist character is so befuddled by relativity. I'm sure there must be real string theorists out there who are confused by the difference between "general relativity" and "quantum fields in curved spacetime" or who don't understand that GR introduces subtleties with things like globally defined time coordinates, but I've never met one (at least not to know it). And it's bizarre to see a string theorist character act so surprised by the notion of spacetime as an emergent property of some very different underlying physics, given that the same thing happens in string theory itself. (Certain fields defined entirely on the two-dimensional worldsheet of a fundamental string interact in specific ways that give them the structure of a spacetime manifold.)