My favorite "fun fact" about gravity is still this one[0]: > [Gravity] shapes the arena in which it acts, unlike other fields which act in a fixed spacetime ba

My favorite "fun fact" about gravity is still this one[0]: > [Gravity] shapes the arena in which it acts, unlike other fields which act in a fixed spacetime background. From what I've seen, this fact is rather underappreciated by many of the folks doing (what they call) "quantum gravity" these days. They often try to treat gravity as a rather ordinary quantum (or string) field theory, living on a fixed background. As Hawking says in [0], "It would be rather boring if this were the case. Gravity would be just like any other field." [0]: Hawking: The Nature of Space and Time (1994), p. 2, https://arxiv.org/abs/hep-th/9409195 https://arxiv.org/abs/hep-th/9409195