Is spacetime quantized?
In general relativity, spacetime is assumed to be ‘smooth’ and ‘continuous’ (not just in the mathematical sense). In the theory of quantum mechanics, there is an inherent ‘discreteness’ present in physics. In attempting to reconcile these two theories, it is sometimes postulated that spacetime should be quantized at the very smallest scales. Current theory is focused on the nature of spacetime at the Planck scale. Loop quantum gravity, string theory, and black hole thermodynamics all predict a quantized spacetime with agreement on the order of magnitude. Loop quantum gravity even makes precise predictions about the geometry of spacetime at the Planck scale.
