Why is it "Forbidden by Gravity" but the "sub-Plankian unknown"? I thought that the Plank length was a hard limit like the speed of light. Is that not true, and there theoretically are unknown features smaller than that?
Plank length is not a hard limit the same way speed of light is. Plank length is where we expect our current models to start producing nonsense, though we fully expect that 'things can happen at smaller than plank length'. The expectation is that there exists some future model that produces meaningful predictions at sub-plank length.
Whereas for speed of light, we currently expect no future models to produce meaningful faster than light predictions, and we fully expect to never find evidence of faster than light predictions.
icegreentea2|2 years ago
Whereas for speed of light, we currently expect no future models to produce meaningful faster than light predictions, and we fully expect to never find evidence of faster than light predictions.