The announcement of the KM3-230213A neutrino is generating a flood of astrophysics studies, mostly investigating its origin. We here focus on aspects of this observation that could be relevant for research programs on quantum gravity and spacetime quantization. It is at least amusing that KM3-230213A most likely traveled billions of light-years, but its rest-frame existence only lasted less than 0.1 seconds and ended with it being hit by a nucleon of Planckian energy. In addition, and perhaps more significantly, KM3-230213A is a remarkable probe of the types of microscopic structure of spacetime conjectured in some quantum-spacetime scenarios, and according to one of these scenarios, there is a candidate source: the gamma-ray burst GRB090401B observed 14 years earlier.
Amelino-Camelia et al. (Tue,) studied this question.