Theoretically impossible
I remember hearing the story about how it was theoretically impossible for bumble bees to fly because their little wings could not possibly generate the lift required to get them off the ground. Obviously bumble bees know absolutely nothing about fluid dynamics and just continued flying around until some researcher discovered that bumble bee wings generate tiny air vortexes that increase airflow and allow them to fly. Sometimes theories are wrong and sometimes all things are possible - nothing is ever settled (in theory).