There is evidence in the form of directional crystal structures, as well as the fact many are able to hear a difference. Either way, evidence.
As for theories, there are theories galore.
Even though most ten year olds could understand that much, it apparently is beyond the realm of theoretical physics and interstellar propulsion engineering.
As for theories, there are theories galore.
Even though most ten year olds could understand that much, it apparently is beyond the realm of theoretical physics and interstellar propulsion engineering.