There is no definite proof, there is also no definite proof that a quantum can even be in a superposition at all (in the sense od being in two states at once) becuae we cannot observe it. Physicist Niels Bohr for example believes that the outcome is already set long before we observe it.
Source? I’ll continue to believe in my quantum super-duck until proven otherwise!
Schrödingers duck
There is no definite proof, there is also no definite proof that a quantum can even be in a superposition at all (in the sense od being in two states at once) becuae we cannot observe it. Physicist Niels Bohr for example believes that the outcome is already set long before we observe it.