Do flying monks described in Buddhist texts contradict with physics?
One of the main pieces of advice in the Buddha Dhamma is verification by trying it yourself (Ehipassiko) and to be open to scientific scrutiny (Sandiṭṭhiko). Hence you can develop the Jhanas and see for your self if this is possible or not. Self-verification and experience is more convincing than people arguing in-favor or against something like this.
Having said this, there is much research in these areas under Parapsychology though this might be view as pseudoscience.