They are conjugate variables (i.e. Fourier transform duals) which arise in quantum mechanics simply due to the matter wave nature of all quantum objects https:

They are conjugate variables (i.e. Fourier transform duals) which arise in quantum mechanics simply due to the matter wave nature of all quantum objects https://en.wikipedia.org/wiki/Uncertainty_principle#cite_ref-Rozema_11-0 https://en.wikipedia.org/wiki/Uncertainty_principle#cite_ref... https://en.wikipedia.org/wiki/Uncertainty_principle#Introduction https://en.wikipedia.org/wiki/Uncertainty_principle#Introduc... https://en.wikipedia.org/wiki/Conjugate_variables https://en.wikipedia.org/wiki/Conjugate_variables