The justification of Kant's Synthetic a Priori in natural sciences

Kant studied the metaphysical foundation of natural sciences in the framework of his transcendental philosophy in his book the Metaphysical Foundations. But beyond that, the natural sciences plays yet another critical role in transcendental philosophy from the differentiation of phenomenon/noumenon to the synthetic a priori. In this study, it will be argued that Kant gets the inspiration for the transcendental philosophy from an understanding in dynamical physics, namely the frame of reference. His study in dynamics and his knowledge on how objectivity works in respect to frame of references has led him to overcome Hume's two important criticism, one on causality and necessity and the other on inference.