We have no right to assume that any physical laws exist, or if they have existed up until now, that they will continue to exist in a similar manner in the future.
There is a real world independent of our senses; the laws of nature were not invented by man, but forced on him by the natural world. They are the expression of a natural world order.
Thus, the photons which constitute a ray of light behave like intelligent human beings: out of all possible curves they always select the one which will take them most quickly to their goal.
