I was reading a book called Catching the Light; a book on the history and other interesting things about light. There is a discussion in the book about refraction such as one might see when looking at a stone at the bottom of a pond when viewed at an angle. I've always just thought of the bending of the light beam at the surface as due to the change in medium and never gave it much thought past that. However, in this book refraction is described as the path that light can and will take to minimize the amount of time it takes for the light to get from the stone to the eye of the observer. It turns out a straight line path is not the shorted time as the light has to propagate through more water (where it travels at less than c) than it would if it followed a shorter path to the surface, and then a longer path to the eye. Too far and the light time increases again due to the longer distance through the air which is why the light doesn't just go straight up then over to the eye. This description of light seems sensible and considering the strange nature of quantum physics, doesn't seem to be unreasonable. So my question is: Is this really what happens?