We started out by introducing philosophy, and then saying that natural philosophy (physics) made a break from other philosophy by emphasizing three things: scientific experiments, control over experiments, and numbers. We have just finished discussing scientific experiments, which involve a real attentive observation of nature and readiness to be both surprised and wrong, which has some similarities to love between people. However the analogy to loving relationships is not complete,: the second major characteristic of natural philosophy (physics) is its emphasis on repeatability and total control.
Natural philosophers restrict their inquiries and do not study a lot of things, saying by definition that many things are just not their problem. This may come as a surprise to many who understand that science gives explanations of everything and considers the whole world as its domain. This is not really true: scientists restrict themselves to studying things that they can repeat at will, things that they can make happen over and over again, and that their colleagues can duplicate. For instance, if I fill a balloon with cold air and then heat it, the balloon will grow bigger. I can repeat this many times with many balloons, and it will never happen that heating the balloon would make it shrink. Moreover my friends, my neighbors, and even you my reader can fill balloons and heat them and observe the same behavior. The balloons are fully under our control: we can keep them at a particular temperature as long as we like, and measure their size, temperature, composition, etc.