Aristotle (384–322 BCE) was an incredibly important thinker in his time; he made contributions to philosophy, mathematics, physics, biology, politics, theater, and more. Nonetheless, he followed the tendency of his time to make unsubstantiated claims based solely on logical reasoning, such as his false proclamation that men eat more than women and therefore must have more teeth. The scientific method, which became common after Aristotle’s time, made careful observations—rather than opinions—the basis of scientific inquiry. Without this method, the hypotheses, theories, discoveries, and inventions we think of as “science” would not be possible. In this chapter, you will be introduced to the field of physics, as well as the methodology of physics experiments.
Physics is the branch of science that primarily studies matter, energy, and their interactions. Using the scientific method, physicists hypothesize relationships, design experiments, and complete tests to turn those hypotheses into theories. Physicists around the world not only work from the same body of knowledge—the same laws and theories—but they also use standard units and the SI system of measurement to ensure that the replication of their experiments is possible. Physics is more than numbers and equations; it is about asking how and why things work and questioning everything we see in the natural world.