- Understand the Scientific Method.
- Define the scope of Physics.
- Understand the difference between theory and model.
- Have a sense of how a physicist thinks.
This textbook will introduce the theories from Classical Physics, which were mostly established and tested between the seventeenth and nineteenth centuries. We will take it as given that readers of this textbook are not likely to perform experiments that challenge those well-established theories. The main challenge will be, given a theory, to define a model that describes a particular situation, and then to test that model. This introductory physics course is thus focused on thinking of “doing physics” as the task of correctly modeling a situation.
A scientific theory...
- must explain the physical world, and it may or may not be experimentally verifiable.
- proves our models to be correct, and it must be experimentally verifiable.
- describes the physical world, and must be experimentally verifiable.
- must disprove other theories, and may or may not be experimentally verifiable.
- 1.1: Science and the Scientific Method
- Science is the process of describing the world around us. It is important to note that describing the world around us is not the same as explaining the world around us. The Scientific Method is a prescription for coming up with a description of the physical world that anyone can challenge and improve through performing experiments. If we come up with a description that can describe many observations, or the outcome of many different experiments.
- 1.2: Theories, Hypotheses and Models
- For the purpose of this textbook (and science in general), we introduce a distinction in what we mean by “theory”, “hypothesis”, and by “model”. We will consider a “theory” to be a set of statements (or an equation) that gives us a broad description, applicable to several phenomena and that allows us to make verifiable predictions.
- 1.3: Fighting Intuition
- It is important to remember to fight one’s intuition when applying the scientific method. Certain theories, such as Quantum Mechanics, are very counter-intuitive. For example, in Quantum Mechanics, an object can be described as being in two locations at the same time. In the Theory of Special Relativity, it is possible for two people to disagree on whether two events occurred at the same time. These particular predictions from these theories have not been invalidated by any experiment.
- 1.4: The Scope of Physics
- Physics describes a wide range of phenomena within the physical sciences, ranging from the behaviour of microscopic particles that make up matter to the evolution of the entire Universe. We often distinguish between “classical” and “modern” physics depending on when the theories were developed, and we can further subdivide these areas of physics depending on the scale or the type of the phenomena that they describe.