Introduction 1: The Scientific Method

The scientific method arose from a need to find out if our common sense beliefs were true. 

If you don't investigate into something (at levels that may even go beyond the technology of your time) then you can end up with some ideas about the world which may seem silly to us now but were common sense back then.

For centuries, people based their beliefs on their interpretations of what they saw going on in the world around them without testing their ideas to determine the validity of these theories — in other words, they didn’t use the scientific method to arrive at answers to their questions. Rather, their conclusions were based on untested observations. 

Among these ideas, since at least the time of Aristotle (4th Century BC), people (including scientists) believed that simple living organisms could come into being by spontaneous generation. This was the idea that non-living objects can give rise to living organisms. It was common “knowledge” that simple organisms like worms, beetles, frogs, amd salamanders could come from dust, mud, etc., and food left out, quickly “swarmed” with life.

Point to ponder: How many common sense beliefs could we have today that our children (or children's children) will laugh at and call us stupid for?

Here is an introduction to the scientific method:

1. Observation and description of a phenomenon or group of phenomena. 

2. Formulation of an hypothesis to explain the phenomena. In physics, the hypothesis often takes the form of a causal mechanism or a mathematical relation. 

3. Use of the hypothesis to predict the existence of other phenomena, or to predict quantitatively the results of new observations. 

4. Performance of experimental tests of the predictions by several independent experimenters and properly performed experiments.

If the experiments bear out the hypothesis it may come to be regarded as a theory or law of nature (more on the concepts of hypothesis, model, theory and law below). If the experiments do not bear out the hypothesis, it must be rejected or modified. What is key in the description of the scientific method just given is the predictive power (the ability to get more out of the theory than you put in; see Barrow, 1991) of the hypothesis or theory, as tested by experiment. It is often said in science that theories can never be proved, only disproved. There is always the possibility that a new observation or a new experiment will conflict with a long-standing theory.