Science as a method Physics Mr. Fisher

A method of inquiry “Science” simply means “knowledge” – Fides, Scientia, Virtus = Faith, Knowledge, Virtue Science is a method or way to know truths about the physical world – Matter and energy The scientific method is the process by which scientists, collectively and over time, endeavor to construct an accurate (i.e. reliable, consistent and non- arbitrary) representation of the physical world There are a variety of ways to implement this method

Origin of the method Galileo Galilei ( ) is often considered the father of modern science – He performed methodical tests to verify the accepted Aristotelian laws of nature (4 min)

Common method – 4 steps 1) Observation of a phenomenon 2) Formulation of a hypothesis to explain it – In physics, the hypothesis often takes the form of a causal mechanism or a mathematical relation. 3) Use the hypothesis to make one or more predictions – Predict existence of other phenomena, or to predict quantitatively the results of new observations 4) Experimental tests of the prediction(s) – Properly performed by several independent experimenters

Result of the method If hypothesis is supported by numerous, independent scientists, then it may be regarded as a theory or a law of nature. If hypothesis is not supported by experiments, then it must be revised or discarded.

Hypothesis, Model, Theory, Law Hypothesis – A first untested attempt to explain the cause of a specific event, “educated” guess – e.g. My car won’t start because the battery is dead. Model – An explanation that has a least limited applicability – e.g. Bohr model of the atom

Hypothesis, Model, Theory, Law - 2 A scientific theory or law represents a hypothesis, or a group of related hypotheses, which has been confirmed through repeated experimental tests. – Laws are universal rules given without explanation – Theories in physics are often formulated in terms of a few concepts and equations, which are identified with "laws of nature," suggesting their universal applicability. Theories can never be proved, only confirmed or disproved.

Endnote “The principle of science, the definition, almost, is the following: The test of all knowledge is experiment. Experiment is the sole judge of scientific ‘truth.’ But what is the source of knowledge? Where do the laws that are to be tested come from? Experiment, itself, helps to produce these laws, in the sense that it gives us hints. But also needed is imagination to create from these hints the great generalizations – to guess at the wonderful, simple, but very strange patterns beneath them all, and then to experiment to check again whether we have made the right guess.” – Richard Feynman, The Feynman Lectures on Physics