The Scientific Method
Since at least the 17th century, the process of observing the world around us and making models has often been formalised in what is called the “scientific method”. While this method developed out of common sense knowledge grown out of the practical concerns of everyday living, it is more than just organised common sense [Nagal 1961] . It aims at providing an explanation of what is observed rather than just noting cause and effect. In addition, steps are taken to establish the correctness of the conclusions drawn and to mitigate the biases which exist in the minds of the investigators.
Applying the scientific method to a question entails a number of steps, illustrated below.
- Careful observations are made
- Interesting questions about the observations are formulated. eg. “Why does this happen?”
- Suggest a possible explanation, or hypothesis, or model, which can be based on intuition, analogy, guesswork or anything else.
- Make testable predictions using this hypothesis and do experiments to see if these predictions are accurate.
- If not accurate then refine the hypothesis or jump to a new one and go back to step 4.
- If accurate then incorporate them into general theories.
It is important that the observations and reasoning of an experimenter, or team of experimenters, is rigorously checked by others who are not involved. This is to minimise the effect of “confirmation bias” in which a person is likely to give undue weight to an observation which confirms what they believe for other, possible irrational or erroneous, reasons and to discount, or not even notice, observations which are contrary. For this reason experiments should ideally be repeatable. Clearly, for subjects such as in astrophysics or the origin of life, that is not possible so other cross-checks need to be introduced.
The goal of a scientific investigation includes describing, predicting and explaining particular observations and to investigate how the observations are influenced by changes in starting conditions or environment.
A scientific hypothesis can provide a simplified or unified description of apparently disparate phenomena. A scientific investigation should also create public knowledge. Knowledge which can be shared and checked by means of the publication of results.
As more experiments are done and this method applied, our models of the external world become more sophisticated and accurate. New results may disagree with old hypotheses and old ideas, and old predictive equipment are replaced by new.
Sometimes the new is a direct development of the old such as when the Laws of Motion and the Law of Gravitation which were expressed in a simple form by Newton were shown by Einstein to be inaccurate under certain circumstances and not consistent with observations of electromagnetic waves and were an approximation to the, more rigorous, Theory of Relativity.
Sometimes there has to be a more radical shift and the old has to be totally discarded because new information, or new situations, have come to light for which the old is not an approximation but something which gives totally the wrong answer. What is needed is a change of paradigm [Kuhn 1962]. The Copernican idea that the Earth was the centre of the Universe had to be replaced with the quite distinct ideas of Galileo in order to make sense of the information provided by the new telescopes.
The only test of the validity of the mental models formed is whether predictions agree with experience. Although a model can, in principle, be proved false in that it gives false predictions, the fact that a model gives the correct result is no indication of it’s closeness to reality. The Copernican model gave very good agreement for a long time but it was found to be false.
On the smaller scale, we form models for the behaviour of things in our world. That chairs can be sat on without collapsing, that fire hurts if we get too close, that if we do certain complicated things with magic wands or computer keyboards then we can make things happen. This doesn’t mean that our model is true, just that it works in the situations in which we have tested it. Of one thing we can be sure, however, is that no matter how sophisticated and accurate our models are, they will be incomplete.
The essence of exploration, whether scientific or geographical, is based on the experience that there are always new things, new places, new experiences to be found. Not even on this Earth, or even in this land, will anyone be able to say: “We know everything there is to know about this”. How much less about the whole Universe?
This approach has been hugely successful in constructing a model of the Universe which describes how observations in Physics, Chemistry, Biology can have come about. Moreover, many predictions based on the hypotheses have been and shown to be correct.