In this article, we’ll take a look at the method applied by scientists, in general terms. An understanding of this will be needed if we are to grasp what it is that science is providing and what its fundamental limitations are.
Science is concerned with uncovering objective truths about the world (or the whole universe, to be more precise). The key word here is objective. The aim of science is to provide a description of the world which is not dependent upon subjective feelings, opinions or beliefs; a description which can be independently verified by different people as long as they apply the same rigorous scientific approach. In short, science is uncovering truths that we can all agree on, assuming we accept a certain degree of rationality.
Science is looking for patterns in the world. A pattern is something that repeats, or is similar from place to place and from time to time. A scientist might state this by saying that a scientific truth is invariant in space and time. So, for example, a glass of water behaves in pretty much the same way in India as in America. And the behaviour of a glass of water today is much the same as it was yesterday. Of course, if I take the glass of water to Antartica, it will turn into ice, but science can accommodate that within its description of the behaviour of water, in which temperature is a factor, rather than the fact that the water is in Antartica per se.
Having spotted a pattern, the scientific method involves constructing a model that represents the pattern. This model is not a physical model but rather a technical statement of the pattern. The model will typically involve a quantification of the pattern – that is, using measurement to state the pattern in numerical terms, with mathematical associations between the various elements that have been measured.
A general principle in the scientific approach is to apply Occam’s razor. This means that a scientist is looking for the simplest possible model, with the fewest assumptions, which will match the observed phenomena. Of course, there is no particular reason why things should be simple, it’s an aesthetic principle – scientists are more in tune with Zen than with the baroque.
To begin with, a scientific model is a hypothesis. The scientific approach then requires a period of thorough investigation. This typically involves different teams of people trying to replicate the experimental observations. It also involves devising new experiments to check whether the model really does match observations in different situations. Often the model needs to be refined as a result of this research. For example, a scientist might assert that water always turns to vapour at a fixed temperature of 100 Celsius. However, an experiment heating water in a reduced atmospheric pressure, for example on a mountain, will show that it sometimes turns to vapour at a different temperature. In such a case, the model would be modified to include the new factor of pressure.
At some point, when enough experimental evidence has been obtained and no counter-examples have showed up, the hypothesis is accepted and the model is promoted to the status of scientific truth. In some areas of science, this transition involves a strict mathematical hypothesis test, which quantifies what the probability is that the observations are down to chance rather than due to the pattern asserted by the hypothesis. If this probability of chance is small enough, the hypothesis is accepted as true.
The scientific method is also trying to ensure consistency. Effectively, there is an attempt to reconcile all the separate models to ensure they are compatible with one another. At any point in time, there are usually some gaps in this unification. For example, at present, the theory of general relativity and the theory of quantum physics – both stunningly mind-bending and successful theories in the field of physics – have not been reconciled with each other. This does not disqualify the scientific method but rather reminds us that our scientific knowledge is a work in progress.
