2.1 Science, the scientific method and scientific laws

The aim of science is to make order out of chaos by producing explanations for what we see around us. These explanations come in the form of rules or laws, which we hope, once described, are universally true. For example, objects of whatever weight, dropped from a tower or other high point, will always fall at the same rate (assuming the same air resistance) – and that rate can be described by a scientific formula. We can also say that this is part of a more general phenomenon known as gravity and that we can produce broader explanations which, among other things, show why the earth orbits the sun in a particular way and that the sun in turn has positional relationships with other stellar bodies.

Typically we are able to derive a scientific law by:

• making an initial observation
• giving a provisional hypothesis which explains what is being observed
• providing a means of testing the hypothesis
• actually testing the hypothesis – the experiment
• examining and analysing the results of the testing to see that they conform with expectations, or some revision thereof
• saying that the hypothesis is now a scientific law that holds good for a given range of the phenomenon – and which can be published as such.

This process is known as the scientific method. The end result of the application of the scientific method is a scientific law.

If we have carried out the exercise properly, we can now predict what will happen for all activities within that range of the phenomenon – and anyone else will be able to do the same. Universality [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)]  and repeatability are key features of scientific laws. You should also be aware that scientists generally agree that nothing can be proven in absolute terms, but we can say a scientific law holds good until it is proven false.

Although findings may be written up in academic journals using a structure rather like the bullet points above, in practice, scientific endeavour is often much more complex than this. Indeed, the actual process may be much more intuitive and haphazard, showing strong elements of creativity and imagination. Here are a few issues that impact on scientific advances:

• It is not unusual for the initial hypothesis to be substantially wrong. It may, for example, be recognised part way through testing that the initial hypothesis is misconceived, in which case a new, preferably more reliable, hypothesis may be produced.
• One of the key features of the scientific method is testing, but what constitutes a test? Experimental activities must be carefully designed to test the precise hypothesis and nothing else. Controls are usually needed to examine and isolate observations of changes under various conditions. Perhaps the single biggest area of dispute within science is that of testing methodology; the second is allegation of falsifying results.
• Real-life formulation of scientific laws is often an iterative process towards fuller and more reliable understanding. Once the researcher is satisfied with the test results, they may be published in an appropriate scientific journal, thereby adding to the pool of scientific knowledge. Before publication takes place, the work will be peer-reviewed for flaws (and originality).

It is also the case that, at any one time, there is a dominant view of how things work, within which most scientific endeavour in a particular field takes place. Every so often that dominant view turns out to be misconceived and/or there is a major discovery and a paradigm shift occurs. It is therefore possible to distinguish between normal science, which is the vast majority of work that is carried out, and the much rarer paradigmatic work.

Established scientific law does change through time, and through agreement and convention of the scientific community. For example, Einstein’s theories on relativity now extend understanding formed by Newton’s ideas on gravity. The same applies in legislation, as new ideas, experiences and, often, criminal practices emerge. As well as considerable improvements in methods of detection, advances such as fingerprints have enhanced the proof allowed in law (although even this has been subject to revision in light of new data, as you will soon see).

Forensic science uses the scientific method too, but we need to distinguish between at least two instances of it:

1. the discoveries of phenomena that we can put rules to and that appear to have a value within an investigation that might end in legal proceedings (such as particular qualities of fingerprints and DNA)
2. the development and proper use in the relevant instances of specialist tools and standard operating procedures based on the above.

Arguably there is also a third instance: when a forensic technician examines a specific item of evidence and reports the findings. This must be ‘scientific’ to the extent that it is repeatable by others. In criminal law procedure, the repeatability should be accessible to an expert instructed by the defence. This requirement to be scientific implies, among other things, having the original material (or some acceptable duplicate) available for inspection and having detailed reporting of what was done.