Science and the Scientific Method
by Amanda Chesworth
As a prelude to a discussion of the scientific method let’s first consider science in general – specifically, the three principal problems that scare many students away from enjoying the buzz you can get from the rigour of a scientific argument.
Three Problems With Science
Briefly stated, the three perceived problems are:
- science is divorced from the rest of human culture
- science is hard
- science doesn’t give absolute answers to questions.
Problem One: Two Cultures?
The word culture is a tricky one. To most people in the English-speaking world it means what Noel Annan calls 'high culture' -- that is the great works of civilization, in music, literature, painting, architecture and so on. The heroes of this conventional view of culture, people such as Homer, Shakespeare, Beethoven, Rembrandt and others are mostly white, male and dead. Kenneth Clark's series of TV films called Civilization makes this plain. If you are female, non-Caucasian or a scientist, chances are you have not been allowed to join the club.
Science in particular is seen as something separate and removed from high culture. Mathew Arnold and T.H. Huxley had a famous argument about this, a hundred years ago. C.P. Snow in The Two Cultures renewed the argument in suggesting that science constituted a separate culture in its own right. He claimed that there was little interaction or dialogue between it and the high culture of the arts and humanities. Although his ideas are not new, and have been extensively criticised by people whose definition of culture differs from his, there is no doubt that he touched a nerve (especially with a Cambridge teacher of English called Leavis, who mounted an extraordinary personal attack on him).
It is surely true that, on the whole, there is a general lack of communication between the two camps. Yet science is as much an expression of the human imagination as King Lear, the Taj Mahal, the Tasili frescoes or Citizen Kane, and the logical framework of thermodynamics, to take only one example, appears as beautiful to those who understand it, as any work of art. You just need to work a bit to understand and appreciate it.
John Brockman has suggested that we need a “third culture”, in which science is presented in a clear, interesting and accessible way, and without being dumbed down to the level of inaccuracy and misunderstanding, – see The Third Culture by Kevin Kelly in Science Volume 279, Number 5353, Issue of 13 Feb 1998, pp. 992-993.
Judith Stone provides a rationale:
"We can't all be Einstein (because we don't all play the violin). At the very least, we need a sort of street-smart science: the ability to recognise evidence, gather it, assess it, and act on it. As voters, we're de facto scientific advisers. In the next few years we're going to be making directly or indirectly, vital decisions about the greenhouse effect, acid rain, the pesticides that taint our food, genetically engineered organisms, how much to spend on mending our torn ozone layer. If we don't get it right, things could go very wrong."
“Street-smart science” – sounds like a good idea to me.
Problem Two: Science is Hard.
Science is hard in the same way that many worthwhile activities are hard – playing a musical instrument, understanding a difficult poem, following a detailed argument, for instance. It needs effort, and the effort is primarily intellectual: we need to think. But we’re lazy, and not thinking, or having someone else do the thinking for us, is easier than developing our own thinking skills. George Bernard Shaw once made the comment that a thoughtful life is so uncommon, we could bring about a revolution if we all thought for five minutes a day. A typical Shaw exaggeration, but you get the point.
What makes science particularly difficult to think about, is the fact that we are largely dealing with abstractions. That science deals mainly in abstract thought is a bit surprising, because all science is based on the belief that there is a concrete, objective world outside our heads. Yet as Alfred North Whitehead pointed out long ago, the best way we have found to explain what’s going on, is by means of abstractions.
For example, to understand and to remediate many of the problems of pollution and contamination in our soil, water and air, involves us in the study of chemical reactions. At their most fundamental these are studied in terms of an abstraction called the chemical potential, and if you follow its derivation in classical thermodynamics, from the real world we describe in terms of a first level of abstraction involving entities such as time, length and mass, you find that you have to go through another four levels of abstraction to get to the chemical potential. Yet, it gives a powerful insight into the chemistry of the earth, including the chemistry of life.
Dealing with abstractions on this scale means that “commonsense” is not always a reliable guide to scientific questions. As a simple example, think of the relationship between the earth and the sun. Viewed from the earth, common sense tells us that the sun goes round the earth. Copernicus was smart enough to view the problem from the perspective of the sun, thereby arriving at the anti-commonsense answer that the earth goes round the sun. When he first proposed it, he had no evidence, all the evidence came later as the idea was tested. Some scientists make the claim that you begin by simply collecting data, and when you’ve got enough to examine a light goes on in your brain and a brilliant hypothesis is born. The fact is, like Copernicus, you begin with an idea. Otherwise, what data would you collect?
In The Unnatural Nature of Science, Lewis Wolpert makes a big deal out of the lack of common sense in science, to the extent of claiming that science is by nature, anti-commonsense. This is going overboard in my opinion – much of science, and especially applied science (which Wolpert might dismiss as “mere” technology), is utterly commonsensical. For that reason, much of science is readily accessible to people who consider themselves to be scientifically illiterate, yet who conduct their lives in commonsensical fashion.
Take the example of getting rid of nuclear waste in a safe way. The knee jerk reaction might be: let’s blast it off into space. Many people might rule out this solution on account of its expensive, energy-intensive nature. But a more telling objection is that the rocket could misfire or explode in the atmosphere, and spread contamination over a wide area.
So what’s the commonsense way of approaching this problem? The first question to answer would be, can we contain the wastes? Remember, they give off harmful radiation for thousands, even millions, of years. We need a container that’s stable for a period of that order of magnitude, and this means that we need to know something about the stability of solids. In particular, we would want to check out gold, silver and copper, the “noble” metals, so-called because like true aristocrats, they may occur pure in nature, uncontaminated by “lesser” materials. In fact, in nature they are relatively inert, persisting more or less unchanged over millions of years. On the north shore of Lake Superior for example, copper has existed unchanged in the bedrock for over two and a half billion years. Our common sense tells us therefore, that copper could form a stable, long-term container for nasty wastes. A thermodynamicist could give you reasons for this based on the chemical potential relationships.
The second question is: where is a safe place to deposit the containers of waste? Again we are looking for an environment that is stable for millions of years, so what does the science of geology tell us? First, a map of the world showing earthquake zones and active volcanoes shows us the parts that are currently unstable and that need to be avoided.
By contrast the map also indicates very stable areas, called cratons, which have been stable for over half a billion years. In fact, Atomic Energy Canada has a research project in the Canadian Shield (the largest exposed craton on the planet) in which a nuclear waste repository has been constructed at a depth of 400 metres in a large body of granite at Lac du Bonnet, Manitoba. It turns out that there are problems even here – the granite is highly fractured at depth and relatively hot and corrosive waters circulate through the fractures.
A possible alternative is the abyssal plains of the oceans. These parts of the ocean floor spread out from their origin along oceanic ridges, to subduction zones where they are taken back into the mantle. The whole process takes about 200,000,000 years, and so they could provide long-term storage. In addition, the containers could be raised for periodic inspection.
So, in other words, don’t believe everything Lewis Wolpert tells you, even though he did win a Nobel Prize. In fact, always be a little bit skeptical of everything you read!
Common sense isn’t a bad way to introduce yourself to the intricacies of science, and to get over the “science is hard” phobia. But remember, the behaviour of human beings is not necessarily constrained by common sense. Americans are preparing to store their nuclear wastes inside Yucca Mountain, an extinct (one hopes) volcano, in the active seismic zone of the southwestern USA.
Problem Three: Absolute Truth Does Not Exist.
Unfortunately, for those who like the “absolute truth” that religion, or dogmatic political philosophies yield, science offers only contingent answers – contingent that is, on the possibility that future knowledge will pull the rug from under our feet, and we’ll be forced by new findings to reject what we once thought we were sure of.
Karl Popper provided us with an idea on the nature of the scientific method. The important point in the present context is his belief that scientific propositions can never be unequivocally proven. We can disprove them, undoubtedly – negative findings can force us to reject any idea we have. But positive evidence only fortifies, never proves, our ideas. There could always be something completely unpredictable in the future, lying in wait for even our most favoured hypotheses. This is what is meant by a scientific idea being falsifiable.
When we are forced by new evidence, or by the creaks and groans developing around old hypotheses, to change our scientific ideas wholesale, we call this a paradigm shift (following a historian of philosophy called Thomas Kuhn). Darwin caused one in biology, Einstein, and others in physics, and Hess, Dietz and Wilson in Geology.
Think of it as an exciting, edgy way to live, rather than a debilitating problem.
The Scientific Method
Carl Sagan (in his Demon Haunted World) calls the scientific method the most effective ‘baloney detector’ yet invented, one of the most important tools in the Homo sapiens survival kit – the Swiss army knife of the intellect. It is the best way yet devised for finding reliable answers to the problems of the real world. Other ways of devising answers, that do not involve testable procedures, ways that depend solely on disembodied arguments about “words, ideas, high moral values, and aesthetic and religious beliefs”, are rejected as being inferior guides to an understanding of our surroundings and to our behaviour in the biosphere.
So let’s now consider how scientists go about their business (or at least, how they are supposed to go about it).
Morris Kline in his book Mathematics and the Search for Knowledge (1985) describes the scientific position in the following way: "Despite the denials of Berkeley, the qualifications of Hume, and the reservations of Heraclitus, Plato, Kant and Mill concerning what we can know about the external world, physicists and mathematicians believe that there is an external world. They would argue that even if all human beings were suddenly wiped out, the external or physical world would continue to exist. When a tree crashes to the ground in a forest, a sound is created even if no one is there to hear it." In other words science is based on the firm belief that there is a real world outside our heads. Ordinary people and most philosophers from Aristotle onwards have the same belief. The five senses, sight, hearing, touch, taste and smell, convey messages from this external world to our brains. Our brains may scramble the message somewhat, and we may need to augment our senses with increasingly sophisticated instruments, but we can discover the physical nature of the world around us if we process our observations through the right kind of filter. Scientists believe that the best filter invented is the scientific method; and that opens a can of worms because there is no general agreement on what the scientific method is.
Many scientists believe that the scientific method involves the following steps:
- Recognition and formulation of the problem,
- Collection of relevant data,
- Formation of a hypothesis by induction,
- Making deductions from the hypothesis,
- Testing the deductions by observation and experiment, and
- Reasoning that if the new results are consistent with the deductions, the hypothesis is strengthened.
Note the phrase "the hypothesis is strengthened". A hypothesis is never proven. You can never rule out the possibility that some future observation will be inconsistent with the hypothesis, which will therefore have to be modified or discarded. Consequently, although a hypothesis cannot be proven, it can be disproved.
This fact is incorporated into Sir Karl Popper's view of the scientific method. He identifies the following steps:
- Start with a hypothesis,
- Reason that certain consequences (deductions) must follow,
- Plan experiments to disprove (falsify) the deductions,
- If you cannot disprove them the hypothesis is strengthened.
Falsifiability, as the chief characteristic of scientific hypotheses, is the central theme of Popperism.
Another important theme in modern science is operationalism. According to the physicist P.W. Bridgeman, concepts and questions that are meaningful in a material, scientific sense, can be defined in terms of an operation or process. The concept of length for instance can be defined in terms of the operation of measuring it against a standard, for example a ruler. Many concepts and questions are not definable by means of an operation and this enables the scientist to ignore them and even to dismiss them as so much hot air, e.g. what is truth, is the soul more important than the body, is there life after death, is science more important than art?
No operation has yet been devised to test such Great Questions, which, although they have occupied the time and energy of many philosophers, are meaningless in a scientific sense. Try the operational approach yourself. Ask yourself a Great Question, “Is there life after death”, say. As Stuart Chase writes in The Tyranny of Words (1938) "Look for an operation which can answer it. Keep on looking. Look under the bed, out in the garage, everywhere except into your own mind. In the end you will find that no operation is possible, and the question, to date, is meaningless. You can argue about it if it amuses you, but neither you nor your opponent can know anything about it. At least not yet."
That 'at least not yet' is a very important rider.
The Importance of Abstraction in Science
Even though science is based on the firm belief that there is a real world outside our heads, the scientist deals with that world in terms of abstractions. The four fundamental abstractions are space, time, mass and temperature. From these we derive further abstractions such as velocity, acceleration, force, kinetic energy, entropy and so on, each taking us further and further from the material world. The interesting thing is that our abstractions have given us a great deal of understanding about the way the universe works. In this context A.N. Whitehead wrote, "The paradox is now fully established that the utmost abstractions are the true weapons with which to control our thought of concrete fact."
Scientists want their ideas to have some correspondence with the world, and are willing to settle for probabilities that fall short of absolute certainty. Some systems of abstraction can offer absolute certainty (pure logic and pure mathematics for example) but for this kind of truth a stupendous price is paid. The price as Martin Gardner points out in The Whys of a Philosophical Scrivener, is that such statements say nothing about the world. They are abstract to such a degree that they are completely divorced from concrete reality.
Members of particular political parties or religions claim absolute certainty over certain issues of importance to them. This has nothing to do with reason but is based on dogma. True scientists will modify their views when they are shown to be wrong. Dogmatists cling to their version of absolute truth through thick and thin, often with tragic consequences. Jacob Bronowski illustrates this very movingly, at the end of his film Knowledge and Certainty.
The ability of the scientific attitude of mind to accept change, and actively to seek it, creates difficulties for non-scientific systems of belief. Arnold Toynbee, a profoundly conservative historian, described the physical sciences as a series of socially and morally subversive intellectual discoveries, for this reason.
Where Do the Paranormal and Supernatural Fit In?
Paranormal is an adjective used to describe supposed psychical events and phenomena such as clairvoyance or telekinesis whose operation is outside the scope of the known laws of nature or of normal scientific understanding, of or relating to such phenomena. The word supernatural is similar in meaning and refers to a realm or system that transcends the powers or the ordinary course of nature.
Martin Gardner defines ideas of this kind as ‘wild beliefs which the entire science community considers close to zero in credibility'. You can find many good examples in the headlines of supermarket tabloids, e.g. 'Space Aliens ate my Washing, and Barfed all over the Yard'. A belief in the supernatural, in miracles and all that rubbish that Dan Akroyd hosts on television, falls into this category.
Supernatural beliefs seem always to have been a part of human society. They were very evident in the classical world, but the Greeks made a break. In the Greek Enlightenment (about 2500 years ago) they began an attempt to look for natural explanations for worldly phenomena, rather than to rely upon a panoply of gods and goddesses. Moses Finley in Aspects of Antiquity underlines this when he points out that Thucydides believed that 'human history....was a strictly human affair, capable of analysis and understanding entirely in terms of known patterns of human behaviour, without the intervention of the supernatural'. Although the Greek Enlightenment didn’t last, since that time the Western tradition of thought has led to the exclusion of the supernatural increasingly to the fringes of society.
The scientific view however, has not had an easy ride. Bertrand Russell in Unpopular Essays (1950) described the conflict in the following words: "Throughout the last 400 years, during which the growth of science has gradually shown men how to acquire knowledge of the ways of nature and mastery over natural forces, the clergy have fought a losing battle against science, in astronomy and geology, in anatomy and physiology, in biology and psychology and sociology. Ousted from one position, they have taken up another. After being worsted in astronomy, they did their best to prevent the rise of geology; they fought against Darwin in biology, and at the present time they fight against scientific theories of psychology and education. At each stage, they try to make the public forget their earlier obscurantism, in order that their present obscurantism may not be recognized for what it is."
The characteristic attitude of the scientist is one of skepticism. When you are presented with a new idea, in no matter what field of learning, question it, look for evidence for and against. Make a decision on the basis of your assessment of the evidence, and always be willing to change your opinion if new evidence surfaces to show that your initial assessment was wrong. Although it is easier said than done, keep an open mind.
There’s a good story told about the famous English economist John Maynard Keynes. Keynes had changed his mind on some issue, and an opponent was taunting him about it. “Well,” said Keynes, “when I’m presented with new facts, I change my mind. What do you do?”
About the Author
Amanda Chesworth is the Educational Director for the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP). She has a lot of fun developing the Inquiring Minds program and working with young people, parents, and teachers. In her spare time she likes to hunt for rocks and fossils, read books, and play on the Internet. Amanda can be reached at firstname.lastname@example.org