The Scientific Method

When I was about 14 our teacher gave us a lesson about the scientific method that I still remember well. He divided the class into groups and we each had a pot of wax that he told us to heat to a certain temperature using a bunsen burner. He then told us to turn the burner off when the wax got to that temperature and to time our subsequent temperature readings. His final instruction was for us to plot a graph of the rate of cooling of the wax and to hand in our reports of the experiment at the end of the class.

In the next lesson he started by teaching us about the latent heat of fusion. He explained that the pot of molten wax lost heat at a rate that was proportional to the difference in temperature between the pot and the air in the room. Therefore the pot started off by dropping in temperature at an approximately linear rate. However, when it reached the freezing point of the wax the temperature stopped dropping because the energy that made the wax form the molten state was being lost. The temperature had remained static until all the wax was solidified and only then did it start dropping again.

Out teacher had guessed that none of us knew about latent heat and had taken the opportunity to teach us a memorable lesson. Every group in the class had been taken by surprise by this sudden stagnation of temperature drop and had begun to suspect we had done something wrong. We had all fudged the results by skewing the graph to show a more linear temperature drop over the temperature range of the experiment.

This story is important to me because it illustrates both human nature and the scientific method. Humans are social creatures and social acceptance is often the most important factor in our lives. Experiments have shown that if we see someone else performing badly in a test then our own performance goes down in sympathy with our fellow test candidates. My class had all wanted to please our teacher so we delivered what we thought he wanted rather than what we had seen. Also, within each group those that wanted to report the results with total honesty had been over-ruled by the majority wanting favour from the teacher. Although he had told us nothing wrong he had withheld just enough information to get us to distort our experimental measurements. This is very important because it illustrates that it is possible for large groups of people to hold a false belief about reality for significant periods.

The scientific method is fundamentally very simple and it is all about the honest observation of reality. Since the period of Galileo Galilei and other heroic pioneers in the use of the method we have seen tremendous advances in our understanding of our world and this has resulted in a huge boost in the standard of living of many people. Science is about thinking up an experiment, doing it as well as we can and reporting the results as accurately as we can. We then contemplate the meaning of those results. That nearly always results in the need for more experiments but in the meantime we can take what we learned from the earlier experiments and apply it to make our lives easier. Using this process we have made cars that travel far faster and further than a horse, aircraft that travel even faster and further, computers that allow us to communicate ideas all over the world in seconds, and so on. Unfortunately we have also chosen to use our greater knowledge for less worthy pursuits but that is not the fault of science. It is the fault of what we humans have chosen to do with our increased knowledge.

Just like my class was tricked into falsifying our thermometer readings there are many examples in the literature where scientists have for one reason or another distorted their results. Sometimes false results come from faulty equipment so there is a system within the global research community where interesting results are repeated by other completely independent groups. Generally it works well and most errors are uncovered and we are able to make technological progress based on a solid understanding of our physical world.

The vast majority of scientists understand the need to be honest in reporting their results if only because it is possible for others to reveal errors, omissions and frauds. However, the interpretation of results is more difficult because it often requires a large body of knowledge to understand where everything fits in. The issue of anthropogenic global warming (AGW) is a good example. Fundamentally it is very simple. The Sun emits radiation that heats our planet and our planet then radiates that energy back out into space. The temperature of our planet is balanced between the temperature of the sun and that of space. The complexity of the issue comes from the fact that life on earth requires that balance to be in exactly the right place. To understand what is going on numerous scientists have had to work long and hard to measure a plethora of factors with all the accuracy they can manage. The subject has become so complex that no one person has the time to investigate all the details. Different teams working on specialist subjects have compiled reports and then other teams have studied those reports and drawn higher level conclusions and so on until a single answer is obtained; does AGW matter and if so how much should we spend on it?

Most top level reviews, incuding the Stern report, have concluded that AGW does matter and it was recommended that we should start spending 2% of GDP on it several years ago. We have 2 big problems at the moment. Firstly the subject is so complex that the certainty of the top level results are not high enough to silence debate. Secondly, humanity world-wide has cultures with an abysmal level of honesty so no one knows who they can trust. An important piece of news is that at the recent (March 2009) Copenhagen conference Stern said that his 2006 report was too conservative and we should be spending significantly more than 2%.

One of the things that struck me when I first started doing research at the professional level is how uncertain the bleeding edge of science is. In school and at the undergraduate level of University maths and science is all about passing exams. There is a tendency to create a curriculum where one answer is right and anything else is wrong. Obviously I knew, even at school, that research is about finding out things that had not been previously known but it still came as a surprise to me how much uncertainty had been covered up in order to make the marking of exams easier.

Whenever we do an experiment there is an uncertainty in the result because no instrument is perfectly accurate. Unfortunately, when the mass media reports the results of important experiments this uncertainty, or error bar, is nearly always ignored. This leaves most people with the impression that the result is beyond question and they do not know what to do when a later report apparently conflicts with the earlier one. In the 1970s the world was nearing the end of a 40 year period of global cooling. The accuracy of our experimental results at the time and the lack of understanding of factors that affect global temperature meant that humanity's influence was hidden in the error bars. However, during the 1990's the record high temperatures made the importance of the issue clear. During the naughties continued warming and increased understanding removed all reasonable doubt that AGW was a major problem.

Unfortunately our cultural tolerance of dishonesty has left a gap that is being exploited by those who do not want to bear the responsibility for AGW. Some sceptics are resisting the messages we are receiving to change the way we are doing things. They have an excuse because many of these messages being sent out do more damage than good. For instance, the campaign against incandescent light bulbs has several flaws. Firstly, in cold climates the heat from these bulbs helps to warm the house for the majority of the year when the temperature outside is uncomfortably cold. Secondly, the compact fluorescent lamps proposed as an alternative contain mercury and their light output is not as pleasant to live with. Thirdly, the total energy we use for lighting is insignificant; something like 2%. Too much fuss is being made about an issue that will not bring much benefit and this is creating an emotional backlash. Fortunately light emitting diodes (LEDs) are coming to the rescue as far as lighting is concerned. A more useful campaign would be against things like powerful security lights left on all night and office lights and computers not turned off when the last person leaves the office.

Another misguided push by an element of the green lobby is biofuels. Huge ecological damage is being done by clearing forests to grow crops to make fuel. In some cases, to add insult to injury, there is a net increase in CO₂ emissions. The biofuel manufacturing projects that are not helping the environment as a whole need to be held back until new technologies have been developed that do not have these problems. More honesty is required by campaigners on both sides of the argument. In fact, a dramatic elevation of our ethical standards is the best thing we could do for our planet.

Human nature makes us comply with the cultural norm we find ourselves in and this works both ways. Therefore if we want to see more honesty in the world we first have to work on our own level of behaviour. It takes time and in my next essay I explain why we have no time to loose. See Ready for Free Energy?.

Page first edition 10/03/2009, last updated 19/09/2009.

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