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The Scientific Method
Introduction
Knowledge can be defined as all that is known. However, all that is known can be perceived differently in different branches of learning. Thus, science, religion, art and the social sciences all have knowledge, but each will attain knowledge differently. A summary of knowledge for each of the above branches of learning will be summarized below:
Science is a body of knowledge about the natural world where evidence takes priority over authority (see below, under religion) and revelation. This knowledge is obtained by asking and answering questions, based on reproducible observations, carrying out carefully controlled experiments and use of theoretical reasoning based on the data from experimentation. However, it is not the only knowledge that humans have. Humans have many different types of knowledge that are obtained and interpreted differently than in science. Let us look at religion, art, and social sciences as examples:
Religion has knowledge that is based on sacred text, revelation, visions and other sources that may not be verifiable. However, your faith accepts these literal truth and it also supercedes observations of the physical world. Religion is often referred to as authority, but the two are not synonymous. Authorities may also be celebrities such as professional athletes, movie and rock stars, authors and politicians. Many people tend to follow/believe statements made by such individuals. It is in this sense that "authority" is used in the definition of science, above. Do you do tend to believe what an authority figure tells you?
Art has no absolute truth! In Art truth is truly in the eyes of the individual that is interpreting what it is that they are seeing. To illustrate this point, there is an old, well known story concerning Pablo Picasso, a Spanish artist, who is probably one of the most important and influential artist of the 20th. Century. This story occurred late in Picasso's life, when he was at the height of his fame. He was riding in a train from Paris to Spain in one of those European compartment cars where passengers are able to face each other. One of Picasso's fellow traveler recognizes him and starts mumbling loud enough for everybody to hear,
"It's a disgrace, a sham, I can't believe people fall for that stuff".
After a while Picasso said "Excuse me, but what are you talking about?"
The man responds with " Modern art, I don't understand it, I don't like it."
" What don't you like about it?"
" It doesn't look like anything. It's not like reality".
Picasso then asks the passenger " What is like reality ?
Passenger thinks awhile, and pulls out his wallet and said "Here, this is a picture of my wife. This is like reality! This really looks like her".
Picasso then takes the picture and said "My goodness, she's a pretty woman, but she's awfully small, and very flat."
This story reiterates what I initially said. That there is no absolute truth in art and that truth is only in the eyes of the individual interpreting what they see. This same story is told in a YouTube video here.
Social Sciences, as in the case of the life and physical sciences, are all grounded on verifiable facts about the world around us. However, in the physical and life sciences, the ultimate goal is to reach a conclusion that strives for consensus, based on experiments and verifiable facts, but in the social sciences, where politics, history and sociology are involved, there are many equal equally valid conclusions that may be reached. The reason for this is because the social scientists' form their conclusions based on in their experiences, which are often richly varied. The richness of experience within these discipline results from the multiplicity of the interpretation of past present and future events.
There is also knowledge based on pseudoscience. This is knowledge that is not science, but has been mistakenly believed or purposely passed on as science. Often such knowledge is based on anecdotal stories that have not been verified. Examples of pseudoscience are astrology, psychic powers and UFOs. These examples are not necessarily out of the realm of scientific studies. Scientists may believe in the existence of UFOs, but without being able to study an actual UFO, their existence has not been demonstrated. Also, there are numerous individuals who claim to have psychic powers, but they have never allowed their "powers" to be rigorously tested in a scientific matter. For example, John Edwards, Figure 01.
Figure 01. John Edwards: Had a television show "Crossing Over" claims to speak to the dead relatives of people in his studio audience. (Image from https://dailyreview.com.au/john-edward-cheerful-chatter-when-contacting-the-dead-state-theatre-sydney/32803/).
What are the Principles of Science?
When using the scientific method, in order for it to be "scientific", the method of inquiry must be based on the principles of science or natural laws. This means that evidence gathered is acquired by experimentation and observations. The principles of science can be divided in three parts:
Causality: Events occur as a result of natural causes and traced to preceding events.
The cause of epilepsy was once thought to be due to supernatural causes. For example, in ancient Greece, it was thought to be a punishment from the gods. In fact, the name for the disease is from the Greek, epilepsis, which means to be "taking hold" because it was thought that the someone's body was being taken over by some greater power (Epilepsy, n.d.).
However, today science has demonstrated that epilepsy is due to reoccurring seizures that results from abnormal brain activity (Epilepsy, n.d.).
Uniformity in time and space: Regardless of where you are and when an event may have occurred, the laws of chemistry and physics will apply.
For example, regardless of where you are in the universe or whether the event is predicted, has already occurred or is occurring now, the laws of chemistry and physics will apply, i.e. the speed of light is a constant, life is carbon based and the laws of gravity.
Common perception: Events are explained based our five natural senses, i.e. sense of sight, smell, hearing, feeling and taste. Explanations cannot be based on special powers of perception, e.g. ESP.
This allows for the ability to repeat experiments. This is important because it allows other researchers to validate an experiment that has been published.
Information/data obtained from experiment must be objective and without bias, i.e. cannot be subjective.
Examples of objective data: Jamaica is closer to Florida than Hawai‘i. Deborah is a lot taller than Dick. A BMW car cost a lot more money than a Ford, Mustang.
Examples of subjective data: I would rather vacation in Hawai‘i than in Jamaica. Dick likes Deborah because she is tall. I would rather drive a Ford, Mustang than a BMW.
The Scientific Method
The scientific method is utilized in science because it provides us with the best means of rationally and/or logically of obtaining answers to questions about the world about us. It provides us with a recipe by which to do. The scientific method can be divided into the following parts:
In perceiving the world around us, you make observations, everyday.
From some observation you have made, you may have a question about what you have just observed.
Along with the question, you probably would likely have thought about a possible answer or answers to your question. This is your hypothesis.
You must now design an experiment by which you will be able to answer the question that you asked that will either demonstrate that your hypothesis is correct or incorrect.
After carrying out your experiment, you will analyze the objective data and observations that you have made and you will try to draw a conclusion from these results.
Lets go over some of the steps in more detail as it may not be obvious what is required in some of the steps that I have summarized:
An hypothesis is a prediction that may explain the observation that you have made. However, it should also be something that you can test to determine if your hypothesis is correct or not. Your hypothesis may or may not be correct. Your results of your experiment will determine if your hypothesis is correct or not. A proper experiment should also have as many repetitions as is possible and have control and treatment groups. Lets look at a specific example:
Hypothesis: Frozen pea seeds will germinate as well as fresh pea seeds. This experiment will be divided into two groups, a control where the peas will be fresh and the treated group where the peas will have been previously frozen. The experiment should be done with as many peas as possible to ensure that the experiment is statistically valid.
Hypothesis: Tylenol will not relieve a headache any better than a sugar pill (placebo). In this experiment the sugar pill will be the control group and the Tylenol will be the treated group.
Other examples of hypotheses will be given. Some of these will be actual experiments that were carried out before better scientific methods were utilized to carried out experiments and flaws in their experiments can be readily determined. Different experiments that were carried out on the occurrence of spontaneous generation, life originating from non-living matter, at various times. Lets look at a few example and see how experiments became more sophisticated with time:
In ancient Egypt, the Nile River could be observed to flood periodically. When this occurred, the land where the flooding occurred became very muddy and large populations of frogs appeared where none or few were present before. The conclusion that was arrived at was that muddy soil gave rise to frogs. This then was evidence that spontaneous generation occurred.
Jan Baptiste Helmont (1715-1790) carried out one of the early experiments in a more controlled environment that he thought demonstrated the occurrence of spontaneous generation. He placed dirty rags and dried wheat in a barrel and after 21 days, mice appeared in the barrel. His conclusion was that mice originated from dirty rags.
However, neither one of these experiments were correctly done according to the scientific method. One reason was that there was no control. Lets look at more sophisticated experiments:
Francesco Redi (1668) carried out an experiment, possibly the first real science experiment, that disproved spontaneous generation. The following experiment was taken from: http://biology.clc.uc.edu/courses/bio114/spontgen.htm
Observation: There are flies around meat carcasses at the butcher shop.
Question: Where do the flies come from? Does rotting meat turn into or produce the flies?
Hypothesis: Rotten meat does not turn into flies. Only flies can make more flies.
Prediction: If meat cannot turn into flies, rotting meat in a sealed (fly-proof) container should not produce flies or maggots.
Testing: Wide-mouth jars each containing a piece of meat were subjected to several variations of “openness” while all other variables were kept the same.
control group — These jars of meat were set out without lids so the meat would be exposed to whatever it might be in the butcher shop.
experimental group(s) — One group of jars were sealed with lids, and another group of jars had gauze placed over them.
replication — Several jars were included in each group.
Data: Presence or absence of flies and maggots observed in each jar was recorded. In the control group of jars, flies were seen entering the jars. Later, maggots, then more flies were seen on the meat. In the gauze-covered jars, no flies were seen in the jars, but were observed around and on the gauze, and later a few maggots were seen on the meat. In the sealed jars, no maggots or flies were ever seen on the meat.
Conclusion(s): Only flies can make more flies. In the uncovered jars, flies entered and laid eggs on the meat. Maggots hatched from these eggs and grew into more adult flies. Adult flies laid eggs on the gauze on the gauze-covered jars. These eggs or the maggots from them dropped through the gauze onto the meat. In the sealed jars, no flies, maggots, nor eggs could enter, thus none were seen in those jars. Maggots arose only where flies were able to lay eggs. This experiment disproved the idea of spontaneous generation for larger organisms.
This experiment is illustrated below:
It was finally admitted that large organisms, such as flies could not originate spontaneously, and must be derived from other flies. However, with the invention of the microscope, new organisms were observed for the first time, e.g. bacteria. It was known that if broth was left out it would develop bacterial growth, even when the broth container was sealed. Where did they come from? The answer was, again, spontaneous generation.
John Needham (1745-1748) carried out an experiment with broth in narrow mouthed flasks that he believed verified that bacteria arose by spontaneous generation. He believed a “life force” was present in all inorganic matter, including air, that could cause spontaneous generation to occur. He carried out an experiment where he briefly boiled a flask with broth and then sealed it and observed that bacteria still formed in the broth. His experiment is illustrated below:
Lazarro Spallazani (1765-1767) Would carry out a similar experiment a few years later in which he concluded that spontaneous generation does not occur. The main difference in their experiment was that Spallazani boiled his broth for a much longer period of time, thereby killing any bacteria that was in the flask before sealing it. His experiment is illustrated below:
Because of the conflicting results, a heated argument arose between Needham and Spallazani. Needham criticized Spallazani's conclusion because he had destroyed the "life force" that would have enabled life to arise from the broth when he boiled it for such a long period of time, whereas in his own experiment, the brief heating of the broth did not destroy the life force and enabled life to spontaneously arise.
The controversy would soon divide the scientific community and became so heated that the Paris Academy of Sciences offered a reward for anyone who could resolve this conflict. It was not until Louis Pasteur (1864) that the prize was claimed and the argument was finally settled. The experiment Pasteur designed took a great deal of thought. He had to demonstrate that there was no "life force" in the air and at the same time demonstrate that bacteria were the cause of the broth spoiling by somehow excluding them. This he did with the experiment below:
The S-shape of the swan neck flask and those plugged with cotton prevented air-borne bacteria from entering the broth after it was boiled, but still allowed the passage of air into the flask that would have enabled the hypothetical "life force" of Needham to generate life. However, this did not occur. Bacterial growth did not occur in those flasks that had cotton plugs and those with S-shaped swan necks. Those flasks with straight necks had bacterial growth because air-borne bacteria could readily enter these flasks. Pasteur also broke the necks of the swan necked flasks, which then became contaminated with bacteria.
It should be clear that following there is more to arriving at a valid conclusion from your experiment than just going through the steps of the scientific method. Your methods, the design of your experiment and how well you've thought out your conclusion is also important in being a successful scientists. After successfully completing your experiment and making a conclusion, this knowledge should be published so that your discovery can now be read by other scientists. This part is very critical! While you may have gone through an exhausting process generating your data and conclusion, other scientists may not agree with the methods used, or even the conclusion arrived at. By publishing your results, you allow other scientists to repeat your experiment and validate what you have done. Also, they may be able to expand/modify your experiment and learn more from it.
Important to concept to understand about the term "Theory"
In time, your hypothesis will be accepted by the science community and it will become a theory, which brings us to one of the biggest misconceptions in the non-scientific community. What exactly is a theory? What it is not, in science, is how it is defined in the everyday usage. In this type of usage, a theory is thought of as a guess, a hazy or vague idea, or a hunch. Very often, you will hear a rebuttal in a discussion concerning evolution that the theory of evolution has not been proven and that "it is only a theory." As has just been described, a theory is much, much more than a guess or speculation! The formation of a theory is the goal in scientific research and is built upon much evidence that have come about through repeated experimentation. There are many examples theories that are not as controversial as evolution and more readily accepted as being proven by science. Examples are Einsteins' theory of relativity, The germ theory of disease, The theory of plate tectonics, the cell theory and many more.
Another misunderstanding that non-scientists may have is that it is commonly believed that scientific experiments "prove" that something is true. Actually, in science, theories are just about never considered proven. Theories may be accepted for a long period of time after they have been formulated, but with the acquisition of new data, a theory may be entirely discarded or be modified in some matter to accommodate the new data. However, when an anti-science person hears this, i.e. creationist or anti-evolutionist, their immediate comment is so "you can't prove that the theory of evolution is correct." The answer to that is yes, we cannot prove any theory is absolutely always going to be correct, but science will advance itself by knowing more about a theory, "tomorrow", than it does "today". Also, certain theories are thought to have more evidence supporting it than others. BTW, the Darwin's theory of evolution, by natural selection is one of the foundations of biology and probably will has not be discarded any time soon.
Lesson to be learned
In order for the scientific method to be useful, the importance of carefully thought out design of experimentation, objective observations and data gathering must be carried out if we are to arrive at a meaningful conclusion. The scientific method should also lead you to become skeptical in your every day life. There are many statements that we hear/see, everyday that we should think seriously about. Some are not very meaningful and I've listed some examples below:
What do you think of these products and to what degree do you believe that they work? Evidence?
Pathological Science
This is a term that was coined by Irving Langmuir, in 1953 and refers to experiments that were poorly carried out by the scientific method through bias and poor methodology. In many instances conclusions from such experiments do not go away, even though they have proven themselves to be non-repeatable and in some cases fasified. I will give some examples below:
Uri Geller is a well known psychic and during the 1970's his "powers" were tested by two scientists, Harold E. Puthoff and Russell Targ, through the scientific method and based on the results of their experiment were convinced that Geller had true telepathic ability. The results of their experiment was published in 1974, in Nature, a very prestigious journal. There was much controversy concerning this article and even the editor of the journal felt it necessary to justify publishing the article. However, no specific trickery, by Geller, was every really demonstrated during and after the experiment.
Andrew Wakefield was accused of falsifying data for a journal article, published in Lancet, in 1998. In his study of 12 children who were diagnosed with regressive autism. The 12 children were normal until very suddenly they became autistic. Wakefield article noted that the autism developed soon after they were vaccinated for measles, mumps, rubella (MMR). These are vaccines that are normally administered to all children in developed countries. With the publication of Wakefield's article, parents of autistic children in both England and the United States rallied around Wakefield and vaccinations were not given to many children that resulted in the increase in the incidents of measles, mumps and rubella. Investigation into Wakefield's experiment soon uncovered that he had falsified a great deal of his data and that he was hired by lawyers to do his research because they were planning to sue the vaccine manufacturers. His article in Lancet has since been retracted by the journal. Also, independent research in Japan and Norway that have not been able to demonstrate any relationship between the MMR vaccine and autism. However, this has not brought parents back to vaccinating their children and the incidents of measles have continued to increase.
Martin Fleischmann and Stanley Pons, two distinguished scientists that published an article on "cold fusion" in 1989. Cold fusion refers to a process by which these two scientists were able to obtain excess heat energy from an experiment where they were measuring nuclear by products. With this report came the hopes of a cheap form of energy. However, after publication, the results of their experiments could not be duplicated. By the end of 1989, most scientists had discounted the experiment as seriously flawed and did not attributed any wrong doing to the two scientists. However, despite the lack of evidence supporting further inquiry into this area of research, even as recently as 2010, there was still interest in carrying out further experiment in cold fusion.
Koch's Postulates
Koch's postulates is named after Robert Koch, a German physician known for a number of discoveries that include the isolation of Bacillus anthracis; the cause of anthrax, Mycobacterium tuberculosis; the cause of most instances of tuberculosis, Vibrio cholerae; the cause of cholera and was awarded the Nobel Prize in Physiology and Medicine, in 1905, for his work on tuberculosis.
Koch's Postulate is used in demonstrating if a particular organism is responsible for a specific disease. It was established by Koch while studying anthrax. The criteria established by Koch is still used today to determine if an organism is responsible for a specific disease. The following steps must be followed in order to demonstrate if an organism is the cause of a specific disease:
Association of the pathogen to its host: The pathogen must be consistently associated with the diseased plant or animal.
Isolation of the pathogen from its host: The pathogen must be isolated and grown in pure culture so that it's characteristics can be described.
Inoculation of the pathogen back to its host: The pathogen that has been isolated is inoculated into a host of the same species from which the disease was first isolated and it must exhibit the same symptoms and signs of the original afflicted host.
Re-isolation of the pathogen from the host: The pathogen must be re-isolated from the newly inoculated hosts and the isolated pathogen must have the same characteristics as the one that was first isolated in step #2.
Important Terms and Concepts
Science: A body of knowledge about the natural world where evidence takes priority over authority.
Authority: Refers to individuals that are well known with celebrity status i.e. professional athletes, movie and rock stars, authors, politicians, etc. whose words, philosophy and ideas can have great influence on the people because of the admiration that they have due to their celebrity status.
Scientific Method: A means for rationally and logically answering questions about the world around us.
Hypothesis: The best "guest" as to what you think the answer to a question is when carrying out an experiment with the scientific method.
Control: In a science experiment, a sample that remains the same in the experiment and is not modified and is used as a means of comparison of samples that may be modified by various means. See example hypothesis in lecture.
Theory: A status that a hypothesis will attain after it is thoroughly tested with repeated experimentation that demonstrates that it is the most likely answer to the question of the hypothesis.
Pathological Science: False science knowledge that has been demonstrated not to be valid by the scientific community, but still persist as being true in the minds of non-scientists and despite evidence that says otherwise.
Questions to Think About
What are the different kinds of knowledge discussed in lecture?
How did we define scientific knowledge in lecture?
Why do we use the scientific method to answer questions in science?
What is a hypothesis?
What science that is not hypothesis driven called?
How do we define the term "theory" in science and how does this differ from its everyday usage?
What is a control in the scientific method and why is it important?
What questions cannot be answered by the scientific method?
What is pathological science?
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