Scientific Method Essay Example for Free

Scientific Method Essay The scientific method has four steps 1. Observation and description of a phenomenon. The observations are made visually or with the aid of scientific equipment. 2. Formulation of a hypothesis to explain the phenomenon in the form of a causal mechanism or a mathematical relation. 3. Test the hypothesis by analyzing the results of observations or by predicting and observing the existence of new phenomena that follow from the hypothesis. If experiments do not confirm the hypothesis, the hypothesis must be rejected or modified (Go back to Step 2). 4. Establish a theory based on repeated verification of the results. The subject of a scientific experiment has to be observable and reproducible. Observations may be made with the unaided eye, a microscope, a telescope, a voltmeter, or any other apparatus suitable for detecting the desired phenomenon. The invention of the telescope in 1608 made it possible for Galileo to discover the moons of Jupiter two years later. Other scientists confirmed Galileos observations and the course of astronomy was changed. However, some observations that were not able to withstand tests of objectivity were the canals of Mars reported by astronomer Percival Lowell. Lowell claimed to be able to see a network of canals in Mars that he attributed to intelligent life in that planet. Bigger telescopes and satellite missions to Mars failed to confirm the existence of canals. This was a case where the observations could not be independently verified or reproduced, and the hypothesis about intelligent life was unjustified by the observations. To Lowells credit, he predicted the existence of the planet Pluto in 1905 based on perturbations in the orbits of Uranus and Neptune. This was a good example of deductive logic. The application of the theory of gravitation to the known planets predicted that they should be in a different position from where they were. If the law of gravitation was not wrong, then something else had to account for the variation. Pluto was discovered 25 years later. Limitations of the Scientific Method Science has some well-known limitations. Science works by studying problems in isolation. This is very effective at getting good, approximate solutions. Problems outside these artificial boundaries are generally not addressed. The consistent, formal systems of symbols and mathematics used in science cannot prove all statements, and furthermore, they cannot prove all TRUE statements. Kurt Godel showed this in 1931. The limitations of formal logical systems make it necessary for scientists to discard their old systems of thought and introduce new ones occasionally. Newtons gravitational model works fairly well for everyday physical descriptions, but it is not able to account for many important observations. For this reason, it has been replaced by Einsteins general theory of relativity for most celestial phenomena. Instead of talking about gravity, we now are supposed to talk about the curvature of the four-dimensional time-space continuum. Scientific observations are also subject to physical limits that may prevent us from finding the ultimate truth. The Heisenberg Uncertainty Principle states that it is impossible to determine simultaneously the position and momentum of an elementary particle. So, if we know the location of a particle we cannot determine its velocity, and if we know its velocity we cannot determine its location. Jacob Bronowski wrote that nature is not a gigantic formalizable system because to formalize it we would have to make some assumptions that cut some of its parts from consideration, and having done that, we cannot have a system that embraces the whole of nature. The application of the scientific method is limited to independently observable, measurable events that can be reproduced. The scientific method is also applicable to random events that have statistical distributions. In atomic chemistry, for example, it is impossible to predict when one specific atom will decay and emit radiation, but it is possible to devise theories and formulas to predict when half of the atoms of a large sample will decay. Irreproducible results cannot be studied by the scientific method. There was one day when many car owners reported that the alarm systems of their cars were set off at about the same time without any apparent cause. Automotive engineers were not able to discover the reason because the problem could not be reproduced. They hypothesized that it could have been radio interference from a passing airplane, but they could not prove it one way or another. Mental conceptual experiences cannot be studied by the scientific method either. At this time there is no instrumentation that enables someone to monitor what anybody else conceives in their mind, although it is possible to determine which part of the brain is active during any given task. It is not possible to define experiments to determine objectively which works of art are great, or whether Picasso was better than Matisse. So-called miracles are also beyond the scientific method. A person has tumors and faces certain death, and then, the tumors start shrinking and the person becomes healthy. What brought about the remission? A change in diet? A change in mental attitude? It is impossible to go back in time to monitor all variables that could have caused the cure, and it would be unethical to plant new tumors into the person to try to reproduce the results for a more careful study. Critical Thinking The scientific method relies on critical thinking, which is the process of questioning common beliefs and explanations to distinguish those beliefs that are reasonable and logical from those which lack adequate evidence or rational foundation. Arguments consists of one or more premises and one conclusion. A premise is a statement that is offered in support of a claim being made. Premises and claims can be either true or false. In deductive arguments the premises provide complete support for the conclusion. If the premises provide the required degree of support for the conclusion then the argument is valid, and if all its premises are true, then the conclusion must be true. In inductive arguments the premises provide some degree of support for the conclusion. When the premises of inductive arguments are true, their conclusion is likely to be true. Arguments that have one or more false premises are unsound. Fallacies Arguments are subject to a variety of fallacies. A fallacy is an error in reasoning in which the premises given for the conclusion do not provide the needed degree of support. A deductive fallacy is a deductive argument where the premises are all true but reach a false conclusion. An inductive fallacy consist of arguments where the premises do not provide enough support for the conclusion. In such cases, even if the premises are true, the conclusion is not likely to be true. Common fallacies are categorized by their type, such as Ad Hominem (personal attack), and appeals to authority, belief, fear, ridicule, tradition, etc. An example of an Ad Hominem fallacy would be to say You do not understand this because you are American (or Chinese, etc. . The national origin of a person (the premise) has nothing to do with the conclusion that a person can understand something or not, therefore the argument is flawed. Appeals to ridicule are of the form: You would be stupid to believe that the earth goes around the sun. Sometimes, a naive or false justification may be added in appeals to ridicule, such as we can plainly see the sun go around the earth every day. Appe als to authority are of the form The president of the United States said this, therefore it must be true. The fact that a famous person, great person, or authority figure said something is not a valid basis for something being true. Truth is independent of who said it. Types of Evidence Evidence is something that provides proof concerning a matter in question. Direct or Experimental evidence. The scientific methods relies on direct evidence, i. e. , evidence that can be directly observed and tested. Scientific experiments are designed to be repeated by other scientists and to demonstrate unequivocably the point that they are trying to prove by controlling all the factors that could influence the results. A scientist conducts an experiment by varying a single factor and observing the results. When appropriate, double blind experiments are conducted to avoid the possibility of bias. If it is necessary to determine the effectiveness of a drug, an independent scientist will prepare the drug and an inert substance (a placebo), identifying them as A and B. A second scientist selects two groups of patients with similar characteristics (age, sex, etc. ), and not knowing which is the real drug, administers substance A to one group of patients and substance B to the second group of patients. By not knowing whether A or B is the real drug, the second scientist focuses on the results of the experiment and can make objective evaluations. At the end of the experiment, the second scientist should be able to tell whether the group receiving substance A showed improvements over those receiving substance B. If no effect can be shown, the drug being tested is ineffective. Neither the second scientist nor the patients can cheat by favoring one substance over another, because they do not know which is the real drug. Anecdotal, Correlational, or Circumstantial Evidence. Where there is smoke, there is fire is a popular saying. When two things occur together frequently, it is possible to assume that there is a direct or causative relationship between them, but it is also possible that there are other factors. For example, if you get sick every time that you eat fish and drink milk, you could assume that you are allergic to fish. However, you may be allergic to milk, or only to the com bination of fish with milk. Correlational evidence is good for developing hypotheses that can then be tested with the proper experiments, e. g. drink milk only, eat fish only, eat fish and milk together. There is nothing wrong with using representative cases to illustrate an inductive conclusion drawn from a fair sample. The problem arises when a single case or a few selected cases are used to draw a conclusion which would not be supported by a properly conducted study. Argumentative Evidence consists of evaluating facts that are known and formulating a hypothesis about what the facts imply. Argumentative evidence is notoriously unreliable because anybody can postulate a hypothesis about anything. This was illustrated above with the example about the channels of Mars implying intelligent life. The statement I heard a noise in the attic, it must be a ghost also falls in this category. Testimonial Evidence. A famous football player appears on television and says that Drug-XYZ provides relief from pain and works better than anything else. You know that the football player gets paid for making the commercial. How much can you trust this evidence? Not very much. Testimonials are often biased in favor of a particular point of view. In court proceedings, something actually experienced by a witness (eyewitness information) has greater weight than what someone told a witness (hearsay information). Nevertheless, experiments have repeatedly demonstrated that eyewitness accounts are highly unreliable when compared with films of the events. The statement I saw a ghost last night. is an example of testimonial evidence that probably cannot be verified and should not be trusted. On the other hand, the statement I saw a car crash yesterday. can be objectively verified to determine whether it is true or false by checking for debris from the accident, hospital records, and other physical evidence. Make full use of your senses. Making use of your senses is the subjective part of the Methodology. This is the stage where your special sensory skills can be put to use. If you have extraordinary hearing, use it. If you have a photographic memory make sure that it gets used for most of your problem solving. Nobody else has your s pecific impressions of your environment. Your point of view and your observations are unique. Part of using your senses may involve using instrumentation or interaction with others. Lucky charms, divining rods, and other magical devices that do not have reproducible and verifiable functionality do not count as instrumentation. If you dont have perfect eyesight and you need to see something clearly, use your glasses. Make observations from several points of view to get good depth perception and to confirm impressions. Take photographs if you need to remember something in great detail. Use a tape recorder or a notepad to record your observations for later review. Make sure that your senses are at their best by avoiding intoxicants that affect your perceptions. Interaction with others may involve using another being (not necessarily human) to make the observations for you. For example, a blind person may use a seeing-eye dog to get around, a truck driver may use directions from someone else when backing up into a tight spot, a hunter may use a dogs sense of smell for tracking game, or a miner may use a canary to warn him of pockets of unbreathable odorless gases. Whenever you trust someone elses perception more than your own you may find that the conclusions that you reach are unsatisfactory. How many hunters have been led astray by dogs that followed a rabbits trail rather than the foxs? And how many truck drivers have crashed while backing up because they misinterpreted their helpers signals? Reliance on your own senses is the only way to avoid such problems, but you dont always have this choice. The application of logic may be necessary to determine which perceptions you can trust. Let us say that you are not under the influence of any drugs and you see an apparition of a dead person, what should you do? How do you distinguish hallucinations from real perceptions? How do you know if your senses fool you or if your observations are real? One time-honored test is to pinch yourself to make sure that you are not dreaming. If you should tell someone else about your experience and they dont observe the same things, does this mean that you are crazy or that something is wrong with you? Or does this prove that you have more refined perception that enables you to see things that others do not see? What would it be like to live in a world where only you have color vision and everyone else is colorblind? The difference between real perceptions and hallucinations is that you can repeat and reproduce results from real perceptions but not from hallucinations. In a world where you are the only person with color vision, you would eventually be able to prove to everyone else by objective means that colors, or at least different frequencies of light, do exist.