Content
The scientific method is a research method that characterizes natural Sciences since the seventeenth century. It is a rigorous process that allows to describe situations, formulate and contrast hypotheses.
To say that he is a scientist means that his goal is to produce knowledge.
It is characterized by:
- Systematic observation: It is an intentional and therefore selective perception. It is a record of what happens in the real world.
- Question or problem formulation: From observation, a problem or question arises that wants to be solved. In turn, a hypothesis is formulated, which is a possible answer to the question posed. Deductive reasoning is used to formulate hypotheses.
- Experimentation: It consists of the study of a phenomenon through its reproduction, usually in laboratory conditions, repeatedly and under controlled conditions. The experimentation is designed in such a way that it can confirm or refute the proposed hypothesis.
- Issuance of conclusions: The scientific community is in charge of evaluating the results obtained through peer review, that is, other scientists of the same specialty evaluate the procedure and its results.
The scientific method can lead to theory development. Theories are statements that have been verified, at least partially. If a theory is verified as true in all time and place, it becomes law. The natural laws they are permanent and immutable.
There are two fundamental pillars of the scientific method:
- Reproducibility: It is the ability to repeat experiments. Therefore, Scientific Publications include all data on the experiments performed. If they do not provide the data to allow the same experiment to be repeated, it is not considered a scientific experiment.
- Refutability: Any hypothesis or scientific statement can be refuted. That is, you must at least be able to imagine an empirically testable statement that contradicts the original statement. For example, if I say, "all violet cats are female”, It is impossible to falsify, because purple cats cannot be seen. This example may seem ridiculous but similar claims are made publicly about entities that are also not observable, such as aliens.
Examples of scientific method
- Anthrax contagion
Robert Koch was a German physician who lived in the second half of the 19th and early 20th centuries.
When we speak of a scientist, his observations are not only of the world around him but also of the discoveries of other scientists. Thus, Koch first starts from Casimir Davaine's demonstration that the anthrax bacillus was transmitted directly between cows.
Another thing he observed were unexplained outbreaks of anthrax in places where there was no individual with anthrax.
Question or problem: Why is anthrax contagious when there is no individual to initiate the contagion?
Hypothesis: The bacillus or a part of it survives outside a host (infected living being).
Experiment: Scientists often have to invent their own experimental methods, especially when approaching an area of knowledge that has not yet been explored. Koch developed his own methods to purify the bacillus from blood samples and to culture it.
Result of the discoveries: The bacilli cannot survive outside a host (hypothesis partially disproven). However, the bacilli create endospores that do survive outside of a host and are capable of causing disease.
Koch's research had multiple consequences in the scientific community. On the one hand, the discovery of the survival of pathogens (that cause disease) outside the organisms initiated the protocol of sterilization of surgical instruments and other hospital items.
But in addition, his methods used in anthrax research were later perfected for the study of tuberculosis and cholera. For this, he developed staining and purification techniques, and bacterial growth media such as agar plates and Petri dishes. All these methods are still used today.
Conclusions. Through his work based on the scientific method, he reached the following conclusions, which are still valid today and govern all bacteriological research:
- In sickness, a microbe is present.
- The microbe can be taken from the host and grown independently (culture).
- The disease can be produced by introducing a pure culture of the microbe into a healthy experimental host.
- The same microbe can be identified in the infected host.
- Smallpox vaccine
Edward Jenner was a scientist who lived in England between the 17th and 19th centuries.
At that time smallpox was a dangerous disease for humans, killing 30% of those infected and leaving scars in the survivors, or causing them blindness.
However, smallpox in the won it was mild and could be spread from cow to human by sores located on the cow's udders. Jenner found that many dairy workers maintained that if they had caught smallpox from cattle (which was cured quickly) they would not get sick from human smallpox.
Observation: Belief of immunity obtained from the contagion of cattle smallpox. From this observation, Jenner went on to the next step in the scientific method, holding the hypothesis that this belief was true and carrying out the necessary experiments to prove or disprove it.
Hypothesis: The contagion of cattle pox gives immunity to human smallpox.
Experiment: Jenner's experiments would not be accepted today as they were performed on humans. Although at that time there was no other way to test the hypothesis, experimenting with a child today would still be completely inadmissible. Jenner took material from the cowpox sore from the hand of an infected milkmaid and applied it to the arm of a boy, the son of her gardener. The boy was ill for several days but then made a full recovery. Jenner later took material from a human smallpox sore and applied it to the same child's arm. However, the boy did not contract the disease. After this first test, Jenner repeated the experiment with other humans and then published his findings.
Conclusions: hypothesis confirmed. Therefore (deductive method) infecting a person with cowpox protects against human smallpox infection. Later, the scientific community was able to repeat Jenner's experiments and obtained the same results.
In this way the first "vaccines" were invented: applying a weaker strain of a virus to immunize the person against the strongest and most harmful virus. Currently the same principle is used for various diseases. The term "vaccine" comes from this first form of immunization with a bovine virus.
- You can apply the scientific method
The scientific method is a way of testing hypotheses. In order to be applied, it is necessary to be able to carry out an experiment.
For example, suppose you are always very sleepy during your math class.
Your observation is: I dream in math class.
One possible hypothesis is: You are sleepy in math class because you didn't get enough sleep the night before.
To carry out the experiment that proves or refutes the hypothesis, it is very important that you do not change anything in your behavior, except for the hours of sleep: you should have the same breakfast, sit in the same place in the class, talk to the same people.
Experiment: The night before math class you will go to sleep an hour earlier than usual.
If you stop feeling sleepy during math class after doing the experiment repeatedly (don't forget the importance of doing the experiment several times) the hypothesis will be confirmed.
If you continue to be sleepy, you should develop new hypotheses.
For example:
- Hypothesis 1. One hour of sleep was not enough. Repeat the experiment increasing two hours of sleep.
- Hypothesis 2. Another factor intervenes in the sensation of sleep (temperature, food consumed during the day). New experiments will be designed to assess the incidence of other factors.
- Hypothesis 3. It is mathematics that makes you sleepy and therefore there is no way to avoid it.
As can be seen in this simple example, the scientific method is demanding when drawing conclusions, especially when our first hypothesis is not proven.
