What is Science?

By Scot Kelchner

The term science means at least two things:  (1) the application of the scientific method, and (2) the human endeavor to understand our physical world by scientific investigation.

The human scientific endeavor is an ongoing accumulation of evidence-based knowledge about the natural world, continually building upon the experiments and findings of many generations of scientists. It relies upon the proper conduct of scientists, the proper design and interpretation of experiments, and the proper consensus by scientists about the meaning of those experiments.

All scientific understanding is evidence-based, but interpretation can vary about the meaning of any piece of evidence. All scientific views are open to revision if convincing evidence is found that counters our current understanding. Invalid conclusions about the nature of the world are eventually overturned. 

Science, as a human endeavor, is cultural. It is a way that humans are trained to think about the world and how to ask testable questions. A scientist is part of a worldwide scientific community that shares its standards and methods in order to best assess the findings of its members.

Scientific evidence is expected to be testable, repeatable, and falsifiable. Results of an experiment are considered relevant only if the experiment can be repeated and if there was a fair chance that the expected outcome would not occur. New ideas tend to be scrutinized more heavily than familiar or accepted ones.

Odd results from an experiment can often prompt a scientist to reject that experiment completely, on the assumption that something went wrong. The experiment will usually be repeated, but if the odd result is again encountered, one of two things will happen depending on the personality of the scientist:

One type of scientist will be convinced they should have seen the expected result. They will not question their original hypothesis but instead will redesign their experiment, or abandon it entirely. Such a scientist usually reports only those experiments that "work" (i.e., that end with an expected result), which tends to confirm the scientist's understanding of the system being studied.

Another type of scientist, however, might question whether their original hypothesis was valid in the first place. This is a far more exciting line of questioning because the hypothesis itself was a logical application of current knowledge. If the experiment was well designed, the strange result could mean that current knowledge of the system might be incorrect, or at least insufficient.

This later kind of scientist is rare, for he/she will report a negative result but will take the time to explore what it means in the context of a revised understanding of the subject knowledge. Important shifts in human understanding of natural systems often derive from "failed" experiments, when a good scientist questions our basic knowledge and finds it wanting.

The Scientific Method

The scientific method is a tool for investigating the physical world. The reason it is such a powerful tool is that it can return a result that counters human expectations. 

The scientific method begins with a logical expectation, based on our knowledge of the system being tested. For example, our long experience with observing gravity on Earth would lead us to expect that a baseball, when thrown upwards, will come back down. In a scientific experiment, this becomes our hypothesis of how the baseball will behave if thrown upwards.

The next step is to design an experiment that tests our hypothesis convincingly. The best experiments control for known factors that are not the focus of our hypothesis. For example, if we wanted to test gravity's affect on a baseball thrown upwards, we would not throw the baseball over an upturned jet engine. Given what we know about wind resistance, it would be far better to conduct the experiment in the still air of a laboratory.

We then conduct the experiment and record its result. Did the baseball fall back down after it had been thrown upward? If not, what did the ball do? Whether the findings match our expectations or not, we repeat the experiment again and again, each time recording the result. After a large number of repetitions, a conclusion is made. The conclusion either supports or rejects our initial hypothesis.

The final step is to present our hypothesis and its reasoning, our experiment and its results, and our conclusion about the nature of a baseball when thrown upwards on Earth. The presentation, whether written or spoken, is then subjected to peer review. Peer review is a process in which other scientists knowledgeable about the subject matter will study carefully the methods and results of an experiment and see if they agree with the conclusion the scientist presented, particularly as to whether the quality of the evidence is sufficient to make the conclusion convincing.

If the experiment was compelling, and if the findings were of general interest, others might independently repeat the experiment to confirm its results. If these experiments are well designed, and the evidence is still compelling, scientists might then form a consensus about how a baseball will behave when it is thrown upwards in a still room.

The consensus will then become the scientific opinion about the matter until further evidence refutes that understanding. Scientific opinion is always open to revision.