Myth #1: Any good scientific theory is falsifiable
This idea was advanced by the philosopher Karl Popper, and has been repeated by many others. The idea is that we can distinguish between a scientific theory and an unscientific theory or idea by asking whether or not the theory can be proven wrong, or falsified. It is argued that whenever you have a good scientific theory, you can always imagine observations that might disprove that theory, or falsify it.
But it is easy to imagine some examples of perfectly good scientific theories that are not falsifiable. The best example is the theory that extraterrestrial life exists. There is no way to falsify such a theory, because we can imagine no series of observations that would prove it wrong.
Imagine what it would take to disprove the existence of extraterrestrial life. You might think that this could be accomplished by making a survey of all planets in the universe. But there is no way that any civilization (even a civilization millions of years more advanced than ours) could make such a survey. Because of the limit of the speed of light, it would take eons to survey the planets in an entire galaxy of billions of stars. Once such a survey had been completed, there would still be billions of other galaxies to check. Surveying them all would take billions of years.
Suppose we imagine some civilization with some warp-drive that allows instantaneous travel. Even with a large fleet of warp-drive starships traveling instantaneously, it would take many millions of years to check all the planets in a universe such as ours with more than 1,000,000,000,000,000,000,000 stars. After such a survey, could you then say that extraterrestrial life doesn't exist? No, because there would always be the possibility that life could have started somewhere during the eons it took to do the survey, on one of the planets that had already been checked.
So while it may be true that most scientific theories are falsifiable, it is not at all true that all scientific theories are falsifiable. The theory that life exists on other planets is a top-notch scientific theory that is not falsifiable.
Myth #2: Scientists are almost all unbiased and impartial judges of truth
I'm sure that many scientists are unbiased and impartial judges of truth, but there are reasons why many scientists far fall short of such a standard. First, let's consider sociological factors. A modern scientist belongs to a relatively small subculture subject to sociological factors such as peer pressure, group taboos, and group norms. When a scientists deviates from those group norms and group taboos, he may be subject to punishing sanctions from his peers, which may include ridicule, non-publication of papers, or denial of promotions. In some sciences we see a strong herd mentality, in which scientists tend to jump on some bandwagon which may or may not make sense to jump on. In some cases there may be a financial reward or incentive to jump on that bandwagon, and a financial penalty or sociological penalty for “running against the herd” and rejecting it. Can we suppose that in such cases our scientists act as unbiased and impartial judges of truth? Often they do not. We should not assume that scientists are more likely to be unbiased and impartial judges of truth than people in most other professions.
Consider also the case of a scientist who specializes in some theoretical area such as inflation theory or string theory or some flavor of quantum gravity. Early in his career, such a scientist is almost “betting the farm” on that theory, by taking years to study its intricacies. Once such an investment is made, that scientist becomes a vested interest. He will flourish if that theory gains support, and may flounder if the theory loses support. Is such a person going to be an objective judge about whether the theory is probably true? No, not any more than someone holding 100,000 shares of a particular company will be an objective analyst of the company's future prospects.
Myth #3: Science is whatever scientists think or assert
A good definition of science is observations and experimental data accumulated through methodical investigation, and theories that have been conclusively proven from such observations and data. Are the assertions of scientists limited to such a thing? Not at all. Scientists are people who have opinions, and those opinions are often group norms enforced by their subculture. Such norms may or may not be anything verified by observations or data.
We must distinguish between two different things: science and the opinions of scientific academia. The relation is illustrated in the Venn diagram below. Since there is too much in science to be understood by the average scientist, there is a red area outside of the purple area.
An example of an item in the blue area but not in the purple or red area is the opinion of many scientists that life arose billions of years purely because of chance chemical combinations. Such an opinion does not correspond to an observation or experiment. It's an opinion.
In quite a few cases, writers will misspeak, speaking as if things in the blue area of the diagram are things that are part of science. A writer will maintain that such and such gloomy opinion is science, because most scientists think it. But a scientist's opinions are a mixture of science, his own inclinations, and most likely the ideological norms of his particular subculture. Such norms may or may not correspond to anything that has been actually proven by facts or experiments.
Myth #4: Science is only produced by scientists, or is only what is published in scientific journals
As I stated before, science can be defined as observations and experimental data accumulated through methodical investigation, and theories that have been conclusively proven from such observations and data. Anyone today can methodically collect observations by using a camera and carefully noting facts relevant to the photos. This means that any average Joe can contribute to science, without having a science degree. 90% of the facts accumulated in a biology textbook (such as the basic facts of internal anatomy) were originated by people who did not have degrees in science, but who merely made observations and systematically recorded such observations.
Consequently, appalling as such an idea may be to some scientists, anyone who at length methodically investigates a phenomenon with sufficient diligence and honesty produces work that is as much science as some result from some fancy expensive particle accelerator, regardless of whether the phenomenon is considered paranormal. There is no sound basis for the claim that only work published in scientific journals is science. If such a standard were applied, we would have to throw out half of the facts in our science textbooks, which were originally established by researchers long ago who did not publish in scientific journals.
Myth #5: A theory that makes predictions is more worthy of respect
Science writers often claim that when a theory makes predictions, it is more worthy of respect than some other theory that does not make predictions. But this is not correct. The fact that a theory may make predictions does not mean that it is more likely to be correct than some other theory that does not make predictions.
Consider the following example. A car strikes a pedestrian walking on the outer edge of the road. The first theory is that this was due to pure bad luck, that the driver just failed to notice the person walking on the side of the road. The second theory is that the driver was intentionally trying to kill a random victim. The first theory makes no prediction. But the second theory predicts that the driver will try such a thing again, given his homicidal nature. Does this mean the second theory is more likely to be true? No, it doesn't. It fact, the second theory is less worthy of belief than the first theory, given that careless people are much more common than homicidal people.
Myth #6: If scientists spend lots of time on something, then it's science
Because their small subculture is strongly subject to herd effects and groupthink, scientists may jump on a bandwagon and waste millions of taxpayer dollars and countless man-years pursuing some dubious enthusiasm, the popularity of which may persist for decades. But such activity does not necessarily mean that the underlying theory is actually science. Science is not automatically what scientists have long labored on – it is only what they have proven.
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