Carl Sagan once wrote that a major problem in education today is that science is often presented to students as a collection of disjointed facts, separated from the method that make sense of them. My own early scholastic experience was a verification of this claim. For this reason, many otherwise bright people are scientifically illiterate, holding to numerous myths about science and the scientific method that I wish to dispel here.
Myth 1 - Science is a body of knowledge, a collection of factsEdit
Anyone who has read the title of this site knows that science is not merely a collection of facts, but a method of learning about the world, and error correcting what we already believe. This differs science from other authoritative bodies of collected "knowledge", such as dogma.
Myth 2 - Science claims to have "All the answers"Edit
This is related to myth #1. While we learn about "science' in "science class" the scientific method itself is typically not taught explicitly in schools. For this reason, we come to see scientific facts devoid of the method of science, we come to see science as just "another subject" like English - a group of facts that we are to learn to the point of memorization, and never question. We are asked to give the 'right' answer and when and if we give a wrong answer we are graded accordingly. Science taught in this fashion appears to us as a mystical and unknown authority, that claims to have answers to everything. This is unfortunate, because science is all about questioning what we know. Science, by its real nature, is humble and tentative, even when in some cases, scientists themselves may be anything but humble or tentative. Science does not claim to have all the answers: what it claims to have is the best way to learn what the answers may be. Those who disagree are invited to offer their critiques of this falsfiable claim!
Myth 3 - Science is arrogant!Edit
This follows from myth #2. While a particular scientist (or advocate of science) may be arrogant, the scientific method is humble and hestiant. We accept that all claims fall short of certainty. The scientific method is the antithesis of the arrogance of strongly held unjustified belief. Those who insist science is arrogant may simply be projecting a repressed sense of intimidation. Scientists themselves often speak with humility for at least one very human reason: no matter how smart any scientist may be, there's always someone smarter, always someone who knows more.
Science asks us to question authority. It depends upon the questioning of authority. New learning often comes from refuting current claims about the world. While much of science does simply add to what we already know, the greatest scientific discoveries turned previous knowledge on its head (i.e. Einstein's relativity, quantum theory, chaos theory)
Myth 5 - Science changes what the 'answers" are all the time, making it unreliableEdit
This myth confuses inductive uncertainty for unreliability. We cannot be completely certain that the heliocentric theory is true, but the current theory certainly makes reliable predictions. It is an error to confuse the "error correcting" abilities of the scientific method as somehow making the scientific claims "wishy washy." The tenative nature of scientific claims only means that we do not hold to our results as a dogma, not that our results are unreliable. Being certain does not make us right; being certain often keeps us from uncovering what really is the truth.
Myth 6 - "That's only a theory" i.e theories are just educated guesses.Edit
This myth creates so many errors at once that it requires a good deal of time and instruction to help those who, thorugh ignorance, hold to it. The idea that scientific theories are 'only a theory' mistakes a scientific theory for a hunch, or educated guess, rather than what it really is - a system of learned concepts that describe,explain, predict and/or guide us in how to control the nature or behavior of a specified set of phenomena, based on a preponderance quantifiable, observed data and supported by experiments that are capable of being replicated. To launch this criticism at science requires that one remain ignorant of science.
Myth 7 - Hypotheses Become Theories Which Become LawsEdit
It is a generally held belief that there is a developmental sequence from hypothesis to theory to scientific law. This is actually backwards: theory is the goal of science, laws often are deduced first! Laws are generalizations, principles or patterns in nature; theories are the explanations of those generalizations. A law allows us to make a prediction, but does not give us an explanation of the forces at work. A good historical example would be the fact that while the ancients could predict an eclipse, they had no idea what exactly an eclipse was. In fact, eclipse prediction was used in China to help avert dragons from eating the sun! Gravity is a modern example of a well-established law for which no really satisfying theory is available. We can make very accurate predictions using the Law of Gravity, but we don't have any consensus notion of how it functions!
Myth 8 - Experiments are the Principle Route to Scientific Knowledge.Edit
While controlled, replicable experimentation are considered the gold standard in research as well as the best way to demonstrrate causal relationships, controlled experimentation is not the sole means of creating scientific knowledge. Many fundamental discoveries in astronomy are based on extensive observations rather than experiments. While experimentation may not be plausible in particular cases, falsifiabiltiy must be. A good example is the famous response of how evolutionary theory could be falsifiable without experimentation. J.B.S. Haldane (1892–1964 is reported to have replied: "Rabbits in the Pre-Cambian". To abstract this statement: a later discovery can always lead to the need to reject or at least radically revise any falsifiable statement.
More information about scientific theories is a mere step away: What is a Theory?