Persons who try to discredit science or otherwise are quite skeptical of the scientific enterprise frequently voice the following claim almost immediately betraying a very fundamental misunderstanding:
You can't trust scientific findings! Scientists got it wrong so much in the past and what we think was a fact constantly gets overturned! Everything we know today is going to turn out to be wrong in the future. Look at [example x theory or idea]. People thought that was true, but now we know it is not. You can't trust scientists.
A recent NPR article titled "Debunked Science: Studies Take Heat in 2011" discusses three non-findings/retractions that lead the author to write, "2011 may go down as the year of the retraction in the scientific world." Additionally, the author noted that "non-discoveries" of 2011 (a genetic basis for longevity, a new form of life, an explanation for autism, and a link between a virus and chronic fatigue syndrome) "have something in common: They involved findings that both scientists and the public badly wanted to believe."
I am worried that the above "you can't trust science" sentiment may be reinforced by this article and am quite dismayed that the author did not dedicate some space to detail why people should not be dismayed (especially when the general public, it seems, does not know too much about science as a discipline, but rather looks at science as a technology mill).
Interestingly, some of what the author mentions to provide evidence to support his claim of "2011 may go down as the year of retraction in the scientific world" is not even a study or otherwise was not even accepted by the scientific community.
The caption for the article's picture of Mono Lake in California where some thought a new form of bacterial life was found says, "The report was immediately greeted with skepticism from the scientific community." Later in the article, regarding the possible new form of life, the author notes, "[M]any experts in field were unimpressed by NASA's event [the press conference announcing the finding]."
One of the researchers, Wolfe-Simon, said the following, according to a Wired.com article:
“These data show that we are getting substitution across the board,” Wolfe-Simon says. “This microbe, if we are correct, has solved the challenge of being alive in a different way.”“It isn’t about arsenic, and it isn’t about Mono Lake,” says Wolfe-Simon. “There’s something fundamental about understanding the flexibility of life. Any life, a microbe, a tree, you grind it up and it’s going to be CHNOPS. But we have a single sample of life. You can’t look for what you don’t know.”
Let's suppose, though, that the scientists did 'jump the gun' and claimed that a new form of life was found and that their statements were later retracted. Would this lead to the conclusion that scientists' findings can't be trusted or that this is somehow a flaw in the scientific process? Peer review is a very important part of the scientific process. Findings of researchers are 'out in the open' so that others can critique the data and possibly lead to either retractions of published findings. This should be considered a great strength of science and should give people good reasons to, in many cases, assent to experts' opinions/findings.
The level of openness in science is much different than, say, what goes on in the minds of young earth creationists (YEC's) or '9/11 truthers' in many cases. In science, when good reasons are presented that should lead one to reject a certain idea, the idea is rejected and scientists are willing to reject the idea. When YEC's are shown that the earth is indeed older than 10,000 years, the YEC's attempt to 'save their theories' by making ad-hoc (unfalsifiable and unjustified) moves such as "Well, the universe was made with the appearance of age" or "God just wants our faith to be tested." Truthers claim that evidence against their ideas are just part of a conspiracy, a distraction from the real conspiracy, or a fabrication of the mass media/government because that is what "they" "want you to believe."
Some theists, additionally, when faced with the problem of natural evil (the argument that belief in an omni-good god is irrational because of the amount of egregious suffering in the universe caused by natural occurrences), seem to employ similar thinking. Instead of giving up belief in an omni-good god when presented with reason, argument, and evidence (vis-a-vis the problem of natural evil), some theists assert "for all we know, there could be a reason that God has, but we just don't know it." What is the reason for this? How can we know that "there could be a reason" and why don't these people apply such skepticism globally? (For all we know, perhaps God requires earthquakes for the salvation of children, so we shouldn't say earthquakes are a bad thing...)
If your belief is immune to being shown false, it seems, that belief ought to be rendered irrational. A wise man, as David Hume once said, proportions his belief to the evidence. When the evidence is greatly weighed against a certain idea, the wise course of action would be to discard the idea instead of making ad-hoc moves to 'save your theory.' Falsifiability, as we see, is a very important characteristic of a good [scientific] explanation while unfalsifiable beliefs, no matter what evidence might come up tomorrow, would not be discarded.
The whole notion of willingness to discard ideas when good reason, argument, and evidence is presented shows a great level of intellectual honesty and should lead people to trust findings generated from such a 'system.' Each retraction in science should lead a person to conclude that, even though they don't have the expertise to thoroughly analyze findings, a great deal of justified trust can be placed in the findings of scientists. After all, other experts are out there who do analyze the findings to 'wipe away' possible biases of the researchers reporting the results or flaws in studies.
Science, contrary to what the NPR article seems to assert, isn't about what scientists want to believe, but rather is concerned with what is true or otherwise can be justifiably asserted given the current evidence. Unfortunately, some reporting by media outlets [and not the scientists themselves] can 'jump the gun' and individual readers will believe a certain proposition when the scientists themselves are not even making a claim.
While it may be the case [or some may even argue is the case] that much of what we believe now about the universe will be either overturned or greatly amended in the future, this should not lead us to despair, but rather should assure us that scientists are honest and willing to amend or overturn findings provided new evidence comes in. This is what we call progress.