This blog is written for a rational audience that likes to have fun wrestling with unique or controversial points of view. It is written in a style that can easily be confused as advocacy for one sort of unpleasantness or another. It is not intended to change anyone's beliefs or actions. If you quote from this post or link to it, which you are welcome to do, please take responsibility for whatever happens if you mismatch the audience and the content.
Let's get this out of the way first...
In the realm of science, a theory is an idea that is so strongly supported by data and prediction that it might as well be called a fact. But in common conversation among non-scientists, "theory" means almost the opposite. To the non-scientist, calling something a theory means you don't have enough data to confirm it.
I'll be talking about the scientific definition of a theory in this post. And I have one question that I have seen asked many times (unsuccessfully) on the Internet: How often are scientific theories overturned in favor of new and better theories?
I assume Creationists are the ones usually asking the question. And if history is our guide, the comments on this blog will focus on that one area and destroy the value of this blog post. I'm hoping we can ignore evolution and creationism and climate change for one day and just ask the following question: How often does a scientific theory get discarded or replaced with a better one?
I don't think there's a good answer to my question, for lots of reasons.
For starters, I doubt anyone has been keeping a stat on overturned theories. And I don't think it's fair to compare theories from a hundred years ago to theories created today because our ability to collect confirming data today is better than it used to be. I would expect that a theory created recently would be more likely to stand than one created last century.
Still, it has always been true that the stuff we believe today looks way smarter than the dumbass things our grandparents believed. Why wouldn't that be just as true for our future great-grandkids looking back at our
primitive beliefs? Some humility is always called for.
Science requires credibility to be useful. And that's a problem. The non-scientist asks "What is your success rate?" and gets no useful answer. Scientists, as it turns out, are terrible at marketing. About 90% of my exposure to science involves media reports that get correlation and causation confused. As a result of that exposure, the more I hear about science, the less credible it feels
To make matters worse, I have a jaded Dilbert mindset about every industry. Unless science is different from all other human endeavors, 10% of scientists are honest and amazing and doing important science while the other 90% are like Dilbert's worthless co-workers. So when I hear that 98% of scientists are on the same side of an issue, I wonder how many unreliable people you have to add together to get an opinion you can trust.
I don't think I'm alone in my views. I'll bet that if you did a poll you'd find that scientists believe theories are fairly dependable and useful whereas the average non-scientist believes that everything we think we know today eventually gets disproved. Part of the problem is that scientists are looking at utility and non-scientists are looking at "truth" which is a fuzzy and overrated concept.
In every other field, your track record of success determines your credibility. Personally, I have no idea what the track record of science is. All I know are anecdotes about wonderful successes and notable mistakes. I don't even have a general sense of whether scientific theories have usually held up over time or not.
So when scientists say a particular theory is backed by the majority of scientists, how much weight should I put on that? Is that a situation in which I can depend on the scientists to be right 95% of the time or 5%? What's the track record?Note to the Bearded Taint's Worshippers:
Evolution is a scientific fact. Climate change is a scientific fact. When you quote me out of context - and you will - this is the paragraph you want to leave out to justify your confused outrage.
Co-founder of CalendarTree.com
Author of a book
on success. (Makes a good graduation gift, btw)