by Doctor Science
Performed by Ken Ham and Bill Nye:
I didn't watch the debate between Ken Ham and Bill Nye, I've been too busy working to devote 3 hours to writhing between embarrassment and rage. And I definitely fall (or fell) in the camp of scientists who thought Bill was just feeding the trolls by agreeing to the debate.
Now, I'm not so sure, because I've seen many comments to the effect that Nye's enthusiasm and joy in science came across really well. And he also was able to convey how much scientists change our minds, and how much we *like* it.
I'll take this opportunity to re-post my favorite metaphor for scientific epistemology, how scientific knowledge works.
Imagine that there is such a thing as objective Truth, represented as a single point. Scientific knowledge is like a spiral, circling the Truth and getting closer all the time:
But you can't get all the way to Truth this way, Truth is a singularity or mathematical limit. You just get *closer*, close enough for one purpose or another -- but you'll never be exactly there. And it's a spiral, not a straight-line, Zeno's-paradox-type approach, because the direction you're coming from is always changing -- you're never heading directly toward Truth, it's always at an angle. A scientist can never be 100% certain, just 99.999...% -- and always striving for another 9. The truth always comes with an error bar.
I think this was the greatest philosophical achievement of 20th-century science: realizing that the quest for capital-T Truth means you have to give up capital-C Certainty. It took a while, but I'd say most scientists are now content with the idea that there are things that are in principle uncertain or unprovable, that one way to learn is to get proved wrong, and that your ideas about the world are going to change. That's why scientists can face situations like oops, we seem to have misplaced 80% of the universe -- AGAIN without getting terribly bent out of shape about it -- not that it wouldn't be nice to have some answers we all agree about, but it's not a horrible epistemological trauma.
What Ken Ham wants is not science, it is 100.000% Certainty. He thinks that he can be absolutely positively sure about some things, without any need to strive for another 9. He believes his Certainty has nailed Truth in place, that there's no singularity or spiral of knowledge. There are no error bars on his Biblical Truth.
The kind of epistemological uncertainty that Bill Nye can accept and even revel in is a trauma for a lot of people like Ham. Perhaps 20 years ago I remember reading an article in Biblical Archaeology Review, in which the author was expressing irritation at historical-critical analysis of the Bible, because "what kind of real knowledge changes every generation?" Well, that would be scientific knowledge, actually, where even if new knowledge doesn't sweep the old away, it changes it so it becomes gradually unrecognizable.
For a lot of people the result will be Future Shock. I think this is what a lot of the "culture wars" are about: people who've been trained to rely on Fundamental Truths, who don't expect the shock of the new, being hit with it wave after wave.
I know it often looks, from the outside, as though scientists are hyper-certain judgmental assholes who can't deal with disagreement. But in fact there's a huge difference between the disagreements and uncertainties within the Pale of science -- which are many and loud -- and those with outsiders who don't come armed with scientific-type evidence.
For instance, right now scientists as a whole "believe" in evolution a lot more than we "believe" in gravity. The basic theory of evolution by natural selection is very well-supported and stable, it's in what Thomas Kuhn calls a period of "normal science". Gravitational theory, on the other hand, is over-ripe for a paradigm shift: physicists are quite certain that most current theories are *wrong*, but they haven't been able to agree on one that might be *right*. And this has been going on for decades.