Tuesday, 6 May 2008

Science 101: How we know that what we know is worth knowing.

I have commented here before that I am not particularly impressed with the quality of the science education that I received at school. I had some great teachers, but they were hamstrung by the curriculum, and we spent all our time doing little experiments, some of which were based on debunked ideas anyway (I never could detect different tastes on different regions of my tongue, and I wonder if the people who laughed at me then ever heard that the whole idea of taste regions is bullshit?) instead of talking about what the difference between science and things like religion is (hint - proof).

Thought: I really should do a post on the definition of Philosophy, as well...

But, in recent years, driven by the professional need to evaluate fringe medicine and alternative medical practices, I have gone on a determined period of self-education, and there are various basic principles that have served me well in understanding where scientific knowledge currently stands, and in separating the crap from the canonical (to use a particularly inappropriate word). And then I run straight into someone who has basic misunderstandings of science and scientific processes, and an attempt at a discussion becomes an argument which becomes a series of statements which get nobody anywhere.

As a part of relieving my frustration at these confrontations, and in the hope that somebody, somewhere, will benefit from my experience, here are those principles, in roughly descending order of importance:
  • Reality is complicated. This means that one quibble does not a theory destroy, one factual error in data used to construct a conclusion will probably be lost in the noise, one error by NASA in constructing climate records doesn't mean jack shit when it comes to analysing the long-term trends, pointing out exceptions disproves no rule and when you complain about a majority consensus on anything you had better be prepared to respond to fifteen different lines of evidence, not one. The result of which is:
  • The language of science is probability, not certainty. Science deals in balance of probability. Any "fact" we think we know can potentially be disproved, even if subtly, and usually is. Newtonian physics was found to be incomplete when Einstein gave us relativity. Matter was once thought to be composed of three fundamental particles, but now we know that not only are protons, neutrons and electrons composed of even smaller particles, but that those particles may themselves be just manifestations of fluctuations in space-time. Darwin didn't know about DNA, but understanding DNA is a key part of modern understanding of evolution. Physics thought it was complete at the end of the nineteenth century, and then quantum physics was needed to solve the black body problem. None of which means that Newton and Darwin and everyone else was wrong the first time. They just weren't as right. Absolute knowledge is for all practical purposes impossible, and a very important consequence of this is:
  • There are degrees of truth. Isaac Asimov: "When people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together." Darwin wasn't wrong about evolution because he didn't know about the underlying chemical processes. He was just a bit wrong, and still produced a brilliantly working explanation of genetic diversity. Newton wasn't wrong about the laws of motion because he didn't realise that he was just working on a particular macro scale in a particular gravitational environment. His work was just a bit more situation-specific than he realised. All of which means that, in terms of language:
  • "Theory" does not mean "guess". This is one of the most tired and pointless arguments trotted out by global warming deniers, evolution deniers and all other shades of deniers. "They're not even certain!" They trumpet, "It's just a theory!" Here is the truth: Something which scientists guess at, hope for or wildly surmise is a hypothesis.
    Something which has been demonstrated, at least once, to be true is a theory. See point one above: Science in general (if not scientists in particular) has enough humility to realise that we are, at the moment, only a little bit further along the road to truth than we were yesterday, and not quite as far as we will be tomorrow. Even a theory which can explain the vast diversity of life on earth, lead to vast improvements in medicine and make accurate predictions of change in entire species is still only a theory, because our understanding is still not yet perfect and we keep fine-tuning the details. Yes, there are "laws", but that's got more to do with the confidence of the person who named them than anything else. Compare the laws of thermodynamics with Moore's law. And speaking of individual people:
  • Individuals can be wrong, which is why we have consensus. You can find, if you look hard enough, or even for five seconds on the Internet, a "scientist" who disagrees with anything: Neurologists who don't believe in evolution, climatologists who don't believe that C02 is a climate forcer, you name it. But do you really think that one mind out of all those who have won recognition in their field is the only one to get it right? Very rarely in science do you find a genuine prophet who is without honour in his own country - Einstein won the Nobel Prize while he was still alive. Max Planck demonstrated (see black body radiation) that physics had been entertaining a fundamental untruth, but was not pilloried until the day he died. Scientists who are correct tend to be on the inner. Scientists who remain on the outer - well, there's probably a a very good reason for that. People who use the religious persecution of Galileo to try and defend the flimsy possibility that somebody who is discredited by "the establishment" might be right would do well to remember the words of Carl Sagan: "But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown."

And finally, as an excellent addition to your bullshit-filter:

  • Extraordinary claims demand extraordinary proof. Also known as the "Wow!" factor, or "Anything which sounds too good to be true, usually is" or "What's the catch?" or "Hey, why hasn't he won the Nobel Prize?" This is where people tend to get very defensive and start saying that "The Establishment" is trying to suppress the truth, or that drug companies or energy companies are beating up on threats to their monopolies, or that other scientists are either too scared to accept the truth or too desperately clinging to their own theories. The simple response to which is: Put up, or shut up, and we mean in front of your peers, not the under-educated mass media. Most rejected theories or claims are rejected not because of inertia or low self-esteem in the scientific community, or aggressive and underhand tactics by stakeholders, but because those new theories or claims are, quite simply, crap. Drug companies pour millions into development and are desperately looking for the next monopoly. Scientists will accept any new theory that works and is useful (there's a whole other argument around "So? Your point being?") - in fact, Max Planck even expected wave mechanics to supplant his own quantum mechanics, but he was wrong about that - and the "Establishment" is simply the collection of individual scientists. Truth really does tend to out.

I'll wrap up here with a piece of advice which more self-proclaimed skeptics should really take to heart: Professional scientists have usually done a research higher degree and operate in an environment of cut-throat competition for university positions and grants funding, and truly vicious attacking of any new theory or position. This tends to mean that they're intelligent, sharp-witted and devote their entire lives to pursuit of further knowledge in their chosen field. If you, personally, think that you have spotted a flaw in their work, how likely are you to be right? If they really are wrong, other people will rip them to shreds soon enough. If they keep standing, your world view is probably wrong. Deal with it.

P.S.: If you wish to argue about climate change, please leave it until you read through this: How To Talk To A Climate Skeptic. If you wish to argue about evolution, shut the fuck up until you read through this: Talk Origins: Introduction to Evolutionary Biology.

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