Teorias: bons conselhos para os teóricos


Often we see arguments that try to equate science with religion, in that “belief” in science is just another faith, just another denomination, and no more or less valid than methodism, confucianism, catholicism, mohammedenism (to give it an archaic name), hinduism etc.

The difference couldn’t be more stark, if you consider “belief” more in terms of placing a bet. A space probe, to Mars or to a comet or asteroid, is a very high stakes bet that Newton (and Einstein, where applicable) got it right to a a remarkable level of detail. That such probes have been successful at all shows that the “theory” is a lot more than just a wild guess over a beer. Putting up the money for the complex of orbiting equipment that is GPS was a very big bet that both Newton and Einstein got it right to an extremely fine level of detail, and using a SatNav is a lower stakes bet on the same thing. Do you believe your SatNav? Will it guide you to your chosen destination? Or will it try to park you in the sea?

There are many “theories”. The scientific ones — those that have stood the test of time and the attention of a great many interested parties — are the ones that work. The ones you can bet on. Bet your life on, in fact, on a daily basis.

You seem to have a misconception over what it means to be “falsifiable”. It means only that a worthwhile theory must be testable. Anyone can think up a “theory”. More properly, a “conjecture”, until it passes some tests at least. So, think up a “conjecture”. Now comes the hard part. Getting it accepted as a Theory.

Use your conjecture to make a prediction, to place a bet on something that can be observed, and, with as many independent observers as possible, see what happens. Repeat, before different sceptical audiences, don’t take one success as a “proof”. But, do take even a single failure as a possible “disproof”. If observations don’t fit with the theory, change the theory, not the observations. If in doubt about the observations themselves, try again.

If the bet wins, again and again, then the theory is accepted, at first grudgingly (raivosamente), by others with rival theories, and then, eventually, those who backed the rival theories run out of funds and stop betting on their loser wannabe theories, and take the evidence of your winning streak as a hint that maybe your theory is good for something after all. And then even the cautious betters place massive stakes on the table — all that proof that Newton and Einstein got it right (or right enough).

So, the path to a successful (scientific) Theory is long and difficult. Every test has to be able to support the theory, or to refute it, show that it is not correct. Those that yield repeatable, practical, valuable results become part of the standard body of knowledge, and all technology is built on this.

The history of human understanding of themselves and the world around them is littered with cast-off, broken down former theories, that have failed to bring in the winnings to those who bet on them. Astrology, Alchemy, Phrenology, Homoeopathy, Faith Healing. While tried-and-tested theories are daily re-proven by every satellite launch, every GPS-guided journey, every elevator ride, every airline flight, every cellphone conversation, every medical treatment, web post, and much more.

Only at the frontiers of our knowledge are new conjectures, potential theories, being devised, along with the experiments to test them, weed out (eliminadas) the failures. The tried-and-tested stuff is relegated to the classroom, to teach the next generation the story-so-far, those things that have already been settled. That can be trusted, are being trusted, all the time. The frontier is alive and dynamic, there’s always more to discover, more to find out, and each new piece of knowledge either fits with existing theories, or it breaks some of them. Exciting stuff, for those who like that kind of thing. And profitable too, for those who place their bets wisely.

Stay, explore, learn. Or you could just take somebody else’s word for it all.

I liked a definition I once heard at a science festival. It was an event by Denis Alexander, an evolutionary biologist (and Christian, as it happens), and he answered the question about the difference between a scientific theory and a fact by saying that, in science, a theory is something that explains a fact or set of facts. So for example (he said) it is a simple fact that organisms evolve from earlier organisms; and the scientific theory of evolution by natural selection explains how that evolution happens.

But I do agree that, to the non-scientists among us, there doesn’t always feel to be a huge amount of difference between the two. Scientists, though, who are always looking to discover new details and new facts, need to be clear in their own minds that the search for knowledge is never 100% complete. The key, I guess, is to match the degree of confidence in a claim to the amount of evidence there is for the truth of it.

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