Saturday, January 28, 2012

Thaaaats Not Science: Part 2

Notes and Thoughts on Imre Lakatos' 'Science and Pseudoscience'

My favourite quote:
"But the history of thought shows us that many people were committed to absurd beliefs.  If the strength of beliefs were a hallmark of knowledge, we should have to rank some tales about demons, angels, devils, and of heaven and hell and knowledge.  Scientist, on the other hand, are very skeptical of even their best theories."

Ok, lets get this out of the way right off the bat:  I don't know if Imre Lakatos had an affinity for drinking milk.

The Demarkation Problem Revisited

Moving on to the demarkation problem and Lakatos' proposed solution.  Here's the short version: A theory is scientific if it predicts novel facts and it's pseudo-scientific if its predictions are consistently refuted and it produces no new facts about the world.  To see how he arrives at this position lets first look at his arguments against the competing demarkation theories including Popper's falsificationism and Kuhn's idea that science is marked by incorporating puzzle solving.  Kuhn's demarkation line was drawn between enterprises that embrace unsuccessful predictions as research puzzles to be solved (sciences) and those that resort to hand waving to explain away unsuccessful predictions and do not incorporate the problems as part of their research (pseudoscience).   

Vs. It's Science Because It's Derived from the Facts

The first argument is directed at the popular notion that what makes a theory scientific is that it is derived from the facts.  But what exactly does it mean for a scientific theory to be supported by the facts?  That Newton was doing science is pretty much indisputable, but did Newton derive his theory of motion from the facts?  Newton claimed that he had deduced his theories from the facts of planetary motion which had been observed by Kepler.  Kepler's observations were that the planets' orbits were elliptical but according to Newton's theory, planets would only follow such a path if they didn't disturb each other, which they do.  Doh!  So much for the facts.  So, Newton devised a perturbation theory which holds that no planet moves in an ellipse. 

The idea here is that facts are facts and theories are theories.  Got it?  A theory is an interpretation of facts, a story linking events together, if you will.  There can be many different interpretations of the same set of facts, all of them conforming to the facts, no matter how wacky the the theory.   There is also this idea that no theory takes into account every fact.  It not uncommon to gloss over particular facts and/or outliers (events that don't conform with what we'd expect) which may be problematic for the theory.

Vs. Popper's Falsificationism (see: 'Thaaaat's Not Science: Part 1')

The prollem with falsificationism (for a full list see part 1) is that scientists don't throw away theories the moment a fact contracts it or doesn't conform to a prediction.  Scientist will cling to theories for a long time before they are discarded.  Disconfirming evidence is called an anomaly.  Sometimes it's ignored for statistical reasons, sometimes the theory is modified to capture it.  The point is, rarely is the whole theory thrown out for the sake of mere disconfirming evidence.  

If scientists, like their pseudoscientist counterparts, don't reject theories based on non-conforming evidence, what makes one theory science and another pseudoscience?  

Lakatos' Solution to the Demarkation Problem

Step one.  We can have lots of fun.  And by fun I mean, instead of considering individual hypotheses and theories to be the basic unit of scientific achievement, we should consider the unit to be "a research programme".  Fun right?  Science isn't simply a matter of trial and error, this would be trivial.  A research programme is something that encompasses several interconnected theories and hypotheses.  

Consider Newtonian physics.  It is more that its four laws.  These four laws form the core of the Newtonian program but are "protected from refutation by a vast 'protective belt' of auxiliary hypotheses".  On top of all this, a programme has a problem solving method which includes mathematical and statistical techniques to interpret evidence and anomalies.  If a planet doesn't move according to what the theory predicts, the scientist can check his hypotheses concerning atmospheric refraction, propagation of light in magnetic storms, and hundreds of other things that are all contained within the programme.

Newton's theory of physics, Einstein's relativity theory, quantum mechanics, evolutionary biology, homoeopathy, "The Secret", and alchemy are all research programmes that have a core and protective belt of elaborate problem-solving machinery.  At every stage in their development there is disconfirming evidence, anomalies; there are problems.  But how do we separate the scientific programmes from the pseudoscientific? 

Step 2, I'll explain it to you.  Scientific programmes are all able to predict novel facts, "facts which had been either undreamt of, or have indeed been contradicted by previous rival programmes."  What are some examples of novel facts?  Einsteinian relativity predicted that the path of light will be altered by objects with large mass.  That's why light seems to bend when I flex my biceptors.  I kid! I kid!  Einstein's prediction was verified during a solar eclipse.  If you're curious about the details, click on these pre-googled links:

Another example is Halley's prediction, within the Newtonian programme, that the comet that bares his name (co-incidence or what?!) would return in 72 years.  He died before it did, but his prediction didn't!  Before Halley, er'body thought comets only travelled in straight lines but from within the Newtonian programme he was able to shew that some move in hyperbolas or parabolas, and others in ellipses.

So, what separates pseudo-scientific programmes from the scientific?  The scientific programmes make predict previously unknown facts; they lead to further discovery; discovery that competing theories could not make.  In a word, they are progressive. 

Pseudo-science, on the other hand, is degenerative.  Theories are retrofitted and modified only to accomodate existing facts.  Has homoeopathy predicted any novel facts about the world?  How about the programme of The Law of Stupidity, oops, Attraction?  Nope.  What people who work within these programmes do is reinterpret existing facts in such a way so that they will conform with their pre-existing model.   Nothing novel about the world ever emerges.   

"What really count are dramatic, unexpected, stunning predictions; a few of them are enough to tilt the balance; where theory lags behind facts, we are dealing with miserable degenerating research programmes."

No comments:

Post a Comment