Thursday, December 17, 2009

Science cannot prove that a theory is true. Is this true?

I would like to discuss the notion, developed by Karl Popper, that science can only disprove a theory. I remember reading somewhere that if a theory is proven wrong, then the complementary theory is actually being proven right, which would then contradict the claim that no theory whatsoever can be proven right.

Let's take an example, the climate, not only because the conference on climate change in Copenhague in on this week, but also because it is the system that I am the most familiar with. Say, a theory states that El-Niño is caused by wind bursts in the western Pacific. As long as observations show that wind bursts do occur before the start of El-Niño, you are only observing the facts that the timing of the events might be related but you are not proving that the wind bursts do cause El-Niño. Each can independently be caused by something else. However, if one year, there is no wind burst but an El-Niño, then you are proving that El-Niño is not caused, at least not all the time, by wind bursts. In this case, we have proven that the theory "wind bursts do not always cause El-Niño" is true.

The difference between the two theories is that the first one is a predicting theory which is supposed to work all the time, while the second is not; in other words, the first one is useful, not the second. To prove a predicting theory, you need to prove that the causation works all the time but because the world is infinite and open to the future, you can never prove it absolutely. The more the theory succeeds the tests, the more likely it is, but that is it, no certainty. However, to prove a non-predicting theory, only one example suffices, which we have done above. And so here is the crux of the argument: Formal definitions of theory do include that a theory should be able to perform predictions. So the second "theory" above is actually not a theory. And so yes, indeed, science cannot prove that a theory is true but it can prove other things!

Sunday, December 13, 2009

Murakami's small lesson

"To be able to grasp something of value, sometimes you have to perform seemingly inefficient acts. But even activities that appear fruitless don't necessarily end up so."
Haruki Murakami, What I talk about when I talk about running, Chapter 9.

Thursday, December 10, 2009

L'Allemagne et l'identité nationale

Christian Estrosi, un parlementaire français, vient récemment de commenter que si l'Allemagne s'était posée la question de l'identité nationale, le Nazisme n'aurait pas existé. Ce commentaire est une distortion de l'Histoire. Même si on ne peut pas faire un lien directe entre la pensée Allemande du 18e et 19e et le Nazisme du 20e, et rendre pour responsable Herder, Goethe et Nietzsche (meme si Heidegger était lui-même un Nazi), il est en revanche faux de dire que l'Allemagne n'a pas participé à la question de son identité. Au contraire! Pendant plus d'un siècle, sous l'emprise d'abord d'un empereur-dictateur, puis envahie par un autre empereur-dictateur, Napoléon, un derivé malheureux de la Révolution Française, l'Allemagne n'a cessé de se poser cette question. Heder a été l'un des premiers a exprimé le plus clairement cette question et a posé les fondations d'une philosophie où le peuple Allemand peut enfin s'épanouir et definir une identité specifique au sein même d'un environnement universalisant.

Dans cette thèse de Cambridge (en Anglais), même si l'auteur démontre qu'il y a une cassure dans la pensée Allemande avec le Nazisme, il ne peut pas ignorer ce grand débat de l'identité nationale qui a fait vibrer l'Allemagne (lisez en particulier le lien "II.The Great Debate" de son introduction).

Restons fidèle à l'Histoire.

Sunday, December 6, 2009

The psyche of the writer

"There's a widely held view that by living an unhealthy lifestyle a writer can remove himself from the profane world and attain a kind of purity that has artistic value. [...]
Basically I agree with the view that writing novels is an unhealthy type of work. When we set off to write a novel, when we use writing to create a story, like it or not a kind of toxin that lies deep down in all humanity rises to the surface. All writers have to come face-to-face with this toxin and, aware of the danger involved, discover a way to deal with it, because otherwise no creative activity in the real sense can take place. [...]
So from the start, artistic activity contains elements that are unhealthy and antisocial. I'll admit this. This is why among writers and other artists there are quite a few whose real lives are decadent or who pretend to be antisocial. I can understand this. Or, rather, I don't necessarily deny this phenomenon. [...]
But those of us hoping to have long careers as professional writers have to develop an autoimmune system of our own that can resist the dangerous (in some cases lethal) toxin that resides within. Do this, and we can more efficiently dispose of even stronger toxins. In other words, we can create even more powerful narratives to deal with these. But you need a great deal of energy to create an immune system and maintain it over over a long period. You have to find that energy somewhere, and where else to find it but in our own basic physical being?
To deal with something unhealthy, a person needs to be as healthy as possible. That's my motto. In other words, an unhealthy soul requires a healthy body. [...] The healthy and the unhealthy are not necessarily at opposite ends of the spectrum. They don't stand in opposition to each other, but rather complement each other, and in some cases even band together."
Haruki Murakami, What I talk about when I talk about running, Chapter 5.