Friday, December 03, 2004

Chemical substance and just theories

A rose is a rose is a rose.

True but even more as I have learnt again recently and especially in people's understanding of science. Driving to IUB I heard a radio progamm on creationists somewhere in the bible belt that put stickers on school books saying that "Darwinism is just a theory". Fair enough. But what do these people really mean? Theories are the best approximation to the truth that science has to offer. Anything based on empirism can a best yield theories. Based on our limited observations, we can never deduce anything that is actually true (meaning guarantied to be true).

Of course, there are other ways to truth than observation and deduction: Mathematical theorems are true (meaning derivable from the axioms). But that truth is only internal and doesn't tell us anything about the world.

And of course there are a lot of people (some with blogs) that even doubt that string theory is really a theory. It is probably impossible to argue with them and I wouldn't go down the road and discuss falsifyability with them as this positivist concept (although still in many physicists box of tools) is from a philosophy of science quite old fashioned.

Thomas Kuhn has taught us that falsifyability is really an illusion and that no experiment or observation has ever falsified a theory. You can always blame it on circumstances of the experiment or the set-up or add some fudge factors to the theory to accomodate that observation. Another common approach is to claim that you don't understand your theory well enough yet to understand if the observation is really incompatible with it. But you will never end up in a state without a theory (or should I say paradigm) because all your candidates have been falsified.

It is only that if there is a new paradigm that more easily accomodates the important (defined by the paradigm!) observations that many people switch over to the new paradigm. But again this is not directly based on logical deduction but much more because the feel more comfortable with the new paradigm.

But I am dirgressing, I don't want to discuss Kuhnianism today (but still I urge everybody to read and think about "The structure of scientific revolutions").

My other encounter with the real world happend in a pharmacy some days ago: A. has a really bad cold and we wanted to buy some cough syrop. The drugist offered two different products: One was the ordinary drug that she described as quite strong and effective but with words that implied that it might be too strong and have side effects. The other bottle contained a syrop based on some thyme extract.

I was only in the back as A. did the shopping but then the druggist said something that forced me to enter the discussion: She said that the first drug contains a "chemical substance". Obviously she wanted to sell drug two (which of course turned out to be more expensive than drug one) but she had intended to scare A. by mentioning chemistry.

Being the way I am, I could not resist and replied that I hoped that drug two would contain chemical substances as well otherwise I could not imagine it to be effective (maybe except for some placebo effect). Of course, she had to admit that (thereby making clear that drug two was not some homeopathic way of selling expensive water and maybe alcohol).

But this druggist's sales strategy made me worry and I hope that when I need a drug I get better advice. If in doubt I would rather take some effective and clean synthetic substance (I assume that is what she ment by 'chemical') rather than some dodgy plant based product that might contain hundreds of different substance that I effective at all might have uncontrolled interactions.

For example, I know many people that swear by echinacea based drugs to prevent getting colds. But from what I heard, none of these drugs has been proven (again according to some scientific standards that of course cannot derive truth but only some level of trust) to be effective apart from irritating the immune system. However, in several cases this irriation got fat too strong and people got life threatening alergic shocks.

So, please people tell me the truth and give sound advice rather than trying to scare me with misused scientific terms such as 'theory' or 'chemical'.

PS: Thanks to Anna Langley for mentioning that in theory theory and practice should be the same but in practice...

PPS: A. bought drug two.


LuboŇ° Motl said...

Right, many people think that the word "theory" means "weird speculation", "chemical substance" means "poison", and Thomas Kuhn and especially some of his followers also think that "falsify something" means to "get enough political influence to force some other people who disagree to surrender". ;-)

Anonymous said...

Wow I don't agree.

Falsification is the central pillar of science. If your theory isn't advanced enough that it cannot make a testable postdiction of some number we understand, and/or is indistinguishable from some other simpler theory, then it is simply not accepted. Nor should it (yet).

Moreover, any new theory must make a testable *pre*diction of some new quantity (that we dont understand) that is subsequently verified. 'Extraordinary claims require extraordinary evidence'

For instance, I would say the standard model makes one central postdiction, and that is the spin statistics theorem. The axioms of field theory simply *must* yield that result. There is no fudge factor that can remove that most basic highly nontrivial truism.
I don't need to list the other famous predictions that were subsequently verified.

Its interesting to note the SM is still plausibly falsifiable. The remaining piece is the Higgs, nonexistance of that field would be disastrous, but still in principle possible! Hence we are still doing science here, and not babbling about philosophy (which isn't very interesting frankly).

Jamie said...

To you post:

Oh the irony.

So I agree, a theory with support is pretty much the best thing going as far as prediction and explanation go.

1st irony:
And yet the fundamentalist discount theories as something less than their unsupported faith -- of which they are certain.

Also agreed, that science is a social activity and all the standard human politics and social-psychology factors play a role.

2nd irony:
So here we are the proponents of what the evidence would show is the stronger epistemological position, doubting, if not the foundation of science (evidentiary thinking), then certainly doubting the infallibility of the scientific community. Fundamentalists would just claim certainty and infallibility here.

On side note, I occasionally hear people say they wished they had the certainly or faith they see in some fundamentalist. What a scary thought to me, as it would imply I knew nothing of the limits of knowledge and decision-making. It is health and advantageous to be aware of your blindspot. That kind of certainty is something I'm sure Usama Bin Laden has plenty of.

To Falsification-Man:

I think he (or is it me ;^) misunderstands that Kuhn wasn’t attacking evidentiary thinking, but rather pointing out that scientific process is carried out by quite fallible humans and is subject to the kinds of politics all group decision-making processes face. Then again maybe Falsification-Man is responding to Lumo.

Anonymous said...

The spin statistics theorem isn't really a consequence of the Standard Model as much as it's a consequence of quantum field theory.

Cough syrup? "chemical substance"? Are you sure she wasn't refering to DXM?