Tuesday, 29 April 2008

The Earth Is Flat

Musings on the Philosophy of Science.

The Earth is flat. Locally.

When travelling to the local shops, it makes more sense to consider the Earth's surface to be a flat plane than anything else. Draw a triangle on the sidewalk in chalk, and you'll see that the 3 angles add up to 180 degrees, a property possessed only by flat surfaces.

The Earth is Spherical.

But when doing long-distance navigation, anything over a day's walk, you get incorrect results with a "Flat Earth Model". You get correct results assuming the Earth is a sphere. Draw a triangle with sides a few hundred kilometres (or miles) long, and you'll see the angles add up to a little more than 180 degrees.

The Earth is an Oblate Spheroid.

When doing really accurate navigation over long distances, a "Spherical Earth Model" won't do. A better model is one where the Earth is almost spherical but has a hint of looking more like an M&M or Smartie. A bit pear-shaped. A bit (gridiron or rugby) football shaped. Only a bit, it's nearly spherical. But enough so that if you fire off a rocket to another continent, it will land hundreds of metres off-target if you use a Spherical Earth in your calculations.

The Earth is an Oblate Spheroid with irregularities

And then you add in the "crinkly bits", mountain ranges, even mass concentrations that distort space-time a smidgin. Not usually enough to make any difference, so they can be ignored. Usually. And it varies with time, the tides, earthquakes, even man-made buildings and open-cut mines.

So which of these models is "true"? Well, all of them, in their domains. They are models, not the thing itself, useful approximations.

That leads me on to talk about Science.

'A scientist is never certain. We all know that. We know that all our statements are approximate statements with different degrees of certainty; that when a statement is made, the question is not whether it is true or false but rather how likely it is to be true or false.'
- Nobel prize-winner, Richard Feynman
And how useful it is under certain conditions in predicting what will happen if we do something.

Science is based on certain propositions - axioms. Things which we take as true because they are useful, not because we can prove them.
  1. There is an objective reality.
  2. That it allows measurements to be taken that are repeatable, over time and over distance
So we assume that a Hydrogen atom here on Earth is no different from a Hydrogen atom a billion light years away. They behave the same. We can't prove that by going out and measuring it, but it seems to work.

Ideally, the process of Science is as follows.
  1. Make some observations
  2. Try to think up an idea, a reason for those observations
  3. Come up with a test to see if that idea is true (or false)
  4. Perform the test, and refine the idea if the test results aren't as predicted
  5. Repeat
  6. After many tests, tentatively accept the idea as being "true enough", though always subject to later falsification when more data comes in
There are some complexities though, which perplex the nice, simple ideal.
  1. We can only use tools based on this Universe to measure this Universe
  2. We are Human, and thus our objectivity is compromised to a greater or lesser extent
The first means that "we see through a glass, darkly" - meaning that we can never "see" the Absolute Truth of reality, we can only take indirect measurements and make inferences. As our measurements get better, we must modify our inferences to accord with the new facts, not ignore the facts to suit our ideas. Well, that's what we should be doing... We also can't wait for all the evidence to come in, because it's a continuing process. We have to assume our approximations are true enough to base further ideas upon them.

The second means that Science is a human endeavour. Being human, we tend to identify with our own ideas, and resent it when those ideas are challenged. We see them as an attack. It's all too easy to ignore evidence against our wonderful theory as being a mere artifact of flawed observation. We confuse what we want to be true with what the objective evidence shows. And we forget that our approximations, ones with myriads of confirmatory observations, are only approximations to Reality, and not Absolute Truth where we should ignore any contradictory evidence as being artifacts of poor measurement.

The fact that Science can never claim Absolute and Perfect Knowledge puts it at something of a disadvantage compared with Superstition.

Common Superstitions include variants of Post-Modernist theory, which claim that as Science is a Human Endeavour, with all evidence being flawed, it has no greater claim to truth than mere supposition without any evidence whatsoever. That Objective Reality does not exist, and the only worthwhile metric for an idea's truth is how useful it is at confirming our own prejudices about what ought to be true on moral grounds.

Although proponents of this idea eschew the idea of "empirical evidence", they actually have quite a lot for their belief. They didn't come to it for no reason, and often it's from entirely worthy motives.

Examples - Drapetomania:
In psychiatry, drapetomania was a mental illness described by American physician Samuel A. Cartwright in 1851 that caused black slaves to flee captivity. Today, drapetomania is considered an example of pseudoscience, and part of the edifice of scientific racism.
...
Cartwright described the disorder — which, he said, was "unknown to our medical authorities, although its diagnostic symptom, the absconding from service, is well known to our planters and overseers" — in a paper delivered before the Medical Association of Louisiana that was widely reprinted. He stated that the malady was a consequence of masters who "made themselves too familiar with [slaves], treating them as equals." In Diseases and Pecularities of the Negro Race, Cartwright writes that the Bible calls for the slave to be submissive to his master, and by doing so, the slave will have no desire to run away. In addition to identifying drapetomania, Cartwright prescribed a remedy to cure the malady. His feeling was that with "proper medical advice, strictly followed, this troublesome practice that many Negroes have of running away can be almost entirely prevented." In the case of slaves "sulky and dissatisfied without cause" — a warning sign of imminent flight — Cartwright prescribed "whipping the devil out of them" as a "preventative measure."
From the Canadian Medical Journal :
In The Nazi War on Cancer, an impressive sidebar to his Racial Hygiene: Medicine under the Nazis (1988), Proctor grapples with a more slippery demon: Nazi programs in health promotion that are oddly consonant with the values of today.

What are we to do with the fact that it was under Hitler's regime that a causal link between smoking and lung cancer was first made, that Nazi anti-tobacco campaigns were ahead of their time, that Nazi physicians identified and attempted to control exposure to carcinogens such as asbestos, pesticides and food additives, advocated an organic, vegetarian diet high in fibre and low in fat, were the first to promote breast examination and that, the destruction of the Jewish intellectual and scientific community notwithstanding, managed to conduct a certain amount of "good" science, notably in epidemiology?
...
Solutions were attempted on the front of public health, in education campaigns, disease registers, mass screening programs and legislation. All of these efforts drew on the essence of Nazi ideology, which might be described as a counterfeit of reasonable desires: beauty, freedom, health, vitality. Proctor calls Nazism "a vast hygienic experiment designed to bring about an exclusively sanitary utopia ... . [A]sbestos and lead were to be cleansed from Germany's factory air and water, much as Jews were to be swept from the German body politic." The metaphors were powerful and replicated themselves in false and murderous equivalences: Judaism was a cancer, cancer was like the Jews.
I might just insert a quote from Oklahoma Representative Dally Kern here:
One of my colleagues said We don't have a gay problem in our community...well you know what, that is so dumb. If you have cancer in your little toe, do you just say that I'm going to forget about it since the rest of you is fine? It spreads! This stuff is deadly and it is spreading. It will destroy our young people and it will destroy this nation.
Now to return to the Nazis..."Einer meiner gesagten Kollegen "wir haben nicht ein j├╝disches Problem in unserer Gemeinschaft", das ist Quatsch" Whoops, sorry. Wrong channel. It's so difficult telling them apart sometimes.
Surveillance, detection, control, eradication: these were activities applicable to diseases and to people equally.

Proctor's account is a disquieting case study of how public health concepts are tied to ideology and, with apparent innocence, can support malign sociopolitical agendas. It also demonstrates, as Churchill was aware on the eve of the Battle of Britain, that science is blind to the motivations of its practitioners. Serving any master, any purpose, it marches on.
Churchill's quote is :
But if we fall, then the whole world, including the United States, including all that we have known and cared for, will sink into the abyss of a new Dark Age made more sinister, and perhaps more protracted, by the lights of perverted science.
Science is a tool, and like a murderer's knife or a surgeon's scalpel, it is not good or evil in itself, merely a test for what is and what is not, not what should or should not be.

Against that... please just look at this video clip.



That is what can happen, what usually happens, even what eventually and inevitably always happens, when you arrogantly claim Moral Superiority for your Utopian ideas over the messy, imperfect, flawed, but constantly improving and very Human endeavour called "Science".

4 comments:

Dave said...

Zoe,
I think you have posted on two very interesting topics that are only tenuously related.
Topic one... the slippery nature of truth; and
topic two... science isn't necessarily "good" or "evil."

As for the second, I've not seen any evidence that scientists are any better or wiser or nicer people than the rest of the population.

Zoe Brain said...

Dave, I agree with the "better, wiser, nicer" bit. But then, scientists don't claim to be better, or wiser, or nicer, just better informed.

The trouble is, there are people who claim to be better, wiser, and nicer than scientists, and on that basis, ignore empirical evidence and substitute their own ideas as Truth. Sometimes the Flying Spaghetti Monster, or invisible unicorns at the bottom of the garden who whisper in their ears tell them this. Or they read it in the Honest Book of Truth, that says on the first page "This is all True", so must be so. Sometimes they come to their ideas via Post-Modernist Philosophy.

Often they are granted power. The Gods of the Copybook Headings eventually call them to account, but that can take centuries. And there are always new ones popping up, it's a lot easier claiming moral superiority when you don't have to provide evidence.

Dave said...

Very true, and I now have a better picture of the point of this post. It could have been titled "Let's be very clear about what science is, and what science is not."
But that's not nearly as catchy as "The Earth is Flat"!
:-)

RadarGrrl said...

"The Earth isn't round. It's shaped like a burrito!" --Berkeley Brethed