Tuesday, September 1, 2015

Not wrong but incomplete

A succinct essay by Asimov on the distinction between something being wrong versus something being less true. From The Relativity of Wrong by Isaac Asimov.
The young specialist in English Lit, having quoted me, went on to lecture me severely on the fact that in every century people have thought they understood the universe at last, and in every century they were proved to be wrong. It follows that the one thing we can say about our modern "knowledge" is that it is wrong. The young man then quoted with approval what Socrates had said on learning that the Delphic oracle had proclaimed him the wisest man in Greece. "If I am the wisest man," said Socrates, "it is because I alone know that I know nothing." the implication was that I was very foolish because I was under the impression I knew a great deal.

My answer to him was, "John, when people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together."

The basic trouble, you see, is that people think that "right" and "wrong" are absolute; that everything that isn't perfectly and completely right is totally and equally wrong.

However, I don't think that's so. It seems to me that right and wrong are fuzzy concepts, and I will devote this essay to an explanation of why I think so.

When my friend the English literature expert tells me that in every century scientists think they have worked out the universe and are always wrong, what I want to know is how wrong are they? Are they always wrong to the same degree?
As he elaborates his argument, he offers up several examples and facts that are just interesting in and of themselves.
Perhaps it was the appearance of the plain that persuaded the clever Sumerians to accept the generalization that the earth was flat; that if you somehow evened out all the elevations and depressions, you would be left with flatness. Contributing to the notion may have been the fact that stretches of water (ponds and lakes) looked pretty flat on quiet days.

Another way of looking at it is to ask what is the "curvature" of the earth's surface Over a considerable length, how much does the surface deviate (on the average) from perfect flatness. The flat-earth theory would make it seem that the surface doesn't deviate from flatness at all, that its curvature is 0 to the mile.

Nowadays, of course, we are taught that the flat-earth theory is wrong; that it is all wrong, terribly wrong, absolutely. But it isn't. The curvature of the earth is nearly 0 per mile, so that although the flat-earth theory is wrong, it happens to be nearly right. That's why the theory lasted so long.
He later quantifies this more precisely. The curvature of the earth is 0.000126 per mile. Impressively close to 0 but still not 0. And the consequences of not being zero are, of course, huge.

Asimov then goes into the next evolution of knowledge with the emerging realization that the earth was not a sphere but an oblate spheroid. A fact known to all school children (presumably even in this era of emotional reasoning and aversion to facts when they contradict felt perceptions). I've known this since a child but I don't know if I ever knew what the differential was. For the record, the earth is 27 miles wider than it is tall.

The concept I use is that all knowledge has some margin of being usefully true and that the measurement needs of a purpose can vary widely. There are essentially two categories of knowledge about something - there is the quantifiable knowledge, how big, how heavy, what dimensions, etc. That is useful and the degree of precision needed is dependent on the purpose. That kind of knowledge is important, but is different in some ways than causal knowledge. I know why this item has the attribute measures it has. Causal knowledge allows some degree of forecasting.

Asimov finishes with:
Since the refinements in theory grow smaller and smaller, even quite ancient theories must have been sufficiently right to allow advances to be made; advances that were not wiped out by subsequent refinements.


Naturally, the theories we now have might be considered wrong in the simplistic sense of my English Lit correspondent, but in a much truer and subtler sense, they need only be considered incomplete.

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