August 25: Science is complified

Figure 126.

Here's a bunch of sentences from today's reading, Kelvin on the tides:
If I were asked to tell what I mean by the Tides I should feel it exceedingly difficult to answer the question.

But I fear I have got into questions which are leading me away from my subject, and as I cannot get through them I must just turn back.

I will not enter into details, as it would be useless for those who already understand the tidal theory, and unintelligible to those who do not.

I would like to explain to you the equilibrium theory, and the kinetic theory, of the tides, but I am afraid I must merely say there are such things...
Kelvin (who, like most scientists, makes us humanities people feel like ignoramuses) was giving this as a public lecture -- this being 1882, before we found ways of filling our evenings that didn't turn us into huge nerds. And, even though he was good at that, and even though tides are something we've all experienced, it turns out to be a subject that's super-tricky to explain.

Kelvin's problem seems to be related to Burke's problem of a couple of days ago -- it's hard to generalize when there are so many particulars that have to be accounted for. In this instance, there's "tide" as a word for "current"; effects of the sun, and the wind, have to be distinguished; and there's math:
The moon attracts the nearest point (B) with a force which is greater than that with which it attracts the farther point (A) in the ratio of the square of 59 to the square of 61. Hence the moon’s attraction on equal masses at the nearest and farthest points differs by one fifteenth part of her attraction on an equal mass at the earth’s centre, or about a 4,320,000th, or, roughly, a four-millionth, of the earth’s attraction on an equal mass at its surface.
The reader may find him or herself back in school, looking up at the ceiling and wondering if an interesting pattern may be derived from the tiles.

The plus side is that, unlike philosophical distinctions, all this distinguishing seems to get us somewhere. At one time we might wonder "Why are there tides?," at another, "What is Beauty?," but we've settled the former question. I think this is why scientists, when they communicate with the general populace, generally seem more excited and happy.

I might also add that a discussion of the tides allows one to use the word "neap," which is an excellent word.