Parallax / Teaching / Thinking Tools /
Mission: to argue that distance counts

The word parallax has specific meaning in a series of artificial languages from astronomy to photography. What I wish to invoke here is a set of metaphors that relate to more than one of the specialized meanings.

If you stand in between the paired rails of a railroad track and look into the distance along the track it looks like the tracks get closer together till they meet at a point. But if you walk along the track toward the horizon the tracks seem to remain approximately the same distance apart.

Among Euclidian axioms parallel lines are always the same distance apart. In other geometries other axioms apply.

Humans living in the northern hemisphere had the advantage of having a sky that seemed to rotate around a single point, a point which we called “north.” note.
Southern navigation remained touchy-feely, whereas northern navigation developed with great precision. The northerners had north; the southerners didn’t. Polynesian navigators accomplished great feats, but they had no Magellan.

If you could somehow calculate true north — an imaginary extension of earth’s axis of rotation, the star Polaris would seem to be very close to it. If you step to the side, Polaris would still seem to be very close to it. Drive a mile away: still. Look at Polaris at t1 and again three hours later when the earth has rotated you thousands of miles further away (and the earth’s movement around the sun has taken you still further): still, Polaris looks very close to true north. note

Now get on a rocket, hitch a ride on a neutrino … leave the earth, leave the solar system … get near Polaris, still remembering where earth’s “north” ought to be pointing. You’re not on a railroad track on earth, walking toward the horizon; you’re riding an illusion, riding it into vapors.

Still: that’s not where I mean to go: at best that just gives us a cart to go in.

When you’re a kid, and God is shoved at you, and the Bible, and the priest and the pope, or a minister, or a rabbi … God, the priest, the truth, the Bible … will look like they’re all on one line. God and the Bible, the Bible and the truth, the minister and the Bible … are coextensive, synonyms, indenties: metaphors forgotten to be metaphors. Get a little older and some light, some distance, may appear between them.

At some early point the minister may fall away from the line that you still see God and truth occupying. At some later point you may lose the Bible but still identify God with truth.

I’ll give myself time to add more to that latter thought. Right now I want to enthymeme other arguments, leave them out, take them as obvious … and jump further along:

Imagine that you’ve left the earth, the solar system, the galaxy … are God and truth still on the same line? Which one is “true north” and which one merely the “north star”? an accident? an illusion?

Points about parallax, about perspective, points that are scientific, formal, logical, belong among my Thinking Tools: and that’s where I’ve put this piece. Analogies I’ve drawn belong among my Society modules; yet these are in here in this Tools module. Good points belong wherever they happen to appear. That’s why cross referencing counts. That’s why domain searches are so important: find your own cross references.

Unfortunately, as I skip around among hosts, those features suffer. Contributions would accelerate the fixing.

2011 10 08 Nope: didn’t happen. The fed jailed and censored me instead. My cross referencing search engines worked only so long as pk domains were all in one folder on one host. The government sabotages scholarship, philosophy, science, but it’s still the government. People who put up with fraud deserve nothing but fraud: and fraud is what they get.



Back in 1982 when I was writing By the Hair of the Comet, I phoned the Hayden Planetarium and asked the director, Mr. Brown, if the sun had a north star. “Gee, that’s a good question,” he said. Of course he didn’t know either. (I’ll bet it does have a north point — the sun would rotate after all, wouldn’t it?)


True North (and Precession):

Look at true north and compare Polaris’ position one thousand years from now or n-thousand of years ago, and you’ll get very different measurements. Thanks to the earth’s wobble, “north” draws a circle in the sky, one cycle measuring in the tens of thousands of years. It just so happens that north pointed near Polaris when Columbus, etc. got going. At some other period it will point “no where,” or at some other start: still, circling near the tail of Ursa Major, or near Draco …


About pk

Seems to me that some modicum of honesty is requisite to intelligence. If we look in the mirror and see not kleptocrats but Christians, we’re still in the same old trouble.
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