Tuesday, August 16, 2022

Uncertainty

 As we cruised US-2 back from vacation, we passed through Rugby, ND, pop. 2,509.  Rugby is billed as the geographic center of North America, and has a cairn set up to that effect.

    Exceeeept...

    More modern analysis with more accurate maps have recalculated the geographic center to be closer to Center, ND (named in 1902, incidentally, so not called that because they thought they were the center of the continent.  Sometimes such things simply happen.).

    This isn't surprising, of course, modern cartographic techniques and improved surveying equipment will always revise the findings of earlier generations.  One of my favorite creators, The History Guy, did a video on The Great Trigonometric Survey.  While the error was incredibly small, especially given the equipment the survey was using, the error was there.

    The dispute between Rugby and Center came up a couple years ago during a family discussion on vacation, and driving by it this year reminded me of that discussion.  During the discussion, one of my family members was adamant that there had to be a real geographic center of North America and there had to be a way to figure that out.

    Truth is, though, there's really not.  The assumption that there is an objective center is a product of enlightenment thinking, which, while useful, is nevertheless incomplete.  And that's what one must always remember when talking about any science:  science is uncertain.

    Couple reasons for that.  As aforementioned, you have instrumental uncertainty.  This is why astrophysics has long made me raise my eyebrows.  I am, among other things, an analytical chemist, and therefore have to both calibrate and QC all my instruments before reporting any results.  Tell me, how precisely do you calibrate instruments to measure past anything we can actually reach?  Originally, they trigonometrically calculated distance using the apogees of the earth's orbit around the sun as the base of the triangle.  But that's analogous to trying to trigonometrically calculate the distance across the Grand Canyon by setting up two transits about a foot apart.  How accurate is that really going to be?

    Even trying to calculate off the speed of light isn't quite as straightforward as we might assume, as Veritasium pointed out.

    I mean, calibrating a chemistry analyzer is about as straightforward as you can get:  you use NERL-grade water mixed with known masses of analyte to make a calibration set, and even then, we recognize that there is uncertainty in the actual amount of analyte in each calibrator, which we acknowledge in, for instance, out use of significant figures.  But we also recognize that there is uncertainty in the instrument itself, and we tailor our reporting to that.  I can run the exact same sample a hundred times, and if I carry out the decimals far enough, I will get a hundred different answers.

    A second reason is methodology.  What definitions are we using of the landmass here?  Are we assuming an ideal flat plane?  Or are we taking into account the Rockies adding many miles to the distance between the center and the western coasts?  A triangle can, in fact, have more than 180 degrees, after all.

    But the third reason, and one that especially hit me this year, is that things simply change over time.

    Our favorite beach in Da Yoop is Miners.  Normally, there is a massive rock that juts out from the beach, with a small, rock-bottomed cove on the east side and a big sandy beach on the west.  This year, however, a good storm or two over the winter blew in enough sand to completely bury not only the cove under several feet of sand, but the rock as well!  Meanwhile Sand Point, another beach, had it's series of little sand islands from last year turned into a solid strip that you can wade to.  And anyone who has lived in Da Yoop can tell you that it only takes one good storm to completely undo both of those changes.

    That's just Lake Superior.  Imagine the power of the Atlantic and Pacific to rearrange the borders of the continent.  Think about the 1999 Cape Hatteras Lighthouse move.  When you add a couple feet (or miles) of land on one side and take away a couple on the other, that is going to move the center.  Those changes--sometimes small, sometimes massive--are always happening.

    Einstein famously observed, “As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.”  This is not a denial of objective truth, simply a caution to be careful how much stock one puts in one's belief that they have it.  And especially what they are willing to vociferously defend.

    In 1848, the border between America and Mexico was set as the Rio Grande.  There was just one slight problem:  depending on rainfall, the river can change course dramatically from year to year.  That farm was Mexican last year, but is it American now?  And will that change next year?  Eventually, the two governments built concrete channels to keep the river from shifting in sensitive areas, but outside those places, the river can still change the "border."  Turns out, nature doesn't really care what squiggly lines men make on paper.

    Borders or numbers, it's always best to continually recognize the fact that reality is not as neat as we would like.  The way things were, are, and will be may or may not be foreordained by a Deity or Fate or what have you, but one thing is for sure:  our perceptions, individually and collectively, of the way things were, are, and will be certainly is not.  Especially that last one.  The human mind is an incredible predictive engine, but history is replete with examples of persons--and even more damaging, peoples--who projected a trend into the future and acted on that prediction.  Some saw a utopia and tried to make it happen (Communism).  Some saw an apocalypse and tried to prevent it from happening (Nazism).

    Turns out, a little humility goes a long way towards not killing millions.  We would do well to remember that whenever anyone calls for en masse action.

No comments:

Post a Comment