I am sounding more and more like my father every day.
Moving on, I want to wish each and every one of you out there a very happy, prosperous, peaceful, and safe 2019, including the newest of commenters, Red in Alberta, Canada!
All I know about Alberta, Canada without looking anything up is that it is between British Columbia and Saskatchewan, and that two of its cities are Edmonton (home of what at one time was the world's largest shopping mall or maybe it was North America's largest shopping mall -- take that, Minneapolis) and Calgary (home of the annual Stampede rodeo and the late Winter Olympics). All I know about Red after perusing his profile and a few of his posts is that he just observed his 79th Christmas (it was my 77th), that he is a retired educator, and that he was born in Saskatchewan. Everybody say hi to Red.
Hi, Red!
Your bit of trivia for the first day of the new year follows, and after that we will speak no more of latitude or longitude henceforth, even forever.
One degree of latitude equals 60 nautical miles. A nautical mile is 6000 feet as opposed to a regular land mile of 5280 feet. The figure I keep reading on the computer is that a nautical mile is 1.15 land miles even though when I use a calculator to divide 6000 by 5280 the answer I get is 1.136363636363636 and I'm not even kidding. Nevertheless, let us proceed with 1.15 (because it produces round figures, I think). In regular land miles, then, a degree of latitude equals 69 land miles (111km). Each degree is composed of 60 minutes, indicated by a single quote or apostrophe ('), and it follows as the night the day, one minute of latitude equals one nautical mile or 6000 feet (0.71km) or 1.15 larger than a regular land mile (0.62km). Even more astonishingly or predictably (pick one), each minute is composed of 60 seconds, indicated by double quotes or apostrophes ("). When you do the math, you find that a second is equal to 100 feet (that is, 6000 feet divided by 60). Isn't math wonderful?
Degrees of longitude, to change the subject, are also 60 nautical miles apart at the equator, to which they are perpendicular, but they gradually become closer together as one progresses north or south, until all the longitudinal lines meet at the poles.
It is therefore true, as French philosopher/Jesuit priest/paleontologist/geologist Pierre Teilhard de Chardin (1881 - 1955) said, everything that rises must converge.
You heard it here first, or maybe not.
Your last item of trivia for today is that although we have used the term "oblate spheroid" in the last couple of posts, I have learned that it is an outdated term. Everyone in the know says "oblate ellipsoid" nowadays.
Here is a pretty map for you to look at and ponder over. It shows the intersection of the equator and the prime meridian, which passes through the Royal Observatory, Greenwich, England. How convenient for them.
If I made New Year's resolutions, I might attempt to be less snarky in the coming twelve months, but I just can't bring myself to commit to it.
Here are some examples of red:
As usual when civil serpents get involved the job goes belly up. Here we are metric. Not really as we still have 360° to a circle. It really should be 100°. The nautical mile is one second of arc and a kilometre is a hundredth of a hundred degrees or summat like that... who cares.
ReplyDeleteBy the way a 2D triangle always has included angles totalling 180° whereas a spherical or 3D triangle has the sum of it's included angles varying from a point, zero; to a full line of latitude, 360°. God knows what it is in French or French Canadian...Who cares?
Adrian, thank you for your almost (to me, at least) incomprehensible comment except for the part about 180° in a 2D triangle. I think 2D is called plane geometry and 3D is called solid geometry. Solid geometry was never my forte, although I think I remember that the volume of a cone is 1/3 the volume of a similarly-dimensioned cylinder. I know just enough to impress someone who knows even less than I do but not enough to impress anyone who is a true student of the subject. Trigonometry went right out of my head early because our teacher didn't make us memorize boring stuff like sines and tangents and secants and cosines and cotangents and cosecants but let us use a little chart during tests, so the facts never embedded themselves in my gray matter. And I was never exposed at all to calculus or differential equations. Yet Yorkshire Pudding presented me with an award yesterday on his blog for, among other things, "intellectual forays into the mysterious worlds of science and mathematics". What I know about science and mathematics wouldn't fill a thimble. But blogging lets me run off at the mouth.
DeleteThanks for the welcome. Nice touch.
ReplyDeleteRed, thanks for the thanks for the welcome, good sir. I don't get many Canadian readers. There's a lady in BC who used to comment fairly often but she hasn't been by lately. So you are in an exclusive club of sorts.
DeleteWell there you go! Red's here and you're spouting numbers.
ReplyDeleteHappy new year, Robert!
kylie, Happy New Year to you as well, kylie! On this funny Earth of ours yours started several hours before mine, but that's okay.
DeleteDo I detect a hint of "same old same old" in your comment?
Being a traditionalist in many areas of life, I am going to stick with "oblate spheroid" as I think the term "oblate ellipsoid" is both vulgar and wrong. If I happened to be walking in downtown Canton, Georgia and you tried to mow me down in your beaten up 1973 Chevvy, I would not shout "Oblate Ellipsoid!" at you while shaking my fist. I would shout something else entirely.
ReplyDeleteBut Neil, "Oblate Ellipsoid" as an epithet directed toward me would be more accurate than whatever else you may have had in mind.
DeleteAs a spheroid is, apparently, simply an elipsoid of revolution and the word is, apparently an ablate ellipsoid of revolution, I'll stick with oblate spheroid - it's shorter and, as I've been using the term since I was 11, I'm more likely to remember it.
ReplyDelete