Rocco Moretti wrote: > Tim Daneliuk wrote: > >> Diez B. Roggisch wrote: >> >>> Tim Daneliuk wrote: >>> >>>> Casey Hawthorne wrote: >>>> >>>>> >>>>> Do your planes fly over the earth's surface or through the ground? >>>> >>>> >>>> >>>> >>>> >>>> Why do you presume this has anything to do with airplanes? >>>> >>> >>> That was supposed to be a funny remark regarding that your >>> "straight-line-distance" makes no sense at all - because that would >>> mean that you'd have to go underground. So it has no >>> real-world-application - unless you actually have underground-planes ;) >>> >>> Diez >> >> >> >> Huh? When traversing along the surface of the earth, it's curvature >> is relevant in computing total distance. An airplane flies more-or-less >> in a straight line above that curvature. For sufficiently long airplane >> routes (where the ascent/descent distance is trivial compared to the >> overall horizontal distance traversed), a straight line path shorter >> than the over-earth path is possible. That's why I specified the >> desire to compute both path lengths. Where's the humor? > > > If you re-read what you wrote you'll see the phrase "straight line > flying distance.": > > > 1) Given the latitude/longitude of two locations, compute the distance > > between them. "Distance" in this case would be either the > > straight-line > > flying distance, or the actual over-ground distance that accounts > > for the earth's curvature. > > Casey was pointing out that, due to the convex curvature of the Earth, a > "straight line" between, say, Hong Kong and New York would happen to > pass several miles below the surface of California. For an extreme > example, a Euclidean straight line from the North pole to the south pole > would pass through the center of the earth. Note that you've attached > "Flying distance" to the phrase "Straight line" - Hollywood not > withstanding, there isn't a machine able to "fly" through the center of > the earth. The fact that it might be an unintentional error only adds to > the humor. (c.f Freudian Slips)
Yikes! And I thought I was being clear. Sigh ... back to English 101 for moi. > > Given the relative thinness of the atmosphere (~10-20 km) in comparison > with the radius of the earth (~6,400 km), any plane flight of a > considerable distance will be curved in the Euclidean sense, no matter > how they changed their altitude inbetween. OK, now *I* get the joke too ;) Sorry for being obtuse ... -- ---------------------------------------------------------------------------- Tim Daneliuk [EMAIL PROTECTED] PGP Key: http://www.tundraware.com/PGP/ -- http://mail.python.org/mailman/listinfo/python-list
