# Given that earth is rounded, why there is no quick flights from Japan to America? **URL:** \ **Category:** Factual Questions\ **Created:** [January 31, 2012, 6:30am UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282 "2012-01-31T06:30:38Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 31, 2012, 7:25pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/41 "2012-01-31T19:25:14Z")
> [@TriPolar](#): > > That’s the easiest way to describe it. Rotation is always relative to something, and can’t be unambiguously described as relative to points on the rotating object. Understood, but given a defined North Pole and South Pole (as we have here on Earth) isn’t east-to-west or west-to-east meaningful? (I mean, I suppose you could describe what’s on the hidden side of the sphere as rotating east-to-west, but west-to-east rotation would, to me, describe the rotation that is observed when looking at the front side of a sphere.) ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [January 31, 2012, 7:28pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/42 "2012-01-31T19:28:12Z")
> [@leahcim](#): > > It helps to think of two points very near the north pole, but with very different latitude. Longitude. 🙂 ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [January 31, 2012, 7:29pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/43 "2012-01-31T19:29:16Z")
> [@Quartz](#): > > Actually, because the Earth is an oblate spheroid rather than an actual sphere, isn’t the northern route shorter than keeping the same latitude? That does factor into it, but it’s not the main effect. The reason you want to go to the upper latitudes is because the longitudes are closer together there, so you can cross them faster. This isn’t an artifact of physics, but just of the math involved. It’s merely because we’ve defined lats and longs to be based off of the north pole. If we were to redefine the coordinate system using “the LAX pole” or wherever instead of the north pole, the effect disappears. Strangely, the fastest way for anyone in the Northern hemisphere to circumnavigate the globe is not to just go across it, but to go up to the north pole, run in a tiny circle around the pole, and run back to where they started. You only travel half the Earth’s circumference, max. > [@pulykamell](#): > > It would look like a parabola (or some sort of arc) on a flat map, yes. If you look at a globe, find two points, and connect them with the shortest line, that’s straightforward and easy for pretty much anyone to do. The thing is, when that route is taken from a 3D sphere and put onto a 2D rectangle, it looks like the arc of a circle, because of the transformation from a round three-dimensional space to a spherical two-dimensional space. It’s not even really the translation to rectangles that does it. Take a basketball and touch a string to two points on the “equator”. It looks straight. Then rotate the ball so that you’re looking at the “south pole”. BAM! A curved path without making it a rectangle at all. ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [January 31, 2012, 7:31pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/44 "2012-01-31T19:31:43Z")
> [@pulykamell](#): > > Understood, but given a defined North Pole and South Pole (as we have here on Earth) isn’t east-to-west or west-to-east meaningful? (I mean, I suppose you could describe what’s on the hidden side of the sphere as rotating east-to-west, but west-to-east rotation would, to me, describe the rotation that is observed when looking at the front side of a sphere.) It depends on your point of reference. Standing away from the Earth, you’ll see New York, then Kansas City, then Los Angeles. That’s east to west. But if you’re in Los Angeles, you’re travelling east, towards where New York was. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 31, 2012, 7:33pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/45 "2012-01-31T19:33:12Z")
> [@Chessic\_Sense](#): > > It’s not even really the translation to rectangles that does it. Take a basketball and touch a string to two points on the “equator”. It looks straight. Then rotate the ball so that you’re looking at the “south pole”. BAM! A curved path without making it a rectangle at all. This is true. Perhaps it’s better to say that it’s the translation from a higher-dimensional space to a lower-dimensional one that creates this effect. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 31, 2012, 7:34pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/46 "2012-01-31T19:34:25Z")
> [@tdn](#): > > It depends on your point of reference. Standing away from the Earth, you’ll see New York, then Kansas City, then Los Angeles. That’s east to west. But if you’re in Los Angeles, you’re travelling east, towards where New York was. Yes. I believe I’m missing the point though. If you’re in LA, you’re travelling to NY, which is from west to east. ETA: Oh, I think I see what you’re saying. I would think that, for most people, from their frame of reference, they would describe the movement of the earth as from west to east. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [January 31, 2012, 7:37pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/47 "2012-01-31T19:37:30Z")
> [@Chessic\_Sense](#): > > Strangely, the fastest way for anyone in the Northern hemisphere to circumnavigate the globe is not to just go across it, but to go up to the north pole, run in a tiny circle around the pole, and run back to where they started. You only travel half the Earth’s circumference, max. That’s not a well accepted definition of circumnavigation. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 31, 2012, 7:41pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/48 "2012-01-31T19:41:24Z")
> [@TriPolar](#): > > That’s not a well accepted definition of circumnavigation. Yeah, I’m not sure how that could even qualify as “circumnavigation.” What circumference are you navigating across in that scenario? ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [January 31, 2012, 7:42pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/49 "2012-01-31T19:42:04Z")
I suspect the OP, like many people, vastly underestimates the size of the Pacific Ocean. It’s not unusual for people who have crossed the Atlantic, Europe -\> USA and back to be confused about the distances between the USA and Asia/Australia. ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [January 31, 2012, 7:44pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/50 "2012-01-31T19:44:15Z")
> [@TriPolar](#): > > Right, but someone in Japan, or the US, is likely to be looking at the conventional view of the earth centered on the equator, and that straight line would look like a big arc. Yeah, I just wanted to highlight the shortness of the great circle route. Same thing you get if use a piece of string on a globe. Question for the pilots out there: When flying a GC route, your bearing is constantly changing is it not? I assume that computers update the bearing constantly these days but in olden times, how often was it done? Hourly? ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [January 31, 2012, 7:45pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/51 "2012-01-31T19:45:04Z")
> [@pulykamell](#): > > Yes. I believe I’m missing the point though. If you’re in LA, you’re travelling to NY, which is from west to east. > > ETA: Oh, I think I see what you’re saying. I would think that, for most people, from their frame of reference, they would describe the movement of the earth as from west to east. Yeah, but in a way it still doesn’t make sense. LA is never really east of NY, it’s always west. They are in fixed locations. What we can say, though, is that looking down on the north pole, the Earth spins counter clockwise. ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [January 31, 2012, 7:49pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/52 "2012-01-31T19:49:26Z")
> [@pulykamell](#): > > Also, that is largely irrelevant unless you leave Earth’s atmosphere (which you certainly don’t in an airplane.) It’s the direction of the prevailing winds that matters the most to whether an eastward or westward flight is faster for the same distance. Not to introduce another variable but the prevailing winds in the northern latitudes tend to be more or less from west to east. AKA the [Westerlies](http://upload.wikimedia.org/wikipedia/commons/1/18/Map_prevailing_winds_on_earth.png). So you got that working against you I guess. Or helping you if you’re returning. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 31, 2012, 7:51pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/53 "2012-01-31T19:51:09Z")
> [@tdn](#): > > What we can say, though, is that looking down on the north pole, the Earth spins counter clockwise. That was the other possibile description I was considering, but thought that maybe there was some other nitpick I hadn’t considered. LA is always west of NY, but when viewed in an orientation away from the Earth, with the North Pole on top, it appears as if it is moving from west to east. I mean, when you show that animated GIF to an earthling who recognizes the North Pole and South Pole and has the standard definitions of cardinal directions in his vocabulary, I’m having a hard time anybody describing that motion as east-to-west. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 31, 2012, 8:02pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/54 "2012-01-31T20:02:50Z")
> [@standingwave](#): > > Not to introduce another variable but the prevailing winds in the northern latitudes tend to be more or less from west to east. AKA the [Westerlies](http://upload.wikimedia.org/wikipedia/commons/1/18/Map_prevailing_winds_on_earth.png). So you got that working against you I guess. Or helping you if you’re returning. Yes, but that’s my point. You have Westerlies and Easterlies (i.e. prevailing winds) that determine flight time. It’s not (much) the rotation of the earth (as the atmosphere rotates along with the earth, otherwise, if you jumped up in your room, you’d find yourself splattered against the wall.) I hedge with the word “much” because I believe the rotation of the earth does contribute to how and where prevailing wind patterns occur the way they do via Coriolis forces, but I’m not an expert in this matter. What I am saying, though, is that some people seem to think that travel from east to west is faster because “the earth spins under you,” which is not correct. It depends on where you are in the world. ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [January 31, 2012, 8:20pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/55 "2012-01-31T20:20:13Z")
> [@TriPolar](#): > > That’s not a well accepted definition of circumnavigation. OK, delete the technical term and leave the idea. The point is that if you want to “touch all the lines”, the shortest route is up to the pole, around, and back down. This works no matter what point the coordinate line emanate from, whether that be Santa’s house or Obama’s. If you want to describe it as a great circle route, that’s fine, but if you’re specifically asking why the shortest route is northward, then the answer is that up there, east is closer to west. If you define something else as north, the shortest route doesn’t change over the ground, it’s just that it can no longer be described as “northerly”. > [@standingwave](#): > > Yeah, I just wanted to highlight the shortness of the great circle route. Same thing you get if use a piece of string on a globe. > > Question for the pilots out there: When flying a GC route, your bearing is constantly changing is it not? I assume that computers update the bearing constantly these days but in olden times, how often was it done? Hourly? On charts, there are lines that all go up to the north pole that describe the [magentic variance](http://en.wikipedia.org/wiki/Magnetic_declination) at a given locale. You use that variance in your preflight planning, whether done on a computer or with pencil and paper. ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [January 31, 2012, 8:28pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/56 "2012-01-31T20:28:52Z")
One wonders if posters like **Tota** ever come back to read replies to their… …oh look, a butterfly… ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [January 31, 2012, 8:35pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/57 "2012-01-31T20:35:18Z")
I think the “Duck up to the North Pole, run around it, then go home” version of circumnavigation points out a flaw in many “around the world” trips. If you stay in the Northern Hemisphere the whole time, then you’re not going all the way around the world. You’re making a much smaller circle than someone who travels a complete circumference of the Earth, despite passing through every line of longitude. So Phileas Fogg who went around the world in 80 days cheated a bit. Not as much as a guy who does the “up to the pole” trick, but a bit, because the circle he traveled was entirely within the northern hemisphere. Obviously, a guy in northern Greenland who says he’s going to travel around the world by heading due east until he gets back to where he started is going to have a much shorter trip than someone in Ecuador. ---
**Author:** ![Kenm](https://avatars.discourse-cdn.com/v4/letter/k/bc79bd/32.png) [@Kenm](https://boards.straightdope.com/u/Kenm)\ **Post date:** [January 31, 2012, 8:47pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/58 "2012-01-31T20:47:52Z")
> [@Quintas](#): > > Jesus Christ!! Whats wrong with that Wikipedia pic? I thought Firefox on my Mac had crashed, so I went to the Force Quit command, only to see that it hadn’t. So it’s the graphic’s fault, not the users’. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [January 31, 2012, 10:07pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/59 "2012-01-31T22:07:22Z")
> [@Revtim](#): > > What was the earth before they rounded it? 1.4 earths? .6 of an earth? > > 😉 It was a cube, and mariners really did fall off the edge sometimes. Rounding the earth was seen as an optimal solution for this problem, but was never practical until accurate chronometers were invented. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [January 31, 2012, 10:09pm UTC](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282/60 "2012-01-31T22:09:19Z")
I guess that if you’re flying from LA to Tokyo, then in an inertial reference frame with the Earth at its center, you could take off, point the plane west, maintain your fixed position while the Earth rotates, and wait for Japan to show up underneath you. That would be a short trip. [Previous page](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282.md?page=2) [Next page](https://boards.straightdope.com/t/given-that-earth-is-rounded-why-there-is-no-quick-flights-from-japan-to-america/611282.md?page=4)