My gyroscope says the world is Flat

gismo said:
Yes, that's called a Rhumb Line. Such a path will normally be longer than a GCR (exceptions are when flying directly north or south (magnetic) or following the magnetic equator.
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So to get an idea, take a piece of string on a globe, point to point. Use New York to Paris as an example. That will represent the shortest route and will be a great circle. So how would the Rhumb Line compare to that, as represented by the string?
 
It would be a horizontal arc on a heading of 081° all the way to Paris, southeast of the GC.

dtuuri
 
dtuuri said:
It would be a horizontal arc on a heading of 081° all the way to Paris, southeast of the GC.

dtuuri
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That might be correct, but "heading" would have to be true heading, since a rhumb line by definition crosses all meridians at the same angle. So it would not be what your DG is telling you, unless you set your DG to true north the entire way.
 
Matthew said:
How about a globe? Put a string from City A to City B and see what happens. There's no such thing as a "straight line" on a curved surface.
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Yet we have plenty of evidence that flight paths correlate with azimuthal maps. Being that the distance on a flat map from point A to point B is much greater than on the globe, the non existent flights like Chile to Australia makes sense on an azimuthal...
 
Patpiccard said:
Yet we have plenty of evidence that flight paths correlate with azimuthal maps. Being that the distance on a flat map from point A to point B is much greater than on the globe, the non existent flights like Chile to Australia makes sense on an azimuthal...
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Why do commercial aircraft use the polar route from US to China?
 
Necro-thread alert!

(Not that there's anything wrong with that! ;))
 
Swampfox201 said:
Does anyone have a link to a good explanation of great circle routes that airplanes take while flying long distances instead of straight lines? I can't find a simple easy to inderstand video on YouTube.
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Imagine you are near the north pole and want to get somewhere kind of on the other side - is it shorter to walk in a great big half circle at constant latitude (a straight line on many map projections) or do you go pretty much straight over the top?

The other problem is, what do you mean by a straight line? Straight lines on different map projections give you different paths over the ground. Which is actually straight?
 
My BIL was shocked to find out he was never more than 30 minutes from land in his Seattle Beijing flight. He thought they went close to Hawaii!!

SEA%20ZBAA.png
 
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Work off of a globe and everything makes sense. It is only because we have flat maps that we think great circle routes are "circles".

If you take a close look at aviation VFR maps you will see that latitude lines "sag". This is so a straight line WILL be a great circle (or close to it). So it depends on what projection a flat map uses (none can be really totally realistic). The world is not flat.
 
Matthew said:
The shortest route is a straight line...,
Of course, it isn't really straight in 3 dimensions because it follows above the surface of the earth. To be truly straight would require a hellacious tunnel.
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So if you dug such a tunnel, upon leaving New York, it would pitch down, say, 30 - 35 degrees (relative to the surface) allowing you to accelerate until you reached the midpoint at which time you would begin a gradual deceleration, now pitching up, until you reached Paris using gravity as the source of propulsion?
 
This is one reason why I went out and bought a globe. I wanted to have something in my house that represents REALITY!
 
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garyb said:
So if you dug such a tunnel, upon leaving New York, it would pitch down, say, 30 - 35 degrees (relative to the surface) allowing you to accelerate until you reached the midpoint at which time you would begin a gradual deceleration, now pitching up, until you reached Paris using gravity as the source of propulsion?
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Maybe that would work if you pumped all the air out of the tunnel and found some frictionless bearings!
 
Matthew said:
How about a globe? Put a string from City A to City B and see what happens. There's no such thing as a "straight line" on a curved surface.
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Yep, google Mr. Wizard. He explained this trick on tv in the 80's right after he created a chain reaction with 2,000 ping pong balls.
 
Don't go quoting me now. I said "curved surface", someone will come back with "Yeah, but a cylinder is a curved surface." And then I'll have to say, "We were talking about a globe."
 
flyingron said:
If you have an ideal gyroscope, gravity doesn't affect it. If you fly 180 degrees around the world your gyro would indeed show you upside down with respect to how it was leveled when you started out.

The problem is that your attitude indicator is not an ideal gyroscope. To allow it to self-erect and compensate for precession effects gyros have devices that attempt over a longer period to return the gyro to a level indication. As a result, by the time you fly around the world, your gyro would have reset itself to the local "this way's up" indication.
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lol. Studying for the IFR written... I was practically yelling "pendulous vanes" at the OP.
 
azpilot said:
My Brother-in-Law just became a flat earther a month or two ago. I can no longer speak with him. All he can see in his life is black helicopters around every corner. It is quite maddening.
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The most depressing part (to me) about Flat Earthers is that I'm still not wealthy. If people are that dumb, there must be a way to separate them from their cash, probably several. I've yet to discover any.

For example:

https://www.kickstarter.com/projects/antsylabs/fidget-cube-a-vinyl-desk-toy

Look at how much they raised. For an adult pacifier.

Arrrrg.
 
Zeldman said:
The world is not flat. It is square. I have undisputable proof.

Stay in Kansas for a while....:lol:
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Bah Humbug! You cannot put squares or even rectangles on a sphere without leaving little triangle shaped parcels of land on the edges. Surveyors call these little triangles "gores" in honor of Al Gore who invented Kansas, I think.... :rolleyes:

-Skip
 
Skip Miller said:
Bah Humbug! You cannot put squares or even rectangles on a sphere without leaving little triangle shaped parcels of land on the edges. Surveyors call these little triangles "gores" in honor of Al Gore who invented Kansas, I think.... :rolleyes:

-Skip
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They should call them "republicans," in honor of politicians who invented misquoting people! ;)
 
coloradobluesky said:
Work off of a globe and everything makes sense. It is only because we have flat maps that we think great circle routes are "circles".
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Ummm... I know I'm being pedantic here... but they're called great circles because they ARE circles.
 
Palmpilot said:
OK, next time I'll just report the political post, instead of responding to it.
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That's what we would like you to do, but don't bother with this thread, it's already been reported, which is why I looked at it.
 
coloradobluesky said:
Also, this isn't in the FAA test set, so some pilots get it taught to them and some don't. The latitude tick marks on the longitude lines are 1 nautical mile apart, which BTW is one minute of angle from the center of the earth. So no need for a scale ruler to measure distances, just use a piece of paper and put it on the longitude and count it up....
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A nautical mile is defined as the length equal to a minute of longitude. So on any map a minute of latitude will be a nautical mile and vice versa, since they're the same thing.
 
ircphoenix said:
Okay. I'll see your pedantry and raise you. Wouldn't a circle have to return to its start point?
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Exactly why I wrote "great circles" there and not "great circle routes", which are only parts of the great circles.
 
Swampfox201 said:
Does anyone have a link to a good explanation of great circle routes that airplanes take while flying long distances instead of straight lines? I can't find a simple easy to inderstand video on YouTube.
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the best one I have ever seen is explained by Mr Wizard. I know this is old post, but I will find it one day and post it. That show was great.
 
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