Flat earth vs Round Earth directional navigation

Are you talking about traveling in a great circle in this thread, or not?  Because the pictures you've drawn don't always show you traveling in a great circle.

I'm kind of confused what exactly it is you're talking about at any given point.

Ok here is what I am trying to say in this thread.

1. We travel in a circle around a sphere in a great circle path.
2. The reasoning behind it is due to Earth being a sphere and how this particular sphere is set up (titled and so on, you know)
3. We can make the circle around Earth without needing to turn ourselves the shape of Earth does that for us because just like Squevil put way better then I can, we are at an angle on the sphere minus at the equator.

Now here is what I am trying to figure out

1. In FE the Earth is a flat plane.
2. On a flat plane we do not stand at an angle.
3. The circle you make on a flat plane is not the same as you would make on a sphere.
4. To make a circle around a point on a flat plane you have to turn.
5. How can you make a circle on this flat plane without turning. What affect is causing this to happen?
6. The circle that you make on a flat Earth map to get from California to Japan is upside down compared to the great circle path you would follow on spherical Earth because you are traveling in the northern hemisphere.

I hope that helps out a little Cat.

Yes, that does help a lot.  I think people were getting confused because if you're not following a great circle your gyroscope should still show some turning, and that's what they kept harping on about.

Ah ok. I was getting frustrated because all people where responding with was how we travel on a sphere. So I think in my frustration I rambled on without thinking straight.

Hopefully I can get a good answer now.

Quote from: Cat Earth Theory on July 15, 2012, 01:45:13 PM

Are you talking about traveling in a great circle in this thread, or not?  Because the pictures you've drawn don't always show you traveling in a great circle.

I'm kind of confused what exactly it is you're talking about at any given point.

Ok here is what I am trying to say in this thread.

1. We travel in a circle around a sphere in a great circle path.
2. The reasoning behind it is due to Earth being a sphere and how this particular sphere is set up (titled and so on, you know)
3. We can make the circle around Earth without needing to turn ourselves the shape of Earth does that for us because just like Squevil put way better then I can, we are at an angle on the sphere minus at the equator.

Okay, I am talking about the RE model here.

First, remember that the only great circle that runs east and west is the equator.  Go due east at (for example) the Tropic of Capricorn and it's not a great circle route.  Only routes that bisect the sphere (cut it in two equal parts, so to speak) are great circles.  Except for the equator there is no great circle route that goes east-west.

The fact that the Earth is tilted has nothing whatsoever to do with the fact that we turn when traveling east or west.  Or that we travel in great circles.  I frankly don't understand where you get that from.  Traveling is done on great circle routes because that is the shortest distance between two points on a sphere, whether upright, tilted, on its side, or whatever.  I'm not sure it really has anything to do with the discussion but if you could elaborate on your reasoning here it would be greatly appreciated.

Finally, about the shape of the Earth turning us for ourselves; it seems to me that you totally misunderstand the point squevil is trying to make to you.  Try to imagine, as he says, a due east path twenty feet from the true north pole.  You are going to travel in a noticeable circle.  Is it your contention that the Earth will somehow be pushing you in the direction of a circle for you?

If I do in fact misunderstand what you're saying, please bear with me and explain to me where I'm wrong.  I won't put past the possibility that you're expressing a valid concern and I just don't understand what it is.

Gotcha, I am just going to not bring up the sphere thing anymore. I am describing it horribly and everything you guys are saying I know, but I am not expressing it in the best way. So for now let us focus on my concerns.


1. In FE the Earth is a flat plane.
2. On a flat plane we do not stand at an angle.
3. The circle you make on a flat plane is not the same as you would make on a sphere.
4. To make a circle around a point on a flat plane you have to turn.
5. How can you make a circle on this flat plane without turning. What affect is causing this to happen?
6. The circle that you make on a flat Earth map to get from California to Japan is upside down compared to the great circle path you would follow on spherical Earth because you are traveling in the northern hemisphere.

Now those are what I am really confused about. The one thing I would want an answer to more so then the rest is the great circle we follow on a sphere, how is that applied to a flat plane. IT seems to me the shortest distance on a flat plane is a straight line. Why do we travel in a circle on a flat plane? and if so how is that we do not turn to mak that circle?

Gotcha, I am just going to not bring up the sphere thing anymore. I am describing it horribly and everything you guys are saying I know, but I am not expressing it in the best way. So for now let us focus on my concerns.


1. In FE the Earth is a flat plane.
2. On a flat plane we do not stand at an angle.
3. The circle you make on a flat plane is not the same as you would make on a sphere.
4. To make a circle around a point on a flat plane you have to turn.
5. How can you make a circle on this flat plane without turning. What affect is causing this to happen?
6. The circle that you make on a flat Earth map to get from California to Japan is upside down compared to the great circle path you would follow on spherical Earth because you are traveling in the northern hemisphere.

Now those are what I am really confused about. The one thing I would want an answer to more so then the rest is the great circle we follow on a sphere, how is that applied to a flat plane. IT seems to me the shortest distance on a flat plane is a straight line. Why do we travel in a circle on a flat plane? and if so how is that we do not turn to mak that circle?

this a response to question 4.



you would have to turn on a pshere, unless your path was a great circle.

if you drew a line in front of you for the path (if you are traversing it on a boat) of  a greatcircle (in this case the equator) it would curve towards the horizon, but as you get closer to either pole, (on a path running parallell to a the equator) the line would curve away  from you, toward either starboad or port, more and more in proportion to the closeness of either pole; a boat would have to compensate for this by turning, otherwise its motion would describe that of a greatcircle, and you would go off path.


P.S I am not a Flat Earther, just a conscientius objector.

Hey Burt, having a rough time understanding exactly what that is reference to. Is what you say how we would do a circle on a flat plane?

I understand what you are saying, just need some clarification on if it answers any of my questions and if so wich one?

Hey Burt, having a rough time understanding exactly what that is reference to. Is what you say how we would do a circle on a flat plane?

I understand what you are saying, just need some clarification on if it answers any of my questions and if so wich one?

sorry read it again, I re-edited it.

Ok, I am going to write a few things now. Bare with me burt as this is kind of how I analyze things.

So, I draw a line in front of me for the path of a great circle.

It curves towards the horizon at the equator (because at the equator you are standing at a right angel correct?)

If I move up in longitude it now curves Towards that pole because I am at an angel on the sphere.

To maintain a true heading I must turn to correct my course or I will now be following the great circle path.

Now I have a couple questions, Burt.

1. If I do not want to do a circle around a sphere I will need to turn or els I will follow the path of a great circle around the sphere, but I am talking about how circles  work on a sphere compared to a flat plane. how would what your wrote apply on a flat plan, Burt?

2. Why would a great circle path be applied to a flat plane?
3. Is the reason we travel in a circle the way we do on a sphere because of the angle we are positioned at on the sphere? And if so How can that be applied to a flat plane?

Now if we cannot apply great circle path's and our angels to a flat plane then why do we travel in circles on a flat plane without turning?

If I need to clarify anything please feel free to let me know.

Ok, I am going to write a few things now. Bare with me burt as this is kind of how I analyze things.

So, I draw a line in front of me for the path of a great circle.

It curves towards the horizon at the equator (because at the equator you are standing at a right angel correct?)

If I move up in longitude it now curves Towards that pole because I am at an angel on the sphere.

To maintain a true heading I must turn to correct my course or I will now be following the great circle path.

Now I have a couple questions, Burt.

1. If I do not want to do a circle around a sphere I will need to turn or els I will follow the path of a great circle around the sphere, but I am talking about how circles  work on a sphere compared to a flat plane. how would what your wrote apply on a flat plan, Burt?

2. Why would a great circle path be applied to a flat plane?
3. Is the reason we travel in a circle the way we do on a sphere because of the angle we are positioned at on the sphere? And if so How can that be applied to a flat plane?

Now if we cannot apply great circle path's and our angels to a flat plane then why do we travel in circles on a flat plane without turning?

If I need to clarify anything please feel free to let me know.

1. the circumeference of a circle would get smaller on a flat plane if you got close to the north pole (this is the same as on a sphere)

2. This still has to be answered by Flat Earther's. my guess is that it does not. because the only greatcircle on a flat earth is the circumference.

3. yes, but the experience of actually getting in a boat and measuring the turning/angle would not be able to differentiate between whether it was flat or spherical, this also applies to an aeroplane. this is probably where the flat earhers get most of their argument.

Now if we cannot apply great circle path's and our angels to a flat plane then why do we travel in circles on a flat plane without turning?

If I need to clarify anything please feel free to let me know.

I think you are misunderstanding; was it not you that said you would not turn on a sphere? and not flat earthers claiming you would not turn on a flat plane?

you turn on a flat plane because you are following a compass. east or west will take you in a circle.

right lets say the earth is flat and thats its 100% truly flat. take this information to any shipping company and show them how much they can save on fuel by traveling in strait lines and adjusting for a flat earth map and rake in the millions.
if popular belief is wrong and the earth is flat, people could save millions by following strait lines and calculating a better route.
4 pages later and i finally see what you are saying, sorry. it wasnt until you mentioned traveling in a strait line on a flat map did i truly understand your point.

but as gps is wrong in a flat world and the only good reliable navigation tool is a compass people will still be wasting time traveling in arks on a flat map.

your mission if you choose to accept it is to now persuade your captain to follow a flat earth map and travel in a strait line and see what happens! if it is possible to do then it would be a good way to prove either theory correct.

for further lurking you should find the thread that discussed under sea power lines. you may enjoy reading that.

Oh nice, im glad you figured it out Squevil!

So I have one more question then since you get what I am saying.

Now I might have to just ask my chief one day about this because it might sound different to people that do not see this on a daily basis. So bare with me and if you need to know anything about charts just ask.

If I make a track leg on a chart going from say San Diego, CA to Hilo, Hawaii. The direction would be about 200 true, distance about 2200 NM (might be off I do not have the chart in front of me)

Now that calculation is using a flat chart. Thinking only in flatness not curves. Never on the bridge of a ship will you hear anything about doing arcs or circles or curving. You will see and hear talk of track legs and their true headings/distances, time to turn, and of course speed. All legs are based off of straight lines between two points. Never are you going to hear or be asked about a curve we are traveling on because we take a true heading, draw the line, mark it, and take off following that line (track line!)

So in short, We do use lines to measure and navigate by, without ever thinking of or about, curving. The shortest distance between San Diego and Hilo is if I draw a straight line between the two points, not if I draw a gradual arc.

tbh you lost me at "if i make.."  you know it could be that we do travel in strait lines but because people believe that they are traveling on a globe they plot what the think is right. like you said nobody actually notices the curve you make when traveling so perhaps the simple answer is you dont!

This has been going for four pages, I have something very short to say, so I'm not going to read all four pages. BoatswainsMate, the gyro used on ships for navigation relies on gravity and the Coriolis Effect to work properly. The Coriolis effect is caused by something rotating. If you were around the outside edge (let's call it the equator for clarity) of this object, and you are heading west, the gyro will read 270, east it will read 90. That is all.

Boatsy, on the bridge, they talk about straight lines because it is convenient.  In reality, you do not just point the ship in the right direction and let it go (I am not talking about some auto pilot or something here).  Wind, currents, and other factors have to be corrected for on the way.

Wind and currents are corrected for by what is called, set and drift. We are constantly correcting for set and drift and the helmsman has to use greater rudder angles to stay at the heading we want.

So set and drift is not at all a factor in this Jroa, that is easy to correct. Hell I don;t even have to do the math anymore, my electronic chart does it for me 

Now Thinkingman brings up a good point. My gyro is keeping me at the heading I want, that heading I want based on the gyro is using gravity and the coriolis   effect to correct what the gyro repeater is saying to the helmsman and me.

So now that Thinkingman (sorry thinkingman my post was a little misleading I already knew this just wanted to bait people into talking about it) explained how my gyro is working, how and why would my gyro do that on a flat plane?

Using straight lines on a flat plane is the shortest distance between two points, and the shortest way to get to where you want to go? So why would the Flat Earth map show that I am going to do a circle to get where I want to go. Makes no sense.

Now a short answer would be, because to get across an ocean to reach another piece of land you have to curve in a circular path. Now answer me this, would your gyro not notice that you are turning in this circle to get there?

I think it would, why would it not? My vessel is turning on a flat plane to reach another land mass.

I love it you all are so confused hahahahahaahaha

The gyro that was designed for naval navigation (vibrating structure gyroscope, or the more expensive Coriolis Vibratory Gyroscope) would not work at all without the Coriolis effect. If there Earth were a disc-like plane, rotating, the coriolis effect would push us out towards it's edge, gyroscopes designed with a spheroid planet in mind would not work properly, and accelerometers would read lateral pull (towards the edge).

So your gyroscope would only detect the change in direction if there was a rotation. If there is none, the gyroscope is useless. Since the gyroscope does work, there must be rotation, and you must be on the side of something. It's the only thing that physically makes sense.

we were confused because you were talking about circles all the time when what you were really getting at was traveling in strait lines. you made the thread far more confusing than it needed be.

as nobody has managed to make a flat earth map how are you able to say that ships do not travel in strait lines? you claim they travel in circles on a flat world yet there is no data to prove this anyway. all you have is round earth data.

What is the stupid freaken affect that would cause my vessel to travel in an arc like fashion on a flat Earth without me knowing it?

1. I understand that because magnetic north is in the center your magnetic compass will not show you turning. 
2. I understand that on a flat plane the shortest distance between two places is a straight line. So a great circle path would not work on a flat plane (why do people account for a great circles then)
3. You say one word about how we travel on a sphere I will be forced to get my good marlin spike out and come find your cars tires.
4. I am talking about a flat plane.

If you still are so lost at what I am trying to get at, go create a track line between two points on a chart, then go compare those charts to a globe and then the flat Earth map in the wiki. Come back to me when you see what I see. I will even give you a hint, I am unable to use most of my calculations for travel.

I swear to god I wish there was another navigator on these forums.

Well I'm not a navigator. I understand you. I was just explaining the finer points of your gyroscope.

While I am not one of the ET's that works on the gyroscope, I do understand how it works, the "why" you helped me out on a bit. I agree that the gyro wont work properly on a flat Earth, but I am more concerned about the calculations and affects navigators are taught. They don;t match or work if the Earth is like the one in the wiki. Or flat period for that matter.

I have preformed various experiments with a kick ball and micro machines and I cannot replicate a rhumb line without turning the micro machine.

that sounds cool Pongo, May I know a couple of the things you di? I would like to try this myself, but with hot wheels!!!

I have preformed various experiments with a kick ball and micro machines and I cannot replicate a rhumb line without turning the micro machine.

That's because a rhumb line on a sphere (except at the equator) is actually a spiral.  A rhumb line is straight only on a Mercator (or similar) projection.
http://en.wikipedia.org/wiki/Rhumb_line

And that is why we navigators use mercator charts, they fullfil the two requirements to account for the distortions!

Just to quickly put, during watch I brang up this subject and my Bos'un along with a BM1 kind of agreed that if traveling on a flat Earth using a map such as the one I showed then from the wiki, you would not be able to follow normal modern navigational principles. The details I do not know, if you think about navigators in a sense of journeyman, expert, professional,master levels.

I would be a expert ( 8 years) and bos'un would be considered a master since he has 20+ years of navigation. BM1 would be borderline professional (he has about 14 years experience)

They both agree that
1. A ships gyro would detect a turn and go a little haywire because the ship is moving, the helmsman would have to turn, yet the heading would be the same as you move around the pole on a flat plane.
2. Placing a track line such as one you would follow on the flat earth map would have to be a arc and not a straight line, due to a Mercator chart being unusable.

Sorry I can not get a direct quote, but that is the just of what they explained to me.

Q: "When traveling in a straight direction, you will always reach the same point on the globe from where you started. How can this happen if the world is flat?"
A: The Earth is in the shape of a disk, as seen below. When one circumnavigates it, one is actually moving in a great circle around the North Pole.

Wrong: http://en.wikipedia.org/wiki/Great_circle

Ta Da!

You cannot make a great circle on a flat disc. Sorry to burt the bubble.

Quote from: Pongo on July 16, 2012, 01:39:08 PM

I have preformed various experiments with a kick ball and micro machines and I cannot replicate a rhumb line without turning the micro machine.

That's because a rhumb line on a sphere (except at the equator) is actually a spiral.  A rhumb line is straight only on a Mercator (or similar) projection.
http://en.wikipedia.org/wiki/Rhumb_line

As I understood it, the OP stated that he followed rhumb lines without turning. Did I misunderstand this point?

You'll follow a great circle if you don't turn, not a rhumb line.

"However the inconvenience of having to continuously change bearings while travelling a great circle route makes rhumb line navigation appealing in certain instances."
http://en.wikipedia.org/wiki/Rhumb_line

This is the paragraph that I thought said you were following a rhumb line and not turning:

"Now in figure 1. That is a boat traveling at a 270 true course, you can tell that boat is traveling west because it is heading in that direction, following the Earths curve and of course not exactly in a straight line path (rhumb line, great circle so on depending on what the vessel is doing exactly) that vessel will meet a piece of land at some point staying at 270. You can see that the vessel is really going in that direction, not making course changes and not turning."