JHelzer

• 180
Flat Earth Map Should Be Easy
« on: September 29, 2017, 01:32:24 PM »
I have started my Flight-time Flat Earth Map Project and will be starting a topic soon to share with ya'll.  Before I do, I want to test out the premise of my map project here on a debate thread.  Here it is...

If the surface of the Earth is flat and the surface of a piece of paper is flat, then it should be easy to make an accurate map.

Also, if the Earth is flat but the paper is curved, it should be problematic to make an accurate map.
Likewise, if the Earth is curved but the paper is flat, it should be problematic to make an accurate map.
Finally, if the Earth is curved and the paper is curved, it should be smooth sailing to make an accurate map.

When I begin my Map Project topic, I don't want it be a debate thread.  So I thought I'd start here.  Please join me in refining my premise here, before I begin the project.
The hallmark of true science is repeatability to the point of accurate prediction.

Tom Bishop

• Zetetic Council Member
• 10236
• Flat Earth Believer
Re: Flat Earth Map Should Be Easy
« Reply #1 on: September 29, 2017, 01:36:45 PM »
GPS and other instruments assume a Round Earth coordinate system when computing distance between two points. Please tell us the distance between New York and Paris without using a method that assumes the earth is round.

JHelzer

• 180
Re: Flat Earth Map Should Be Easy
« Reply #2 on: September 29, 2017, 01:50:33 PM »
That's a good point.
My 2nd premise for the project is that flight times are a good-enough measure of distance from one place to another.
I will not use the distances calculated by the airlines, just the raw flight times.
I am gathering several flights from different airlines going both ways and averaging them together.

This is a link to the data I have started collecting.

To my mind, the flight time that a passenger experiences is a raw, real-world measure.  I would argue that it is not based on GPS systems, but rather, shortest path.  Follow the money should be a principle that works to make this a good measurement.
The hallmark of true science is repeatability to the point of accurate prediction.

Tom Bishop

• Zetetic Council Member
• 10236
• Flat Earth Believer
Re: Flat Earth Map Should Be Easy
« Reply #3 on: September 29, 2017, 02:04:44 PM »
1. In order to derive distance from time you would need to know how fast the plane is flying. The flight speed of a plane varies quite a bit throughout a flight. It's flying in mediums moving within mediums, not anything like vehicles on the ground.

2. The secondary concern is that an aircraft's groundspeed indicators may be made using Round Earth coordinates as plot points to calculate speed. Airspeed instruments are not really accurate and are not used in navigation.

3. It has been brought up that we should use a plane's listed cruising speed for this; but those are just averages, as it relates to point one, and the speeds actually vary throughout the flight. The average cruising speed may also have been computed with groundspeed, which may be in error if they are computed with RE coordinates, as mentioned in point two.

JHelzer

• 180
Re: Flat Earth Map Should Be Easy
« Reply #4 on: September 29, 2017, 02:25:17 PM »
1. In order to derive distance from time you would need to know how fast the plane is flying. The flight speed of a plane varies quite a bit throughout a flight. It's flying in mediums moving within mediums, not anything like vehicles on the ground.
To solve this I'd like to let total average flight times of several flights from different airlines smooth all that out.  Instead of a precise measure of distance, I want to convince you that an rough average of time is good enough for a general picture.  I would argue that if I average all the flight paths then errors should be distributed evenly.

2. The secondary concern is that an aircraft's groundspeed indicators may be made using Round Earth coordinates as plot points to calculate speed. Airspeed instruments are not really accurate and are not used in navigation.
This is why I plan to use raw flight time.  No calculated distances.  I want to rely on the fact that all flights need to ascend, cruise and descend to skirt past the need for precise distance calculations.  No distance, just the time a passenger experiences.

3. It has been brought up that we should use a plane's listed cruising speed for this; but those are just averages, as it relates to point one, and the speeds actually vary throughout the flight. The average cruising speed may also have been computed with groundspeed, which may be in error if they are computed with RE coordinates, as mentioned in point two.
I'd like to leave ground speed and air speed out of it.  I don't believe that the differences in cruising speeds of jet powered airplanes averaged together can create enough effect that it would turn a flat earth into a round earth (or visa versa).  I am asking that we recognize that there will be error, and the times will be averaged and fuzzy, but the data should be good enough to give a fuzzy picture of the layout of the continents on the Earth.
The hallmark of true science is repeatability to the point of accurate prediction.

JHelzer

• 180
Re: Flat Earth Map Should Be Easy
« Reply #5 on: September 29, 2017, 02:35:22 PM »
As an example, here is North America.
I traced it from a known round-earth model and gathered flight times from LA to New York to Miami to LA.
When I plotted the lines, I had to move Florida a little to make the flight times work.  You can see my original Miami dot on there.
As I expand the map, I will redraw the continent lines to make them match my flight time data.  With the flight time data, the map of the continents should reveal themselves.

If my 1st premise is true and a flat earth on a flat paper is easy, then I'll get this done.

The hallmark of true science is repeatability to the point of accurate prediction.

Curious Squirrel

• 1338
Re: Flat Earth Map Should Be Easy
« Reply #6 on: September 29, 2017, 03:04:52 PM »
I saw when you first presented this idea, and then as now I continue to agree it should produce a good map of the Earth. Whether it be round or flat, flight times should correspond well to a fair distance metric. I look forward to seeing what you come up with.

3DGeek

• 1024
• Path of photon from sun location to eye at sunset?
Re: Flat Earth Map Should Be Easy
« Reply #7 on: September 29, 2017, 03:27:42 PM »
As an example, here is North America.
I traced it from a known round-earth model and gathered flight times from LA to New York to Miami to LA.
When I plotted the lines, I had to move Florida a little to make the flight times work.  You can see my original Miami dot on there.
As I expand the map, I will redraw the continent lines to make them match my flight time data.  With the flight time data, the map of the continents should reveal themselves.

If my 1st premise is true and a flat earth on a flat paper is easy, then I'll get this done.

I predict that when you add a fourth city at some large-ish distance from the current three choices - and presuming you measure the length of both diagonals consistently - then the resulting figure will not be able to be drawn on a 2D map because one of the diagonals will be "too small".

I've already demonstrated that this definitely happens using published airline flight distances.   I compared the airline's claimed long distance flight times (verified independently from 3rd party "On-Time flight" records) - and the distances they publish are a perfect fit for the published cruise speeds of the aircraft.

So the chain of reasoning is thus:

1) We know the flight times from examining the airline's schedules.
2) We know that they fly "on time" for the vast proportion of flights because multiple consumer watchdogs and government offices monitor them...so the published schedules are DEFINITELY CORRECT.
3) We can obtain the cruising speed of the airplanes from multiple sources - including both airlines and manufacturers.
4) We can infer the distances travelled from that.
5) We can compare that with the airlines published distances - and THEY AGREE.
6) We can find distances for four widely spaced cities laid out in a quadrilateral and construct two flat, 2D triangles using one of the two diagonals.
7) We can then calculate what the other diagonal distance should be if the world is flat.
We compare the calculated second diagonal distance with the airline route distances - and they DO NOT AGREE!!!

So one of these steps is broken...I contend it's that the world ISN'T flat - and when you work it out, the data we have is 100% consistent with a round earth.

The only FE "get out" is that Tom claims that the published cruise speeds of modern airliners is incorrect (assumption (3), above) and is therefore claiming that neither airlines nor airliner manufacturers are aware of the speeds that their planes actually fly(!!) - he seems to believe that they determine the practical cruise speeds of their planes by flying some long route with a stopwatch...which is...beyond crazy!

Since you're gathering flight TIMES (not actual distances) in the same basic way we did - your map will fall foul of the exact same critiques that our efforts did.

HOWEVER: There is a second part to this.

9) If (as Tom claims) the airliner cruise speeds that we have are (say) 20% too low - then all of the distances that the airlines are stating in their route maps are 20% larger than the airlines believe them to be.
10) This scales up my "quadrilateral of cities" diagram by 20% - but the diagonal calculations are still incompatible with the flat earth hypothesis.

So even if Tom is right - my disproof of the flat earth still works.

The ONLY way to escape my trap is to claim that the airlines deliberately vary the speeds that they fly in order to make it APPEAR as though the world is round, even though it's clearly not.

Since airliners fly most efficiently only at one particular speed - this would be costing them a TON of money every year.   It seems highly unlikely that every airline around the entire world would keep the conspiracy silent.

Tom then deflected the conversation into arguments about GPS's and such.

Hence, it's largely a waste of time to try to create your map because it just leads down the exact same rabbit hole.

If the FE'ers adamantly refuse to accept any form of distance measurement whatever, they cannot make a good map.

But here's the thing: They don't WANT a good map!

Having no map is actually their defense against a whole slew of arguments.   They know that the very moment they come up with an "official" map, I 100% guarantee that I can instantly debunk it - because their compass readings and positions of the Pole Star and Southern Cross cannot POSSIBLY agree with reality as observed by ship's captains and navigators for the past 1000 years or so...airliners will have to fly at Mach 2 on some routes and at 200mph on others.

The laws of topology are on the side of the RE'ers here.  Mathematics doesn't tell lies and it doesn't take sides.  Math says, clearly and unambigously that you can't make a flat earth map that reproduces the important features of a round earth map.   It's called "The Hairy Ball Theorem" (or "The Hedgehog Theorem" in situations where "hairy balls" have an entirely unfortunate connotation!).   You can look it up on Wikipedia.

According to hairy ball, you can't make a spherical map (a globe) without creating two points on the sphere that are "special" (for stellar cartography, the north and south geographic poles - for magnetic cartography, the north and south magnetic poles).   Flat surfaces do not have this property - which means that 100% of all flat earth maps are doomed.

Basically - you're screwed.
Hey Tom:  What path do the photons take from the physical location of the sun to my eye at sunset?

Ga_x2

• 178
Re: Flat Earth Map Should Be Easy
« Reply #8 on: September 29, 2017, 03:36:26 PM »
Seems reasonable, as long as you pick flights within approximately the same range, because of the time proportionally spent at cruise speed, and the type of aircraft used.
I'd like to ask how the error bars are coming along (I'm using a mobile and can't open the spreadsheet).
Also, i'm curious to know how you're going to physically produce the actual map without going crazy threads of different length?

JHelzer

• 180
Re: Flat Earth Map Should Be Easy
« Reply #9 on: September 29, 2017, 03:42:34 PM »
Please tell us the distance between New York and Paris without using a method that assumes the earth is round.

It takes a while to get the data but I have added New York to Paris to my spreadsheet.  You can find it in rows 37 - 43.
The distance between New York and Paris (for my map) is 7 hours and 34 minutes.

The hallmark of true science is repeatability to the point of accurate prediction.

JHelzer

• 180
Re: Flat Earth Map Should Be Easy
« Reply #10 on: September 29, 2017, 03:54:25 PM »
I predict that when you add a fourth city ...
...Basically - you're screwed.

Yes, yes.  I've checked your math and you are correct.
I am going to try this anyway.
The hallmark of true science is repeatability to the point of accurate prediction.

JHelzer

• 180
Re: Flat Earth Map Should Be Easy
« Reply #11 on: September 29, 2017, 04:33:08 PM »
I'd like to ask how the error bars are coming along (I'm using a mobile and can't open the spreadsheet).
Also, i'm curious to know how you're going to physically produce the actual map without going crazy threads of different length?

Between New York and Paris all the west-bound flights took about an hour longer than the east-bound flights.
The fastest flight was 6:30 on a boeing 777 and the longest was 8:37 on a boeing 767.  The average was 7:34. That gives an error of 14% and 12% for the extremes. That is higher than I'd like, but if I take the two mode flight times of 7:03 and 8:07 it is a 7% error up and down from the average.

Even with the large variances in the flight times, I still think this will work out by using the same averaging method between each of the cities I measure.  I believe, and I want the community to agree, that averaging flights going both ways will remove jetstream issues.

As for producing the map without going crazy.  I originally suggested using wires between rigid content to make the map.  Instead I am going to just draw the lines on a flat piece of paper.  When I need to move the edge of a continental shoreline, I will move it.  (like I did with Florida in the posted example)
The hallmark of true science is repeatability to the point of accurate prediction.

3DGeek

• 1024
• Path of photon from sun location to eye at sunset?
Re: Flat Earth Map Should Be Easy
« Reply #12 on: September 29, 2017, 04:46:07 PM »
I'd like to ask how the error bars are coming along (I'm using a mobile and can't open the spreadsheet).
Also, i'm curious to know how you're going to physically produce the actual map without going crazy threads of different length?

Between New York and Paris all the west-bound flights took about an hour longer than the east-bound flights.
The fastest flight was 6:30 on a boeing 777 and the longest was 8:37 on a boeing 767.  The average was 7:34. That gives an error of 14% and 12% for the extremes. That is higher than I'd like, but if I take the two mode flight times of 7:03 and 8:07 it is a 7% error up and down from the average.

That route is especially hit by the Jet stream.  East/West routes do need to be averaged each way to account for that...but there is a possibility that pilots may be choosing altitudes that do not "fight" the jet stream in one direction while deliberately "riding it" in the other.   The intelligent thing to do is to use flight times to verify that the airline's distance measurements are not being methodically faked - and then to use them "as is" rather than trying to analyze jet stream influences.

For this reason, the Qantas flights are good choices because most of them are predominantly North/South and they are long enough to factor out takeoff and landing time wastages.

When you do the "quadrilateral cities" thing - you can pick routes that don't run along the course of the jet stream AND put them far enough apart that the "diagonal distance error" is so large as to be impossible to explain by these means.  But map-making is more susceptible to problematic flights like this one.

Quote
Even with the large variances in the flight times, I still think this will work out by using the same averaging method between each of the cities I measure.  I believe, and I want the community to agree, that averaging flights going both ways will remove jetstream issues.
Where the difference is this large, it's probable that pilots are flying at altitudes to avoid it in one direction - so choosing the longest of the two flight times (the unassisted one) would be more correct than averaging them.
Quote
As for producing the map without going crazy.  I originally suggested using wires between rigid content to make the map.  Instead I am going to just draw the lines on a flat piece of paper.  When I need to move the edge of a continental shoreline, I will move it.  (like I did with Florida in the posted example)
May I suggest establishing the general locations of the continents relative to each other FIRST - then picking a second route between each pair of continents to establish relative rotations.   However, you're not at liberty to futz with things that screw up which way is North or South.  People know those things rather well.
Hey Tom:  What path do the photons take from the physical location of the sun to my eye at sunset?

JHelzer

• 180
Re: Flat Earth Map Should Be Easy
« Reply #13 on: September 29, 2017, 05:14:23 PM »
3DGeek,  I suspect that I will get different results (different continent shapes) depending on what I make the center of my map.
If I start at LA - New York, the map will get more accurate in North America and more distorted the further away I get in all directions.
If I start in Europe, the same thing will occur with Europe being shaped correctly, but other contents distorted.

If this happens as you and I feel certain it will, I will have shown that the flat Earth is having problems mapping to a flat surface.  According to my original premise in this topic that should not happen if they are both flat.  if I get a wavy looking map.  That is just my 7% error.  Ok so it should be flat, but I messed up here and there and got it wavy.  No big deal.  If it impossible, well... that's another story.  My uniformly spread 7% error shouldn't make it impossible.
The hallmark of true science is repeatability to the point of accurate prediction.

TomInAustin

• 1363
• Round Duh
Re: Flat Earth Map Should Be Easy
« Reply #14 on: September 29, 2017, 05:30:52 PM »
1. In order to derive distance from time you would need to know how fast the plane is flying. The flight speed of a plane varies quite a bit throughout a flight. It's flying in mediums moving within mediums, not anything like vehicles on the ground.

2. The secondary concern is that an aircraft's groundspeed indicators may be made using Round Earth coordinates as plot points to calculate speed. Airspeed instruments are not really accurate and are not used in navigation.

3. It has been brought up that we should use a plane's listed cruising speed for this; but those are just averages, as it relates to point one, and the speeds actually vary throughout the flight. The average cruising speed may also have been computed with groundspeed, which may be in error if they are computed with RE coordinates, as mentioned in point two.

The good news Tom, we don't have to rely on aircraft's groundspeed indicators, GPS, or airspeed.   We can see live ground speed in publicly available ATC live radar data.

I assume you are ready to prove that a round earth mile is not equivalent to a flat earth mile.  Based on comments in the burden of proof thread, it's on you.

As junker has stated, the burden of proof is on the claimant. When you come to this forum and start making claims, we expect that you work to demonstrate your claims.

Do you have a citation for this sweeping generalisation?

TomInAustin

• 1363
• Round Duh
Re: Flat Earth Map Should Be Easy
« Reply #15 on: September 29, 2017, 05:37:14 PM »
I have started my Flight-time Flat Earth Map Project and will be starting a topic soon to share with ya'll.  Before I do, I want to test out the premise of my map project here on a debate thread.  Here it is...

If the surface of the Earth is flat and the surface of a piece of paper is flat, then it should be easy to make an accurate map.

Also, if the Earth is flat but the paper is curved, it should be problematic to make an accurate map.
Likewise, if the Earth is curved but the paper is flat, it should be problematic to make an accurate map.
Finally, if the Earth is curved and the paper is curved, it should be smooth sailing to make an accurate map.

When I begin my Map Project topic, I don't want it be a debate thread.  So I thought I'd start here.  Please join me in refining my premise here, before I begin the project.

I attempted a similar project using Sketchup, a quite accurate free program that handles 3d geometry that's good enough that I've used it to draw plans for 2 small construction projects.

It didn't take long to see the errors pop up

See this post

Next stop...

Using the last example, I added a new point. Johannesburg.  This is placed a the intersection of D and E.

Rio   Moscow   7103   A
Moscow   Sydney   8960   B
Sydney   Rio   8520   C
Rio    Johannesburg   4447   D
Moscow   Johannesburg   5625   E

The model starts showing the errors here. It shows Johannesburg to Sydney at 4366 miles where the true distance is 6904.
Do you have a citation for this sweeping generalisation?

3DGeek

• 1024
• Path of photon from sun location to eye at sunset?
Re: Flat Earth Map Should Be Easy
« Reply #16 on: September 29, 2017, 06:22:43 PM »
1. In order to derive distance from time you would need to know how fast the plane is flying. The flight speed of a plane varies quite a bit throughout a flight. It's flying in mediums moving within mediums, not anything like vehicles on the ground.

2. The secondary concern is that an aircraft's groundspeed indicators may be made using Round Earth coordinates as plot points to calculate speed. Airspeed instruments are not really accurate and are not used in navigation.

3. It has been brought up that we should use a plane's listed cruising speed for this; but those are just averages, as it relates to point one, and the speeds actually vary throughout the flight. The average cruising speed may also have been computed with groundspeed, which may be in error if they are computed with RE coordinates, as mentioned in point two.

The good news Tom, we don't have to rely on aircraft's groundspeed indicators, GPS, or airspeed.   We can see live ground speed in publicly available ATC live radar data.

I assume you are ready to prove that a round earth mile is not equivalent to a flat earth mile.  Based on comments in the burden of proof thread, it's on you.

As junker has stated, the burden of proof is on the claimant. When you come to this forum and start making claims, we expect that you work to demonstrate your claims.

The thing is that to "fix" this problem you can't apply something uniformly.   You can't fix it by saying "a mile is really 1.5 miles" or "the cruising airspeed of a 747 is 800mph".

You also can't build a flat map (for 100% sure) with the data we have.

The ONLY way to have a Flat Earth map is to have some "fix" that varies non-uniformly.

Quote
Rio   Moscow   7103   A
Moscow   Sydney   8960   B
Sydney   Rio   8520   C
Rio    Johannesburg   4447   D
Moscow   Johannesburg   5625   E

The model starts showing the errors here. It shows Johannesburg to Sydney at 4366 miles where the true distance is 6904.

So doubling all of the distances (because airplanes fly twice as fast as we think - means that the error goes from 2,500 to 5,000) but halving them doesn't help either - there would still be a an error of 1,250.

You have to come up with a mechanism that SELECTIVELY shrinks the Johannesburg/Sydney route while leaving all of the other alone.

More precisely, you have to imagine some source of error that makes the flat earth work EXACTLY as if it was round.

That implies that whatever pilots fly Johannesburg/Sydney are very deliberately flying at around 60% of their airplane's designed cruising speed on that route.

Many FE theories are like this...the sun, moon, planets and stars CAREFULLY tippitoe around the world in some bizarre dance that seems to have no rhyme or reason EXCEPT to make it seem like the world is round.

It makes no sense.   Why are all of these completely independent laws of nature all conspiring to camouflage the fact that the Earth is Flat - and to do so in a manner that makes it look PRECISELY as the Round Earth theory says it should?!

This is the thing that is crazy here...more than all of the other debunkery.

So with the airline flight times and distances - if the Earth is Flat then it can ONLY be that airliners are flying at different "cruise speeds" on different routes - with speeds very carefully calculated to convince everyone on board that the Earth is Round.

Since pilots have the ability to control the speed of the airplane - it could ONLY be that 100% of all airline pilots are conspiring to carefully tweak airplane speeds to make the earth look this way.

If the Earth is flat, it isn't just NASA that are doing this...it must include all airline pilots, all ship captains, etc.   It would be impossible for them to disguise the extra fuel this would take - so the airlines themselves must be fully aware of it.

This conspiracy would have to spread until an enormous percentage of people in places like the USA and Europe would have to be aware of it.
Hey Tom:  What path do the photons take from the physical location of the sun to my eye at sunset?

Tom Bishop

• Zetetic Council Member
• 10236
• Flat Earth Believer
Re: Flat Earth Map Should Be Easy
« Reply #17 on: September 30, 2017, 01:42:27 AM »
1. In order to derive distance from time you would need to know how fast the plane is flying. The flight speed of a plane varies quite a bit throughout a flight. It's flying in mediums moving within mediums, not anything like vehicles on the ground.
To solve this I'd like to let total average flight times of several flights from different airlines smooth all that out.  Instead of a precise measure of distance, I want to convince you that an rough average of time is good enough for a general picture.  I would argue that if I average all the flight paths then errors should be distributed evenly.

If the groundspeed is based on RE coordinate points then you are just getting the RE version of the average speed.

Quote
This is why I plan to use raw flight time.  No calculated distances.  I want to rely on the fact that all flights need to ascend, cruise and descend to skirt past the need for precise distance calculations.  No distance, just the time a passenger experiences.

That is fine. You will need a method of finding the speed that does not use a Round Earth coordinate system.

Quote
I'd like to leave ground speed and air speed out of it.  I don't believe that the differences in cruising speeds of jet powered airplanes averaged together can create enough effect that it would turn a flat earth into a round earth (or visa versa).  I am asking that we recognize that there will be error, and the times will be averaged and fuzzy, but the data should be good enough to give a fuzzy picture of the layout of the continents on the Earth.

Again, if the speed is based on the distance between Round Earth coordinates then you are getting the average RE speed, which would be invalid for your purposes.

Not so easy anymore.

Tom Bishop

• Zetetic Council Member
• 10236
• Flat Earth Believer
Re: Flat Earth Map Should Be Easy
« Reply #18 on: September 30, 2017, 02:15:42 AM »
The only FE "get out" is that Tom claims that the published cruise speeds of modern airliners is incorrect (assumption (3), above) and is therefore claiming that neither airlines nor airliner manufacturers are aware of the speeds that their planes actually fly(!!) - he seems to believe that they determine the practical cruise speeds of their planes by flying some long route with a stopwatch...which is...beyond crazy!

Average cruising speed is just an average. The plane isn't a locomotive. Its speed changes while in flight by large amounts. The plane is flying within mediums which move within mediums.

Average cruising speed is based on groundspeed, meaning that the system is using external reference based on ground coordinates in some manner. If those reference points are broadcasting Round Earth coordinates, then that speed was created using the Round Earth coordinate system.

This is all very unhelpful in attempting to map out a world which is not round.

Curious Squirrel

• 1338
Re: Flat Earth Map Should Be Easy
« Reply #19 on: September 30, 2017, 02:30:24 AM »
1. In order to derive distance from time you would need to know how fast the plane is flying. The flight speed of a plane varies quite a bit throughout a flight. It's flying in mediums moving within mediums, not anything like vehicles on the ground.
To solve this I'd like to let total average flight times of several flights from different airlines smooth all that out.  Instead of a precise measure of distance, I want to convince you that an rough average of time is good enough for a general picture.  I would argue that if I average all the flight paths then errors should be distributed evenly.

If the groundspeed is based on RE coordinate points then you are just getting the RE version of the average speed.

Quote
This is why I plan to use raw flight time.  No calculated distances.  I want to rely on the fact that all flights need to ascend, cruise and descend to skirt past the need for precise distance calculations.  No distance, just the time a passenger experiences.

That is fine. You will need a method of finding the speed that does not use a Round Earth coordinate system.

Quote
I'd like to leave ground speed and air speed out of it.  I don't believe that the differences in cruising speeds of jet powered airplanes averaged together can create enough effect that it would turn a flat earth into a round earth (or visa versa).  I am asking that we recognize that there will be error, and the times will be averaged and fuzzy, but the data should be good enough to give a fuzzy picture of the layout of the continents on the Earth.

Again, if the speed is based on the distance between Round Earth coordinates then you are getting the average RE speed, which would be invalid for your purposes.

Not so easy anymore.

Tom, he's not using speed at all. He's using flight time as a distance analogue. So there's no flight speed involved what so ever.