Offline edby

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Re: The Circularity Objection
« Reply #20 on: June 07, 2018, 01:07:22 PM »
The mapping of the world in means of distances in kilometers on one hand, and the system of longitude/latitude on the other hand was done long before GPS was even invented. It's not recently that people in Australia know how far two cities there are apart from each other. The same for any other country in the world, north and south, it doesn't matter. The same with respect to coordinates. The whole system was introduced hundreds of years ago.

Therefor it is just known, how to calibrate a degree of longitude or latitude around the world.
Be careful - Pete objected before that we can't, in this forum, simply state 'it is known for 100 years that'. I hope I am not misquoting him.

Found it:
Not only are you misquoting Tom's claim in the thread's subject (and very obviously targeting him), the thread you've created consists of nothing but "You're wrong. Why are people still wrong?". As I said, you are welcome to discuss ideas in the upper, or individuals in CN/AR.
« Last Edit: June 07, 2018, 01:13:36 PM by edby »

Offline Tontogary

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Re: The Circularity Objection
« Reply #21 on: June 07, 2018, 01:14:30 PM »
I can sort of see where this thread might go, and what it might hope to show, but i dont want to jump ahead of the OP.

Apart from the Circularity objection, it also started out by trying to get some common ground on how to measure distances, that are distances irrespective of if the world is flat or round is that a fair comment?

However to do so we also have to get an agreement that a foot is indeed a foot, a fathom is a fathom, a metre is a metre, and so on, can we accept that they are, and they can be accepted as a unit of measure, that is not reliant upon the globular or planar nature of the world? If we cannot there is not a lot of hope for any debate going forward.

Can we agree that GPS is not required or relevant to the discussion, because of the huge volume of measurements taken place before the advent of GPS? We dont need GPS to calculate distance, so we should be able to carry on without it being a factor?

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

Offline edby

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Re: The Circularity Objection
« Reply #22 on: June 07, 2018, 01:17:54 PM »
I can sort of see where this thread might go, and what it might hope to show, but i dont want to jump ahead of the OP.

Apart from the Circularity objection, it also started out by trying to get some common ground on how to measure distances, that are distances irrespective of if the world is flat or round is that a fair comment?

However to do so we also have to get an agreement that a foot is indeed a foot, a fathom is a fathom, a metre is a metre, and so on, can we accept that they are, and they can be accepted as a unit of measure, that is not reliant upon the globular or planar nature of the world? If we cannot there is not a lot of hope for any debate going forward.

Can we agree that GPS is not required or relevant to the discussion, because of the huge volume of measurements taken place before the advent of GPS? We dont need GPS to calculate distance, so we should be able to carry on without it being a factor?
Yes to all of that. I have been researching how they actually did this long before GPS.

Pete seems to agree that there are in principle non-circular ways of establishing distance.

I would like other views from the FE side before we go any further, however.

If we cannot reach agreement, then we have what is called the 'nuclear position'. If the objection is that it is in principle impossible to measure distance at all, then that is that, end of argument.

Can we agree that GPS is not required or relevant to the discussion, because of the huge volume of measurements taken place before the advent of GPS? We dont need GPS to calculate distance, so we should be able to carry on without it being a factor?
And because those measurements relied entirely on a sophisticated version of the tape measure. More later.

« Last Edit: June 07, 2018, 01:21:09 PM by edby »

Offline Tontogary

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Re: The Circularity Objection
« Reply #23 on: June 07, 2018, 01:26:54 PM »
I also noted the picture at the beginning, (of a surveying chain) which is an old method of measuring distance, it was referred to in EnaG, so I would have thought there are no great objections to it, and I have seen comments on other threads where it was noted that the use of chains as a measure of distance would be acceptable, at least to some Fe proponents.

However we do need to get an agreement that an inch is reasonably well defined, as is a foot, because the chains refer to those units. Without an acceptance that they are the same unit irrespective of the shape of the earth, we will ultimately end up without any consensus or there will be a potential derailing of the thread on the definition of an inch or foot, and how it was defined.

I hope we can swiftly agree to such basic points, and get to the interesting debate.

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

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Offline Tumeni

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Re: The Circularity Objection
« Reply #24 on: June 07, 2018, 01:28:20 PM »
Inches, Feet and Yards are/were defined here, many years ago.

https://untappedcities.com/2013/02/05/london-trafalgar-square-standard-units/

Is there any dispute over these as a basis of measurement?
=============================
Not Flat. Happy to prove this, if you ask me.
=============================

Nearly all flat earthers agree the earth is not a globe.

Nearly?

Offline edby

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Re: The Circularity Objection
« Reply #25 on: June 07, 2018, 01:33:28 PM »
I also noted the picture at the beginning, (of a surveying chain) which is an old method of measuring distance, it was referred to in EnaG, so I would have thought there are no great objections to it, and I have seen comments on other threads where it was noted that the use of chains as a measure of distance would be acceptable, at least to some Fe proponents.

However we do need to get an agreement that an inch is reasonably well defined, as is a foot, because the chains refer to those units. Without an acceptance that they are the same unit irrespective of the shape of the earth, we will ultimately end up without any consensus or there will be a potential derailing of the thread on the definition of an inch or foot, and how it was defined.

I hope we can swiftly agree to such basic points, and get to the interesting debate.
This https://en.wikipedia.org/wiki/History_of_the_metre gives a history of how the metre was defined. But we should be able to agree in principle that if we take any rigid object, such as a platinum bar, at a certain temperature, and call its length 1 XXX, then whatever has the same length as it, has length of 1 XXX.

But people might still disagree with this. Suppose we calibrate a ruler to the 1 XXX rod, and go round measuring things. Perhaps the length of the ruler is constantly changing? How would we know?

(Actually, we would know if the lengths of the things we were measuring remained the same length. We could compare them with each other, and thus find out that the length of the ruler was changing relative to them. But a more sophisticated objection is that the lengths of all things are constantly changing, in proportion.)


Inches, Feet and Yards are/were defined here, many years ago.

https://untappedcities.com/2013/02/05/london-trafalgar-square-standard-units/

Is there any dispute over these as a basis of measurement?
Yep, that kind of stuff. I still would like to see if FE supporters are agreed on that type of unsophisticated (but still accurate) method of measurement.

« Last Edit: June 07, 2018, 01:36:16 PM by edby »

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Offline AATW

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Re: The Circularity Objection
« Reply #26 on: June 07, 2018, 01:41:01 PM »
You're getting too bogged down with units.
The units don't matter.
What matters is can we determine the distance in whatever unit been some far flung cities in a way that we can all agree that those are the true distances.
If you can do that you can then look at whether there is any way of arranging those cities on a flat map so that those distances are accurately represented.
If you can then it means the earth could be flat, if you can't then it's because your arrangement is a projection and the earth is actually another shape.
You might be able to work out what that shape is from the distances.
Tom: "Claiming incredulity is a pretty bad argument. Calling it "insane" or "ridiculous" is not a good argument at all."

TFES Wiki Occam's Razor page, by Tom: "What's the simplest explanation; that NASA has successfully designed and invented never before seen rocket technologies from scratch which can accelerate 100 tons of matter to an escape velocity of 7 miles per second"

Offline edby

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Re: The Circularity Objection
« Reply #27 on: June 07, 2018, 01:47:45 PM »
You're getting too bogged down with units.
The units don't matter.
What matters is can we determine the distance in whatever unit been some far flung cities in a way that we can all agree that those are the true distances.
If you can do that you can then look at whether there is any way of arranging those cities on a flat map so that those distances are accurately represented.
If you can then it means the earth could be flat, if you can't then it's because your arrangement is a projection and the earth is actually another shape.
You might be able to work out what that shape is from the distances.
Not about units essentially, but measurement. You need a way to measure the length of something, right? So you need to express it in some unit. How else would you do it?

Quote
If you can do that you can then look at whether there is any way of arranging those cities on a flat map so that those distances are accurately represented.
You are jumping too far forward. I want to see if FE agrees

1. we can measure short distances (say 100m)  accurately, and without circularity
2. we can measure much longer distances (say 5,000km) accurately, and without circularity
3. What this implies for shape of earth.

We have not reached (1) yet.
« Last Edit: June 07, 2018, 01:52:31 PM by edby »

Offline hexagon

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Re: The Circularity Objection
« Reply #28 on: June 07, 2018, 02:36:27 PM »
Quote
If you can do that you can then look at whether there is any way of arranging those cities on a flat map so that those distances are accurately represented.
You are jumping too far forward. I want to see if FE agrees

1. we can measure short distances (say 100m)  accurately, and without circularity
2. we can measure much longer distances (say 5,000km) accurately, and without circularity
3. What this implies for shape of earth.

We have not reached (1) yet.

I think, first you have to find out how accurate you can measure longitude and latitude coordinates. Then you know the minimum distance over which you would have to do a length measurement with equivalent accuracy.

Then you have to look for the systematic error, comparing a flat surface and spherical surface on that length scale. Then you know how significant your results are.

Let's say you can measure 100m with an accuracy of 1m. That's one percentage of error. And on the same distance you can measure the degrees latitude/longitude with 1% accuracy. 10000km you can then measure with an accuracy of 10km if you know the corresponding coordinates. Discrepancies for flat-earth maps can reach errors in the order of 50%. That's far beyond your accuracy...

And I guess no one can deny that we can measure 100m with an accuracy of 1m. But I have no feeling about how accurate you can measure degrees of longitude/latitude.   

Offline edby

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Re: The Circularity Objection
« Reply #29 on: June 07, 2018, 02:43:12 PM »
Quote
If you can do that you can then look at whether there is any way of arranging those cities on a flat map so that those distances are accurately represented.
You are jumping too far forward. I want to see if FE agrees

1. we can measure short distances (say 100m)  accurately, and without circularity
2. we can measure much longer distances (say 5,000km) accurately, and without circularity
3. What this implies for shape of earth.

We have not reached (1) yet.

I think, first you have to find out how accurate you can measure longitude and latitude coordinates. Then you know the minimum distance over which you would have to do a length measurement with equivalent accuracy.

Then you have to look for the systematic error, comparing a flat surface and spherical surface on that length scale. Then you know how significant your results are.

Let's say you can measure 100m with an accuracy of 1m. That's one percentage of error. And on the same distance you can measure the degrees latitude/longitude with 1% accuracy. 10000km you can then measure with an accuracy of 10km if you know the corresponding coordinates. Discrepancies for flat-earth maps can reach errors in the order of 50%. That's far beyond your accuracy...

And I guess no one can deny that we can measure 100m with an accuracy of 1m. But I have no feeling about how accurate you can measure degrees of longitude/latitude.   
You don't in fact have to appeal to long and lat in order to map very large areas of the earth's surface. Then you can of course calibrate one against the other, as you rightly mention.

However we are still waiting for the views of FE supporters on whether we can measure short distances by 'tape measure' type methods.

Offline hexagon

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Re: The Circularity Objection
« Reply #30 on: June 07, 2018, 03:14:21 PM »
The advantage of that method is, that you have not to measure every single distance, especially across large areas of water like oceans. And I'm not aware of severe objections by flat earth believers on the longitude/latitude system as such. I have the impression they usually accept that coordinates of places like London or Sydney, etc. are indeed known or which places are on the equator and so on.

The grid of coordinates seems to be a common starting point. The disagreement is on the metric of this grid. To get this metric, its easier to go for short distances, because then the influence of the assumed shape is much smaller.

It doesn't matter if you measure 100m on a sphere as big as the earth or on a flat surface. On this length scale such a sphere can be seen as locally flat.

And you can do this in a direct measurement, with a ruler, with a laser, with a car whatever you have. But if you want to make a direct measurement on a scale of thousands of kilometers, it's getting more and more difficult. Already the definition of a straight line as shortest distance is not equivalent on a sphere and on a plane on this scale.

Offline edby

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Re: The Circularity Objection
« Reply #31 on: June 07, 2018, 03:28:19 PM »
While we are waiting, and that may be for some time, let’s move on to the next part of the argument.

See below for part of the Great Indian Survey, this part performed about 1834, therefore well before GPS. The method was as follows. Establish two ‘baselines’, one at Dehra Doon (now Dehradun), the other at Sironj. The baseline is measured using the chain type tape measure, but with sophisticated and then state of the art compensation for thermal expansion. Drive a pillar into the ground, mark an arrow on it, then roll out the chain to full length and construct a second pillar, with an arrow marking the end point of the chain. There was all sorts of stuff they did to ensure the measurement was accurate.

Once the baseline is established between points A and B, find a third point C, measure the two angles BAC and ABC using a theodolite. From this it follows from Euclidean geometry (which is the geometry of a flat plane) that we can calculate the distances AC and BC.

Perhaps FE supporters might disagree with Euclid at this point, but that doesn’t matter. It least we know where they disagree.

Knowing all three distances we can then find a fourth point, find the two relevant angles, then work out two new distances and so on. The point is to avoid the laborious tape measure method and extensive labour.

You note from the picture that they worked their way down from Dehradun to Sironj by this method, distance about 500 miles. Two of the final triangulation points were the Sironj baseline, so they could compare the tape measure method with the triangulation method, including any accumulated errors. Supposedly the error was 7 inches in 500 miles, or 0.011%. That’s not bad, in my view.

Furthermore you can see they had another three sets of triangulation systems. In this way, over about 60 years, they covered the whole of India.

We still haven’t mentioned latitude and longitude (Hexagon please take note), nor the shape of the earth. Nothing but painstaking tape measure and angular measurement, with unbelievable accuracy for the time, in my view.



« Last Edit: June 07, 2018, 03:31:16 PM by edby »

Offline edby

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Re: The Circularity Objection
« Reply #32 on: June 07, 2018, 03:30:53 PM »
The advantage of that method is, that you have not to measure every single distance, especially across large areas of water like oceans. And I'm not aware of severe objections by flat earth believers on the longitude/latitude system as such. I have the impression they usually accept that coordinates of places like London or Sydney, etc. are indeed known or which places are on the equator and so on.
They don't disagree with longitude/latitude as far as it measures positions. They object to inferring a distance from those positions, o/a of the circularity.

That is the whole point of my describing in detail how they measured distance in 1835 without using long/lat.
« Last Edit: June 07, 2018, 03:33:13 PM by edby »

Offline hexagon

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Re: The Circularity Objection
« Reply #33 on: June 07, 2018, 03:50:51 PM »
The advantage of that method is, that you have not to measure every single distance, especially across large areas of water like oceans. And I'm not aware of severe objections by flat earth believers on the longitude/latitude system as such. I have the impression they usually accept that coordinates of places like London or Sydney, etc. are indeed known or which places are on the equator and so on.
They don't disagree with longitude/latitude as far as it measures positions. They object to inferring a distance from those positions, o/a of the circularity.

That is the whole point of my describing in detail how they measured distance in 1835 without using long/lat.

Yes, that's what I meant with metric. It gives you coordinates, but no distances. To get distances you have to assign a metric.

In the map you showed, I assume, the terrain was not flat. Is the apparent length of the edges of the triangles a measure of that? Or in other words, they always used chains of constant length but the effective distance on the map varied due to hills and valleys?

And how did they placed the cities outside the area covered by the triangles in to relation with each other? How did they defined the starting point? I assume that they did this with the help of longitude and latitude coordinates?     

Offline edby

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Re: The Circularity Objection
« Reply #34 on: June 07, 2018, 03:54:56 PM »
And how did they placed the cities outside the area covered by the triangles in to relation with each other? How did they defined the starting point? I assume that they did this with the help of longitude and latitude coordinates?   
The purpose was to establish an accurate 'skeleton', on which flesh could later be covered. This was the principle of all surveying and map making until very recently.
« Last Edit: June 07, 2018, 04:04:17 PM by edby »

Offline Tontogary

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Re: The Circularity Objection
« Reply #35 on: June 07, 2018, 04:16:12 PM »
And how did they placed the cities outside the area covered by the triangles in to relation with each other? How did they defined the starting point? I assume that they did this with the help of longitude and latitude coordinates?   
The purpose was to establish an accurate 'skeleton', on which flesh could later be covered. This was the principle of all surveying and map making until very recently.

Which is why most hills and high points in the uk have “trig” points on the top. They can be seen from other trig points and the distance worked out between them. This distance between them is based on the chains and the solid measuring tape and the shape of the earth has no influence on the distances.

Can we hope that this method might be accepted and agreed upon by all to be independant of the shape of the earth?

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

Offline hexagon

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Re: The Circularity Objection
« Reply #36 on: June 08, 2018, 07:18:41 AM »
Can we hope that this method might be accepted and agreed upon by all to be independant of the shape of the earth?

Not entirely. If you take this chains of equal length and like in the map above build hexagons consisting of equilateral triangles out of them, this will work only on a perfectly flat surface. On a sphere this will not fit together. How do you distinguish now a shallow hill on a flat-earth from a "flat" part of a spherical earth?  Or take a shallow valley on spherical earth. In this case the chains would fit together as a perfectly regular hexagon. Same for a flat area on a flat earth. 

In end the spherical shape gives a slit offset for all the measurements, that you have to take into account depending on the accuracy you want to achieve. 

Edit: See also the Wikipedia article about the great trigonometrical survey of India. It's not explained in detail, but the problem is obvious:

https://en.wikipedia.org/wiki/Great_Trigonometrical_Survey#Correcting_deviations


Same for the Principal Triangulation of Great Britain:

https://en.wikipedia.org/wiki/Principal_Triangulation_of_Great_Britain#Corrections
« Last Edit: June 08, 2018, 07:51:18 AM by hexagon »

Offline edby

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Re: The Circularity Objection
« Reply #37 on: June 08, 2018, 08:33:15 AM »
On a sphere this will not fit together.
So the Flat Earth objection would be that this method is inherently flawed, because of distortions produced by the round shape of the earth? Sounds OK.

Offline hexagon

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Re: The Circularity Objection
« Reply #38 on: June 08, 2018, 08:44:52 AM »
On a sphere this will not fit together.
So the Flat Earth objection would be that this method is inherently flawed, because of distortions produced by the round shape of the earth? Sounds OK.

Yes, because at some point you have to take the spherical shape into account.

But, as I explained above, this are tiny corrections compared to the distortions you have in any imaginable flat-earth map. E.g. look at the prototypical monopolar map and check the size of Australia. The width is two to three times too large. You can't explain this with systematic measurement errors that would be orders of magnitude smaller.   

In the end, both things, the corrections surveyors have to take into account and the impossibility of a correctly scaled flat-earth map, have the same origin, the incompatibility of Euclidean and spherical geometry.   

Offline Tontogary

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Re: The Circularity Objection
« Reply #39 on: June 08, 2018, 09:00:06 AM »
If you can quantify those corrections, say to a percentage, 0.1% for example, then it might be reasonable to suggest that the distances obtained were within that accuracy if they were on a flat earth, or a globe earth yes?

It would be helpful if there was an agreement from both sides of the debate, trying to find some common ground.

If not the subject is not going to progress, and there is not debate.

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.