Can one of the FE's explain how Eratosthenes calculated the circumference of the Earth, if it supposedly flat? Pretty easily explainable for an RE. Would like to hear the other side. 

Can one of the FE's explain how Eratosthenes calculated the circumference of the Earth, if it supposedly flat? Pretty easily explainable for an RE. Would like to hear the other side.

https://wiki.tfes.org/Erathostenes_on_Diameter

Essentially it becomes calculations for the diameter and height of the sun.

Offline 3DGeek

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I have a diagram that may help:



The two sticks in different cities cast different lengths of shadow.

That could EITHER be because the Earth is 4,000 miles in radius and the sun is a very, very long way away (not really "infinite" but a hell of a lot further than the radius of the Earth)...OR it could be because the Earth is flat and the Sun is 4,000 miles above the ground.

I'm not sure why the FE'ers use 3,000 miles though...that's a little bit too low.
Hey Tom:  What path do the photons take from the physical location of the sun to my eye at sunset?

The solution to being unable to distinguish between the two rival interpretations of the Eratosthenes experiment is that if you do the measurement from more than two locations, you get different answers in one model, and the same answer in the other model. This argues for either one model to be wrong, or for Magic Perspective to come to the rescue of the failing model, and sheer coincidence to allow the other model to be wrong though it predicts consistent answers.

So a single Eratosthenes experiment can't distinguish between the two situations in your model, the iterated Eratosthenese experiment can, by getting conflicting values for the distance to the Sun.

The sun moves 15 degrees every hour. At the equator, 15 degrees of longitude is about 1000 miles. if you did an east-west Eratosthenes experiment where you measure the angle to the sun at a given time over 4 different timezones, you would find the following distances to the sun:

1000 miles / tangent(15 degrees) = 3700 miles
2000 miles / tangent(30 degrees) = 3500 miles
3000 miles / tangent(45 degrees) = 3000 miles
4000 miles / tangent(60 degrees) = 2300 miles

Of course, this would resolve to the sunset problem - at 90 degrees, the sun is touching the earth. The solution to the sunset problem is "perception" so I guess they would give you the same answer to this. And, "perspective" changing in ways that nobody has a model for means that the answer to how far the sun is from the earth is "nobody has any idea."

This might bother someone who thought they knew how far it was from, say, New York to Paris, but if you disclaim knowledge of such things then why would you be worried about the sun possibly being closer to the earth than San Francisco is to New York?

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Offline AstralSentient

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The solution to being unable to distinguish between the two rival interpretations of the Eratosthenes experiment is that if you do the measurement from more than two locations, you get different answers in one model, and the same answer in the other model. This argues for either one model to be wrong, or for Magic Perspective to come to the rescue of the failing model, and sheer coincidence to allow the other model to be wrong though it predicts consistent answers.

So a single Eratosthenes experiment can't distinguish between the two situations in your model, the iterated Eratosthenese experiment can, by getting conflicting values for the distance to the Sun.

The sun moves 15 degrees every hour. At the equator, 15 degrees of longitude is about 1000 miles. if you did an east-west Eratosthenes experiment where you measure the angle to the sun at a given time over 4 different timezones, you would find the following distances to the sun:

1000 miles / tangent(15 degrees) = 3700 miles
2000 miles / tangent(30 degrees) = 3500 miles
3000 miles / tangent(45 degrees) = 3000 miles
4000 miles / tangent(60 degrees) = 2300 miles

Of course, this would resolve to the sunset problem - at 90 degrees, the sun is touching the earth. The solution to the sunset problem is "perception" so I guess they would give you the same answer to this. And, "perspective" changing in ways that nobody has a model for means that the answer to how far the sun is from the earth is "nobody has any idea."

This might bother someone who thought they knew how far it was from, say, New York to Paris, but if you disclaim knowledge of such things then why would you be worried about the sun possibly being closer to the earth than San Francisco is to New York?
Do you mean this?
Proud advocate of the Relativity Non-Euclidean plane

https://forum.tfes.org/index.php?topic=7191.0

Yes, that diagram is relevant. It conflicts with observations that degrees of longitude are the same distance apart at a given latitude such as on the equator, or in the north-south case that degrees of latitude are the same distance apart everywhere.

In order to do the experiment you would have to be able to measure distances accurately. It appears that the only acceptable options for Flat Earth theorists to measure such distances is to be able to drive or walk the distance, so you'd need to pick somewhere with long distances over land, and it would be helpful to pick somewhere that the sun goes directly overhead. You would then coordinate by telephone to measure the angle to the sun at different times.

If you accept measurements over the oceans, I contend that this experiment has been done thousands of times by the Royal Navy in the 18th and 19th centuries, and clearly disproves flat earth.

As you can see from your diagram, if you measured the distances between 20 and 30 degrees, and between 40 and 50 degrees and came up with identical numbers, that would either disprove Flat Earth or require magic perspective or some other explanation.