Why "it looks flat so it is flat" is a logical fallacy

No you should take it as you are too stupid to understand the process of elimination. What shapes can Eratosthenes's formula be used to measure ACCURATELY??? A circle.

What if Earth were a cube?
Back in 1884, a Swiss astronomer by the name of Arndt made headlines when he claimed to have discovered a very curious planet in an orbit beyond Neptune -- a surprisingly cubical planet.

From: What if Earth were a cube?

• a circle,
• an ellipse,
• a parabola or
• a hyperbola.

You are correct that when Eratosthenes performed that experiment, he already took two previous observations as facts: that the Earth was a sphere and that the sun was very far away; far away where it's rays would be virtually parallel.

Setting aside the first of those, let's focus on the second. What previous observations could Eratosthenes and his contemporaries have made that would have brought them to that conclusion? The answer lies in altitude. Suppose you measure the angle of the shadow of a stick in the ground when the shadow is perfectly parallel with the stick. Suppose another person is doing the same at the same time miles up on the side of a mountain. The difference between those angles ought to be small but measurable if the sun is nearby. But if the angles are identical, then it is evidence that the sun is very far away.

It is that kind of observation that led to treating the rays of the sun as originating from very far away.

Quote from: EvolvedMantisShrimp on December 22, 2017, 04:39:28 AM

You are correct that when Eratosthenes performed that experiment, he already took two previous observations as facts: that the Earth was a sphere and that the sun was very far away; far away where it's rays would be virtually parallel.

Setting aside the first of those, let's focus on the second. What previous observations could Eratosthenes and his contemporaries have made that would have brought them to that conclusion? The answer lies in altitude. Suppose you measure the angle of the shadow of a stick in the ground when the shadow is perfectly parallel with the stick. Suppose another person is doing the same at the same time miles up on the side of a mountain. The difference between those angles ought to be small but measurable if the sun is nearby. But if the angles are identical, then it is evidence that the sun is very far away.

But how do you ascertain that the local verticals are parallel or not?
The difference in angles could be due either to the local verticals diverging, as on the Globe or due to a nearby sun.
Some independent evidence of the distance to the sun is necessary.

Measuring the angles from more the two points can provide that evidence, as I have tried to point out in numerous posts.
For example, Re: trigonometry « Reply #43 on: December 09, 2017, 08:47:55 PM »

Quote from: EvolvedMantisShrimp

It is that kind of observation that led to treating the rays of the sun as originating from very far away.

I believe the first evidence of the sun and moon being great distances away came from the fact that neither the sun nor the moon change in apparent size as they appear to move across the sky.

Quote from: Marvin the Martian on December 22, 2017, 12:56:53 AM

No you should take it as you are too stupid to understand the process of elimination. What shapes can Eratosthenes's formula be used to measure ACCURATELY??? A circle.

What "process of elimination"? Who says that the earth could only be flat or spherical? Why could it not be very ellipsoidal?
Or even a cube:

Quote from: BY ROBERT LAMB

What if Earth were a cube?
Back in 1884, a Swiss astronomer by the name of Arndt made headlines when he claimed to have discovered a very curious planet in an orbit beyond Neptune -- a surprisingly cubical planet.

From: What if Earth were a cube?

Yes, I think it's ridiculous too, but some earthlings even believe the earth to be flat, honest!

But, you really are an ignorant little Martin aren't you?
You're probably playing hookey from your Martian School to come here and make a nuisance of yourself!
Just wait till I get onto your Mummy Martian and tell her what you've been up to!

Now, down to business:
Please explain how measuring the shadow angles at only two points could tell between:

• a circle,
• an ellipse,
• a parabola or
• a hyperbola.

Eratosthenes knew that the earth was a Globe, so all he was doing was measuring its circumference.

But, just suppose (hypothetically of course) that these modern flat earthers are right and what Eratosthenes actually measured was the different shadow angles due to a comparatively close sun, as in:

The distance and angles in the above diagram could be from a flat earth with a sun about 5000 km high or from a Globe earth of circumference 40,000 miles in circumference.

Old Eratosthenes, of course, measured the angles in Alexandria and Syene (Aswan), only about 800 miles apart.

Without further information the Eratosthenes experiment cannot tell you whether the earth is curved or flat and cannot even tell what type of curve.

By the way, this video you posted:

How Do You Calculate Circumference? (Mr. Wizard)

does not replicate Eratosthenes measurement. I'll let Mr Smarty-Pants, Marvin the Martian work out why!

No, I base my argument on the fact that you do not have enough data to solve for all variables.

I have only said that that experiment (i.e. without any other data) can't be used to prove Earth is round. It is entirely consistent with a FE as well.

Yes, 2 sticks are used to demonstrate his experiment. But when just using 2 you rely upon the assumption that Earth is round and the sun is far away. The experiment itself works equally well when assuming a flat Earth with a close sun. As such, it does not prove a round Earth or prove FE inaccurate.

The same measurements can be used to show the height of the sun over a FE. It is only by assuming a spherical Earth and distant sun that you determine the circumference.
The experiment is unable to tell the difference between a near sun over a flat Earth and a distant sun away from a round Earth
Again, the same experiment can determine the height of the sun above a FE.

Quote from: John Davis on December 07, 2017, 01:20:04 PM

Unfortunately for the OP, trigonometry actually shows us a flat earth.

No it doesn't.
The trigonometry used in your pathetic image can't distinguish between them.
The image on the left does not show it to scale as it does not show the sun 150 000 000 km away.
However, the results obtained from reality do match that 150 000 000 km distant sun and a round Earth.

The right hand side just blatantly lies.
It starts with the assumption that Earth is flat.

So no, using just those 3 points, even with the distance between them, you cannot determine the shape of Earth.

But the really killer is that it also completely ignores other points. (i.e. other locations where you can observe the apparent location of the sun).
These are points that are needed to be able to actually determine the shape.
At the poles the sun is observed at 0 degrees then.
Notice how that matches a RE, but not a FE.
you clearly see FE does not match, a RE with a distant sun does.

The sun was over the well. That does not change between the FE and RE models.
And no one has ever been able to duplicate his experiment and prove a round Earth, as it relies upon the assumption that Earth is round to determine the circumference of Earth.

Quote from: Marvin the Martian on December 22, 2017, 12:56:53 AM

By the way... Have a look at my sig! thanks for that gold nugget of "wisdom/failure" haha!!!

You mean more of your pathetic dishonesty?

You are correct that when Eratosthenes performed that experiment, he already took two previous observations as facts: that the Earth was a sphere and that the sun was very far away; far away where it's rays would be virtually parallel.

Setting aside the first of those, let's focus on the second. What previous observations could Eratosthenes and his contemporaries have made that would have brought them to that conclusion? The answer lies in altitude. Suppose you measure the angle of the shadow of a stick in the ground when the shadow is perfectly parallel with the stick. Suppose another person is doing the same at the same time miles up on the side of a mountain. The difference between those angles ought to be small but measurable if the sun is nearby. But if the angles are identical, then it is evidence that the sun is very far away.

It is that kind of observation that led to treating the rays of the sun as originating from very far away.

Quote from: EvolvedMantisShrimp on December 22, 2017, 04:39:28 AM

You are correct that when Eratosthenes performed that experiment, he already took two previous observations as facts: that the Earth was a sphere and that the sun was very far away; far away where it's rays would be virtually parallel.

Setting aside the first of those, let's focus on the second. What previous observations could Eratosthenes and his contemporaries have made that would have brought them to that conclusion? The answer lies in altitude. Suppose you measure the angle of the shadow of a stick in the ground when the shadow is perfectly parallel with the stick. Suppose another person is doing the same at the same time miles up on the side of a mountain. The difference between those angles ought to be small but measurable if the sun is nearby. But if the angles are identical, then it is evidence that the sun is very far away.

It is that kind of observation that led to treating the rays of the sun as originating from very far away.

I don't think they would have had the precision for that. There are other options such as noting the sun rises due east for everyone on the equinox (which I'm not sure if they would have been able to do), or noting that the apparent size remains fairly constant.

Quote from: JackBlack on December 22, 2017, 01:22:30 AM

Quote from: Marvin the Martian on December 22, 2017, 12:56:53 AM

By the way... Have a look at my sig! thanks for that gold nugget of "wisdom/failure" haha!!!

You mean more of your pathetic dishonesty?

Actually that's more of your pathetic dishonesty... Care to expand on what you meant by "it spins on its axis and orbits the sun. The 2 are fundamentally different... Because when an object spins, it does so about its axis"

Clearly you claim Earth's orbit around the Sun has no axis, then in the same post you claim objects spin on an axis... So which is it???

Funny thing is Mr Wizard credits Eratosthenes for the formula in the video... So how do you figure it does not replicate it? One stick is directly under the Sun and they accurately measure circumference of the table.

The shadow angle tells the direction and angle of the Sunlight dumbass not the shape.

Quote from: JackBlack on December 22, 2017, 01:22:30 AM

No, I base my argument on the fact that you do not have enough data to solve for all variables.

No, you based your argument on the same FET theory you refuted back in the beginning of the thread.

Let's look at how many times you contradicted yourself... We see who the liar is now...

Actually that's more of your pathetic dishonesty... Care to expand on what you meant by "it spins on its axis and orbits the sun. The 2 are fundamentally different... Because when an object spins, it does so about its axis"

<< Irrelevant ravings of Marvin the Moronic Martian expunged >>

You haven't explained shit

You also told me Eratosthenes supports FET but told John Davis it does not...