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  #51  
Old 06-01-2017, 01:55 PM
DPRK DPRK is offline
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As long as we are discussing this, you do not need to climb to a great height to see ships disappear over the horizon due to curvature of the Earth. Not sure how various conspiracy theorists explain that one. Here is a good artist's depiction of what a flat earth is supposed to look like.

As for these conspiracy theorists, I suspect they are just 100% flim-flam artists who enrich themselves in various ways (selling books and so forth). Not exactly a new phenomenon, but unfortunately one which is not sufficiently roundly condemned.
  #52  
Old 06-01-2017, 02:15 PM
Weisshund Weisshund is offline
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I just thought of a test where the flat earthers can prove themselves beyond shadow of doubt.
(prove themselves wrong)

Water is inherently flat and level.
The ocean is naturally a flat level place.
Yes, there are waves and tides, but being water the ocean is always attempting to put it self flat, it does not have 500 foot tall piles of water laying about, no mountainous outcroppings of H2O, no matter the disturbance the water is always seeking to come back to a nice flat resting state.

So with that in mind, we should be able to infinitely plot a relative elevation from point A to any point across the ocean until we hit the edge of the earth correct?

Factoring in waves tides storms etc, our point should always be at a given average height above the water?

So, if we fix a laser to a verifiably leveled platform on the shore.
I sturdy platform that can not move, and can be rechecked for level at any time it is doubted.
And we aim this so it is an average of 12 feet above sea level.

The laser beam, if the earth is flat, should be found the same average distance above the water at 30 miles, 50 miles, 90 miles, 300 miles, 1000 miles.

Given that laser light does not bend, not under natural earthly circumstances, if the earth is flat, this should be 100% true.

But, if the earth is a ball, at only 90 miles we should find we are now noticeably up above the water, at 1000 miles there should be no debate about our elevation.
By the time we get to Honolulu the fall would kill us?

There ya go flat earth dudes, get to it, prove we are living on a pizza pan
  #53  
Old 06-01-2017, 02:30 PM
Blue Blistering Barnacle Blue Blistering Barnacle is offline
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Originally Posted by CurtC View Post
This guy was off-base in trying to do this experiment with a level, but it could be done with a gyroscope.
If you placed accelerometers on each end of the level, and calculated relative positional changes through the trip, would you see the calculated level invert after flying halfway around the world?
  #54  
Old 06-01-2017, 03:03 PM
Intergalactic Gladiator Intergalactic Gladiator is offline
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The thought that the earth is flat is so ridiculous. If it was, then it would always tip off the giant turtle.
  #55  
Old 06-01-2017, 03:08 PM
bikerdruid bikerdruid is offline
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It is just a silly thing for silly people to argue about.
The very thought that the Earth is flat is ridiculous beyond belief.
  #56  
Old 06-01-2017, 03:11 PM
Machine Elf Machine Elf is offline
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Originally Posted by Weisshund View Post
I just thought of a test where the flat earthers can prove themselves beyond shadow of doubt.
(prove themselves wrong)
There are many such tests:

The flat-earth theory does not explain the behavior of a Foucault pendulum.

It also does not explain the behavior of a fully-gimbaled gyroscope. If we were on a flat earth, a gyroscope oriented vertically would behave the same way at all locations on the surface of flat-earth, but it behaves differently at different points on the real earth (at a pole it will remain vertical indefinitely, but at the equator it will appear to do a complete flip every 24 hours).

The flat-earth theory doesn't explain global circumnavigation, or the existence of a south pole:

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Originally Posted by Wikipedia
The Flat Earth Society's most recent world model is that humanity lives on a disc, with the North Pole at its center and a 150-foot (45 m) high wall of ice, Antarctica, at the outer edge.
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Originally Posted by DPRK
As long as we are discussing this, you do not need to climb to a great height to see ships disappear over the horizon due to curvature of the Earth.
Indeed, if you're on a ship, you can watch as cities on the shore appear to "sink" into the water as you move away from shore.
  #57  
Old 06-01-2017, 03:29 PM
eschereal eschereal is offline
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Hmm. I read that the Earth is a flat disc with an ice wall at the peripheral edge that we call "Antarctica", which rises 200+ feet out of the sea at 78°S and disappears outward in a haze of fog and mist. This means that the circumference of the earth-disc at its outer edge must be over 63,300 miles; a circumnavigation of the southern sea, from/to South Georgia Island should take nearly three times as long as an equatorial circumnavigation. This some does not seem quite right.
  #58  
Old 06-01-2017, 03:36 PM
eschereal eschereal is offline
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Indeed, if you're on a ship, you can watch as cities on the shore appear to "sink" into the water as you move away from shore.
They explain this as a matter of perspective. Things only appear to sink below the horizon because they just get smaller and smaller. Perhaps they can gin up some story about how atmospheric refraction accounts for the horizon effect.
  #59  
Old 06-01-2017, 03:44 PM
Weisshund Weisshund is offline
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There are many such tests:
Yes but what better than a simple test thought up by an idiot (scientifically) to be carried out by idiots (literally)
  #60  
Old 06-01-2017, 04:16 PM
Bones Daley Bones Daley is offline
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Originally Posted by Weisshund View Post
.

The laser beam, if the earth is flat, should be found the same average distance above the water at 30 miles, 50 miles, 90 miles, 300 miles, 1000 miles.
Good luck finding a portable laser beam that will stay parallel and visible over 1000 miles.

There is a far easier experiment which could be carried out, if anybody felt the necessity to do so, which doesn't involve farting around with laser beams.

Over a measured straight mile, you erect 3 posts, one at each end and one in the middle.

Using a mile long water level, you mark the level on all three posts. At each datum you tap in a nail. Using a surveyor's theodolite, or even a pair of binoculars, you ascertain if all three nails are in the same horizontal plane. If they are, then the earth is proved flat. If the center nail is higher , then the earth is round.

If my memory serves me right, the center nail should measure something like three inches higher than the two end nails.

Last edited by Bones Daley; 06-01-2017 at 04:19 PM. Reason: spelling
  #61  
Old 06-01-2017, 04:26 PM
eschereal eschereal is offline
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Originally Posted by Weisshund View Post
I just thought of a test where the flat earthers can prove themselves beyond shadow of doubt.
(prove themselves wrong) … if we fix a laser to a verifiably leveled platform on the shore.… The laser beam, if the earth is flat, should be found the same average distance above the water at 30 miles, 50 miles, 90 miles, 300 miles, 1000 miles.…
This is slightly problematic. A laser beam will not traverse a perfectly straight line, for the same reason that the sun remains visible for some while after it is below the horizon: air is refractive and will bend the beam downward. Not quite to match the curve of the Earth, but enough that it will not match the raw measurement.
  #62  
Old 06-01-2017, 04:44 PM
Bones Daley Bones Daley is offline
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Originally Posted by eschereal View Post
, for the same reason that the sun remains visible for some while after it is below the horizon:
If the sun is visible, then AFAIAC , by definition, it is above the horizon.
  #63  
Old 06-01-2017, 05:06 PM
Andy L Andy L is online now
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Originally Posted by Weisshund View Post
I just thought of a test where the flat earthers can prove themselves beyond shadow of doubt.
(prove themselves wrong)

Water is inherently flat and level.
The ocean is naturally a flat level place.
You can use the levelness of water in a simpler way. Build a large pool, in a rectangular shape. Make sure the sides are absolutely straight - then fill it with water. You'll find that water drains off the short sides, because of the curvature of the Earth, if the pool is large enough.

For that matter, try to create anything that is both straight (measured by laser) and level throughout (measured by spirit level) - at some point, these requirements will conflict.
  #64  
Old 06-01-2017, 05:21 PM
CurtC CurtC is offline
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Originally Posted by eschereal View Post
This is slightly problematic. A laser beam will not traverse a perfectly straight line, for the same reason that the sun remains visible for some while after it is below the horizon: air is refractive and will bend the beam downward. Not quite to match the curve of the Earth, but enough that it will not match the raw measurement.
In certain atmospheric conditions, the refraction can be increased. I've seen flat earth essays where they found a picture of a far-away city that you can see above the horizon, due to refraction. It's probably a cold Lake Michigan and very still air in the morning, but the flat earthers don't seem to comprehend that light can be refracted by air.

ETA: A good example here.

Last edited by CurtC; 06-01-2017 at 05:24 PM.
  #65  
Old 06-01-2017, 05:28 PM
Bones Daley Bones Daley is offline
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In certain atmospheric conditions, the refraction can be increased. I've seen flat earth essays where they found a picture of a far-away city that you can see above the horizon, due to refraction. It's probably a cold Lake Michigan and very still air in the morning, but the flat earthers don't seem to comprehend that light can be refracted by air.

ETA: A good example here.
The atmospheric refraction only applies to objects which are on the surface of the Earth.

It is meaningless to talk of the Sun being "below the horizon yet still visible".
  #66  
Old 06-01-2017, 05:32 PM
eschereal eschereal is offline
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Originally Posted by Bones Daley View Post
The atmospheric refraction only applies to objects which are on the surface of the Earth.

It is meaningless to talk of the Sun being "below the horizon yet still visible".
Bullshit. If the earth had no atmosphere, the position of the sun would be "below" (obscured by) the horizon earlier than it is with atmospheric refraction (which is also what reddens sunset/sunrise).
  #67  
Old 06-01-2017, 06:06 PM
Colophon Colophon is offline
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But at 42,000 feet, we can see further than 42,000 feet ... I'm not saying it's easy to see the curvature of the Earth from altitude ... but I believe we can ...

Not sure what the "round table" analogy means ... put our eye at table level and the table top looks flat ... like the Earth ...
My point is that it's hard to discern the curve from so close to the surface. Imagine a giant spherical water tank or something, 40 feet in diameter. The plane is then half an inch off the surface, to scale.


The round table analogy is meant to show that the horizon itself is flat, the same as the rim of a table is flat. (Of course, the ground between you and the horizon isn't flat, so a better analogy would be a slightly domed circular table.) You're not seeing the curvature of the Earth, you're seeing the curve of the "rim", which will look more curved the more you look "down" on it.
  #68  
Old 06-01-2017, 06:42 PM
bonzer bonzer is offline
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Originally Posted by Bones Daley View Post
Good luck finding a portable laser beam that will stay parallel and visible over 1000 miles.

There is a far easier experiment which could be carried out, if anybody felt the necessity to do so, which doesn't involve farting around with laser beams.

Over a measured straight mile, you erect 3 posts, one at each end and one in the middle.

Using a mile long water level, you mark the level on all three posts. At each datum you tap in a nail. Using a surveyor's theodolite, or even a pair of binoculars, you ascertain if all three nails are in the same horizontal plane. If they are, then the earth is proved flat. If the center nail is higher , then the earth is round.

If my memory serves me right, the center nail should measure something like three inches higher than the two end nails.
Though this sort of experiment is actually rather hard to do in practice. It's essentially the Bedford Level controversy that so bedevilled Alfred Russel Wallace in the 19th century. The experimental complications give the deniers lots of quibble room, at least in their own minds.
  #69  
Old 06-01-2017, 07:07 PM
Bones Daley Bones Daley is offline
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Though this sort of experiment is actually rather hard to do in practice. It's essentially the Bedford Level controversy that so bedevilled Alfred Russel Wallace in the 19th century. The experimental complications give the deniers lots of quibble room, at least in their own minds.
Similar in concept, agreed, but what I am suggesting would involve far fewer variables than in the Bedford Level experiment....Occam's razor would be the watchword .

A mile long water level would be difficult in practical terms, but the same result could be achieved with a shorter, more manageable level, and increasing the number of posts accordingly.
  #70  
Old 06-02-2017, 12:18 AM
Princhester Princhester is offline
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Excellent. Great rhetorical question, to be saved and used in any number of situations, stupid conversations, etc.
You know the reference to turtles wasn't random, right?

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Originally Posted by Weisshund View Post
Yes but what better than a simple test thought up by an idiot (scientifically) to be carried out by idiots (literally)
The professional debunker James Randi will only countenance challenges where the results of the challenge are immediately self evident. I can't speak for Randi and I don't think I've ever heard him say why he has this requirement, in so many words.

But I think it is because idiots - and particularly determinedly self-deluding idiots - will find a way to discount the results of any experiment or challenge that cannot be taken in at a glance. It is said that "justice must not only be done but be seen to be done". Similarly, I think that to convince such idiots the results must not only be correct they must be so obviously correct that even an idiot can see it.

That's really the flat earth thing in a nutshell. Of course many purported "believers" are scammers or have their tongue in their cheek. But for many the reason they believe in a flat earth is that's just the way earth looks from where they are standing. And unless you can provide them with a a proof of a globe earth that is similarly as self evident, they are never going to accept it.
  #71  
Old 06-02-2017, 12:38 AM
eschereal eschereal is offline
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I guess the real test of the Earth pizza is to take an airplane to the southern ocean (near the edge) and fly west from Ushuaia, keeping the Antarctic coastline at a fairly constant distance. If the Earth was flat, the plane would constantly be bearing to the right to keep from flying into the ice that encircles the world. One should train the FE in flying the airplane, so that they can observe for themself – if that is possible.
  #72  
Old 06-02-2017, 01:14 AM
Princhester Princhester is offline
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But I thought you said they thought the wall of ice was only 200ft high?

If so, and if you can find an FE'er who can fly a sufficiently long range plane, why not just get them to fly south from Ushuaia and see what happens?
  #73  
Old 06-02-2017, 01:27 AM
eschereal eschereal is offline
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Honestly, I think I would be disinclined to engage FEs in debate the first place. They can believe whatever they want to believe, as they are so very fringe that they harm no one. Though, it is an interesting thought experiment, to prove heliocentrism conclusively to a person standing on the ground. It is kind of difficult.
  #74  
Old 06-02-2017, 02:02 AM
Princhester Princhester is offline
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Originally Posted by eschereal View Post
Honestly, I think I would be disinclined to engage FEs in debate the first place. They can believe whatever they want to believe, as they are so very fringe that they harm no one. Though, it is an interesting thought experiment, to prove heliocentrism conclusively to a person standing on the ground. It is kind of difficult.
It depends on the level of abstraction they can cope with.

For example, to me,
  • I can stand on the ground in the very early morning and evening and see bright specks of light going overhead.
  • I can look on websites and see that people are able to predict, to the second, when those bright specks will go over.
The only plausible way I can explain these two facts is by assuming that the people running the websites understand really well the way the bright specks move. And those people say the earth is a globe. I think they must know what they are talking about.

There are alternative explanations; there could be a worldwide conspiracy of astronomers who know the earth is flat but just lie about how they actually predict the positions of the bright specks. Or I guess the bright specks might move in a way that exactly imitates the way the specks would move if the earth was a globe (even though it isn't one). But both of these theories seem immensely implausible.
  #75  
Old 06-02-2017, 02:24 AM
eschereal eschereal is offline
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What they say is that the Earth is a pizza and the sun-lamp-thing moves in a circle above it. That the sunset is just an illusion of perspective (it only appears to be setting because it looks close to the horizon because it is so far away). This glaring flaw in this argument is that you can watch a sunset and see the sun get bigger as it crosses the horizon – as with the harvest moon. I cannot see how the perspective model could address that. For most of the day, the sun subtends exactly the same angle, except at sunrise and sunset, when it is supposed to be farther away but somehow looks bigger.
  #76  
Old 06-02-2017, 02:52 AM
Richard Pearse Richard Pearse is offline
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Originally Posted by Colophon View Post


The round table analogy is meant to show that the horizon itself is flat, the same as the rim of a table is flat. (Of course, the ground between you and the horizon isn't flat, so a better analogy would be a slightly domed circular table.) You're not seeing the curvature of the Earth, you're seeing the curve of the "rim", which will look more curved the more you look "down" on it.
But the earth is not flat or even "slightly domed", any curve in the rim is the same as the curve of the dome therefore if you are high enough to perceive the curve of the rim, you are effectively seeing the curve of the dome and therefore the curvature of the earth.
  #77  
Old 06-02-2017, 05:07 AM
Colophon Colophon is offline
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But the earth is not flat or even "slightly domed", any curve in the rim is the same as the curve of the dome therefore if you are high enough to perceive the curve of the rim, you are effectively seeing the curve of the dome and therefore the curvature of the earth.
No you're not. The rim is not curved "up and down", it is flat, totally horizontal. Think about it: the horizon is the set of points that are as far away as you can see over the curve of the earth. It is the intersection between a cone centred at your eye and the surface of the Earth, therefore it is a circle. (Ignoring local topography, of course).

You can ignore the curve of the Earth between you and the horizon, because by definition you are looking over the top of it, and it is not blocking your view of the horizon. You might as well imagine slicing a small portion off the Earth, centred under your feet, and defined by the circle of the horizon. That circle is totally flat, regardless of what the ground you sliced off is doing.

The higher up you go, the more you are looking down on this circle (and meanwhile the circle is getting bigger because you can see further to the horizon), so the more it looks like a circle rather than a straight line, until you get to the extreme case where you are out in space and you can see the whole circle of the horizon, which will get closer and closer to the circumference of the Earth the further away you get.

Last edited by Colophon; 06-02-2017 at 05:10 AM.
  #78  
Old 06-02-2017, 05:14 AM
Colophon Colophon is offline
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You can use the levelness of water in a simpler way. Build a large pool, in a rectangular shape. Make sure the sides are absolutely straight - then fill it with water. You'll find that water drains off the short sides, because of the curvature of the Earth, if the pool is large enough.

For that matter, try to create anything that is both straight (measured by laser) and level throughout (measured by spirit level) - at some point, these requirements will conflict.
As had to be compensated for by some rather clever engineering when they were building the LIGO observatory, each site of which consists of two 4km-long tubes, which had to be laser-straight.

Quote:
The beam tubes needed to be aligned
along the propagation direction of light in vacuum and not
along the direction perpendicular to local gravity on the surface
of the Earth. The curvature of the Earth will cause the
Earth’s surface to deviate from the straight line propagated
by light in vacuum by 1.25 m over a 4 km path if the line
starts out level with the surface. The alignment was, therefore,
not the same as that for a level highway or pipeline.
In other words, the ends of the tubes had to be about 4ft higher than they would be if they were gravitationally level.

Last edited by Colophon; 06-02-2017 at 05:14 AM.
  #79  
Old 06-02-2017, 08:15 AM
Andy L Andy L is online now
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Originally Posted by Colophon View Post
As had to be compensated for by some rather clever engineering when they were building the LIGO observatory, each site of which consists of two 4km-long tubes, which had to be laser-straight.



In other words, the ends of the tubes had to be about 4ft higher than they would be if they were gravitationally level.
Thanks! A great example of what I was thinking of.
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Old 06-02-2017, 08:28 AM
Chronos Chronos is offline
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Not, of course, that any argument involving LIGO is likely to carry any weight at all with a flat-earther.
  #81  
Old 06-02-2017, 08:39 AM
Andy L Andy L is online now
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Not, of course, that any argument involving LIGO is likely to carry any weight at all with a flat-earther.
True (sadly). We need an argument using LEGO.
  #82  
Old 06-02-2017, 09:53 AM
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"Someone has to stand up to the experts!" said by John Donald "Don" McLeroy, Republican dentist in Bryan, Texas, and former Chairman of the Texas State Board of Education, which establishes policy for the state public school system. Referring to teaching Creationism equally with the Theory* of Evolution in Texas schools.

He probably believes in the Flat Earth, too.


*After all, it's only a theory.
I've always been amused at those who reject evolution because "it's only a theory" yet enthusiastically use electrons, which are only a theory as well.

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If you have the plane follow a laser beam, which has no normal choice but to be straight, the plane will fly off into space (granting said plane has the engines to do so)
Tolkien explored this idea. Arda was originally flat and anyone could sail from what is now Middle Earth to Númenor and westward to Arda, the Undying Lands, but mortals were forbidden to do so. When Ar-Pharazôn was inveigled by Sauron into invading the West, Ilúvatar destroyed his fleet, pushed Númenor under the sea (I'm imagining a giant thumb descending from the sky) and to ensure that the Undying Lands would never again be threatened by mortals, bent the earth. Thereafter, only Elven ships could follow the Straight Road to Arda; the ships of Men would follow the curved surface of the earth to circumnavigate the globe instead.
  #83  
Old 06-02-2017, 11:49 AM
Chronos Chronos is offline
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As an aside, one of my relativity textbooks included a map of Middle Earth with four cities marked on it, as well as the crow-flight distances between all of the cities, and then asked the reader to calculate therefrom the radius of Middle Earth.
  #84  
Old 06-02-2017, 11:51 AM
Andy L Andy L is online now
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Originally Posted by Chronos View Post
As an aside, one of my relativity textbooks included a map of Middle Earth with four cities marked on it, as well as the crow-flight distances between all of the cities, and then asked the reader to calculate therefrom the radius of Middle Earth.
Don't keep us in suspense...
  #85  
Old 06-02-2017, 01:07 PM
bonzer bonzer is offline
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Originally Posted by Bones Daley View Post
Similar in concept, agreed, but what I am suggesting would involve far fewer variables than in the Bedford Level experiment....Occam's razor would be the watchword .

A mile long water level would be difficult in practical terms, but the same result could be achieved with a shorter, more manageable level, and increasing the number of posts accordingly.
At which point, the hypothetical flat earther you're trying to convince will object that all you've done is found a small, inconspicuous hill on an area that looks flat. Unlike with a body of water, there's no particular reason to accept that any such area is "flat" until you've measured it.
You could, of course, try to respond by repeating the experiment in lots of different places or piecemeal over a larger area. At which point you're essentially doing a geodetic survey. That's a) getting complicated and b) getting sufficiently complicated that it's unlikely to meet a flat earther's usual standard of simple, everyday measurements.
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Old 06-02-2017, 02:01 PM
eschereal eschereal is offline
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I guess I kind of have an answer to the OP
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Originally Posted by A Planet Ruth
From Copernicus to Galileo to Newton to Kepler, all validated “proven” science came from the Royal Society of London. Starting with the Industrial Devolution , at the beginning of the 20th century, all school text books and teacher accreditation’s were founded and funded by Robber Baron’s, Rockefeller, JP Morgan, Ford et. al

After WWII, with the critical assistance of the Vatican “ratline” passports, the United States brought Nazi Rocketeer “Wunderkind”, Werhner Von Braun, into the country through Operation Paperclip.

Von Braun ran NASA’s Saturn rocket program for 25 years. All feeds that came from the Moon on the alleged first Man on the Moon transmission came from one feed at NASA where all TV broadcasters had to copy from.
Maintain a lie or secret for one generation and the next generartion becomes easy pickings, particularly if the lie is echoed in school textbooks, TV cartoons, The History and Discovery Channels. Confuse one generation and the next will happily ingest the media gruel prepared for them.
~ Elana Freeland
Since the 1800’s, very few have challenged the Heliocentric theory because it is “settled science”.

Until now.
but it is still amusing to peruse the gyrations of the FECTs.

Last edited by eschereal; 06-02-2017 at 02:02 PM.
  #87  
Old 06-02-2017, 05:05 PM
Chronos Chronos is offline
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I'm probably getting whooshed here, but I suspect that that site name is meant to be parsed as "a plane truth", not "a planet Ruth".
  #88  
Old 06-02-2017, 05:09 PM
eschereal eschereal is offline
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Hey, all the letters were jammed together, how could I tell?
  #89  
Old 06-02-2017, 05:27 PM
LSLGuy LSLGuy is offline
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Originally Posted by Bones Daley View Post
If the sun is visible, then AFAIAC , by definition, it is above the horizon.
Nope.

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Originally Posted by Bones Daley View Post
The atmospheric refraction only applies to objects which are on the surface of the Earth.

It is meaningless to talk of the Sun being "below the horizon yet still visible".
Not so.

There are competing definitions of "horizon". The geometrical or geodesic horizon is where an absolutely straight line from the observer's POV intersects the edge of the planet.

The astronomical horizon is what you see from the observer's POV looking through the actual atmosphere. Which refracts everything you see at any appreciable distance. The refraction is negligible at zenith, and is maximal when looking towards the geodesic horizon.

The Sun subtends an angle (~1/2 degree) smaller than the typical amount of atmospheric refraction. The net effect is that during many sunsets the entire Sun has dipped below the geodesic horizon while still being fully visible, albeit probably distorted, just above the astronomical horizon.

A similar effect applies at sunrise. The sun often becomes fully visible before any of it clears the geodesic horizon.

Last edited by LSLGuy; 06-02-2017 at 05:29 PM.
  #90  
Old 06-02-2017, 06:46 PM
Bones Daley Bones Daley is offline
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. Unlike with a body of water, there's no particular reason to accept that any such area is "flat" until you've measured it.
I think you may be misunderstanding what I was proposing. The flatness or otherwise of the terrain doesn't enter into the equation ...although from a common-sense, practical, logistical point of view it would obviously be more sensible to do the experiment on a reasonably flat piece of terrain.

Y'all do know what a "water level" is, right ? It's a flexible tube, filled with water, usually about 1/2" ID, , which can be of any length you choose, with two transparent vials at either end ; in use, the meniscus of the water at either end is marked at points 1 and 2, and subsequently at points 2 and 3, 3 and 4 ... and so on. The fewer the number of datum points, the more accurate the survey is.
  #91  
Old 06-02-2017, 07:15 PM
Dr. Strangelove Dr. Strangelove is online now
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there could be a worldwide conspiracy of astronomers who know the earth is flat but just lie about how they actually predict the positions of the bright specks.
This one is provably wrong by anyone with high-school math skills. You only need seven numbers to predict where a satellite will appear. You can grab these numbers yourself and run them through the calculator (which can easily be inspected or programmed from scratch). As it happens, I've done all of this, starting with the TLE (orbital parameter set) of the ISS and ending with pointing an antenna at a nice bright speck where the ISS should be, and hearing relayed messages from Colorado.

Arbitrary curves need a lot more than seven numbers to describe them, but it's easily seen that every object needs just those. There's no room for a conspiracy; even if all satellites were placed in orbits that somehow corresponded to elliptical orbits around a round Earth, collisions, failures, and even non-artificial satellites would show things moving in a way that needed more than the seven numbers. But it never happens.
  #92  
Old 06-02-2017, 09:12 PM
Princhester Princhester is offline
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Originally Posted by Dr. Strangelove View Post
This one is provably wrong by anyone with high-school math skills.
Let me stop you right there...
  #93  
Old 06-02-2017, 09:48 PM
Dr. Strangelove Dr. Strangelove is online now
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Let me stop you right there...
You can read about the math here. The equations may look daunting, but you don't have to understand them, just verify that they do indeed produce a prediction based only on the TLE data. And they're all composed of basic high-school math operations like sin/cos, square roots, and so on. There's no mysterious place where a conspiracy could hide and fudge the math. It all comes out to a few dozen lines of code (which is also easy to verify).
  #94  
Old 06-02-2017, 11:44 PM
Richard Pearse Richard Pearse is offline
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No you're not. The rim is not curved "up and down", it is flat, totally horizontal. Think about it: the horizon is the set of points that are as far away as you can see over the curve of the earth. It is the intersection between a cone centred at your eye and the surface of the Earth, therefore it is a circle. (Ignoring local topography, of course).

You can ignore the curve of the Earth between you and the horizon, because by definition you are looking over the top of it, and it is not blocking your view of the horizon. You might as well imagine slicing a small portion off the Earth, centred under your feet, and defined by the circle of the horizon. That circle is totally flat, regardless of what the ground you sliced off is doing.

The higher up you go, the more you are looking down on this circle (and meanwhile the circle is getting bigger because you can see further to the horizon), so the more it looks like a circle rather than a straight line, until you get to the extreme case where you are out in space and you can see the whole circle of the horizon, which will get closer and closer to the circumference of the Earth the further away you get.
Well, yeah. It's a circle because the earth is a globe. If you can see the curve of the circle that is the horizon then you are seeing the curve of the earth.
  #95  
Old 06-03-2017, 01:00 AM
eschereal eschereal is offline
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Originally Posted by Dr. Strangelove View Post
You can read about the math here. The equations may look daunting, but you don't have to understand them, just verify that they do indeed produce a prediction based only on the TLE data. And they're all composed of basic high-school math operations like sin/cos, square roots, and so on. There's no mysterious place where a conspiracy could hide and fudge the math. It all comes out to a few dozen lines of code (which is also easy to verify).
They must be doing that with lasers or something. A searchlight kind of deal. They have those set up on mountain tops, moving in slow circles to make us think there are satellites up there. The NASA scam must be ridiculously elaborate.

How that eclipse business works, though, that is hard to explain.
  #96  
Old 06-03-2017, 10:34 AM
Princhester Princhester is offline
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Originally Posted by Dr. Strangelove View Post
You can read about the math here. The equations may look daunting, but you don't have to understand them, just verify that they do indeed produce a prediction based only on the TLE data. And they're all composed of basic high-school math operations like sin/cos, square roots, and so on. There's no mysterious place where a conspiracy could hide and fudge the math. It all comes out to a few dozen lines of code (which is also easy to verify).
.

You miss my point. How much overlap do you think there would be between those who genuinely can't understand that the earth is a globe and those that can do even relatively basic high school math?

Not much, is my guess.
  #97  
Old 06-03-2017, 12:23 PM
Dobbs Dobbs is offline
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With the mention of satellites and orbit predictions, a thought occurs to me.

Back in the day, I would travel around a bit, and set up satellite communications terminals. Because of the directional nature of the antennas, we would have to calculate the 'look angle' to the 'bird'. Because we used geostationary satellites, it was a fairly straightforward thing to do with a full function calculator and the correct instructions (which I may have around here somewhere). It could also be done with a basic 4 function calculator and trig tables (hey, it was the dark ages of the 70's and 80's).

If you were to calculate the look angles for, say, 200 cities in N & S America, or Africa, then project where those cities would be on a flat earth to have the same look angle, I wonder what that map would look like.

Trying to picture it in my mind, the areas near the sub-satellite point would be minimaly distorted, sure. I think the edges would just be spread out to such a degree that the distance between, say, Santiago, Chile and Buenos Aries, Argentina would be tens of thousands of miles.

Dayum, I have things to do today. This is going to be stuck in my head all weekend.
  #98  
Old 06-03-2017, 01:32 PM
DPRK DPRK is offline
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This is just a way of generating a map projection, no? In fact, if the number of satellites is small, you could just carry around a chart for each one from which you could read the bearing and elevation, no trigonometric tables required.
  #99  
Old 06-03-2017, 02:29 PM
Blue Blistering Barnacle Blue Blistering Barnacle is offline
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... snip...



How that eclipse business works, though, that is hard to explain.


"Eclipse business" is absolutely right. They have been gathering tithes and fees for millennia, going back at least to ancient Egypt and Babylon. There are some deep pockets there!

Big Eclipse (in collusion with Big Globe) is responsible for the mess we're in. That's why we should support Flat Earthers in their efforts to set things straight and make America great again!
  #100  
Old 06-03-2017, 03:10 PM
Dr. Strangelove Dr. Strangelove is online now
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How much overlap do you think there would be between those who genuinely can't understand that the earth is a globe and those that can do even relatively basic high school math?
I really have no idea. But my observation on all kinds of pseudoscience crap is that there's not much relationship between educational attainment and belief in nonsense. If anything, belief in pseudoscience goes down at very low educational levels because they don't think about this stuff in any capacity. But it's possible to have just enough enough education to get into trouble.
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