The Instigator
Pro (for)
The Contender
Con (against)

The earth is spherical in shape.

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Voting Style: Open Point System: 7 Point
Started: 1/11/2018 Category: Science
Updated: 3 years ago Status: Debating Period
Viewed: 1,020 times Debate No: 106626
Debate Rounds (5)
Comments (14)
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A similar debate was already posted and accepted, but I don't think it's going to have the depth I was looking for. Repost. Must have completed at least 5 debates before it is possible to accept this debate.

Please read the rules.


I'm looking for a serious debate on this topic, so trolls need not apply. We'll be shooting for an evidence-based inquiry into the shape of our planet. In the past, I've seen that it can be trying to find the time (or in this case, space) to present all possible arguments on the issue, so we're going to be doing a "best two" format here. See below.


1. This is a "Best Two", traditional format. "Best Two" indicates that both sides will be presenting at most two arguments for their position. (Ideally, the "best two" arguments for your position.) When your position is critiqued it is sometimes necessary to bring in more evidence or explain a related phenomenon. This is fine -- just ensure that your entire argument can be largely separated into no more than two points.

2. Burden of Proof is shared. Regardless of how "silly" this topic is interpreted by most people, both the claim "The world is flat," and the claim "The world is round," are positive claims and so both sides have a burden to prove their claims. Voters are instructed to choose the winner based upon whichever debater presents a more compelling set of arguments (or argument).

3. Semantics arguments need not apply. While arguments based on semantics are important in some areas, particularly philosophy, this is a science-based discussion and arguments which rest entirely upon "defining ones way to victory" are not allowed here. It is difficult to define exactly what one of these arguments looks like, but when you see one, you know what it is.

4. 10k character limit. A debater should post a minimum of 4,000 characters in rounds 2-4. The purpose of this is to ensure that both debaters are actively involved in the conversation.

--Round Structure--

R1: Intro / Con Opening Arguments
R2-4: Normal Debate
R5: Wrap It Up.

The only important thing to note here is that Con will be leading with their opening arguments in their acceptance. No reason to waste space or time with a purely introductory round.

--Last Minute Clarifications--

Even though I said that no semantics based arguments should be made, I will clarify this anyway. When I say "The earth is a sphere," I mean "The planet on which we live is spheroid in shape."

Thanks in advance to my opponent. Let's have fun!


I accept the debate and terms.

I posit that there is absolutely no evidence for the existence of a spherical and spinning earth. I intend to show, with the scientific method and everyday observation, that the earth is flat. The opponent wishes to limit the arguments to 2, so I'll try to pick the best arguments.

1. All bodies of water are measurably flat. Since a majority of the surface of the earth as we know it is water, we can safely deduce that the earth is flat. Or not spherical. Anyone can test this. Find a body of water that is at least one mile across and measure it.

This test is currently being performed all over the plane. From 6 miles:

12 miles:

30 miles

57 miles

Even 160 miles away:

Water has been found to be flat. This is a direct contradiction to the mathematics of the conclusion, and the earth couldn't possibly be a ball.

2. Motion of the earth. To have a workable model, you must have a means of falsifiability. To say that the earth is spinning, wobbling, tilted back at 66.6" axis, orbiting the sun at 66,600 miles per hour, as it follows the sun around the universe, which is in turn going around "the great attractor" at some 800 miles per second is an astounding claim, and has never been demonstrably proved. Many experiments trying to prove the earth's motion have failed miserably. An easy way to falsify this claim is with a simple gyroscope.

Gyroscopes maintain "rigidity in space" because they resist a force that would cause it to change orientation. Foucault claims to have demonstrated that the gyroscope resists the force of the earth's motions:

But I can't seem to find a demonstration anywhere. So it is so far, an assumption.

"Rigidity in space: the gyro has a tendency to resist forces applied to it, it is stable on the axis it spins. This is the principle behind which a spinning top stays upright, and the incorporation of gyroscopes in flight instrument have resulted in instruments like the artificial horizon which by maintaining rigidity in space allow for flight solely by reference to the instruments."

When reproduced, the experiment produces nil results.

If Foucault invented a crude gyroscope that long ago, and it resisted the earth's motion, why can't we reproduce these results today, after all the advancements in every field? This is a direct contradiction of one of the heliocentric model's main tenants, the motion of the earth. Which means that the two tenants, curvature and motion have been refuted using the scientific method.

I await your response.
Debate Round No. 1


I thank my opponent for his thorough response.


I'll start by discussing the opponent's arguments, then I'll move on to my own. I will note that the opponent posted in excess of 70 minutes of Youtube video. I think it is reasonable to expect that I am going to skim the videos to absorb their content, but I won't be watching them through. The point of limiting each side to two arguments is so we have plenty of room to talk about each topic in depth. This goal could be harmed if it's expected that one responds to video that is nearly as long as a feature-length movie. That said, I will review it. Don't want to miss anything.

The Opponent's Arguments

1. The Shape of Water

The opponent argues that bodies of water are flat, whereas in the round earth model they should be curved. If they are flat, this implies that the world is also flat. The opponent is correct that, if water were flat, the round earth model (as well as much other science) would be in grave peril.

Fortunately, a simple exercise in mathematics will explain that the opponent's evidence fits squarely into the round earth model.

For his first example, he shows a video of a man standing at a body of water with his wife 6 miles away on the other side. He has a camera, which he has set up about 4 ft off the ground and his wife has a 4 ft mirror. If one does some plug-and-play with some math regarding arc length and chords [1], you find that one expects a "bulge" of 6 ft in between the man and his wife. He should not be able to see the mirror at all, and yet he does. How is this possible?

The answer here is the answer for all of the videos and it has to do with how one thinks about "drop off" and how one measures "bulge".

In the [1] source, you see a picture with a chord connecting two points along the edge of a circle. Think of these two points as the "viewer" and "object", the chord being the "direct line of sight" and the bulge in between being the bulge of the water. When I refer to bulge height, I am referring to the largest distance from the line of sight to the edge of the circle. In other words, in the picture provided it is a directly vertical line segment connecting the chord to the edge of the circle, such that this segment is as long as possible. (This height is called "h" in the image.)

Note that this model will not tell you anything of use when used alone. We do not observe things from the exact surface of the earth; we stand taller than that. For example, in the first video the man"s camera and the top of the mirror are both about 4 ft off the ground. In the "30 mile" video, the man is about 20 ft from the water line. (It is difficult to tell, though.)
To correct this, we draw another circle around the one already there, such that it has a radius "f" ft. longer, where f is the distance the viewer and object are off the ground. (We assume they are the same to ease calculation.) We then subtract the radius of the earth (which corresponds to the "top" of the bulge from the distance from the origin to the chord of the second circle (the line of sight) in order to get a new bulge value -- one which describes the height of the bulge from the viewer"s actual perspective.

Formulas: If R is the radius of the earth, f is the distance from the surface to the viewer and object, and s is the distance along the ground between view and object:

Then the height of the bulge when seen from the surface is: R * (1 - cos( s / 2R ) ),

and the height of the bulge when seen from the viewer is: (R + f) * cos( s / 2R ) - R.

Finally, note that once we have the bulge height when seen from viewer, we have to multiply that number by 2 to get the final height being obstructed. This is because one has to look "over" the bulge, which is exactly halfway between the viewer and the object. Since a line of sight is an actual line, when we double the run we must double the rise.

Ok, let"s look at each example.

In the 6 mile example, we calculate the bulge-from-ground as about 6 ft. The bulge-from-viewer, however, is 2 ft (assuming the viewer and object are 4 ft off the ground). Double this, and we get our final obstruction of 4 ft. That"s exactly the height of the mirror, so shouldn"t it be covered? Not enough evidence to tell. Given the choppy conditions, refractive effects and the inability to tell how much of the mirror is revealed -- this is well within the margin of error.

In the 12 mile example, things are more clear. The 12 mile bulge-from-viewer is 24 feet, so 48 ft obstruction. We do note some obstruction in the video and it is not clear if it is 48 ft. We shouldn"t expect it to be exactly that, either, again due to refraction. [2] The effects of refraction are not large at short distances, but one would expect to see tens of feet of difference in the evening time when looking across a lake, when the land temperatures would be cooler than water temperatures (since water holds heat better than the ground.)

At 30 miles, we have a 120" bulge-from-view, giving 240" of obstruction. This is in line with what we see, given that there are at least 49 building in Toronto which are over 500 feet tall. [3]

At 57 miles, we should expect about 1000" of obstruction from the viewer"s perspective. The big tower in the video, Willis Tower, is 1700" tall. Note that it appears we can see more than half of it, so we are missing about 400" of obstruction. This is, again, well explained by atmospheric refraction. [4] The effects of refraction become greater at longer distances, especially over bodies of water and at times of day when the temperature change is greatest. (This creates varying air density across the line of sight, which is exactly the conditions under which refraction is observed.) Note that [4] includes other videos which show the same skyline at varying degrees of visibility. Sometimes, it can"t be seen at all (usually mid-day, when refractive effects should be minimal) and sometimes it can. If the Earth were flat, we would expect to *always* be able to see the skyline, and more so we should be able to see *all* of the buildings. If anything, this video demonstrates that Earth isn"t flat.

The same is the case for the mountains in the last video.

As we"ve seen, the behaviors viewed in the video are what would be predicted on a spherical earth. I think the confusion mostly arises here because people thinking about the flat earth tend to consider "drop off" in curvature rather than "bulge height". The former doesn"t speak to what can be seen while the latter does. Incidentally, the latter produces less extreme amounts of obstruction at small distances.

2. Gyroscopes

Respectfully, this is less of an argument and more a critique that the Flat Earth community doesn"t have enough cash to perform experiments using expensive equipment, which is a requirement here.

You see, a gyroscope does try and resist changes in motion when it is rotating. This is most usually noticed in a top"s ability to stay upright while spinning. However, one cannot compare the expectations of a theoretically perfect gyroscope to one you can buy at a store. A perfect gyroscope would rotate as the earth does, provided its axis of rotation is not inline with Earth"s. A cheap gyroscope has to deal with friction from bearing resistance, physical changes due to minute temperature differences, and varying local atmosphere behavior.

This is why gyroscopes capable of demonstrating this effect often have magnetic components, are vacuum sealed and cost a fortune. Also, this experiment has been done with such expensive equipment. [5]

That"s all that really needs to be said about gyroscopes. It should be noted that the easiest way to see that the earth is spinning is to measure the location of the sun and then measure its location two hours later.

My Arguments

1. A flat earth is incongruous with current technology.

This argument is simple -- so much of the technology we have would not work or would not be necessary on a flat earth.
To start, satellites. One notes that in all of his videos, the people use google maps or an actual GPS, both of which rely upon satellite technology. If the earth were flat, it"s not clear how satellites would work. In a flat earth scenario, gravity as we know it cannot exist. Instead of everything attracting everything else, there would just be one, "global" down direction. And if "down" can ever only point one way, satellites cannot stay in the air. They would fall to the ground or into the abyss.
The space station is one such satellite, and you can literally see it when it passes over at night. Given that we see the space station and that we use GPS, we must conclude that satellites exist. For them to exist, gravity must exist -- and if gravity exists then the world is most certainly round, as no other shape could form naturally form.

Abrupt Cutoff

I"m out of room. I"ll finish this argument and present my next immediately in the following round.

For the purposes of being fair, my next argument will be probabilistic. I will argue that either all engineers even remotely related to aerospace, most government officials of most countries, all pilots, all flight control crews, etc. are lying to us, or there is no conspiracy and the Earth is indeed round. I"ll be discussing the likelihood of each scenario and concluding that the former scenario is so unlikely it can be disregarded.

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Debate Round No. 2
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Debate Round No. 5
14 comments have been posted on this debate. Showing 1 through 10 records.
Posted by Youngastronomer 3 years ago
Edl, why the CGI excuse? Anyways, what causes lunar eclipses?
Posted by Edlvsjd 3 years ago
"The claim that the heliocentric model is wrong and that geocentrism is the case is a bold claim requiring evidence."

The flat earth is the evidence. As is the many proofs of the firmament, or "ther.

"What reason do we have to believe that other planets aren't physical things when we can get out a telescope and literally see them?"

Just because you can see them, this doesn't mean they are physical terra firma. Are you going by NASA CGI pictures? The "Mars" rover? Lol

It sounds like "flat earth implies geocentrism which implies flat earth" circular reasoning."

Now, most of the refutations you gave for distances sighted use "refraction" as an excuse for the earth looking flat over any distance, THIS is circular reasoning. Do you have scientific evidence that supports the claim?

"As for the calculator, I'll need to check out the first one. The second chart appears to be correct. How is the discovery special "demonstrably fake"?"

Hawking does not factor in for observer height obviously, so there is far too much curvature in the experiment. Check for yourself. They saw the distance in miles squared formula and ran with it, ignorantly. Rainbows prove the firmament.
Posted by Septune 3 years ago
The claim that the heliocentric model is wrong and that geocentrism is the case is a bold claim requiring evidence. What reason do we have to believe that other planets aren't physical things when we can get out a telescope and literally see them? It sounds like "flat earth implies geocentrism which implies flat earth" circular reasoning.

As for the calculator, I'll need to check out the first one. The second chart appears to be correct. How is the discovery special "demonstrably fake"?
Posted by Edlvsjd 3 years ago
"We also know that there isn't some universal "down", as the planets would be unable to orbit if that were the case. They'd just fall."

The heliocentric model is wrong. The earth is geocentric. Up is up, down is down, the "planets" aren't physical terra firma, and have no bearing on the shape of the earth.
Posted by Edlvsjd 3 years ago
The curvature of the earth should be very measurable. Even globe earth proponents recognize this. In this discovery channel special.

Which is demonstrably faked. Do you agree with this formula and calculator, for easy verification and less chance of human error?

The last formula does not account for observer height.
Posted by Septune 3 years ago
I think the most compelling scientific argument for a round earth is gravity. We know that some force exists which pulls us in a particular direction at all times. It's why when we jump it comes back down. We also know that there isn't some universal "down", as the planets would be unable to orbit if that were the case. They'd just fall.

The best explanation for the planets' behavior is that all things with mass attract one another. It's why we can talk about the motion of the planets and accurately predict their behavior without a lot of math.

And if gravity (as the force I've described) exists a flat earth cannot exist. First, it would not be structurally stable and would collapse on itself if it somehow managed to "appear" flat. There is also no known physical mechanism by which a planet could form "flat". Gravity would not allow the particles to arrange themselves in such a high energy state. Third, even if the earth did form flat and didn't collapse upon itself, there would still be noticeable changes in the apparent direction of "down" as you approached the edge of the disk, since "down" would be all vectors pointing toward the Earth's center of mass.
Posted by Septune 3 years ago

I don't find either of those arguments very convincing. I spent way too much space on your first argument, so I think I've pretty well detailed why I don't find that convincing. But the bigger problem with that that I didn't mention was the fact that it's just poor experimentation. We are talking about the curvature (or lack thereof) of a literal planet. At observable distances on the ground, the world is going to look flat. Trying to design a ground-based, observational experiment that meets any scientific standard is extremely difficult since the curvature is so tiny.

Which, incidentally, is (in my view) the reason why "Flat Earth" is so popular. Cheap, "garage" experiments demonstrating curvature don't seem to exist.

The gyroscope argument also doesn't do it for me. There have been a few studies using lab grade gyroscopes which indicate rotation. Videos with cheap gyroscopes failing to do this may be aplenty, but it's very easy to use cheap equipment to try and fail to measure something only quality equipment can detect. I wish there were more rigorous experiments dedicated to this, but unfortunately, the amount of people who believe in the Flat Earth is too small for scientific institutions to dedicate time to prove what is already a widely accepted fact.
Posted by Edlvsjd 3 years ago
Sorry, worked a few too many late days and weekends lately. Converse in the comments, Septune?
Posted by Septune 3 years ago
Mostly because it now seems like I'm talking about inches. I'm not talking about inches -- I'm talking about feet.
Posted by Septune 3 years ago
All of my " where turned into ' and vice-versa when transferring from Drive. I know that's super annoying and I apologize.
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