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Resolved - The earth is spherical

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Voting Style: Open Point System: 7 Point
Started: 2/2/2015 Category: Science
Updated: 1 year ago Status: Post Voting Period
Viewed: 1,525 times Debate No: 69283
Debate Rounds (3)
Comments (5)
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I invite my opponent, lannan13, to debate the resolution of whether the earth is spherical.

I will be arguing in support of the veracity of the resolution.


Spherical: shaped like a sphere (1)

If my opponent disputes this definition then he can do so in the comments section before round 2, I will then evaluate the contention.
My opponent is also free to present further definitions in round 1, if I dispute them then I will do so in the comments.


Round 1: Acceptance & terms/definitions
Round 2: Opening argument(s)
Round 3: Rebuttals
Round 4: Final rebuttals and closing statements

I look forward to a great debate!

(1) Google: 'Define spherical'


I accept and for the sake of having a visual this is what a sphere would look like.

Debate Round No. 1


I thank lannan13 for accepting this debate. Just to clarify, my burden of proof is not that the earth is EXACTLY geometrically spherical, but it has a general spherical shape.

Pictures from orbit

Ever since 1946 (1), we have been able to photograph the earth from space. Every single one of these photographs show a roughly spherical earth. This proves beyond reasonable doubt that the earth is spherical.


If someone was to be placed in the middle of a becalmed ocean on a flat earth, they should be able to see the coastline through a telescope even if it was 1000 miles away. This is because there would be no obstruction to the light reflecting off the coastline and into the observer's eyes.

However, in reality this is not the case. No matter how good my telescope is I cannot see the coastline if I am placed in the middle of, say, the Pacific Ocean. Therefore there must be an obstruction that prevents the light reflected off the coastline from reaching my eyes.

As we do not see a ridge of water in the ocean, what then is the obstruction? If the earth was flat then the obstruction could only be a hill or ridge, but such forms cannot be formed by water. There only remaining feasible explanation is that the surface of the earth is curved, which would explain why we cannot look at things beyond the horizon.

As you can see from this photo (, the spherical shape of the earth would explain why we cannot see the areas marked in red (the part of the earth's surface beyond the horizon).

The Moon

We know that the moon is circular, as we have observed full moons. However, we also observe that the moon can appear to have a crescent shape. This change in shape is not caused by the moon being diminished in mass, because we can see a very faint outline of a circular moon even when only the crescent part is illuminated (2).

This suggests that the change in apparent shape is caused by a change in the way that the moon is illuminated - it goes from being fully illuminated to being partially illuminated. We know that the moon is illuminated by the sun (3), and that the sun's light is constant (4), so any lack of illumination is caused by a shadow. As the earth is the closest large celestial object to the moon, it is reasonable to suppose that this shadow comes from the earth.

In order to move from illuminating a circle to illuminating a crescent, the shadow must be circular (5). As this shadow is caused by the earth, the earth must be circular in order to cast this shadow and so the earth is round. As crescent moons are observed from all over the world, the earth must be round from all orientations. This is therefore, geometrically, a spher(oid).

Therefore, the earth is spherical.

I will now pass over to my opponent!



Okay so let's get down to some crazy things for this wounderous debate.
So to clarify I will be debating that the Earth is flat by using the Neo-Classical Model with the following descripition.
  1. The earth is finite disk.
  2. The earth is being accelerate upwards at approximately 9.80665 m/s2.
  3. The earth is the only known "disk" in the universe.
  4. The laws of physics are the same in every inertial reference frame.
  5. The speed of light, measured in any inertial reference frame, always has the same value, c. (
Contention 1: Rotation of sun and the seasons.
Day/night cycle on a Flat Earth
One of the greatest questions you have right now is probably if the Earth is flat how does day and night work. Well the answer is actually that the Sun and the moon rotate around the Earth in a circular motion. As seen in the gif that I've provided above you can painly see that ti's a spotlight type roation as it rotates around the Earth illuminating only a certain portion of the Earth at a time simulating both night and day.
Seasons in Flat Earth Theory
Seasons are explained above. As the Sun moves closer to the poles it becomes colder in the northern hemisphere while when the Sun is closer to the equatro it is actually summer time. (
If we use the Corpurnicus model we can see that the Earth is indeed the center of the Universe. Though the other planets may orbit the sun we can see that the sun and the rest of the solar system orbits around the Earth.
Further proof that the Earth is flat is when we observe cosmic rays and that they travel the speed of light. Now if we look at the simulator that I have provided you we can see that as things approach the speed of light they are flattend. ( Cosmic rays called Muans are better known to collide in our atmosphere and we shouldn't be recieving barely any, however we get a whole lot more then expected, but since they're going so fast the Earth is flatter and the distance they have to cover is a whole lot closer. If you were a proton moving 99.999999% the speed of light you can see that the Earth would only appear to be 17 meters thick.
Contention 2: Gravity

Now before you jump to several statements that Gravity should collapse the Earth into a sphere there is just one problem with that. Gravity doesn't exist. How in the world is this you may ask. Well you can see that the Earth is actually accelerating up at the acceration of 9.88 meters per second. This explains Newton's gravitationial theory, but Newton was incorrect here. ( With the increased accerlation it becomes apparent that this also causes you to be shorter at the end of the day. Now to further this I would like to clarify that gravitation, not gravity exists. This explains the tides as stars and the moon/other celestial bodies all have slight gravitationial pull.
Here is a list on how they are different in order to clarify the debate up a tad bit.

- Gravity or the gravitational field is a vector field, while gravitational force is only a vector.

- Gravity lies in the radial direction from the mass, while gravitational force is in the direction of the line connecting the two masses.

- Gravitational field requires only one mass, while two masses are required for gravitational force.

- Gravitational force is equal to the product of the mass of the test object and the gravitational field intensity. (

Now I want you to imagin living on this Earth, which as I showed earlier is just a flat disk. The gravitational force is actually angled to the point to where as you get further and further away from the center (the north pole) you can see that the increasing gravitationial force would cause you to want to fall back towards the center and not want to go towards the edge of the Earth. The people living away from the north pole would have their living conditions inclined in order to meet such a force. It would feel like you are trying to clime up a steeper and steeper hill. Contary to belief you wouldn't fall off the edge due to the gravitationial vector pointing back towards the north pole, the actual fear would be falling off the edge and rolling back towards the center as shown in the picture above.

That is all for my opening arguments and my rebuttles shall come in the next round as requested by my opponent.

Debate Round No. 2


I congratulate lannan13 for arguing so well considering the difficulty of his stance on the resolution. Nonetheless I do not believe he actually proves that the earth is not spherical.

Flat-earth theory

I will argue that this theory is flawed.

My opponent's image appears to explain how the sun and moon circle above the earth, thus creating what we know as day and night. However, the fundamental problem with this theory is that the sun's light is not focused like a spotlight is. The sun's light is radial (1)(it is emitted in all directions at equal intensity) and so there would be no reason why the sun's light would not reach all areas on the disc-world at all times.

Con makes the following statement:

'If we use the Corpurnicus model we can see that the Earth is indeed the center of the Universe.'

But Copernicus actually promoted a heliocentric view of the solar system, he never said that the earth was the centre of the universe. (2)

The next argument presented by Con is that the earth would appear flat relative to cosmic rays that are travelling at the speed of light. However, this debate is over the shape of the earth in actual geometric reality, not whether it appears to be flat from the perspective of a relativistic particle. That logic would mean that, just because I put on red-tinted glasses, everything is actually red. Obviously this is incorrect.


My opponent makes the rather extreme claim that gravity, as a force, does not exist. Instead, gravitation exists.
The problem with this is that gravity and gravitation are mutually inclusive. The gravitational field (which is what Con appears to mean when he says 'gravity') scientifically entails that a gravitational force will be exerted if a mass enters the field (otherwise it wouldn't be a gravitational field)(3). Likewise, a gravitational force cannot exist without a gravitational field (4).

My opponent then explains that the force we feel that brings us 'down to earth' is not gravity; instead, the earth is accelerating upwards at a speed of 9.88 ms-1 and therefore, according to Newton's 3rd law, we exert a downward force on the earth that 'roots' us to the ground.
However, according to Newton's second law (F=ma)(5), the earth can only be accelerating upwards if there is a resultant force being exerted on the earth from directly above us. But what could this force be? We see no evidence of a force accelerating the earth upwards, nor any conceivable reason why it is being accelerated upwards.

Furthermore, the evidence for the existence of gravity is not just limited to earth. On the moon, we have observed a gravitational force/field by dropping hammers and feathers (6). We know the moon is spherical so this 'down' force cannot be created by upward acceleration like my opponent claims is the case with the earth. We have landed at many different points on the moon (7)- yet if the appearance of gravity is merely the result of an upward acceleration, then the force on the hammers/feathers would be different if dropped at different parts of the moon. But this has not been found to be the case.

My opponent's last point about how the gravitational force is towards the centre (the north pole) does not actually prove anything. All it does is say 'if the earth is flat, this is how it would work'. But it does not actually provide any evidence that the earth IS actually flat.
Yet again, a gravitational force cannot exist without a gravitational field (because all non-contact forces require a field)(3). So to talk about a gravitational force, having previously denied the existence of a gravitational field, is incoherent.

I'll pass this debate back to you now!



Please null this debate. There is not enough rounds as we will do a rematch of this debate. I repeat once more. Leave voteless.
Debate Round No. 3
5 comments have been posted on this debate. Showing 1 through 5 records.
Posted by lannan13 1 year ago
Posted by Philocat 1 year ago
Will do :)
Posted by lannan13 1 year ago
Hey could you please hold off your arguments until Saturday? Please and thank you.
Posted by Philocat 1 year ago
Oops, sorry! I'll do that now
Posted by lannan13 1 year ago
Your photo album is private and I cannot view it. Please lessen the restrictions so I can view it/
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