Earth, from 170,000 km away. Credit: NASA/Goddard Space Flight Center/University of Arizona
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Earth, from 170,000 km away. Credit: NASA/Goddard Space Flight Center/University of Arizona

Science Behind the Fiction: The Flat Earth movement is growing. It's very scary.

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Nov 21, 2018, 11:00 AM EST

Almost four years ago, Mark Sargent uploaded his first video discussing his belief in a flat Earth. Since that time he's amassed almost 70,000 subscribers, hundreds of videos, millions of views, and become something of a celebrity among the growing Flat Earth community.

Sargent isn't alone within the ranks of true believers. This idea has gained traction in recent years after several celebrities, including Kyrie Irving, B.o.B., and Tila Tequila took to the internet to express their feelings on the subject.

Sargent is the subject of a new documentary, Behind the Curve, which debuted at Hot Docs in Toronto April 30 and is now available digitally. The documentary follows several prominent figures in the Flat Earth movement, including Sargent, as well as several scientists as they discuss the evidence for and against a Flat Earth model of our world.

It might be tempting to dismiss globe skeptics as a lunatic fringe, supporters of an idea as antiquated as ancient Mesopotamia, where belief in a disk Earth covered in a dome was common. But the documentary makes a compelling case — not for their ideas, but for compassion and calm discussion. The subjects on screen are painted, not as charlatans or kooks, but as genuinely inquisitive folks who have been misled either by themselves or others. And, according to a recent study, they may not be as fringe as you might think.

Published on April 2, 2018, the study asked more than 8,000 adults in the United States whether or not they believed in a flat or globular Earth. A surprising 16 percent expressed some degree of skepticism. If these results are representative of the U.S. population as a whole, then nearly one in six adults are, at the very least, unsure about the nature of our world.

While, to most people, the question was settled thousands of years ago, results like that demand at least a second thought. So let's look at some of the claims made by Flat Earth believers and consider the evidence.


The FAQ on the Flat Earth Society site poses a reasonable question: "What evidence do you have?" The answer provided sounds equally reasonable: "The evidence for a flat earth is derived from many different facets of science and philosophy. The simplest is by relying on one's own senses to discern the true nature of the world around us. The world looks flat, the bottoms of clouds are flat, the movement of the Sun; these are all examples of your senses telling you that we do not live on a spherical heliocentric world."

It's easy to see why this might be an appealing answer, especially to those with a tendency toward distrust of authority, scientific or otherwise. Don't believe what you've been told; believe your gut. This section begins with the first half of a quote from Galileo, "Where the senses fail us," and continues with the admonition "reason must step in." Likewise, Deschartes is quoted as having said, "The senses deceive from time to time, and it is prudent never to trust wholly those who have deceived us even once."

As you navigate the world on a day to day basis it is acceptable, even necessary, to trust and act upon our own senses. They're what will save you from the crush of an oncoming car or the singe of a burning stove.

There is, however, considerable evidence that your senses cannot be trusted.

Your brain is taking in all sorts of varying, and sometimes contradictory, stimuli and doing the best it can to paint a coherent picture. Take a look at this video which shows how easily you can be fooled.

The brain has been honed to interpret specific sets of data and give you a most-likely truth. That truth is not always in perfect sync with reality, especially when considering things outside of our natural landscape, like the ultimate size and shape of the planet. So while the idea of trusting your own senses might feel satisfying, we must remember how easily we can be fooled and maintain, as Galileo suggested, a healthy respect for reason.


Belief in a flat Earth requires a whole host of other beliefs in order to even begin to build a coherent hypothesis. Primary among these is a reworking or complete dismissal of gravity.

Gravity, as we understand it, is a product of or a function of mass. In short, the more mass an object has, the more the effect of gravity impacts it. While the nature of gravity isn't wholly understood, its effect is. Objects with mass all exhibit a pull. It's as if every particle with mass has a tether it's using to pull every other particle toward it. Larger collections of massive particles, like planets or stars, have more tethers and thus exhibit more pull. As such, objects or systems gravitate toward or around the center of gravity.

This is why the solar system orbits the Sun (or at least a center of gravity almost indistinguishable from the center of the Sun). There are, of course, other forces at work in the universe. Tidal forces and surface tension push and pull at objects in various ways but, on the whole, gravity wins out when dealing with large celestial objects.

At a certain stage, depending on the materials involved, gravity overpowers the other forces at play and pulls the surface of objects toward the center, resulting in a sphere.

Given the size of the Earth, gravity insists that it be spheroid in nature.

If the Earth were flat, gravity would still pull toward the center of mass, requiring that its effects increase as you travel toward the rim. The below video demonstrates how that would impact life on our planet.

Proponents of a flat Earth must, in order to make their model work, disregard gravity entirely. From the Flat Earth Society: "The earth isn't pulled into a sphere because the force known as gravity exists in a greatly diminished form compared to what is commonly taught. The earth is constantly accelerating up at a rate of 32 feet per second squared (or 9.8 meters per second squared). This constant acceleration causes what you think of as gravity."

There are a number of problems with this model, not the least of which is the light speed limit. Starting at a velocity of zero with a constant acceleration of 9.8 meters per second squared, as suggested by the FES, the Earth would reach light speed in a little less than 355 days, breaking all manner of laws of physics.

Relativity states that as an object with mass approaches light speed, the amount of energy required to continue accelerating increases. In addition, any object with mass cannot attain light speed because it would require an infinite amount of energy.

There is no plausible model of physics than can account for a constant acceleration of this kind, even if we disregard the fact that the Earth must either be less than a year old or have well exceeded light speed by now. Alternatively, the Earth would stall at its maximum speed and all of us would go floating off the surface.

The Flat Earth Society, of course, invokes dark energy and mathematical equations explaining away this problem.


Modern models of the solar system put the Sun at roughly 93 million miles from Earth. Flat Earth models suggest it is much closer and much smaller. They believe it to be a sort of spotlight which shines circles the flat Earth in a circular path. This accounts, in their minds, for the day/night cycle, but something doesn't quite add up.

While most of us have never been high enough to observe the curvature of the Earth on our own, there are some basic observations we can make, right here on the surface.

The Earth is broken up into time zones, accounting for the Sun's apparent position at any given time. We know that the Sun moves along its path at approximately 15 degrees per hour. Multiply that by 24 hours and you get 360 degrees of a circle. This is an observation that is without dispute and is compatible with either a globe model or a flat Earth with the sun tracing a circle.

The trouble, as outlined by GreaterSapien above, is when you consider the consistent movement from various points around the world.

If the world is flat and the Sun is a moderately near object tracing a circle, you cannot explain the consistent movement.

Locations nearer the rim would observe the sun moving erratically, moving shorter distances per hour as it got closer and larger as it moved further away. This isn't observed.

A consistent 15 degree per hour trajectory is, however, consistent with a spherical model and a Sun at a greater distance, even if you disregard all of the evidence provided by NASA and other space organizations which show a globular planet from space. Speaking of which…


Let's get down to the bottom line. There are a few fundamental ideas most of us know from a very early age. Sargent mentions this in his first video, linked above. Every school-aged child learns that the Earth is round, to disbelieve this fact is to accept a vast global conspiracy of untold proportion.

Again, from the Flat Earth Society's website when asked about evidence provided via space exploration, "The most commonly accepted explanation of this is that the space agencies of the world are involved in a conspiracy faking space travel and exploration."

Surely conspiracies exist on some level. There have been, at various times and for various reasons, groups of people intent on perpetrating lies to the public. But, the old adage holds true that three can keep a secret if two of them are dead.

A conspiracy of this nature, considering the modern state of space travel, would require a secret being kept by a vast number of individuals. Countless astronauts, physicists, astronomers, and commercial entities would all need to be willing to perpetuate the lie. How many companies rely on satellites? How many military organizations from how many countries have the technological means to verify the reality of the world? And all of them have been and are still keeping the secret, to what end?

Belief in a flat Earth requires not only that a person disregard the scientific evidence but also the flat fact that no such secret could be kept by so many divergent groups and individuals for so long a time.

The question of the shape of the world is, perhaps, the quintessential example of Occam's Razor, that within any given question, the one with the fewest assumptions is most likely true. Belief in a flat Earth simply requires too many special circumstances to be plausible, and this article has only scratched the surface.

Should you so desire, you could spend hours, days, even weeks diving into flight paths, eclipses, and satellites on balloons.

Say what you will, but the Flat Earth community has been masterful at crafting a narrative that can seem, on the surface, to hold water better than a massive ice wall encircling the disk.

Behind the Curve doesn't reveal a paradigm-shifting model of the world, but it does reveal the humanity inherent within those who believe divergent ideas. It reminds us that while certain ideas might invite ridicule, individuals deserve respect, and that we can all benefit from asking hard questions just so long as we're willing to honestly explore the answers.

Behind the Curve is available now on demand.