The Flat-Earth Psy-op

David Chandler
21 min readSep 18, 2022


The modern day flat-earth “conspiracy theory” is not just a bizarre contrarian throwback, it’s a cynical con job with a high probability of being a psy-op of the CIA or some other 3-letter agency. It’s not a joke. It is toxic, both personally and for the health of a rationally functioning society. (I’ll get back to that later.)

I have taught physics, math, and astronomy since 1972 and am currently retired. My only interest in interacting with flat-earthers on social media, which I do very infrequently, is to toss out some instant education morsels to challenge true believers and rescue the gullible who may be about to drink the Kool-Aid. What I have gotten back are not rational arguments but virulent personal attacks. That is not the path to productive dialogue or the search for Truth; it is a sign that something deeper is going on. So apart from occasionally dabbling in this activity, with minimal investment of my time and energy and with low expectations of satisfaction, I try to stay away. However, I get re-motivated when people I know, or otherwise respect, wander too close to the quicksand.

Here’s the big picture.

All the cultures of ancient Mesopotamia, saw the earth as a flat disk with the sky as a solid dome overhead. The Babylonian version, told in the Enuma Elish portrays Tiamat, the primordial goddess of the sea, personified as a sea monster, and ancestral mother of all the other gods, defeated in a cosmic battle of the gods, led by Marduk. Tiamat was killed, then split in half, end to end, with one half used to form the earth and the other half to form the firmament. So we end up with a flat earth and a solid dome for the sky.

Genesis 1, in the Bible, looks like the Babylonian cosmology, stripped of its polytheistic context, retrofitted with Hebrew theology, and organized as a stylized liturgy for use in worship. It is based on a 7-day sabbath cycle, asserting the preeminence of Israel’s God as the sole creator and the “goodness” of creation, culminating with man (male and female) who are given dominion over the earth. The picture, again, is of a flat earth with the sky, the firmament, as a solid dome overhead. The Book of Job reaffirms the solid dome of the sky, using the same Hebrew word translated in Genesis as firmament; “Can you, like him, spread out the skies, hard as a cast metal mirror?” In Genesis 1, the central act of creation consisted of pushing back “The Deep,” leaving a “bubble,” bounded by the earth below and the firmament above, as a habitat where mankind could live.

The Hebrew and Babylonian view of the cosmos was common to the entire region of Mesopotamia at the time.

The flat-earth-solid-dome cosmology served well enough for early civilization, and it is the cosmology intuitively adopted by children even today. My (very intelligent) daughter, in third grade at the time, came home to announce that she had learned that the earth was round! Having been immersed in studying the process of concept formation in science education, I sat her down and gave her a blank sheet of paper. I asked her to show me the earth. She drew a big circle. I then asked, “Where are we?” She immediately pointed to the center of the circle. “Where are the mountains?… the ocean?….” All of these she drew inside the circle. “Where are the sun and moon?” Those she put outside the circle. “How did the astronauts go to the moon?” Somehow they had to poke through the sky. She wasn’t clear just how. Then I said, “I thought we lived on the outside.” She said, “Oh no. If we were out there we would die!” “Why?” I asked. “There is no air out there.” The moral of this story for education is that just because a child says the right words, it doesn’t mean they have actually updated their preexisting conceptual framework.

So why did civilization move away from the flat-earth cosmology, and what would motivate my daughter to do so in her own development? In my daughter’s case she had experiences with travel, maps, globes, time zones, star gazing with her dad, etc. in the process of growing up. It wasn’t the evil educational system ramming anything down her throat. The system obviously failed to even break through her preconceptions! She simply outgrew her early flat-earth concepts. In the case of civilization, the change came with the rise of long distance trade and navigation. Simply traveling back and forth across the Mediterranean, from Greece to Egypt, revealed anomalies that contradicted the flat-earth paradigm. People standing on the shore could watch ships disappear over the horizon, then reappear when they climbed to higher ground. Also, the stars visible near the southern horizon in Egypt could not be seen at all in Greece. Traveling north and south is like going around a bend in the earth. You are IN FACT going around the bend. This effect would amplify as they sailed farther south along the Nile.

Early navigators in the Mediterranean were smart enough to realize that the dominant cosmology of their day was wrong and came to adopt a new model: a spherical earth. Eratosthenes, who lived in Alexandria, Egypt about 200 BCE, recognize that he could measure the size of the earth by measuring its curvature over a known distance. It was known in his time that on a certain day of the year in the Egyptian town of Syene, near what is now Aswan, the sun at noon would shine straight to the bottom of a deep well without illuminating the sides. In other words, the sun passed directly overhead on that day. Eratosthenes noted that on the same day, an obelisk in Alexandria, where he lived, cast a shadow, from which he could measure that the sun was a little more than 7 degrees from the vertical (7.2 degrees, actually). The north-south component of the distance from Alexandria to Aswan, using modern units of distance, is about 780 km. 780 km for 7.2 degrees of curvature translates to 39,000 km for 360 degrees of curvature. His numbers, using antiquated units, were very close to these. This was a phenomenally accurate estimate of the earth’s circumference (within a few percent), given the crude technology and limited mobility available to him. (I have had high school students in Southern California coordinate with a high school in Montana to duplicate Eratosthenes measurement, with good results.)

Tell this story to a flat-earther and they will immediately pounce on you and say this depends on the assumption that the sun is at an essentially infinite distance, so the rays illuminate Alexandria and Syene along essentially parallel lines. Note, this is never brought up as an attempt to refine the discussion. It is always a “gotcha.” If the sun were smaller and closer, Eratosthenes’ method would be wrong, they say.

OK, let’s look a little closer: What does the flat-earth model predict for the distance to the sun? We have a right triangle with the sun above one point and 7.2 degrees off vertical at another point, 780 km away. Work out the trig and you have a distance to the sun of about 6,174 km. Is this sounding silly yet? We know that the moon is ~384,000 km away… we’ve been there!


But measuring the distance to the moon does not depend on NASA. Archimedes, a rough contemporary of Eratosthenes, figured out for himself, by observing eclipses, that the moon is ~30 earth diameters away and about one fourth the size of the earth. He went beyond that to deduce, by timing how long it took for the moon to go from first quarter to third quarter phase and back again, that the sun is ~40 times as far away as the moon. Since the sun appears to be about the same size as the moon in the sky it must be ~40 times as large as the moon, or in other words 10 times the size of the earth.

Archimedes found an ingenious way to calculate the distance to the sun. The bright half of a first or third quarter moon serves as an arrow pointing to the direction of incoming sunlight. If the sun were close to the earth, as shown in the diagram, the time to go from first quarter to third quarter should be longer than from third quarter back to first quarter. He found only a tiny difference in the times, which indicates the two lines pointing at the sun were nearly parallel, and thus the sun was very far away compared to the distance from earth to moon. His estimate was the sun was ~40 times as far as the moon. But this method is subject to measurement uncertainties such as judging the exact time of the quarter moons. Modern measurements put the sun at ~400 times the distance to the moon.

His measurements for the sun, were logically correct but highly sensitive to small errors in measurement, so he was off by a factor of 10. The sun is actually ~400 times the distance of the moon and ~400 times as large as the moon, or ~100 times as large as the earth. If you really want to see Archimedes’ brilliance at work, read The Sand Reckoner, in which he describes all of these measurements! Based on the fact that the sun was so large, Archimedes agreed with Aristarchus before him that the sun, not the earth was the center of the “universe.” Even taking Archimedes’ gross underestimate of the distance to the sun at face value, it is sufficiently far away to justify Eratosthenes’ measurement for the size of the earth. (The sun is not 6,300 km from the earth. It is 149 million km away!)

So even by 200 BCE we have a secure and quantitative foundation for believing that the earth is a sphere. The flat-earth model was consigned to the dustbin of history, until resurrected by modern-day, anti-intellectual charlatans.

By the way, why does the sky appear to be a dome? It’s a matter of depth perception. Your eyes can judge relative distances across the room, or across a school yard using parallax: triangulation. You have two eyes, giving you two points of view of the world. The offset produces small shifts in the view depending on distance, so more distant objects are viewed along the sides of longer, thinner triangles.

Parallax, as perceived by our binocular vision, is adapted for discriminating the distances of nearby objects. Objects that are out of range are perceived as all at the same distance, i.e. on a distant sphere. This perceptual limit, when looking up, is perceived as the “sky,” a dome overhead.

The ability to judge distance fails once you extend out on the order of miles because the lines of sight to distant objects appear to be essentially parallel. Since you can’t tell relative distances to distant objects, except by secondary clues, the foothills and the much more distant mountain peaks, that may be more than 10 times as far away, appear to be flattened up against each other. Since you can’t distinguish the relative distances to the sun, moon, and stars, they all appear to be the same distance away. A figure in three dimensions, where all the points are the same distance from a single point is called a sphere. That sphere, generated by the limits of our depth perception, is the solid shell of the sky perceived by children today, and children in the distant past who grew to adulthood with no way to correct their misperception. The universe, for the people of the ancient world, was very small indeed, until they learned to use reason to work their way past their perceptual limitations. Growth in understanding is incremental and cumulative. That is the intellectual heritage the flat-earthers of today are asking us to give up.


Let’s ask a different question. Why do things fall? The response for ancient people would be to give you a quizzical look for even asking such a question. This was not the kind of question they thought about and not the kind of thing their cosmology could answer. There is simply an up and down to the universe. Duh! Heavy objects move downward and light objects, like fire, move upward. End of story.

In a flat-earth cosmology “the gravitational field” would consist of parallel field lines. This is the picture of gravity used in the first few weeks of a physics class where the assigned problems are limited to the scale of a football field and the height of a tall building or possibly an airplane. For such a scale, a flat-earth and a uniform gravitational field are reasonable approximations. But this model doesn’t scale up to cosmic dimensions. If it did, there would be nothing to keep the moon from simply falling out of the sky. Since it is moving sideways, the moon might miss the earth, but it would follow a parabolic trajectory, passing the earth only once, then continuing to accelerate past the earth and off to infinity. You can’t have a closed orbit of any kind without a central force, and the uniform gravity of a flat-earth cosmology does not provide a central force.

For a flat earth, the gravitational field consists of vertical, parallel, “lines of force.” There is no possibility of a closed orbit in this kind of field, only vertical motion or parabolic trajectories for objects launched sideways.

The people of the ancient world, in fact everyone prior to Newton, divided physics into two separate realms: terrestrial physics and celestial physics. The two realms followed different laws. Newton’s law of universal gravitation is what unified physics, for the first time, and fully integrated the earth into the cosmos. You can’t re-import a flat earth into a post Newtonian world. It doesn’t work. If you want a flat earth you need to divest your mind of all thoughts of space, give up travel beyond a few miles from home, stop asking about how things work, and give up all technology based on Newtonian principles. Newtonian physics is an outgrowth of the Copernican Revolution that took the earth out of the center of the universe and made it into a heavenly body, like all the rest. Copernicus avoided the wrath of the Church by releasing his writings when he was on his death bed, but his followers met the full brunt of theocratic authoritarianism for speculating that if the earth is a heavenly body, perhaps the heavenly bodies included other earths, with other civilizations, which messed up their tidy earth-centric theology.

“What’s wrong with using Newtonian physics in the context of a flat earth?,” you ask. Newtonian gravity is a force of attraction between all pairs of particles in the universe that have mass, with a strength that diminishes with the distance between them. (This description is a little bit oversimplified, but this is not intended to be a full physics course.) Gravity is the reason planets (including the earth) are spherical. All the mass in the planet is pulling inward on all the other mass, causing everything to pull together, to crunch in as close as possible. Even the largest asteroids are spherical for this reason. The only bodies in our solar system that are not spherical are the smallest asteroids, which have minimal mass, and therefore weak gravitational fields that are not sufficient to overcome the material strength of the rock resisting the compression. If Newtonian gravity applied on a flat earth, people would be pulled together, sliding across the surface and piling up in the middle. So would all the loose material on the surface. Every fracture in the rock would trigger landslides toward the center, so the initially flat earth would quickly crush into a ball.

Direct Perception of a Spherical Earth

Let’s come back to the question of direct perception. How can someone tell that they live on a spherical earth, not a flat earth, without relying on arguments from authority (what you were told by teachers, the Discovery Channel, NASA, etc.)? I routinely assigned this question to my students when teaching astronomy. The classic answers to this question (classic, literally in the sense that these proofs were cited in ancient literature, long before Columbus), are:

(1) When you watch a ship sail off to sea it disappears hull first. Conversely, when you are on a ship approaching the shore, someone up in the crows nest can spot land before someone on the deck. The height of the observer allows them to see farther over the horizon. Flat-earth theory, on the other hand, would predict you could see any point on the earth from any other point, with a sufficiently powerful telescope, because there is no curvature to limit the view.

You can calculate the distance to the horizon, ignoring atmospheric refraction of light, for a spherical earth with simple geometry, as an application of the Pythagorean Theorem. It turns out that the distance (in km), to good approximation, equals 3.57*sqrt(h), where “h” is given in meters, but mention this to a flat-earther and they will jump all over it with examples where you can see farther than predicted. That is because the simple geometric derivation ignores the effect of atmospheric refraction.

Interactive derivation of the distance to the horizon for h in feet. The formula described in the text of this article is is equivalent, but in metric units. This derivation does not take atmospheric refraction into account.

It’s like an inverted mirage. Lines of sight, especially close to the horizon, are bent because of the temperature gradient of the air. This effect deflects the image upward by about a half degree, on the average, which means when the sun appears to be just touching the horizon it has already completely set, geometrically speaking. The math needed to derive the formula that takes refraction into account is actually quite difficult, and the result depends on the exact temperature profile of the atmosphere (called the lapse rate) which varies greatly from day to day, but on the average you can see about 8% farther than what is predicted by the simple geometric formula. Bottom line, use 3.86 instead of 3.57 in the previously cited formula for typical results, but expect significant variations. In other words, you might be able to see ships farther out to sea than the simple formula would predict, but you are never going to see a fireworks show in Hawaii or Japan from the coast of California, regardless of your telescope, because of the curvature of the earth.

One way to get around the atmospheric variability is to compare the horizon distance for two different elevations at about the same time. I once proposed this on a flat-earth Facebook page. Use a drone at the beach, photograph the horizon as the drone rises, then again as it returns to the beach. A drone at 100 m elevation should be able to see ~7 times farther than a drone at 2 m elevation. Pick a day when there is a lot of boat activity. A similar demonstration would be to have a drone photograph the sun as it disappears at sunset, then send it up ~100 m to see the sun reappear, then return to ground level. That would be fun to see, and utterly inexplicable in terms of a flat-earth model. (In researching this article I found a video that beautifully supplies the drone footage I was asking for, and more. Super cool!!!

Another way to directly detect the curvature of the earth without atmospheric refraction interfering, came to me when an employee at J.G. Boswell company (one of the world’s largest corporate farming operations) set up an appointment to consult with me during office hours when I was teaching physics and astronomy at Porterville College. He said he was involved in “laser grading” the fields. This involves setting up a tripod with a spinning laser beam that defines a horizontal plane of light which is detected by a sensor on a mast attached to the grader.

Laser grading of agricultural land. A truly flat field does not conform to the curvature of the earth, so it results in pooling of water at the middle when irrigated.

The grader automatically adjusts the height of the blade to maintain a constant offset from the horizontal plane of light, resulting in a precisely flat field. He told me that a problem with these fields, however, was that when irrigated, the water tended to pool up in the middle. We did the calculations and concluded that the effect he was observing was due to the curvature of the earth. It’s like making a shallow slice near the edge of an orange. The center of the slice is “deeper” into the orange. Water, under the influence of gravity, maintains a constant radius from the center of the earth, so it conforms to a sphere, making a laser-graded field deeper at the center. This would not happen on a flat-earth.

(2) When we watch lunar eclipses, we are seeing the shadow of the earth projected on the moon. This shadow is always circular, no matter the orientation of the earth, which varies with the time of night when the eclipse occurs. Flat-earthers will point out that non-spherical objects, such as disks, can cast circular shadows but the key element of this argument is that the effect is the same regardless of where the eclipse occurs in the sky, overhead or near the horizon. A sphere, but not a disk, casts a circular shadow from any angle.

Multiple exposures as the moon passes through the shadow of the earth. The camera is tracking the center of the earth’s shadow. This photograph illustrates not only the round shadow of the earth, but the basis for Archimedes’ measurement of the size of the moon. He was able to show, using geometry, that the diameter of the shadow of the earth equals the diameter of the earth minus the diameter of the moon. This photograph shows the earth’s shadow to be ~3 moon diameters, so the earth must be ~4 moon diameters. From the fact that the moon is 1/2 degree wide in the sky, one can calculate that it is ~30 earth diameters away. Clever fellow!

(3) The stars you can see vary with latitude. This, to me, is the clearest and most irrefutable proof accessible to direct observation that the earth is spherical. If you are in the northern mid-latitudes, say 40 degrees north latitude, Polaris would be 40 degrees above the horizon, stars within 40 degrees of the north celestial pole would always be visible, and stars within 40 degrees of the south celestial pole would never rise above the southern horizon. If you took this to the extreme and traveled to the North Pole, you would see Polaris directly overhead and only see the stars north of the celestial equator. You would never see Scorpius or the bottom half of Orion or the bright star Sirius. As you travel south, however, Polaris gets closer to the horizon, and more stars become visible near the southern horizon. If you travel to Ecuador, Polaris would be on one horizon, and the south celestial pole would be on the opposite horizon. All the stars, of both hemispheres, would rise and set each night. In Australia or New Zealand, the south celestial pole would be always visible to the south at an angular elevation equal to the south latitude of your location.


Do you realize that the seasons are reversed in the northern and southern hemispheres? Have you noticed that the variation in the length of the day, summer to winter, is more extreme at far northern latitudes and less extreme near the equator? The extremes of the Arctic and Antarctic regions experience 24 hour daylight and 24 hours of darkness in mid summer and mid winter. All of these facts are easy to explain on a spherical earth, but not on a flat earth.

Have you ever seen the Southern Cross from your home? (Not if you live in the northern half of the United States. You can see it from southern Florida or Hawaii, however, near the southern horizon in the springtime sky.) Whenever I hear Joan Baez sing “A Song for David,” which has the lines, “And the stars in your sky are the stars in mine,” the Sheldon in me immediately goes to the thought that the singer and her lover must be at the same latitude!

The latitude variation of the visible stars shows curvature in the north-south direction; time zones show curvature in the east-west direction. You have a phone. If you are on the East Coast try calling a “friend” on the west coast on a nice spring or autumn day at 7:00 am, when the sun is shining brightly. You will likely get an angry response for wakening your one-time friend from deep sleep in a dark room at 4:00 am. That can’t happen on a flat-earth because when the sun is above the horizon it illuminates the entire disk, so it would be visible to the entire earth at the same time.

One more thing. We are not reliant on just the classical proofs. We do in fact have modern technology including satellites and space travel, and we have in fact traveled to the moon and looked back. That is not a popular thing to say on flat-earth blogs, because a lot of their conspiracy bait is an appeal to anti-authoritarianism. The government lies, NASA is the government, so you can’t believe anything that comes out of NASA. It’s true, the government lies, when it seems expedient to do so, but the belief that the government lies all the time, or that they can maintain a coherent deception, propagated over decades, involving billion dollar projects and the entire careers of thousands of scientists and engineers, who would be in a better position than any self-appointed blogger to detect such a gigantic ruse, puts this notion at the bottom of the plausibility scale. Yes, we’ve been there, and we’ve looked back, and this is what we saw.

Earth rising over the limb of the moon as seen from Apollo 8.

That is not a disk we are seeing. It is a sphere illuminated from one side.

Why didn’t I just show this picture at the beginning and do a mic drop? It’s because I too value skepticism; not cynicism, but skepticism. I don’t want to simply be “told.” I want to “understand,” and to assess what is true for myself. The government does in fact lie whenever it seems expedient. But the Iraq weapons inspectors (who certified the absence of WMDs) had a saying, which I just learned came from a Russian proverb, “Trust but verify.”

If we are driven by unbridled cynicism, we impoverish our lives. However, digging in, to confirm or dis-confirm what we are told, actually increases our understanding and enriches our experience. What we can see if we engage with this process is that the Newtonian world view is indeed well founded. Yes, physics has moved beyond Newton, but that is another story. It is another instance of “standing on the shoulders of giants.”

The Flat-Earth Psy-Op

Given the absurdity of the flat-earth model in the modern world, where we can literally travel to and be in instant communication with people over the entire sphere of the earth, and make direct observations that would make Eratosthenes and Archimedes drool with envy, promoting flat-earth theories in today’s world would, you would think, be nothing but a joke. But you would be wrong. Try having a rational conversation in a flat-earth forum on social media. I have wandered into that arena on a few occasions and found that what is going on is not a joke. It is far darker.

I started this essay saying I believed the modern flat-earth “theory,” or flat-earth “conspiracy theory,” as some would say, is a psy-op. Why would government security agencies care what people believe about the shape of the earth? Clearly they don’t. What they do care about is what people believe about possible government wrongdoing, like the JFK, RFK, and MLK assassinations, 9/11, and other, more current events, where some people allege corrupt insider involvement. Direct evidence that the CIA has made efforts to manipulate domestic opinion that could affect public policy is found in CIA memo 1035–960, dated Jan 4, 1967, shortly after the release of the Warren Commission Report on JFK’s assassination. A central issue in the JFK assassination case was whether Lee Harvey Oswald was a lone gunman (the official position) or whether there was a broader conspiracy, which would open the door to characterizing the assassination as an outright coup. Open discussion of this question, which would supposedly be free speech protected by the First Amendment, was seen as a serious threat, so the CIA circulated memo 1035–960 giving talking points aimed at smearing “conspiracy theorists” as irresponsible, unpatriotic, Communist sympathizers. Lance deHaven-Smith, in his book, Conspiracy Theory in America, shows a graph derived from the Google Ngram tool that counts word frequency in published books, documenting the precipitous rise in the occurrence of the term “conspiracy theorist” since the JFK assassination. It has become the “go-to” smear word to be applied to anyone who looks into any topic they want to suppress.

If you look at that graph you will notice that the use of the term “Conspiracy Theorist” has been accelerating since 9/11. (There is a lag time due to the publishing process because this tool is counting word usage in printed books.) Few, if any, of the recent controversies labeled as “conspiracy theories” have anything to do with the question of an actual lone perpetrator vs. a conspiracy. (In the case of 9/11 the official story was itself a conspiracy, in the legal sense of the term.) Instead, it has become a generic term of derision to signal that any member of the press, or person in a position of authority, or anyone who wants to be taken seriously in academic circles, should dismiss the supposedly crazy ideas without so much as a hearing. Books and articles have been written pathologizing “conspiracy thinking” as a form of mental illness.

So how do they weaponize the “conspiracy theorist” label? My hypothesis, and I am not alone in thinking this, is that they aggressively promote truly crazy theories about just about anything, the more absurd or grotesque the better, so they can associate true craziness with the “conspiracy theory” label. Once there is public buy-in for the unacceptable nature of conspiracy theories in general, the term is applied with a broad brush to any topic the “powers that shouldn’t be” want to silence. Being personally involved in the scientific research relating to the events of 9/11, I am very conscious of how this smear tactic plays out in that arena. But the same process is going on all around us today. Pick your topic.

The process has entered a new phase recently where mere public scorn has morphed into active censorship. They started, of course, with low hanging fruit, like Alex Jones, but that was just to get their foot in the door. The First Amendment is being trashed right in front of our eyes every day. (I have to be careful because if I say the wrong thing, Medium will censor this article. Why, in America, should I ever have to worry about something like that?) Do I think flat-earth theories should be censored? Absolutely not. They should be exposed, examined, and rejected on their merits. People should learn to think critically and be careful not to become enamored of charlatans, because what they are doing is not only crazy, but it demeans public discourse. It’s playing into the hands of the would-be totalitarians among us.



David Chandler

BS physics/MA education/MS math; retired from ~35 years teaching physics, math, & astronomy in high school and college.