In a recent post about conspiracy theories, I mentioned that flat Earth is my favorite ridiculous belief of all—arguably, the king of all conspiracy theories. This is the one you graduate to when you’ve run out of crazy shit to believe.
If you’re a reasonable person, you’ve probably never bothered to investigate this outrageous idea. Why would you? We have known—not just believed, but known with absolute, 100% certainty—that Earth is a spherical planet for over 2,000 years.
At the same time, if you’re like most people, you haven’t studied science in many years and you might have forgotten just how we know. And if that’s the case, some of the flat-earthers’ arguments can sound somewhat convincing.
Fortunately (or maybe not), I’ve spent a lot of time learning what these people believe. I find it fascinating and frustrating at the same time. Fascinating that people can fall for this, and especially that they are able to completely disregard all evidence. Frustrating, for the very same reasons. Prove them wrong and they just double-down.
The biggest thing I’ve learned about flat-earthers (and perhaps about conspiracy-theorists in general) is: They don’t want to know the truth. They love their conspiracies.
What do flat-earthers believe?
This is a big question. A reality of flat Earth “theory” is that there is no one “theory.” When your “theory” has no basis in reality, you don’t need consensus. There are a lot of different and conflicting beliefs among flat Earth devotees.
There does appear to be a few ideas that are more common, though. If you know someone (or, God forbid, you are someone) who believes something different… I don’t need to hear about it. I’m not claiming that these are the beliefs of every fan of flat Earth. They just seem to be the most common.
The flat Earth is a finite, disk-shaped plane

There are some who claim the plane is infinite, others who claim that we have no idea how big it is, but most think it’s a disk with a definite edge.
The “edge” is a place that’s technically possible to visit, but only “THEY” are allowed to go there. “THEY,” in this case, being the military and other “elites.”
“Which military?” you ask. Who the hell knows? All of them? The U.S.? A super-secret Illuminati military? Some flat-earthers say it’s the militaries of all parties to the Antarctic Treaty, which is all the U.N. membership. Personally, I like the Illuminati idea. It’d be especially cool if they’re lizard-people.
Antarctica is an ice wall surrounding the plane

If there’s an edge, there must be something keeping the oceans from spilling out, right? Well, of course! That’s what Antarctica is! It’s not a continent, as we’ve been told. That’s why the Antarctic Treaty forbids civilians from going there… except that it doesn’t.
If you’re thinking, “Ice floats. Wouldn’t the ‘ice wall’ float on top of the water, allowing it to spill out underneath?” Congratulations. You’re smarter than the average flat-earther. Or to put it more kindly, they don’t like to ask questions that might jeopardize their belief. As with many questions they can’t answer, flat-earthers have always deflected when I’ve tried to ask. If you have an answer, leave it in the comments.
There’s a giant dome over the plane
Many flat Earth believers are fundamentalist Christians who believe in a literal interpretation of the Bible. The Biblical creation story in Genesis mentions Earth being covered by a “firmament,” which many flat-earthers interpret to mean a giant dome covering the entire disk.
Their “evidence” for this? You can’t go to the edge, so that’s out. Nobody’s ever seen the dome (except “THEY,” but “THEY” aren’t telling). The best evidence flat Earth proponents have is that we have an atmosphere, and it doesn’t just get “sucked” into the vacuum of space (which doesn’t exist… I’ll get to that).
Being the rational person I assume you are, you’re probably thinking, “Gravity! That keeps the atmosphere here on Earth.” Yep. I’ll get to that, too. For now I’ll just say, they don’t accept that explanation.
You might also be thinking, if you remember your junior-high science class, a vacuum doesn’t suck. Yep. Also correct—a perfect vacuum (which doesn’t exist in reality, but inter-planetary space is close, interstellar space is very close, and inter-galactic space is extremely close) is just the complete lack of “stuff,” e.g. dust, air, gases, etc. But try telling that to a flat-earther.
Space is fake!

Now venturing away from Earth’s surface, we get to space. According to flat-earthers, it doesn’t exist. There’s Earth, and above that is atmosphere, and that’s contained within the “firmament,” a.k.a. the dome. It’s not possible to go beyond that, so they won’t speculate on what’s there (unless it’s mentioned in the Bible, because of course, that is irrefutable fact).
What about stars? We don’t know what they are, according to flatties, but they’re definitely “not what we’ve been told.” Where are they? According to some, they are lights on the firmament itself. Or, they might be outside the firmament. But, really, we can’t possibly know for sure (even though we can and do).
What’s their evidence for this claim? Denial. Incredulity. That’s it.
I have not heard a single piece of positive evidence to support the positive claim that space is fake. I have seen a few out-of-focus photos/videos of stars that flat-earthers convince themselves are evidence that stars “aren’t what we’ve been told.” But show them properly-focused photos of the same stars—“FAKE! CGI! NASA lies!”
Also, every space agency on Earth is NASA.
Gravity doesn’t exist
If this “theory” is not yet batshit-crazy enough for you, hold my beer.
They don’t believe in gravity! I’m serious.
Why???
Why on Earth would anyone deny gravity? [Humorous side-note: Grammarly thinks I meant to say “defy”—even Grammarly can’t imagine anyone denying gravity].
Very simply, a flat Earth is not possible if gravity exists. Every object in the sky that we are able to observe is roughly spherical for a reason—gravity pulls everything toward the center of mass. Smaller objects like asteroids don’t have enough mass to make a difference, but large objects like planets and stars cannot be any other shape than a sphere.
So, they must deny gravity. And once again, you should be wondering, what’s their evidence?
Once more, denial is all they have. They come up with lots of excuses for why they think gravity can’t work, but no positive evidence for their positive claim that gravity doesn’t exist.
Einstein supersedes Newton
One of the more popular excuses flat Earth charlatans have come up with is that Isaac Newton described gravity as a force. Einstein said it’s not a force but rather the warping of spacetime. So, for some reason, if gravity can’t be described as a force, that’s the same as it not existing, apparently.
The obvious problem is that, it still exists and the effect is still the same.
The perhaps less-obvious problem is that, even Einstein said that his theory does not replace Newtonian gravity. For most practical calculations, like figuring out the trajectory of a sniper’s bullet, general relativity needlessly complicates things and Newtonian gravity gives the exact same results.
When we’re dealing with very large objects like stars and planets, general relativity gives us more accurate results. For most normal calculations here on Earth, the difference is insignificant.
Regardless of how you look at it, objects in free-fall accelerate toward Earth at 9.8 m/s2. If you recall high school physics, you know that you can’t have an acceleration without a force. F=ma. a=F/m.
The sun and moon are small and local

Can we get crazier than “gravity isn’t real”? That’s debatable. Would you say the Sun being approximately 3,000 miles above Earth is crazier? Because that’s what many flatties believe.
They’ve kind of started to shy away from making such concrete claims as “3,000 miles,” although that was the most common number given a few years ago. Now, most of them just say it’s “close.”
How close?
“We don’t know. But it’s closer than we’ve been told.”
The sun and moon are also the same size
They look the same size, and if you’re a flat Earth zealot, that’s irrefutable proof. It can’t possibly be that one is a lot farther away—that would mean that space exists.
They move in a circle above the disk
They can’t orbit, of course. That would mean that there’d have to be complete darkness everywhere on Earth for about half the day. So they just move in circles.
What keeps them up there? Your guess is as good as mine. That’s a question they dodge, every time. Once more, if you have an answer, post it in the comments. I’d love to know.
What causes them to move in that circular pattern? Same answer.
What about seasons? Their best explanation doesn’t work at all, but here it is: Throughout the year, as the sun circles above us, it moves back and forth from the Tropic of Cancer to the Tropic of Capricorn. When the sun is over the Tropic of Cancer, it’s summer in the north (can’t call it a “hemisphere” though) and vice-versa.

There’s a very simple reason that can’t be right, in case you’re entertaining the idea. On a flat disk with the North Pole at the center, the Tropic of Cancer is smaller than the Tropic of Capricorn. That means the sun has to speed up during the northern winter. It doesn’t do that.
What about sunrise and sunset?
“It’s perspective.” Since the sun is small, it just gets too far away to see, and that’s night.
But, perspective doesn’t make things drop below the horizon. They just get smaller and smaller until you can’t see them.
“Nuh uh!”
That about sums up the argument.
Some of the more deluded/dishonest flat Earth believers will claim that the sun actually does get smaller. It just looks like it stays the same size all day long due to “flare.” They like buzzwords. They can rarely explain what they mean.
You can use a solar filter to eliminate flare and see that the sun doesn’t shrink.
“Nuh uh!”
Ok, so let’s say “Nuh uh” is a satisfactory answer. What makes it appear to sink below the horizon?
“Perspective!”
Try to get them to explain how that works. Or to show that it works for any other object. I dare you not to laugh.
Earth is not flat
Also, unicorns don’t exist and Santa isn’t bringing you presents at Christmas (sorry, kids).
I was planning to discuss how we know but this post is already much longer than I intended, so I’ll just go with the simplest, most obvious way we can tell: The sun rises and sets. It doesn’t get smaller as it disappears from view, and it does sink below the horizon.

There’s no reason to get more complicated. Flat-earthers will just deny it, and rational people already get it.
I might go over additional ways we can know this in a future post—let me know in the comments if you’d like me to. There are many ways we can be absolutely certain.
A note to flat-Earth believers
If you’re a flat-earther reading this who’s planning to try to argue with me, I’ll be happy to discuss it. However, we need something to discuss.
I should insist that you provide a coherent model that we can compare with the standard model—the one that perfectly explains everything I’ve mentioned above and a lot more.
I’ll settle for a map, though. Simple enough. Show me a complete map of the flat Earth, with an accurate scale. One we could use to navigate the way we can with our existing maps that are based on a spherical Earth.
If you want to claim that our maps aren’t based on a spherical Earth, that’d be easy to prove: Just transcribe all the data from the existing maps onto a single flat map. If you’re right, it should fit perfectly and all distances should be accurate. It’ll be time-consuming, but it shouldn’t be difficult.
Do that and we won’t even need to discuss. I’ll just concede that I’m wrong.
I’m not holding my breath.
Want to know when I post new content? Drop your email address below!