Why do people believe the Earth is flat?

That’s a hard question, with a lot of different answers — I’m more accustomed to addressing a similar question, “why do people believe in creationism?”, and I agree with one of the assertions of this blogpost that says flat-earthers (and creationists) aren’t necessarily stupid. It’s true! The problem with these misbegotten questions is that smart people get derailed into defending them, at painful length. It’s tragic, because these are people who are deeply interested in what are scientific questions, and they’ve become committed to the wrong answers, because humans are better at deciding their presuppositions are correct, rather than in questioning whether they might be wrong. So I’ll accept half of this statement.

I, as many people in science communication, am fascinated with flat earthers. Here you have a group of people steadfastly rejecting evidence that’s right in their face. Today, I want to tell you why I nevertheless think flat earthers are neither stupid nor anti-scientific. Most of them, anyway. More importantly, I also want to explain why you should not be embarrassed if you can’t remember how we know that the earth is round.

The part I disagree with is the claim that they are not anti-scientific. Not stupid, sure, but the whole problem is that they are using their intelligence to promote anti-scientific perspectives. I think the author is trying too hard to be charitable and infer a shared respect for the scientific method. I also think she’s fitting the breadth of weird views into too narrow a range, even while acknowledging the diversity of flat earth beliefs.

But first I have to tell you what flat earthers actually believe and how they got there. The most popular flat earth model is that of a disk where the North pole is in the middle and the south pole is an ice wall on the edge of the disk. But not all flat earthers sign up to this. An alternative is the so-called bipolar model where both poles are on the disk, surrounded by water that’s held by a rim of something, maybe ice or rocks. And a minority of flat earthers believe that earth is really an infinite plane.

They mostly agree though that gravity does not exist, and that the observations we normally attribute to gravity come instead from the upward acceleration of the flat earth. As a consequence, the apparent gravitational acceleration is the same everywhere on earth. I explained last week that this is in conflict with evidence – we know that the gravitational acceleration is most definitely not the same everywhere on earth.

Here’s a problem: I’m not an expert on flat-earth belief, but I’ve seen the documentary Behind the Curve, and a scary number of YouTube videos, and I’ve never seen this claim that the flat earth is constantly accelerating upwards. Most of the stuff I’ve seen is people also freaking out over the idea that the earth is in motion, spinning and moving through the universe. It’s the notion of movement that is part of their objection.

They do often deny the reality of gravity (and also of space, in general), but the most common explanation is “density” — that denser objects sort of “sink” downwards, which kind of misses the question of what defines “down” in the first place. Their rationalizations are an incoherent mess, and there is a multitude of bad explanations. Should we give them credit for honestly trying to answer the question, but being hindered by a weak notion of evidence? Like creationists, flat-earthers do seem to only be aware of evidence from personal experience, and are unpersuaded by mathematical abstractions or theoretical considerations or observations that aren’t a product of simple eyewitness interactions.

Where I object is in the idea that their disagreement ought to be taken seriously philosophically, or that they are really trying to address a question scientifically…they just lack the tools to get the answer.

What’s wrong is that flat earthers’ claim they are leading a scientific argument. But there is no scientific argument about whether the earth is flat. This argument was settled long ago. Instead, flat earthers’ argument is about whether you should trust evidence that other people have collected before you. And it’s an important argument because this trust is essential for society and science to progress. The only alternative we have is that each and every one of us has to start over from scratch with birth. You see, flat earthers would eventually figure out the earth is round. But it might take them a thousand years until they’ve reinvented modern science.

This is why I think scientists should take flat earthers’ philosophical problem seriously. It’s a problem that any scientifically advanced society must address. It is not possible for each and every one of us to redo all experiments in the history of science. It therefore becomes increasingly important that scientists provide evidence for how science works, so that people who cannot follow the research itself can instead rely on evidence that the system produces correct and useful descriptions of nature.

Except there’s a fundamental misapprehension here that they want a correct and useful description of nature. They don’t. They have a conclusion already, and what they actually want is a rationalization that only looks scientific that delivers them to their desired answer. That is the opposite of scientific reasoning. They want validation, preferably in the form of buzzwords from physics or biology or whatever discipline they realize has more credibility than their uninformed speculations.

Ultimately, most of these people are trying to defend religious beliefs. Many of them are painfully overt about it — the Bible says we were created in 6 days, or that the Earth is flat and has corners — and openly declare that science is atheistic and not to be trusted. Scratch a creationist or a flat-earther, and you’ll typically find a religious zealot.

Again, that doesn’t imply that they’re stupid. The most effective supporters of their religious beliefs have been smart people who are very good at twisting logic to deliver their predetermined conclusion. Look at Philip Johnson, for instance: a clever, educated man who used lawyerly logic to support an unscientific claim of Intelligent Design creationism, and he was darned effective.

What I’m saying is don’t underestimate your opponents, don’t assume they’re ignorant yokels, but at the same time don’t give them credit for sharing your appreciation of rational, scientific thinking, because that’s not what they’re doing.


  1. Matt G says

    High intelligence is a double-edged sword – it can make you very good at reasoning, and very good at rationalizing.

  2. says

    I have to say that the problem of trusting the scientific consensus is different here than in the case of say, quantum mechanics or cosmology. You don’t need to recreate the observations that led the ancient Greeks to conclude that the earth is a sphere. You just need to realize that there is an airline industry and an international shipping industry and communication satellites and earth observation satellites and 100% of the people who work in those industries know that the earth is roughly spherical and their operations are so configured. Unless you believe that half a billion people are in on the conspiracy.

  3. says

    I would first want to figure out a way of establishing that they really believe that. The easiest explanation for their behavior is not belief, but rather that they are just posturing.

  4. says

    That leads to the difficult question of what “belief” means, though. I think a lot are just knee-jerk anti-establishment fanatics, and a lot of others are professing because they think it’s a part of their deeply held religious beliefs, so where do we say belief is different than pretense? When you are so well known as a defender of the flat earth that Netflix has a documentary about you, where do we draw a line between posturing and a belief so deeply held that they’ll endure immense ridicule to preserve it?

  5. PaulBC says

    How many actual flat earthers exist? (Assuming they have had a grade-school level education about the solar system.) I can’t help thinking it is a contrarian pose rather than an actual belief. On the other hand, I don’t know. If I were betting, I would say that among self-identified flat earthers, actual believers are in the minority. For the rest, it is a shibboleth for identifying like-minded people. (And I sometimes think this is true of nearly any religion, so maybe I’m just wrong and I just don’t get people like this.)

    I agree that it is anti-scientific, as is any practice involving such an extreme degree of motivated reasoning. On the other hand, the earth can be any shape you want it to be, if you make local assumptions about the coordinate system. You can backfit all your formulas to be consistent with your preferred geometry and arrive at conclusions that match the evidence. Because this leads to a far more complex cosmological model, it something ruled out by Occam’s razor.

    But Occam’s razor is really just a heuristic. The simplest explanation is not guaranteed to be “true” and may be contradicted as new information comes in. I prefer to spend less time arguing about “truth” and more about finding the most tractable model consistent with evidence. That is clearly not a flat earth. But taking it all to extremes, I can see how some people find flat eartherism appealing as word game. Again, I wonder how many people really believe it. If I offered to take them on a trip to the great Antarctic ice wall, would they be interested?

  6. Nathan Mauk says

    My impression is that many flat-earthers delight in being contrarian: by defending an outré and unlikely idea they get to portray themselves as brave freethinkers piloting their lonely embattled course against the herd of complacent sheeple (to mix some metaphors). P.Z. is quite right that they, like creationists, put the conclusive cart before the evidentiary horse. But I think a closer analogy would be anti-vaxxers, or better yet the kind of reactionary “skeptics” endemic to contemporary atheism, the sort who defend “race science” and inborn sexual inequality. We see that they’re defending discredited theories against the better evidence, but they see themselves as smashing received pieties. Perhaps most rewardingly, they get the social and ego boost of considering themselves members of a small and superior gnostic elect.

    In other words, don’t be so skeptical your brain falls out.

  7. says

    Well, if you went by ship they would see an ice wall. And if you sailed around it they wouldn’t be able to see whether you were turning left or right. So that probably wouldn’t work. However, if you took them up in an airplane they would be able to see that it is not ring shaped and doesn’t have the rest of the earth inside it. Actually I think that at the highest altitudes reached by commercial airliners the curvature of the horizon is just perceptible. But I suppose they would argue that is some sort of illusion.

  8. whheydt says

    Silly comment first….

    If the Earth were flat, the cats would have pushed everything off the edge by now.

  9. whheydt says

    Now the serious comment…

    But the force of gravity isn’t constant over the surface of the Earth. It is higher near the poles and less near the Equator. There are two related reasons for this. The first is that the Earth is spinning, which generates a (small) outward force that increases the farther one is from the spin axis. The other is that, also because of that, the Earth is an oblate spheroid and at the Equator one is farther from the center of mass than at the poles.

    There are additional minor corrections do to the distribution of mass within the body of the planet, but the factors above are big enough to have actual consequences, and thereby hangs a tale…

    The US Treasury used to use spring scales to measure the weight of Gold ingots. There was a time when shipments of Gold from Alaska to San Francisco were coming up short. Much effort was put into finding out where the extra Gold was disappearing–assumed to be being stolen. Eventually, it traced to the difference in local gravitational acceleration between where the Gold was shipped from in Alaska and where it arrived in San Francisco. The mass hadn’t changed, but the weight had.

    So much for “gravity is the same everywhere” argument.

  10. Matt Cramp says

    I think it’s interesting that flat-earthers, at least some of them, have gone to great effort to design reasonable experiments to test the curvature of the world. The supposition there is not, I think, in the actual theory itself, like it is with creationists, who see a theory that challenges their world view and thus have to find any way to attack it. For flat-earthers, it seems like the supposition is that authorities will pointlessly lie to you just because they can, and the idea that the earth is flat just happens to fall out of that.

  11. ORigel says

    The idea that the Earth is accelerating upward is held by the Flat Earth Society, which most flat-earthers think are trolls.

  12. stroppy says



    Which suggests that maybe their thinking could best be explained in terms of conspiracy theory.

    Just an aside, stupidity appears to be independent of level of intelligence.

  13. Artor says

    If the Earth were accelerating at a constant 1G, in only 10 years, it would reach lightspeed. I would thing someone would have noticed.

  14. Matt G says

    This year is the tenth anniversary of the “First Annual Catholic Conference on Geocentrism,” held near Notre Dame. The tag line was “The Church was Right, Galileo was Wrong.” Not sure if there was ever a second annual conference….

  15. says

    #10: Yes, there’s something going on here. In that “Behind the Curve” doc, for instance, the flat-earthers spent $20,000 on a laser gyroscope that would show there is no angular rotation of the earth — and they were wrong. They didn’t accept the observation, but it says something about their commitment that they would spend that much on a gadget.

  16. says

    @Matt Cramp, #10,

    But when they carried out those experiments and got findings that proved that the earth is round, they denied the results and made up some other stupid thing that supposedly tainted the experiments.

    Even their own proof wasn’t enough to convince them they were wrong.

  17. mnb0 says

    ” I’ve never seen this claim that the flat earth is constantly accelerating upwards”
    The biggest Flat Earth organization in the world has made this:


    So now you can see it.

    “flat-earthers do seem to only be aware of evidence from personal experience”
    Actually they think repeatable experiments important. Cf Samuel Rowbotham in the 19th Century, but on that Tfes wiki you can find more. For physicists they are quite fascinating in a perverse way.
    So I can understand “nor anti-scientific”, though in the end I don’t agree.

    “Where I object is in the idea that their disagreement ought to be taken seriously philosophically.”
    Only as far as making clear why scientists reject theories (one big problem with FET is Ockham’s Razor) and to help determine the Demarcation Line. You yourself take it seriously philosophically starting with “Except there’s a fundamental misapprehension here that …..” (there is quite some psychology involved as well).

    “don’t give them credit for sharing your appreciation of rational, scientific thinking”
    Indeed, but you only can do so by taking them seriously philosophically. That allows us to mock them (intelligent or not) when they claim to do science.

  18. mnb0 says

    @2 Cervantes: don’t understand math. It’s possible to develop a model, assuming a Flat Earth, that addresses the problem you describe. Like I said you have to forget about Ockham’s Razor.
    What’s really a problem is the fact that you can’t see the Southern Cross in Sweden nor the Polar Star in Patagonia. If you ever meet a FETer, ask him (rarely a her). It’s highly amusing.

    @5 PaulBC: “How many actual flat earthers exist? ”
    About ten years ago Flat Earth Society claimed to have 6 000 members.

    @12 ORigel: “which most flat-earthers think are trolls.”
    Interesting. Do you have a source?

  19. consciousness razor says



    Well this is confusing. I want the Earth’s surface to be a real projective plane. Which formulas will give me that, provided that they’re consistent with all of the available evidence?

    Or what if I did want it to be a disk? Or a torus, Klein bottle, sphere? I don’t see how I could get all of these different surfaces for free, using the same empirical evidence.

  20. PaulBC says

    consciousness razor@20

    Find. I exaggerated. But within topological constraints, you can get a variety of geometries and claim one as your “flat earth.”

  21. PaulBC says

    And for example, you might want to offer as a counterexample that you traveled along a great circle and arrived back at the same place. I would just have provide an alternative explanation in which you really turned back rather than following a geodesic. Of course, in 3D space, you really did turn back. It doesn’t seem that difficult. I agree that Klein bottle earthers probably would have a more difficult task, though I’m not convinced it’s insurmountable.

  22. PaulBC says

    @20 Sorry for not clustering my response into a single comment. Anyway (similar to one of the explanations in the OP) just take an https://en.wikipedia.org/wiki/Azimuthal_equidistant_projection as your coordinate system. Then all your geodesics back to the starting point are revealed to be simple backtracking. I’m not sure what this does to the rest of the cosmos, but I’m pretty sure you could get a continuous mapping.

    To some non-Eucliean model of the earth, sure, maybe not.

  23. consciousness razor says



    That would give things that are topologically a sphere, which isn’t all that much variety. (Not a disk, for one thing.) But we’re not just doing topology. We have distances and angles that we can measure. We know it’s not a cube or a tetrahedron, for example. It just doesn’t have features like that.

    You seem to be wedded to the idea that it only comes down to Occam’s razor, that it’s only some notion of “simplicity” which supports the standard cosmological picture rather than every conceivable alternative. I just don’t think that’s right. It’s an empirical question, and the empirical evidence is not consistent with just any old arbitrary math you may feel like writing down. (So the “best” we can hope to do is pick the “simplest” one out of the lot, for some values of “best” and “simplest.”)


    But assuming the South pole is on the boundary (for example), that’s actually a single location — a point, not a very large circle which surrounds the rest of the planet. People have been to the South pole, and they’ve planted a sign, a flag, set up a base nearby, performed lots of scientific experiments, etc. We can measure the distances and angles between things there and elsewhere, and they just don’t conform to what would be observed if the planet were a disk.

    Beyond that, there wouldn’t be different parts of the sky (with different sets of constellations, etc.) which aren’t visible at the same time elsewhere on the planet (at antipodal points, let’s say). A flat disk model also needs to account for evidence like that, but it doesn’t.

    Anyway, you’re “not sure what this does,” so what makes you confident about it?

  24. PaulBC says

    consciousness razor@24

    Look, I was making an intentionally sophomoric point as a brief aside and I am not sure what we are arguing about here. I am confident that if you introduce sufficient epicycles such as adjusting the passage of time and human perception as you move towards the poles, the result is absolutely indistinguishable from the more conventional coordinate system. I am “confident” though I could be wrong. I just don’t see why you’re so confident that I will eventually reach an “aha” moment in which the coordinate transformation is not merely unfalsifiable, but actually provably wrong.

    I could certainly take coordinates x,y,z, and t, mass, force, etc. for a classical dynamic system, make up four new variables with an invertible mapping, rewrite equations of motion, etc. in these terms, develop an isomorphic set of physical laws that would give a different shape to the earth, maybe not flat. I could insist this is the “truth”. I am not merely confident in this. I know it’s correct, though I don’t have the time or motivation to give an example. (And actually sometimes it is useful to make a new coordinate system, such as in system with some constrained degrees of freedom, like a pendulum.)

    We generally consider such an idea sophomoric because it introduces a trivial objection without introducing any new insight. If that’s your point, I agree (which is why I avoided belaboring it till now.)

    You could make the argument that at some point that what I have introduced is not just a model that violates parsimony, but a set of absurd assumptions. I see that primarily as a difference in degree, not kind.

  25. blf says

    On flat spherical society members: A long time ago, when I was in University, the then-society had a rather neat nice-looking “certificate of membership”. Membership cost all of 5$, within many students’s budget. Hence, at my University, there were those neat-o certificates all over the place — not because anyone believed the spheroid is flat — just for the giggles factor and the impressive piece of dead tree. (I myself considered buying a membership, but ultimately did not for reasons I do not now recall.)

    I have no idea how common this was (elsewhere), but it does mean the then-society’s supposedly-impressive / -discouraging number of members was perhaps (probably?) a poor proxy for the actual number of believers, at least at that time. (From memory, the society’s records were all destroyed when the founder’s(?) house-trailer — also the HQ — burned down.)

  26. PaulBC says

    Now I wonder what great circle routes look like in an https://en.wikipedia.org/wiki/Azimuthal_equidistant_projection The equator is just a circle (a real question for cartographers). A route that goes between poles is problematic. You take a line of longitude down to the Great Southern Circle, at which point you must follow it instantaneously to the diametrically opposite point and follow the line back up to the North pole. Other great circles should avoid this singularity, though they will be distorted.

    This is silly and unfalsifiable, but I don’t see how it is inconsistent. I’m not sure about the problem of embedding it in the universe as a whole.

  27. Rob Grigjanis says

    PaulBC @25:


    No, a description in a different set of coordinates doesn’t change the shape of anything. It changes the description. If you want a link to the real world, you still need stuff like standard rods and standard clocks; a metric for your coordinate system which tells you the actual distance (or generalized distance) along any path. It’s the metric which decides the ‘shape’ of your world, not the coordinate system.

  28. PaulBC says

    Rob Grigjanis@28

    Eh, maybe. It seems like a matter of definition to me. I agree that all those standard rods are actually very wiggly. That’s why it is so hard to see the real shape of the earth. (And now I really will shut up.)

  29. kwc20 says

    Why do people believe the Earth is flat?

    Because they are human, and humans have a tendency to do extremely stupid things.

  30. consciousness razor says


    You said that there are some options “within topological constraints,” so I thought that meant you had already conceded that a disk and a sphere are not equivalent, because among other things a disk has a boundary and a sphere doesn’t. Gluing together two disks (e.g., the northern and southern hemispheres) would make a sphere. But that’s not a single disk, as in a flat Earth model … it’s a sphere, which is just what you wanted to avoid. I don’t get what it has to do with coordinates. If you switch from Cartesian to polar coordinates, for instance, you still have either a disk or a sphere, and in either case, you’re just representing that disk or sphere with a different set of numbers. It will not create a physical boundary out of thin air (or make one go away).

    And if you have to fuck around with our understanding of human perception (or memories, etc.) to make all of this work, there comes a point where you’re just rejecting empiricism altogether, because that’s what it is built upon. Note that I’m not appealing to Occam’s razor here. It’s that you can’t honestly claim this is plain old empiricism, because what you actually did was rig up a theory which isn’t using our perceptions/experiences, as they present themselves to us in everyday life (with no extra sciencey/mathematical stuff attached, even when we’re young children or what have you). That sort of theory wants to suggest something else can make up for it, or that it can somehow explain away the empirical experiences we actually have. So you can conjure up vast cosmic conspiracies/coincidences or unshakable collective illusions or whatever, which prevent people from ever observing things as they are. There’s no logical problem with this, but the same can be said of solipsism and so forth, which means it doesn’t really get us anywhere. It doesn’t honestly have that kind of empirical content on closer inspection, because it gives up on all that once it tries to tell some other kind of story about how its claims are supported.

  31. nomdeplume says

    There seems to be something of a trend in bending over backwards to make allowances for fundamentalists, creationists, flat earthers, anti-vaxxers, conspiracy theorists – oh, they really are intelligent, we shouldn’t be mean to them, telling them they are wrong is counter-productive and so on. This approach seems to me to just be encouraging anti-science.

  32. Rob Grigjanis says

    nomdeplume @32: There’s nothing wrong with being mean, but just yelling at them that they’re wrong seems kind of pointless. They might well have beautiful arguments going from A to B to C to D. The problem is convincing them, or the people listening to them, that A is complete bollocks, so the beauty of their arguments is irrelevant.

  33. A Sloth named Sparkles says

    We could keep on how this earth is not flat or vaccines don’t work that way, but at the end of the day, it all comes back to this one thing: lack of trust in institutions, especially scientific institutions.

    Looking back to that one scene in Behind the Curve, where one flat-Earther complains that “NASA are keeping us dumb” we should’ve have seen this growing distrust of every known scientific institutions. The idea that institutions are seen as the establishment, thus holding an alleged monopoly on the sciences, is something to be taken seriously.

  34. aziraphale says

    Every flat-Earth model that I know of has the Sun and the Moon orbiting a few thousand miles up and within the limits of the disc. I have pointed out to flat-Earthers that this has two consequences: the apparent size of the Sun and Moon must vary greatly from point to point on the flat Earth, and it must be impossible for the disc of the Sun or Moon ever to be bisected by a water horizon. Anyone with access to an ocean can verify that the second is false, and any two people with cameras a few thousand miles apart can verify that the first is false. You don’t need to appeal to NASA or the airlines or any other group that might be part of the conspiracy.

    They usually mutter about the laws of optics being wrong.

  35. tacitus says

    Very interesting and timely video just posted on science experts: Who’s Afraid of the Experts? | Philosophy Tube ft. Adam Conover

    Covers a lot of ground – what makes a good science communicator, what happens when the public mistrusts the experts, what happens when people play politics with science, and why some people love to believe in conspiracy theories.

    The video is divided between the interview with Adam Conover and the story of what happened during the 1980s AIDS crisis, drawing on a scary number of parallels with what’s been happening during the current pandemic.

    Well worth a watch.

  36. pengothylacine says

    I really don’t get these people, at all. There are TONS of empirical, personal observations one can do that prove the Earth is round. The Greeks, famously, noticed it by how a ship would disappear over the horizon. Have these people ever been on a plane? Because if you fly transatlantic, and the sky is clear, you can subtle perceive the curvature of the earth. It’s there, and it’s not an effect of the windows, because you don’t see that on the ground. Personally, I kinda think these are people who are just proud to say FUCK SCIENCE. It’s… really unfortunate.

  37. weylguy says

    Dr. Myers, your older readers may remember Bizarro Superman, an offbeat clone of the superhero whose race inhabited the Bizarro World, a perfect cube with eight corners. As youngsters we never considered the fact that the planet’s gravitational field would gradually bring it into a perfect sphere, but then it was all just good fun. It would seem that Flat Earthers, who are similarly ignorant of basic gravitational physics, have yet to grow up.

  38. stroppy says

    Flat Earthers. I can’t help seeing them as people with too much time on their hands stuck for a hobby, sort of a Gong Show for frustrated scientists who are too wimpy for the Society for Creative Anachronism.

    Applying to NASA, Space Cats.

  39. says

    I have to disagree that these people are not stupid for one simple reason. You can ignore all the flat earthers attempts to use scientific language to argue about gravity, density and the rotation of the earth. While they spout ridiculous anti-science bullshit to defend their ludicrous beliefs I think all that is largely irrelevant as to why they are wrong and why they are idiots.

    The simple fact is that we know the earth is round because there is undisputed photographic evidence. For example, the Japanese Himawari satellite is locked into a stationary orbit above New Guinea and takes 144 photographs of the entire planet a day. To deny this evidence you have to be a moron.

    These idiots are also effectively labelling as liars, people such as Neil Armstrong and Buzz Aldrin who have viewed the earth from space.

    I have watched numerous YouTube videos from scientifically literate YouTubers who constantly debunk the flat earth nonsense with actual science and it is clear when you do travel down that rabbit hole what a massive overlap there is between flat earthers and bible literalists (google Nathan Thompson for evidence of just how deranged these people are!).

  40. garnetstar says

    I also disagree that there is not an element of stupidity in such delight in 1)being contrarian at all costs, and 2) self-centeredness and self-importance, in the flat-eath confirmation bias: I have never heard such people speculate about whether other astral bodies are similarly flat. Is the moon flat? Is Jupiter, or Saturn? The Sun, Alpha Centauri? Are any cosmic bodies all the same shape, or do some have different shapes? An actually-inquiring mind would want to know.

    A mind that’s solely fixated on its own emotional satisfaction and enjoyment in being “right” can latch onto anything, I suppose. If QAnon had come along before the flat-earth idea did, I suppose they could have inflated their egos and salved their emotions by investing in that instead.

    And, anyone who wants to clearly see the curvature of the earth should stand at one end of I-90 in South Dakota and look straight ahead. Since there’s nothing in the way, no buildings or overpasses or hills, no curves in the road or even slight deviations from a straight line, nothing at all, you could absolutely see the far border of the state except that the road curves down out of sight.

    These people could do this experiment, but it’s not that it’d take them a long time to re-invent all of science. It’s that they carefully avoid any occasion of acquiring data about their emotionally-cherished beliefs. If they ever drive across South Dakata, they’ll have to keep their eyes shut the entire way, which would be quite a feat. So, they won’t be driving that route much!

  41. garnetstar says

    LOL, this brings up such a wonderful memory: the “debate” between PZ and that crazy guy who thought that carbon atoms are irreducibly complex. He was whining about universities, etc., censoring “unorthodox” scientific views by not hiring Intelligent Design professors, and as an example, proclaimed: “There aren’t any flat-earthers on the science faculties of any US universities!”

    Silence follows, then PZ quietly and slowly asks “And the problem with that is……?”

    So are you shrieking? It always, always, makes me laugh out loud, one of my favorite mic drops ever.

  42. says

    Within the framework of classic Newtonian Mechanics, if the earth were constantly accelerating at 9.8 m/s², it would reach the speed of light in slightly less than a year (~354 days).

    Within the framework of relativity, however, as v approaches c, M approaches infinity and a approaches zero, which also annihilates the ‘constant 9.8 m/s² acceleration’ hypothesis.

  43. Rob Curtis says

    how high do you have to go to be able to see the curvature of the earth?

    First, what do you mean by curvature.

    The curvature of the earth is not the downward curving of the horizon from left to right. it is the downward curving of the earths surface away from you. this is why ships disappear from the bottom as they sail away.

    to see that the horizon is always flat, go someplace outside and do this:

    look at the horizon. now point your arm at the horizon. your arm will make an angle with your torso. if you are standing on the ground, it is nearly 90³. if you are very high up, it will be less than 90°. now turn in a complete circle. your arm will always keep the same angle as you turn, and when you complete one full turn you will be pointing at the horizon. if the horizon were curved, you would have to raise or lower your arm as you turned, so when you completed one full turn, you would be pointing above or below where you pointed when you started. which is not possible. you have to be pointing at the same spot on the horizon, with the same angle.

    the horizon is flat, no matter how high you go. you cannot see the curvature of the earth as a curvature of the horizon.

    in order to see the roundness, the curvature of the earth, you have to be able to see the whole disc of the earth in you field of view. that happens at 1000 km. less if you let yourself turn your head.

    check out this vsauce youtube vid. the curvature part is at about 17 min.

  44. Rich Woods says

    @whheydt #9:


    The example I recall from my distant schooldays was a trade which ran in the opposite direction. In the 17th and 18th centuries Northern European merchants would sail south to Equatorial Africa to buy diamonds mined locally. They would classify the uncut stones into batches and weigh them there, to determine what price they were willing to pay the miners. When they sailed back to England and the Netherlands, though, they would find that the same batches of stones weighed slightly more and happily sell to the diamond cutters on that basis.

  45. GerrardOfTitanServer says

    I still think the best evidence for a spherical earth as opposed to flat earth is airline and waterborne shipping routes. There so many people involved in going long long distances every day, with travel times that are fundamentally incompatible with anything but a spherical Earth. So, it’s either spherical, or every ship captain and navigator and airline pilot in the whole world are in on a conspiracy to make travel times look as if it was a sphere.

  46. Mrdead Inmypocket says

    Flat Earther: “The earth is flat”

    Me: “You’re one of those ‘the earth exists’ establishment tools eh?”

    Asserting contrarian dominance is key.