How do we know the Earth is round?
May 18, 2019 10:09 AM   Subscribe

100 proofs the earth is a globe. David Morgan-Mar, author of the webcomic Darths and Droids and otherwise qualified person, is spending this year posting 100 short essays with different points of scientific evidence/proofs that the earth is round.

Current index of articles, with many more to come:

1. The Blue Marble – What does Earth look like from a distance?
2. Eratosthenes’ measurement – Can we measure the size of the Earth with a stick?
-- 2.a Making Eratosthenes’ measurement
-- 2.b Eratosthenes’ measurement results
-- 2.c Eratosthenes and the flat Earth model
3. Meteor arrival rates – When is the best time to see meteors? And why?
4. Airy’s coal pit experiment – How does gravity change down t’ pit?
5. Horizon dip angle – Is the horizon actually horizontal?
6. Gegenschein – Can we observe an effect of the sun being behind the Earth?
7. Supernova 1987A – How was this event detected all over the Earth?
8. Earth’s magnetic field – Why is it the shape it is?
9. The South Pole – Where is the South Pole on a flat Earth?
10. The Sagnac effect – Can we measure the Earth’s rotation speed at different places?
11. Auroral ovals – Where do aurorae occur, and why?
12. The sun – How far away and how big is it, and does it shine in all directions?
13. Hydrostatic equilibrium – How tall a mountain can there possibly be?
14. Map projections – Why can’t we draw an accurate map of the whole Earth?
posted by LobsterMitten (83 comments total) 58 users marked this as a favorite
 
It’s really come to this, has it?
posted by Segundus at 10:14 AM on May 18, 2019 [31 favorites]


You might say it’s come all the way back around to this. And then you’d be challenged to prove it, for which this list is quite handy.

Circular logic for circular logic? Count me in.
posted by Revvy at 10:20 AM on May 18, 2019 [2 favorites]


Seeing flat-earthers cave in and use magic GPSs to travel is proof enough for this old skeptic.
posted by They sucked his brains out! at 10:22 AM on May 18, 2019 [12 favorites]


How can you even think for half of a second that gravity is a thing that works, and still flat-earth? Conclusion: it’s all a troll.
posted by Mei's lost sandal at 10:38 AM on May 18, 2019 [7 favorites]


Linear logic for globular truths
posted by dis_integration at 10:50 AM on May 18, 2019


....it’s all a troll.

Well, it may have started that way, but it really isn't, for many of the .....whatever they call themselves. They call you a "gravitard".
posted by thelonius at 10:50 AM on May 18, 2019 [4 favorites]


Ya ya, no problem, but with the right straps it's easy to balance a sphere on the back of a tortoise.
posted by sammyo at 10:51 AM on May 18, 2019 [10 favorites]


-- 2.b Eratosthenes’ measurement results [couldn't get the URL given on his site to work properly]
Here
posted by thelonius at 11:00 AM on May 18, 2019


because it's 2019 and idiots don't deserve a platform for their idiot arguments

anyway we should eat them
posted by poffin boffin at 11:03 AM on May 18, 2019 [17 favorites]


Don't let the framing dissuade you; these are really fun!
posted by phooky at 11:04 AM on May 18, 2019 [4 favorites]


Mod note: Updated that link, thank you!
posted by LobsterMitten (staff) at 11:05 AM on May 18, 2019 [1 favorite]


Well, it may have started that way, but it really isn't, for many of the .....whatever they call themselves.

Yep.

Something that's important to keep in mind, here: people believe things for lots of different reasons, but the overarcing theme is that we believe things that we perceive to be useful in some fashion. For many of us, this will lead to valuing science because it gives us things like our GPS or antibiotics or Twinkies. I believe a number of things that make me uncomfortable because I have empirically observed them to work, and I value concrete material results.

In many instances, it will lead to people believing things because those beliefs are emotionally comforting. Believing in a flat Earth makes a certain sort of person feel better about themselves. It makes them a rebel, a truth-teller in the face of The Establishment or whatever other bullshit they're telling themselves.

As for whether they 'truly' believe it: doesn't matter. If they're willing to hurt people over a belief, it is sincere enough to count.

Moving on to the actual post content: that's neat, and I wish we didn't live an age where it feels necessary to be angry about this instead of just enjoying how cool it is that you can figure these things out.
posted by mordax at 11:07 AM on May 18, 2019 [24 favorites]


I think I told this story here before...I was talking to my yoga teacher, and she mentioned that she had conversed with someone who had numerous arguments for a flat Earth, which he had quickly run through, and she seemed genuinely disturbed by this; that there were so many ways to make the case seemed to indicate that there was something to it.....this was disturbing evidence to me that the Gish Gallop works. Like most informal fallacies, it is psychologically effective.
posted by thelonius at 11:13 AM on May 18, 2019 [18 favorites]


Attention paid to the flat Earth foolishness probably encourages them. I admire the fact-based approach, but people who choose to believe the Earth is flat are unlikely to be able to parse facts effectively. My favorite illustration of this is of the solar system, with round Sun, round planets, round Moon, and flat Earth. Sure, makes sense dunnit? I have had the actually awe-inspiring pleasure of looking at the moon, Saturn, and Mars through good telescopes. I see the shadow the Earth makes on the moon, and while in some Bizzarro-Mxyzptlk land they could be disks facing us, it just doesn't make sense.

Thank you for the term Gish Gallop, thelonius, nifty and useful.

We have this amazing planet full of resources and beauty. We have evolved to be able to create and appreciate such cool and great stuff. So Doofuses use that capability to be intentionally, obstinately, stupid.
posted by theora55 at 11:26 AM on May 18, 2019 [3 favorites]


The word 'round' can denote a circle, cylinder, or sphere - - let's hope the flat earthers don't evolve into cylindrical earthers
posted by fairmettle at 11:27 AM on May 18, 2019 [1 favorite]


You know in your heart it's flat.
posted by Nelson at 11:29 AM on May 18, 2019 [1 favorite]


Though the Flat Earthers are upsetting, I love this basic science stuff! Asking really fundamental questions about how we know the things we know can be very enlightening. The explanation of Eratosthenes measurement is awesome.

A few weeks ago I started wondering about why the constant pi is the number it is, and how the ancients calculated it, and the whole thing gives me weird brain tingles every time I’ve come thought about it since.
posted by chrchr at 11:36 AM on May 18, 2019 [7 favorites]


Figuring things out and knowing bits about things has such a way richer payoff than just believing things.
posted by parki at 11:40 AM on May 18, 2019 [6 favorites]


i think there's a certain fraction of people who just can't conceive of things they can't see with their own eyes (and are similarly inclined to believe what they see without critical thinking), and those people will always default to believing what is most convenient for them. in pre-modern times it probably wasn't as evident to others because very little of life depended on advanced technology that worked in non-obvious ways. but i suspect the fraction of people who are disposed to think this way has always been the same. now they're just more visible.
posted by wibari at 11:42 AM on May 18, 2019 [2 favorites]


Thank you for the term Gish Gallop, thelonius, nifty and useful.

I think it's named after a Creationist debater
posted by thelonius at 11:57 AM on May 18, 2019 [1 favorite]


The documentary Behind The Curve is worth watching if you’re interested in what goes on in the mind grapes of flat earthers.
posted by chrchr at 12:06 PM on May 18, 2019 [4 favorites]


How can you even think for half of a second that gravity is a thing that works, and still flat-earth?

There's a direction down and gravity exerts a force along that axis?

I remember being six or seven and watching a Star Trek TOS rerun. The Enterprise flew "underneath" a planet and I thought it was cool and said so. My father, with the Ph.D., got incomprehensibly testy with me because there is below or above in space. I didn't get it.

There is nothing intuitive about gravity working in opposing directions depending on where you stand on a spherical Earth. I think Newton's gravity is about as related to our daily experience of gravity as Einstein is to Newtonian mechanics..
posted by mark k at 12:07 PM on May 18, 2019 [2 favorites]


You can't be reasoned out of a position you didn't reason yourself into.
posted by signal at 12:10 PM on May 18, 2019 [12 favorites]


The documentary Behind The Curve is worth watching if you’re interested in what goes on in the mind grapes of flat earthers.

Currently streaming on Netflix!
posted by Going To Maine at 12:24 PM on May 18, 2019 [5 favorites]


Flat-eartherism is a joke. It has always been. It was the stock joke used to describe if someone is stupid. that's older than the internet. And now it's a meme. The whole flat-earther-sphere is people that think everyone is being too serious all the time. And we really are.
The underlying rationale here is the crux of the problem. That this should be taken seriously. The flat earther has tricked you into taking flat-eartherism seriously. That's the joke. And it's on you. It's a fairly harmless prank if you don't take yourself too seriously. So, don't. The world is still alive. Enjoy it while it lasts.
Also, the world is flat. I mean. Look at the horizon. Come on!
posted by svenni at 12:25 PM on May 18, 2019 [1 favorite]


- Also, this comes from an icelander, and we've had the running joke for 50 years to lie to every foreigner that we all believe in elves.
posted by svenni at 12:27 PM on May 18, 2019 [9 favorites]


FWIW I posted this because I think it's a cool project and the content is interesting in its own right.
posted by LobsterMitten at 12:27 PM on May 18, 2019 [15 favorites]


Flat-eartherism is a joke.

Some people (quite a few?) surely watch because it's funny. But I 100% guarantee that there is a core that thinks it's real and that thinks every government is aligned in covering it up. You don't organize multiple conferences if you think people are only going to show up and laugh.
posted by Going To Maine at 12:29 PM on May 18, 2019 [10 favorites]


FWIW I posted this because I think it's a cool project and the content is interesting in its own right.

This is an admirable attempt to rerail!
posted by Going To Maine at 12:31 PM on May 18, 2019 [15 favorites]


Yeah this is super useful for when my kids ask things like, "But HOW did we know the earth was round before airplanes and manned space flight?"

Like I get Eratosthenes but I definitely need help explaining it! And it's super-neat to be able to DEMONSTRATE some of them and prove it right in your own backyard.
posted by Eyebrows McGee at 12:37 PM on May 18, 2019 [7 favorites]


Flat-eartherism is a joke. It has always been. It was the stock joke used to describe if someone is stupid. that's older than the internet. And now it's a meme. The whole flat-earther-sphere is people that think everyone is being too serious all the time. And we really are.
Maybe it started out that way, but so did Trump. And there are a huge amount of Americans who believe God created the world in 7 days less than 10.000 years ago. And people who believe vaccines cause autism. There is no limit to angry ignorance.
posted by mumimor at 12:44 PM on May 18, 2019 [22 favorites]


This is something I posted last year on the blue:
If you believe in the flat Earth, it also means you believe that over human history millions of people had and are in on the conspiracy. The military, scientists, cartographers, explorers, sailors, pilots, etc. not a single person has revealed the workings of the conspiracy. During WWII both the Allies and Axis agreed not to reveal the truth. During the Cold War, the US and Soviets kept quiet about it. Keeping hidden the knowledge of a flat Earth has transcended all countries' political and military objectives.
posted by ShooBoo at 12:49 PM on May 18, 2019 [4 favorites]


“But HOW did we know the earth was round before airplanes and manned space flight?"

Watching a sailing ship go out to sea on a clear day, you can see the hull gradually sink below the horizon while the sails are still visible. You can see this with the naked eye, but it’s especially apparent with a simple telescope or binoculars. This was well understood in the age of Columbus and probably well before that.
posted by chrchr at 1:06 PM on May 18, 2019 [5 favorites]


I think it's no coincidence that, at a period in history when our everyday activities (driving to the store, flying all over the place, and etc.) are literally destroying the planet at the same time they make our individual lives so much better moment by moment and month by month — though not decade by decade — than they would be if we didn't do them, more people are denying that what goes around actually does come back around even down to the level of basic geometry.

In a sense, everyone in the developed world is (living like) a flat-earther.
posted by jamjam at 1:19 PM on May 18, 2019 [5 favorites]


Watching a sailing ship go out to sea on a clear day, you can see the hull gradually sink below the horizon while the sails are still visible. You can see this with the naked eye, but it’s especially apparent with a simple telescope or binoculars. This was well understood in the age of Columbus and probably well before that.
Yeah, this is an everyday experience in every coastal community, and I was really surprised to discover that there are flat-earthers in places near the ocean. I guess this is an example of how disconnected modern humans are from their sensory experience. (Seafarers have never believed in a flat earth, obviously, since they wouldn't be able to navigate if they did. It's not like the horizon is far away).
When I was a kid I learnt a folk song about "countries beyond the horizon". I've tried to google it, but with no luck. I think it was either Russian or Baltic, in any case from the Baltic Sea which is tiny. If they knew the earth is round, I can't imagine any seafarers who didn't.
posted by mumimor at 1:19 PM on May 18, 2019 [6 favorites]


i think there's a certain fraction of people who just can't conceive of things they can't see with their own eyes

The thing is, the world doesn't look particularly flat. Those who say that the world doesn't "look like it's round" need to explain what they think would look different if it did. I think people's reasons for adopting this sort of nonsense nearly always involve some degree of motivated reasoning. Once it becomes a group, the fact that it is a group belief becomes a motivation in itself, and encourages both entrenchment and proselytisation.

The whole flat-earther-sphere is people that think everyone is being too serious all the time. And we really are.

It genuinely isn't. As has been noted above, although it is doubtless the case (as with most conspiracy theories) that there are different levels of seriousness and affectation, but there are a bunch of people who are definitely as strongly committed as any Birther. Go and listen to the various Oh No, Ross and Carrie! episodes on flat earthers. This isn't just a joke, although it is doubtless frequently that too.

Not believing people who show us who they are is what got us to the point where we're having to have this conversation.
posted by howfar at 1:35 PM on May 18, 2019 [13 favorites]


more people are denying that what goes around actually does come back around even down to the level of basic geometry.

Aaaand the simple (but time-consuming) way to empirically prove this would be to travel in a straight line until you end up back at your starting point.

Which begs the question . . . Why aren't flat earthers inspired to make a trip to the edge of the earth to prove, once and for all, the validity of their theory?

It's not like they lack funding. The movement seems to be large enough to bankroll a Lewis-and-Clark-like expedition into the great unknown, buying whatever supplies, transportation, guides and personnel that might be required.

Not to mention that flat-eathers, at least until recently, are often seen on cruise ships, for crying out loud. Why not arrange a expedition with the cruise company in advance, or, failing that, bribe the captain to step on the gas midway and make a longer voyage?

I remember reading somewhere that they believe that a massive, Winterfell-scale wall lies at the end of the world in the vicinity of--what was it?---Antarctica? If that's the case, it should be trivial to fund an expedition to the base of this wall. What's holding them back?
posted by Gordion Knott at 1:45 PM on May 18, 2019 [5 favorites]


As a person working in academic geography, the correct answer to any flat-earther is "fuck off, I've got work to do." But I never see those. I don't know where they are, or why anyone would seek them out.

Most of our scientific, navigation and communication technologies are predicated on the notion of a spheroidal Earth. It's not so much that we know that the Earth is round, it's that, on a practical level, if our models of the Earth were wildly incorrect (i.e. if the Earth was flat), nothing world work, at all.

It's true of all physical models: Classical Dynamics doesn't correspond perfectly to the behaviour of physical objects, but if it were abjectly wrong, nothing, like nothing would work. All modern technology would be impossible.

Scientific models don't usually fall out of favour until they begin to fail to explain a newly-observed phenomenon, or until they fail to operate on a practical level. So on that level, it's kind of pointless to even think about flat-eartherism, because it doesn't entail any kind of advance over current models. Nothing is doable under the flat-earth hypothesis that isn't doable now, and no more accurate predictions could be made.

Of course I'm ignoring the larger context of Dunning-Krugerism-as-religion, but addressing the particular fallacies inherent in flat-eartherism does nothing to address that.
posted by klanawa at 2:11 PM on May 18, 2019 [8 favorites]


This is going to sound naive, but are there real actual flat earthers? I thought it was just an internet joke / troll. I dunno ... I feel like I’m being had. No one’s that stupid, right?
posted by freecellwizard at 3:10 PM on May 18, 2019 [2 favorites]


This is going to sound naive, but are there real actual flat earthers? I thought it was just an internet joke / troll.

Yes, there are real flat earthers. I have a neighbour who is absolutely dead serious about it. He is also into various other conspiracy theories, sovereign citizen crap, etc. It's all the same paranoid mindset.

Years ago flat earth stuff was mostly people joking and trolling on the internet, but then Poe's law kicked in and it's now largely driven by people either taking it seriously or grifting off those who do.

It's fucking terrifying.
posted by automatronic at 3:35 PM on May 18, 2019 [16 favorites]


Of course the earth isn't flat. There are hills and things.
posted by Kiwi at 3:42 PM on May 18, 2019 [8 favorites]


You know how sometimes parents will tell little kids that if they keep making a funny face, eventually their face will stick that way? Same thing.
posted by Huffy Puffy at 3:50 PM on May 18, 2019 [5 favorites]


These are great.

Serious question: is “if you start traveling east you eventually get back to where you started” not the most simple possible proof?
posted by TheShadowKnows at 3:53 PM on May 18, 2019 [1 favorite]


I wonder if the clipper route (which let you go around the world easier by using the high winds and shorter distances at high southern latitudes) will make the list.

Needed to get to the South Pacific, but having trouble making it around the Horn? You could just go around the other way!
posted by Huffy Puffy at 3:54 PM on May 18, 2019 [1 favorite]


This is a fun exercise and an excuse to write about interesting science topics with an engaging hook. I'm glad it exists. Thanks for sharing it!

It's pretty hard to believe much of it would be compelling to a sincere flat-Earther, though. Take the Supernova 1987A example: to find it convincing, you have to believe that neutrinos exist, that we understand how they interact with matter, that mechanical conservation laws are true, that we understand how the detectors work, and that the teams working on these experiments are telling the truth about what they've built and the data they collected, and that their data weren't tampered with before they saw it.

Even if you buy all of that, you need either quite sophisticated statistics and hours of work, or a willingness to accept on faith that the authors have done the statistics properly to claim that the directional signal can't be a coincidence. Looking at the plot shown, I'd expect many grad students taking qualifying exams to have a tough time answering the question, "why are there so many events from the wrong direction?" As proofs go. . . it's mighty abstract.

I claim to have seen the sun rise from the south pole. Believing in a flat Earth only makes sense if you also assume that I'm part of the conspiracy. In which case, surely the Kamiokande team is too. Convincing a hand full of physicists to lie about 24 neutrino events sounds a lot easier than convincing the entire commercial airline industry to keep an expensive secret for a century.
posted by eotvos at 4:26 PM on May 18, 2019 [5 favorites]


Serious question: is “if you start traveling east you eventually get back to where you started” not the most simple possible proof?

You didn't actually travel east the whole way; you just went in a circle, and Big Globe manipulated all your navigation devices (GPS, maps, compasses, etc.) to make you think you were travelling east the whole way. Or, as soon as no other Flat-Earthers were around, Big Globe kidnapped you and bribed/persuaded/coerced you into joining their conspiracy.

The great thing about conspiracy theories is that you're never wrong; the conspiracy was just even more diabolical than you realized.
posted by J.K. Seazer at 4:34 PM on May 18, 2019 [8 favorites]


I mean, it's easy to believe whatever you want if you dismiss every scrap of evidence as further proof of the conspiracy. I could claim the sky is green and there's nothing you could do to convince me otherwise if I won't even engage with the most basic evidence.
posted by Mr.Encyclopedia at 4:39 PM on May 18, 2019 [3 favorites]


For those surprised to learn there are at least hundreds of apparently sincere people who believe in a flat Earth, I recommend the eight part Oh No Ross and Carrie podcast podcast discussion. (Though, be warned the "experiment" they take part in during later programs is so poorly designed, it's embarrassing. The rest of it is pretty good.)
posted by eotvos at 4:46 PM on May 18, 2019 [2 favorites]


Behind the Curve opens with a guy standing on Double Bluff beach, on Whidbey Island not far from where I live, pointing south to Seattle, and expressing incredulity that he can see the city, and using it as an argument that the Earth is flat. About six months prior, I stood on the same beach, and thought "what a wonderful spot to demonstrate the roundness of the earth" because you can see Seattle, and all the buildings are known heights, and you can see how low they are, and there's a point where you can find the true horizon, so you can do the geometry with simple tools. The beach itself is so flat, and the water often so calm that you can get your head right down to sea level and simplify the math down to one triangle if you like.

What I'm saying is these are great, and David Morgan-Mar is doing a hero's work.
posted by surlyben at 4:48 PM on May 18, 2019 [8 favorites]


If you start traveling east you eventually get back to where you started  [circumnavigation needed]
posted by oulipian at 4:56 PM on May 18, 2019 [4 favorites]


Genial MIT physics teacher Phil Morrison made a great TV science ed series in 1987 called 'The Ring of Truth'. Each topical episode, for all ages, is approached with plain language, humor, and everyday and common-sense evidence.

The episode called 'Mapping' [SLYT] goes through the history of that art, answering the question: how were (fairly accurate) maps of the whole world made long before planes or satellites?

It starts with Phil and his spouse driving a rental-truck stencilled with the name 'Eratosthenes' - discoverer of the Earth's circumference - several hundred miles through Kansas to repeat that evidence. The rest of the episode recreates the history of mapping ... and along the way gently makes its countless points. Splain that !
posted by Twang at 5:02 PM on May 18, 2019 [4 favorites]


If the Earth is flat, where does Santa live, huh?
posted by sjswitzer at 5:13 PM on May 18, 2019 [2 favorites]


What really gets me about the flat earth shit is that the supposed conspiracy is just so pointless.

The moon landings were faked? Well, sure - you'd need the whole of NASA and god knows how many others to be in on it and keep the secret for decades, but there's a believable motivation for the US government to have done so - to "win" the space race against the Russians.

9/11 was an inside job? Again, you'd need a whole bunch of people to be in on it and keep the secret for going on twenty years, but there were plenty of rich and powerful people who stood to gain from creating an excuse to go start some wars in the Middle East.

But flat earth?

You need basically every single pilot, sailor, astronomer, cartographer, geologist and fuck even knows how many other professions - all of them, in every country in the entire world, in all of history for the past several centuries at least, to be in on the conspiracy and never reveal it.

And for all that effort they gain... what, exactly? Why would it be so terrible for anyone to know the truth?

It's just so fucking stupid.
posted by automatronic at 5:14 PM on May 18, 2019 [23 favorites]


The point of the flat earth conspiracy is not that some people believe the Earth is flat. It's the everything else they are willing to believe and have accepted to maintain that core, false idea.
posted by Going To Maine at 5:15 PM on May 18, 2019 [1 favorite]


And for all that effort they gain... what, exactly? Why would it be so terrible for anyone to know the truth?

Some Flat Earthers believe that the purpose of the conspiracy is to conceal what’s on the other side of the ice wall. Some believe that there are extra, paradisaic continents beyond the wall that only the rich and powerful know about.

Others believe that the conspiracy is motivated by a desire to deny the existence of God.

Most Flat Earthers tie their beliefs to some version of Christian fundamentalism, though this is not universal.
posted by chrchr at 5:32 PM on May 18, 2019 [7 favorites]


As a die hard agnostic (can you *prove* god does not exist) there are a number of psychological/sociological conditions that need a lot more serious research, Flat earthers, vaccination deniers, belief in, well anything, Santa Claus (post-three year old), various gods, the One True God (which ever one that is), luck, life after death, pixies, magic, a good ending to GoT.

Mostly those that put children at risk makes it vital to discover a real understanding of the cultural, genetic or chemical cause for the very odd irrational beliefs that seem to be going around. I don't think it's something that can be worked out chatting about in any forum, it needs actual scientific inquiry. And disturbingly increasingly so.

(oh but anyway: TEAM Tortoise, can you prove that the globe is not rolling along on the back of an infinite stack of invisible tortoises?)
posted by sammyo at 5:46 PM on May 18, 2019 [2 favorites]


And for all that effort they gain... what, exactly? Why would it be so terrible for anyone to know the truth?

Sadly, this is often the point in the conversation where the conspiracy theorist brings up The Jews.
posted by rhamphorhynchus at 6:20 PM on May 18, 2019 [7 favorites]


Are there any flat-mooners?
posted by They sucked his brains out! at 9:07 PM on May 18, 2019


Are there any flat-mooners?

Only if they skip squat day.
posted by klanawa at 9:17 PM on May 18, 2019 [5 favorites]


Nah, most think the other planets and the Moon are spheres. It's just Earth that's flat.

I wish I were joking.
posted by Revvy at 11:16 PM on May 18, 2019 [3 favorites]


How can you even think for half of a second that gravity is a thing that works, and still flat-earth?

Don't think they haven't thought of this. Gravity works because the earth is constantly accelerating, as explained here on the Flat Earth Wiki. Somehow, this doesn't entail that we're now traveling faster than light, because Relativity.

I prefer a much simpler explanation though. The earth is flat, but has considerable thickness: that mass pulls in the usual way. Now you might think this would make gravity stronger in the middle of the pancake (the north pole) than at the edges (south pole), but perhaps the edges are flared -- or the composition of the pancake is denser at the edges.
posted by bleston hamilton station at 12:46 AM on May 19, 2019


flat earth is old news. im on fat earth now.
posted by Bwentman at 1:13 AM on May 19, 2019 [5 favorites]


OK, I'll ask a really naive question. The Earth rotates around its own axis, and it also rotates around the Sun. What force is driving this rotation? Is it just left over movement from the rotating cloud of gas, dust etc out of which the Earth was formed?
posted by Termite at 2:47 AM on May 19, 2019


You can see power line towers dip below the horizon in Google Street View at about 30.078311, -90.405531
posted by eustatic at 2:56 AM on May 19, 2019 [1 favorite]


Is it just left over movement from the rotating cloud of gas, dust etc out of which the Earth was formed?

The Earth rotates because of "left over" (inertial) force, and it is in fact slowly slowing down (which is why we have leap seconds). It revolves around the sun because of gravity (rocks were swirling around and slamming into each other until the sun "caught" them in a stable orbit)
posted by dis_integration at 5:35 AM on May 19, 2019 [2 favorites]


You can see power line towers dip below the horizon in Google Street View at about 30.078311, -90.405531

Google is part of the conspiracy. Those pics are Photoshopped. You can tell because pixels.
posted by Thorzdad at 6:47 AM on May 19, 2019 [1 favorite]


Some Flat Earthers believe that the purpose of the conspiracy is to conceal what’s on the other side of the ice wall.

Okay, fine, fine, I'll admit it. Yes, the Earth is flat and yes, we built the ice wall. But it was to keep out the Night King! You wanna tangle with him? FINE, BE MY GUEST.
posted by pelvicsorcery at 9:04 AM on May 19, 2019 [1 favorite]


100 simple proofs for a round Earth isn’t to change the minds of the flat earth crowd but inoculation for everyone else.

Also, it shows that science isn’t knowable only to a select few. Rather, it is available to anyone who takes the time to understand.
posted by Big Al 8000 at 9:26 AM on May 19, 2019 [2 favorites]


FWIW I see the curvature of the earth very easily just about any time I look out the window.

The cloud deck is generally at a certain altitude. If the earth were flat, you would see the cloud deck tending towards a vanishing point right on the horizon, rather like in this video of a single point perspective drawing.

Instead, you can clearly see that the cloud deck dives below the horizon rather quickly, far before it gets to the vanishing points. It's pretty obvious that the cloud deck is going below the horizon after only a relatively few miles, maybe 50-100-150 miles for low-ish cloud decks. Certainly not 1000 miles or the like!

Which you could see rather easily if on an actually flat earth and on, say, a very slight rise or elevation.

Instead, you can see how big the clouds are right above you and how big they are when they are disappearing below the horizon, and this gives you a really direct sense of the distance when they are curving below the horizon.

Again, it's just not that far.

This is a basic fact you need to know to draw something like a simple landscape with clouds.

Like the ship sails slowly disappearing below the horizon, you don't need fancy calculations or measurements to see it. You just need your own vision and sense of distance by comparing like-size things as they get further away.
posted by flug at 9:40 AM on May 19, 2019


Is Earth Actually Flat? has an interesting computer animation of what life would look like closer and closer to the edge of a disc-shaped planet.
posted by They sucked his brains out! at 10:30 AM on May 19, 2019 [1 favorite]


Like the ship sails slowly disappearing below the horizon, you don't need fancy calculations or measurements to see it. You just need your own vision and sense of distance by comparing like-size things as they get further away.

If you live near a big shipping port, you can watch the container ships disappear hull-first over the horizon. It's easier to see with binoculars, but you can see it with just your eyes. Flat-Earthers will tell you it's an illusion, because, I guess, believe your eyes except when you don't.
posted by surlyben at 10:30 AM on May 19, 2019


The difficulty with "things you can easily see" is that, just because you're only aware of one possible (in this case, correct) explanation, doesn't mean there aren't others. This is the sort of logic that gets us evolutionary psychology and Objectivism. On that basis alone, we should be skeptical of it.

The disappearing ship thing could easily be a trick of refraction. If the Sun revolved around the Earth, the sunset would look exactly as it looks now. Etc. A person who doesn't have the means to measure or reason knowledgeably about a phenomenon can arrive at a wrong, but perfectly-reasonable-under-the-circumstances conclusion.

All of us here are relying on the products of a long history of collective scientific endeavour. We aren't reasoning this shit out from first principles ourselves. Which which is why, though for practical reasons we should accept these facts, we should accept them as provisional and proceed with humility.

Will I follow my own advice? Ha! Fat chance.
posted by klanawa at 10:56 AM on May 19, 2019 [3 favorites]


I think it's inevitable that eventually Trump will give a speech where he says "Some people think the world is round, some think it's flat. Nobody knows. There's just no way of knowing." And then that will be a Republican talking point.
posted by happyroach at 11:15 AM on May 19, 2019 [3 favorites]


The bit about how gravity decreases the closer to the center of the Earth you get, with zero gravity at the core, kinda freaks me out. I know there's like no chance of experiencing that for a host of logistical reasons but still.
posted by Aya Hirano on the Astral Plane at 11:35 AM on May 19, 2019


I know there's like no chance of experiencing that for a host of logistical reasons

Not with that attitude!
posted by thelonius at 11:49 AM on May 19, 2019 [2 favorites]


> "If the Sun revolved around the Earth, the sunset would look exactly as it looks now."

Interestingly, current flat-earth ... thought? ... is that the Sun does not revolve around the Earth. It's like a little lamp that circles around in the sky above the flat Earth.

Would the effect such a thing produced resemble sunrise and sunset as they are seen? No. Do they care? So far as I can tell, no.
posted by kyrademon at 12:52 PM on May 19, 2019 [2 favorites]


Nah, most think the other planets and the Moon are spheres. It’s just Earth that’s flat.

I wish I were joking.

Mark Sargent, the lead flat earther profiled in Behind The Curve (though there are surely others who could claim leadership) holds that we are all inside an immense, Truman Show-esque dome with with a projection system that incorporates technology beyond our imaginings. (At least, as of this 11/30/2017 interview.) The moon and sun may be on immense tracks, but the other planets are quite possibly just ghostly images projected at us.
posted by Going To Maine at 12:56 PM on May 19, 2019 [1 favorite]


Dis_integration:

We mostly have leap seconds because the length of a day isn’t exactly 24 hours. In fact the earth’s rotation has, since 1900, slowed by .001 second, meaning 1 second for every 100,000 years or so.
posted by argybarg at 10:43 PM on May 19, 2019 [1 favorite]


I had the idea that historical belief in a flat earth was just a myth put about by some Darwinians to discredit their Creationist opponents, back when that was still a hot topic of debate in the nineteenth century.

https://en.wikipedia.org/wiki/Myth_of_the_flat_Earth :
Russell claims "with extraordinary few exceptions no educated person in the history of Western Civilization from the third century B.C. onward believed that the Earth was flat", and ascribes popularization of the flat-Earth myth to histories by John William Draper, Andrew Dickson White, and Washington Irving.
Then trolls just ran with it, and sucked in others who already wanted to believe in a Conspiracy of Science vs intuitive reality.
posted by ver at 12:42 AM on May 20, 2019 [3 favorites]


Something that doesn't seem to get much attention in the resurgence of flat-earth ignorance is that it's also one of the social fissures that Putin is using to drive wedges into and undermine society and western nations. (It appears in the Twitter dump of IRA disinformation posts.) So at least one of the reasons that more people are falling into flat-earthism is that other people are being paid to suck vulnerable people into believing their fellow citizens are working against them, because divided we fall.
posted by anonymisc at 4:56 PM on May 20, 2019 [1 favorite]


This is going to sound naive, but are there real actual flat earthers?

Yes, you'll find them under the people who go on about "Jewish science" and "cultural marxism" and "moral relativity" and such.

Being a flat earther is a symptom of being a nazi, a warning sign if you will. Because flat eartherism ask ou to swallow as many impossible things as antisemitism does.
posted by MartinWisse at 11:00 PM on May 20, 2019 [1 favorite]


We mostly have leap seconds because the length of a day isn’t exactly 24 hours. In fact the earth’s rotation has, since 1900, slowed by .001 second, meaning 1 second for every 100,000 years or so.


A NASA sponsored PDF gives the rate of day lengthening as .0024 seconds/century over the last 70 million years.

That could be out of date, but if the .001 seconds/last 120 years figure is correct, it would be interesting to know why the rate of slowing is so much less than it used to be.
posted by jamjam at 1:24 AM on May 21, 2019 [1 favorite]


How do you know it's not round?
posted by ddra90n at 10:04 AM on May 23, 2019


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