How do you know the Earth is round?

flannel jesus January 10, 2025 at 15:09 4725 views 91 comments
I'm not a flat earther, but I do think the flat earth conversation is an important one to ponder philosophically.

One approach to "what shape is the earth?" is "Scientists and experts say it's round, and video footage shows it round, so I believe it's round", and there's all sorts of philosophical conversations one could (should, even) have about if and why we should trust expertise.

However, I believe the question of the shape of the earth is one where we can actually kinda go along with the flat earthers in rejecting expertise entirely, and say "no, no really, how can I personally demonstrate the shape of the earth?" Not all questions are within the grasp of the average person, but I believe the shape of the earth is. It's a difficult enough question for someone to answer on their own that it's interesting to talk about, and yet, I believe, not so difficult that we can't even try and have confidence in our answers.

So, if you were challenged, someone said "Don't rely on any experts, scientists, NASA photographs -- prove yourself that the earth is round," what do you do? Don't look up the answer, try to come up with one yourself.

Comments (91)

Dawnstorm January 10, 2025 at 15:18 #959517
Travel in one direction until you end up where you start. (Unless you think the flat Earth was Pacmanesque warp points?)
flannel jesus January 10, 2025 at 15:23 #959519
Reply to Dawnstorm great idea! What's your preferred method of guaranteeing you're travelling the same direction? Even a slight angle off from 'straight' could lead you in a circle on a flat earth.
wonderer1 January 10, 2025 at 15:40 #959523
Reply to flannel jesus

Measure the length of a sundial's shadow at noon at different latitudes.

Shoot a laser horizontally across a large still lake to measure the curvature of the lake's surface. There was a documentary on flat earthers (I think on Netflix) where this was done, but the flat earthers dismissed the results falsifying a flat earth.
Philosophim January 10, 2025 at 15:44 #959524
First, we can take the claim of scientists and experts and test them ourselves. We can test with measuring shadows like in ancient Rome. We can test by finding flat land and assessing when the visibility of distant objects should vanish according to predicted angles. We can attempt to travel around the world ourselves.

The question of "Pondering flat Earthers" can be more abstractly applied to, "How can we verify our trust in authority?" Good authority will tell you how they arrived at their conclusions and let you test it yourself. Bad authority will refuse to divulge their methods, or proper testing will reveal flawed results.
flannel jesus January 10, 2025 at 15:46 #959526
Quoting Philosophim
We can test by finding flat land and assessing when the visibility of distant objects should vanish according to predicted angles


The weird thing I've discovered with this is that there's actually a bit of an unexpected result here (at least, unexpected to me) -- you can actually see a little bit more than you would expect if you just considered the geometry of the globe. Have you heard of this?

https://sciencemeetsfiction.com/2020/12/22/flat-earth-challenge-follow-up-refraction/
jkop January 10, 2025 at 15:49 #959529
Quoting flannel jesus
prove yourself that the earth is round


The earth's curvature is visible wherever there's a visible horizon. What's an example of a place from which the Earth could appear flat? Is there good reason to doubt that the curvature that we can see does not imply a round shape?
flannel jesus January 10, 2025 at 15:51 #959530
Quoting jkop
The earth's curvature is visible wherever there's a visible horizon


That's not my experience. Go to the beach, look out to sea, it looks pretty flat to me. Take a photo, I'm pretty sure it's not visibly curved.

Does this look curved to you? It doesn't to me.
noAxioms January 10, 2025 at 15:56 #959532
1 Go up in one of those tourist rockets or even a good airplane. It gets high enough to see the curvature.

2 Learn ocean navigation. One can tell where one is on a globe given visibility to sun/starts and a good clock. Can't do any of that on a flat Earth. It was the sea people that first knew the Earth was round, and also how big it was. Interesting that Columbus, the original BS artist, had to convince those loaning him his boats, that it was smaller than what was measured. He knew his stuff, but he was looking for somebody with boats but without the smarts. Yay Portugal!

3. Not a personal test, but look at airplane schedules. Surely the guys in it for a buck are not in it to perpetuate the hoax.
flannel jesus January 10, 2025 at 15:59 #959534
Reply to noAxioms

Tourist rockets? Like the one jeff bezos went up in? Is there something affordable for a normal person?
Philosophim January 10, 2025 at 16:00 #959536
Quoting flannel jesus
Have you heard of this?


Sure, I'm quite sure the specifics of it are going to be slightly different from my example. My point is the same: Look at how the experts formed their answer, then try it yourself.
flannel jesus January 10, 2025 at 16:02 #959537
Reply to Philosophim

Absolutely. It's just interesting that, if the earth were the size oficially claimed, you would actually expect to see less than you do - that's something that a lot of flat earthers notice, it gives them ammo. "I can see more of chicago than I geometrically should if you were right". They're actually right about that.
noAxioms January 10, 2025 at 16:05 #959538
Quoting flannel jesus
Tourist rockets? Like the one jeff bezos went up in? Is there something affordable for a normal person?

It costs about the price of a normal house. I could afford it if I had different criteria about how my earnings are best spent.

No comment on the other two? Both are pretty easy and less expensive.
flannel jesus January 10, 2025 at 16:06 #959539
Reply to noAxioms definitely less expensive. I don't think sailing around the world is easy!
noAxioms January 10, 2025 at 16:08 #959540
Quoting flannel jesus
I don't think sailing around the world is easy!

Don't need to. Just be in a few different places, enough to show the curvature. You do need to leave home, something not necessary for option 3.
Philosophim January 10, 2025 at 16:08 #959541
Quoting flannel jesus
Absolutely. It's just interesting that, if the earth were the size generally claimed, you would actually expect to see less than you do - that's something that a lot of flat earthers notice, it gives them ammo. "I can see more of chicago than I geometrically should if you were right". They're actually right about that.


Ever heard of the saying, "Enough knowledge to be dangerous?" The problem with the flat Earthers is they're only taking one part of the equation and not factoring in refraction. Here's an example:

I believe I can't survive under water for more than 10 minutes. I go to a deep diving class and read up to the point that says, "Deep sea divers can survive anywhere from 30-60 minutes underwater..." "Rubbish!" I say. I hold my breath until I pass out. I cite scientific information about brain damage from patients who lack oxygen for 15 minutes. But what I didn't do was continue to read the rest of the sentence on the scuba diving page. "...with a working air tank and diving gear."

Yes, I'm right that people cannot survive 60 minutes without air. But I'm not right people with proper air tanks can't survive underwater for 60 minutes. So again, the flat Earthers are either being willfully ignorant, or refusing to understand the entire justification of the argument for why the Earth is round when observed from X distance away.

Dawnstorm January 10, 2025 at 16:15 #959543
Quoting flannel jesus
What's your preferred method of guaranteeing you're travelling the same direction?


Try lots of times, and if you never find the edge of the world... (It's not practical anyway, since you need to fly. This means you need to make a pilot license, and then you'd need to trust your instruments...)
flannel jesus January 10, 2025 at 16:16 #959544
Quoting Philosophim
Ever heard of the saying, "Enough knowledge to be dangerous?"


Indeed! There's just a bit of a trap around the hole 'seeing stuff beyond the curve' question because of this. If you went in not knowing about refraction, you would think you've just proven that the earth is flat.

And if we're not relying on expert opinions, we might have to prove refraction too. I'm not sure how that proof would go.
Srap Tasmaner January 10, 2025 at 16:17 #959545
Quoting flannel jesus
The earth's curvature is visible wherever there's a visible horizon — jkop


That's not my experience. Go to the beach, look out to sea, it looks pretty flat to me. Take a photo, I'm pretty sure it's not visibly curved.


Dan Olson has done the test for you:

flannel jesus January 10, 2025 at 16:21 #959547
Reply to Srap Tasmaner that is over an hour long. I assume I don't have to watch over an hour of content to find out if the horizon of the sea visually looks flat or not. Do you have a timestamp to the part you think is relevant?
Srap Tasmaner January 10, 2025 at 16:23 #959548
Reply to flannel jesus

That covers the whole flat earth cultural thing. He made a companion piece just about the experiment:

flannel jesus January 10, 2025 at 16:29 #959549
Quoting Srap Tasmaner
That covers the whole flat earth cultural thing


Ah okay, the context you quoted made it seem like there was some specific claim in the video about the (un)flatness of the horizon.

This isn't that, this video is more a general reply to the op.
Srap Tasmaner January 10, 2025 at 16:33 #959552
Quoting flannel jesus
this video is more a general reply to the op


And a reply to things "looking pretty flat."

Dan Olson happens to live not too far from a perfect spot to test whether the earth is curved or flat, a very long straight lake. He's just an ordinary guy who makes videos and is capable of being careful and thorough. More or less exactly what you said you wanted.

He looked. The earth is not flat. Case closed.
flannel jesus January 10, 2025 at 16:34 #959553
Reply to Srap Tasmaner so he does disprove that the horizon looks visibly flat to the naked eye in that video? So... where's the time-stamp for that?
Christoffer January 10, 2025 at 16:37 #959556
Quoting flannel jesus
However, I believe the question of the shape of the earth is one where we can actually kinda go along with the flat earthers in rejecting expertise entirely, and say "no, no really, how can I personally demonstrate the shape of the earth?" Not all questions are within the grasp of the average person


Yes it is, you can test it yourself. You can just walk the footsteps of everyone who was able to measure the curvature of earth before we had rockets that went into space. You can use telephoto lenses yourself etc. Without it being out of reach for a common citizen. The folding ideas video is a good example of this.

I think the major problem with all this is that people aren't questioning or are critical of scientific facts because they've measured anything. Their beliefs are rooted in the laziness of never looking for actual answers and facts themselves.

They operate on pure belief, no different from religion.

The reasons for them doing so comes not from a genuine interest of what is true or not, but the emotional foundation of wanting to be better than others. And without education or intellectual capacity, they are jealous of scientists and experts. So they form a cognitive bias in which they manifest a truth of their own making that contradicts what experts say about some specific thing, in order to feel like they're the ones in the know and everyone else is stupid.

It's basic Dunning Kruger biases forming.

It is never about earth being flat, it is about people feeling lost in a world in which experts dominate the consensus of truth. These kinds of cognitive limitations are the basis for all forms of populism, it's the basis for MAGA and other extreme movements around the world (pun intended). People find a family and social structure within these groups as they don't feel welcome anywhere else.
Christoffer January 10, 2025 at 16:37 #959558
Quoting flannel jesus
so he does disprove that the earth looks visibly flat to the naked eye in that video? So... where's the time-stamp for that?


I recommend watching it in its entirety. It's very thorough about the whole thing and the people believing earth is flat.
flannel jesus January 10, 2025 at 16:38 #959560
Quoting Christoffer
Yes it is, you can test it yourself. You can just walk the footsteps of everyone who was able to measure the curvature of earth before we had rockets that went into space. You can use telephoto lenses yourself etc


Judging by how you cut off my quoted post, and your subsequent response, I think you missed the part where I explicitly said that THIS question is within the realm of a normal person. I think you got mixed up in what I said there.
flannel jesus January 10, 2025 at 16:39 #959561
Quoting Christoffer
I recommend watching it in its entirety. It's very thorough about the whole thing and the people believing earth is flat.


I would love to, it looks like a really interesting video. It was linked in a very specific context though - the context was, someone claimed that the horizon is visibly curved, and I'm doubting that.

I'm 100% sure that the video is a great reply to the OP. What it ISN'T a great reply to, is the quote of the conversation it was given as a reply to, which was specifically about the apparent visibility of the curve of the horizon.
Christoffer January 10, 2025 at 16:40 #959562
Quoting flannel jesus
Judging by how you cut off my quoted post, and your subsequent response, I think you missed the part where I explicitly said that THIS question is within the realm of a normal person. I think you got mixed up in what I said there.


Oh, sorry, my bad. However, the rest of my answer is about why they don't do it.
Srap Tasmaner January 10, 2025 at 16:40 #959563
Reply to flannel jesus

For the second video I posted, the first five minutes goes over his camera setup and the math he is going to be checking. He explains exactly what measurements he will confirm or disconfirm in the video. The entire rest of the video is just a whole bunch of the footage he shot for the first video.

If you watch for a few minutes, you can see the curvature of the earth perfectly clearly.
Christoffer January 10, 2025 at 16:41 #959564
Quoting flannel jesus
I'm 100% sure that the video is a great reply to the OP. What it ISN'T a great reply to, is the quote of the conversation it was given as a reply to, which was specifically about the apparent visibility of the curve of the horizon.


I'm just giving a note on that. I've seen the whole thing and it's a really good video. All of Folding Ideas' videos are masterfully done arguments.
flannel jesus January 10, 2025 at 16:41 #959565
Reply to Christoffer No worries, at least we can agree - this is within the grasp of most people to figure out!

Most flat earthers believe that the earth is also 6000 years old. I'm not that concerned with their psychology to be honest, I'm more concerned with honest thinking peoples approaches to how they'd demonstrate it.
flannel jesus January 10, 2025 at 16:45 #959567
Quoting Srap Tasmaner
If you watch for a few minutes, you can see the curvature of the earth perfectly clearly.


I watched that second video and cannot see anything like that.
flannel jesus January 10, 2025 at 16:51 #959568
Here's a write-up on why the curvature of the earth is not visible to the naked eye when looking at, say, the horizon of the sea at a beach.

https://flatearth.ws/standing-on-a-beach

There IS a slight curve, but it's proportionally so tiny that you can't discern it. The apex of the curve is only 0.01% higher -- I don't think anybody can honestly say "that curve is clear".

It's there, but you'd genuinely have to have super-human vision to perceive it.
Philosophim January 10, 2025 at 16:56 #959569
Quoting flannel jesus
If you went in not knowing about refraction, you would think you've just proven that the earth is flat.


No, you would have proven that the world is less round then the experts listed. Again, proven off of incomplete information. Testing refraction is the same. Look up how the experts proved refraction, then test yourself.

There is also one other thing you're forgetting. Flat Earthers would also need to prove the Earth is flat. If they are discounting experts due to a lack of physical evidence, they have to discount their own claims due to a lack of physical evidence as well. Deciding, "I don't trust the scientists, but its flat because I say so," is just ignorance masquerading as skepticism.
flannel jesus January 10, 2025 at 16:58 #959570
Quoting Philosophim
Flat Earthers would also need to prove the Earth is flat


Flat earthers don't often like to prove anything. They don't even tend to make clear claims. I saw a flat earther recently claim they can triangulate the distance of the sun (because no way is it over 90million miles away) -- but one thing I've never seen a flat earther do is *actually triangulate the distance of the sun*. That's because actually making specific claims takes bravery and integrity. You're putting yourself at risk of being wrong.
Srap Tasmaner January 10, 2025 at 17:00 #959572
Quoting flannel jesus
I watched that second video and cannot see anything like that.


It does work better as a companion to the first video.

The basic idea is that he has his camera mounted on a jib so that he can raise and lower it. At maximum height, you can see the far shore of the lake, which is like 7 km away, I think; when you lower it closer to the water, the far shore disappears. It disappears because it is now below the horizon. That's the math he explains in the second video.

I don't know what else to tell you.
noAxioms January 10, 2025 at 17:01 #959573
Quoting flannel jesus
"I can see more of chicago than I geometrically should if you were right". They're actually right about that.

I've been at the sand cliffs on the eastern short of lake Michigan. Interesting place. Houses fall down it now and then, inevitably. You can stand at the edge of it and the wind is enough to turn your eyelids inside-out, but step back 3 meters and you can set up a table and play cards.
Yes, refraction lets you see further than geometry suggests, but nowhere near as far as the flat Earth would suggest. You should see Chicago from my cliff instead of a very visible sky against water.

I personally can barely make out the curvature looking out over the Hudson river, from a vantage right at sea level, about 160 km inland. There are places you can look a long way, enough that the boat bottoms disappear behind the water, if not the horizon which is the hills in the distance. Maybe you can write that off as refraction in the other direction. Takes a good clear day to do this. This all sounds like a similar observation at the lake in the video, but without any actual instruments.

Quoting Srap Tasmaner
If you watch for a few minutes, you can see the curvature of the earth perfectly clearly.
Seemingly with the benefit of drawing straight lines onto the image. I have no such benefit when gazing at the Hudson.


Quoting Philosophim
So again, the flat Earthers are either being willfully ignorant, or refusing to understand the entire justification of the argument for why the Earth is round when observed from X distance away.

I would say 'willfully misleading'. I seriously doubt that flat earthers actually believe their own schtick. The whole point to buck the consensus. One of their advertisements urged you to join the flat-earth society. "We have members from all across the globe".

Quoting flannel jesus
And if we're not relying on expert opinions, we might have to prove refraction too. I'm not sure how that proof would go.

And that's the general question, having many of the same issues as solipsism: How can any external information be trusted? How much science could one demonstrate (not prove) if one had knowledge of the goal, but one still had to start from scratch? You probably could demonstrate Newtonian physics without too much reliance on prior expert work. The moon landing real? Not a chance, especially with all the doctored photos they published. But just because they're faking the photos doesn't mean they weren't there. The footage still looks better than the best stuff hollywood puts out today, and they didn't have AI to deep fake it back then.

Quoting Christoffer
I think the major problem with all this is that people aren't questioning or are critical of scientific facts because they've measured anything. Their beliefs are rooted in the laziness of never looking for actual answers and facts themselves.

There you go! It seems that a great deal of people with crazy personal ideas that are claimed to be their actual beliefs, seem to justify them via avoidance of actual evidence. Humans are not by nature rational, but they're probably the best species at rationalization. Answer first. Weak justification if one actually feels the need. Ignore anything contradicting.

Quoting flannel jesus
Most flat earthers believe that the earth is also 6000 years old.

Fantastic example of rationalization as opposed to rational. Most of the churches have abandoned this assertion by now, but per last-tuesdayism, it cannot be falsified by empirical evidence.
flannel jesus January 10, 2025 at 17:01 #959574
Reply to Srap Tasmaner Well none of those words relate to visibly seeing the horizon curving. You could tell me, "yes, I understand that you can't visibly see the horizon curving". That would be cool.
Philosophim January 10, 2025 at 17:01 #959575
Quoting flannel jesus
Flat earthers don't often like to prove anything. I'm not that concerned with their psychology to be honest, I'm more concerned with honest thinking peoples approaches to how they'd demonstrate it.


For the actually honest person without psychological issues that wishes to prove the world is round, there are a host of resources to do so. The people who insist the Earth is flat are mostly deluded people who elevate what they want to believe over truth and facts. Most people do this to a certain extent, but are eventually willing to bend once the evidence clearly shows their belief is wrong. These people are so deep into this that they are unwilling to bend to any evidence that is contrary to their beliefs.

Its mental illness at that point. You cannot reason with mental illness, nor can you reason with someone who refuses to enter into reasonable discourse.
flannel jesus January 10, 2025 at 17:03 #959576
Quoting noAxioms
There are places you can look a long way, enough that the boat bottoms disappear behind the water, if not the horizon which is the hills in the distance. Maybe you can write that off as refraction in the other direction


They actually do write it off that way, funnily enough.
jkop January 10, 2025 at 17:21 #959579
Quoting flannel jesus
I'm pretty sure it's not visibly curved.


How can you be sure? The curvature might be too small to notice, say, if you only see a narrow piece of the horizon, but I'm pretty sure it's curved, also visibly if you'd look closer.

Compare it with seeing the complex tangle of shapes, textures and colours of a birch tree. You might not pay attention to all of them, yet they are there, visible, and they are the object of your visual experience.

flannel jesus January 10, 2025 at 17:26 #959580
Quoting jkop
How can you be sure? The curvature might be too small to notice, say, if you only see a narrow piece of the horizon, but I'm pretty sure it's curved, also visibly if you'd look closer.


It's been calculated to be imperceptibly small. If your view of the horizon from a beach front is x "pixels" wide, so to speak, the curvature of the horizon is 0.01% of x - as in, the number of pixels the apex of the curve is above the lowest point of the curve is x times 0.0001. That's 1 pixel of rise for every 10,000 pixels of width of an image. I linked the article calculating it on the previous part of the page.

I do not believe you can actually perceive it. I know I can't - I go to the beach pretty often, I see the horizon a couple times a month, and there's no apparent curve from a vantage point of 6-8ft above sea level.

edit. link here: https://flatearth.ws/standing-on-a-beach
Paine January 10, 2025 at 17:32 #959582
On a large body of water or the ocean located next to a tall treeless hill, embark perpendicular to the shoreline after placing large brightly colored flags every 10 feet up the hill. As you get further from shore, the flags will sink out of sight. The first will disappear at around 3 to 4 miles.
flannel jesus January 10, 2025 at 17:33 #959584
Reply to Paine Yeah this is a good one. I saw an image with something like telephone poles curving down over the horizon.
flannel jesus January 10, 2025 at 17:37 #959585
Reply to Paine this is the image I'm thinking of

https://www.google.com/search?q=telephone+poles+over+sea+horizon+curve&client=firefox-b-1-d&sca_esv=16501dcb6f6c1178&udm=2&biw=1280&bih=559&sxsrf=ADLYWIIcaNJt_9jG3BosNMEDH2Fk0C-DlQ%3A1736530546173&ei=clqBZ52lCsaehbIPsf2l0Qc&ved=0ahUKEwidpuKy2OuKAxVGT0EAHbF-KXoQ4dUDCBA&uact=5&oq=telephone+poles+over+sea+horizon+curve&gs_lp=EgNpbWciJnRlbGVwaG9uZSBwb2xlcyBvdmVyIHNlYSBob3Jpem9uIGN1cnZlSJIKUI0DWLoJcAF4AJABAJgBQKAB5QKqAQE2uAEDyAEA-AEBmAIAoAIAmAMAiAYBkgcAoAeOAg&sclient=img#vhid=RmI4MnBl40TscM&vssid=mosaic
jkop January 10, 2025 at 18:50 #959602
Quoting flannel jesus
I do not believe you can actually perceive it. I know I can't - I go to the beach pretty often, I see the horizon a couple times a month, and there's no apparent curve from a vantage point of 6-8ft above sea level.


Granted there's an angle of view from which a visibly curved object may look straight. Its straight look arises from the angle of view, unlike its curved look which arises from its true shape. That's why it's called curved.

Like "scientific" skeptics about perception, also "unscientific" flat-earthers fail to distinguish between what an object may look like and its true visible shape.
flannel jesus January 10, 2025 at 19:14 #959615
Quoting jkop
Like "scientific" skeptics about perception, also "unscientific" flat-earthers fail to distinguish between what an object may look like and its true visible shape.


Kind of like what you did when you claimed you could just see the curve
jkop January 10, 2025 at 20:40 #959621
Quoting flannel jesus
Kind of like what you did when you claimed you could just see the curve


No, my claim is that the curve is visible, and that its straight or flat looks are features of some angles of view. We could limit our visual field to a vanishing point on the horizon, which is a feature of central projection, not the observed object. The vanishing point is not a visible object, nor are the straight or flat looks of the earth.
LuckyR January 10, 2025 at 20:40 #959622
Listening for the flat earthers declaring where the edge of the flat surface is located, yet hearing silence.
Arcane Sandwich January 10, 2025 at 20:45 #959624
I'm trying to think of a Moorean answer to the OP's question but I can't think of any. That doesn't necessarily mean that there aren't any. Moorean answers, that is.
Banno January 10, 2025 at 21:24 #959634
Reply to flannel jesus

Choose a clear cool day and take a strong pair of binoculars or a small telescope to the headlands to watch a ship sail over the horizon. You will not see the ship shrink to nothing, but sink until at last the superstructure disappears.

Observe a number of lunar eclipses. The shadow of the Earth on the moon is always curved, both at the start and the end of the eclipse.

Consider how many other of your beliefs would have to be false if the world were indeed flat. And how many navigators would have to be in on the conspiracy.

But most especially, why not look up the answer, why doubt the consensus view, why think that your own experiences should have a primacy that is beyond doubt? Think about the attitude that folk take into a discussion such as this - are they looking to disprove their existing view, or just to confirm it? What, for them, counts as a disproof?

Becasue no evidence ever forces you to a particular position. There are always auxiliary hypotheses that you can employ to prevent your pet doctrine from being falsified. For some, the cup really contains the blood of Christ, despite all the evidence to the contrary. At some stage you, and only you, must decide what to believe, and that is about you, not about the way the world is.

Arcane Sandwich January 10, 2025 at 21:40 #959640
Quoting Banno
Choose a clear cool day and take a strong pair of binoculars or a small telescope to the headlands to watch a ship sail over the horizon. You will not see the ship shrink to nothing, but sink until at last the superstructure disappears.

Observe a number of lunar eclipses. The shadow of the Earth on the moon is always curved, both at the start and the end of the eclipse.

Consider how many other of your beliefs would have to be false if the world were indeed flat. And how many navigators would have to be in on the conspiracy.

But most especially, why not look up the answer, why doubt the consensus view, why think that your own experiences should have a primacy that is beyond doubt? Think about the attitude that folk take into a discussion such as this - are they looking to disprove their existing view, or just to confirm it? What, for them, counts as a disproof?

Becasue no evidence ever forces you to a particular position. There are always auxiliary hypotheses that you can employ to prevent your pet doctrine from being falsified. For some, the cup really contains the blood of Christ, despite all the evidence to the contrary. At some stage you, and only you, must decide what to believe, and that is about you, not about the way the world is.


Ok, this could be a Moorean answer in some sense. And Moorean answers tend to be correct. Perhaps not due to the right reasons, but Moorean arguments tend to have true conclusions. Just gotta make sure that the premises are also true, and that the reasoning is deductive.
Wayfarer January 10, 2025 at 21:45 #959643
Quoting flannel jesus
"Don't rely on any experts, scientists, NASA photographs -- prove yourself that the earth is round," what do you do?


Find a large area of flat terrain (here in Australia that is not difficult.) Point to a feature on the horizon of said area. Drive to that feature and observe it is no longer on the horizon. More or less the same argument as in @Srap Tasmaner's video.

An aside. Eratosthenes of Cyrene (c. 276 BCE–c. 194 BCE) was an ancient Greek philosopher who calculated the circumference of the Earth with remarkable accuracy using differences in shadow lengths. Here's a brief outline of his method:

Observing Shadows: Eratosthenes knew that in Syene (modern-day Aswan, Egypt), the Sun cast no shadow at noon on the summer solstice, as it was directly overhead (evidenced by sunlight reaching the bottom of a well). However, in Alexandria, some 800 kilometers north, the Sun did cast a shadow at the same time.

Measuring the Angle: By measuring the angle of the shadow in Alexandria, Eratosthenes determined it was approximately 7.2 degrees, or 1/50th of a full circle.

Calculating the Earth's Circumference: Eratosthenes reasoned that if the Earth were a sphere, the arc between Syene and Alexandria corresponded to 1/50th of the Earth's total circumference. Knowing the distance between the two cities (measured through caravan travel), he multiplied this distance by 50 to estimate the full circumference.

Result: His calculation, about 40,000 kilometers, was astonishingly close to the modern measurement of the Earth's circumference.
Banno January 10, 2025 at 21:57 #959649
Quoting Wayfarer
Find a large area of flat terrain (here in Australia that is not difficult.) Point to a feature on the horizon of said area. Drive to that feature and observe it is no longer on the horizon.


Did you leave something out here?

Find a tower on a large salt plain. Drive away from it and you will notice that the bottom of the tower disappears below the horizon. Did it just go below a slight rise, previously unseen? That's the reason for using a body of water, which could not have a "hill" in it.
Arcane Sandwich January 10, 2025 at 22:09 #959655
Quoting Banno
That's the reason for using a body of water, which could not have a "hill" in it.


Why are you using scare quotes? Honest question, genuinely curious. Like, just say it: a body of water cannot have a hill in it. It has waves. And a hill is not a wave.
Paine January 10, 2025 at 23:09 #959664
Reply to Arcane Sandwich
I read the quote marks to refer to the problem of barely perceptible changes of grade. Salt flats are even enough to permit driving over at very high speeds. But that is not as reliable a measure of continuity as a fluid that seeks its own level.

It is true that waves involve local variations but average out in the limits of the visible. These observations are best made while not experiencing a tsunami.
Arcane Sandwich January 10, 2025 at 23:29 #959668
Quoting Paine
I read the quote marks to refer to the problem of barely perceptible changes of grade.


Sure, so did I. That wasn't my point though.
ssu January 11, 2025 at 07:27 #959731
Quoting flannel jesus
So, if you were challenged, someone said "Don't rely on any experts, scientists, NASA photographs -- prove yourself that the earth is round," what do you do? Don't look up the answer, try to come up with one yourself.

Go to the ocean shoreline on a clear sunny day and look at how outgoing ships simply "sink" into the horizon and incoming ships emerged from the horizon. If the Earth would be flat, the ships would just get tinier and tinier.

User image

And this is why there's a very common "submarine sighting" on the ferries going from Helsinki to Tallinn. Observing people notice the "submarine" emerging, then slowly going past the ferry and later submerging again. Well, it's not a submarine, it's a well known rock that simply looks like a tower of a submarine.

User image

Or if you have a friend, put your head on the ground (perhaps at the shore) and watch the sun go down while your friend is behind you somewhere higher, perhaps on the fifth floor of a building. Talk to each by phone and yell "now!" when the last glimpse of the sun's circle has dissappeared to the horizon. The difference is notable. Now I've done both of these "experiments" and have seen how large ships drop into the horizon as well as seen the difference between the sighting of the sunset.

User image

There is a difference of about three minutes between the first sunset and the last sunset. For Islamic ritual purposes, the building is divided into three zones. In Ramadan, people in the highest floors have to break their fast about 2 minutes later than people on the lowest levels.
flannel jesus January 11, 2025 at 10:19 #959748
Reply to ssu Yeah totally.

I came across this response to that type of experiment the other day: https://www.reddit.com/r/globeskepticism/comments/1dej3ox/perspective_not_curvature/

Of course, the difference is, when you zoom in on the reddit scenario, the bottom comes back - when you zoom in on the ship in the horizon, it doesn't.
unenlightened January 11, 2025 at 11:48 #959757
Of course, if you haven't been turned on, you wouldn't know, so no blame:

Jamal January 11, 2025 at 12:14 #959760
I went for a walk in Spain, starting at the beach then heading inland and up to the top of the mountain called El Montgo. Visibility was good all day. I couldn't see Ibiza from the beach but I could see it from the mountain.

I've also seen ships sinking over the horizon.

But the thing is, I knew it before these confirmations.
flannel jesus January 11, 2025 at 15:55 #959784
Quoting unenlightened
Of course, if you haven't been turned on, you wouldn't know,


What does any of this have to do with sexual arousal?
flannel jesus January 11, 2025 at 16:07 #959791
Recently there was an expedition to the South pole, that cost 35k per head, for flat eathers to go observe the 24 hour sun. It's called The Final Experiment.

I've devised a similar experiment that should be much cheaper than 35k. It should, in my opinion, be convincing to any honest flat earther if carried out. The plan is this:

Visit 4 destinations, 2 in the north and 2 in the south. Each hemisphere of our planet has night time vision of what's called a Celestial Pole, enough is just the part of the night sky corresponding to our axis of rotation. In the north, the celestial pole is very near to the North Star, and in the south it's very near to the Southern Cross.

So, the 4 destinations could be Canada, England, South Brazil and South Africa. Obviously they don't have to be those exact places, but they're a good example.

At each place, you set up a camera on a tripod to observe that celestial pole. You'll use that footage to create time lapses like this:

https://youtu.be/TZOg8EPJ_yk?si=Zryt1GUcldohiFpu

The reason you want 2 places in each hemisphere is to handle all possible objections. A flat earther can easily explain the celestial pole of the north. But to explain not just one, but two celestial poles in the south is actually much harder. The firmament would have to be rotating from east to west in order for the southern celestial pole to go from South Africa to Brazil - but the time lapse would show that in fact the southern celestial pole is not moving east to west, but is quite stationary.

Now of course i know this wouldn't actually convince them, but the theory crafting about it is just fun for me. This experiment would reduce the cost from 35k to something closer to 5k.
ssu January 13, 2025 at 10:53 #960305
Reply to flannel jesusJust how easy it is to prove these issues simply question just what on Earth this Flat-Earth nonsense is about. Is it simply trolling? Is it simply an attempt to try to make nonsense so credible, that people fall for it and have a laugh about it? It looks a conspiracy theory pushed to the extreme, as an outrageous extrapolation of the sum of all conspiracies. Or the intent is to get the "science people" to be angry about the ignorance of the common folk and thus show their hidden elitism and how they look down upon others.

It reminds me of Sasha Baron Cohen's skit playing the character Ali G interviewing a former US Surgeon General, who obviously didn't know who Cohen was (or his character Ali G), seemed to have genuinely thought that that the "hip hop rapster"-interviewer was as idiotically ignorant as Cohen portrays Ali G to be. It's just an extremely hilarious exchange about (def) death starting at 3:50. If you haven't seen it, worth watching.



Flat Eartherism is perhaps something similar: if we believe that people are so ignorant and dumb to believe that the Earth is flat, what does that tell of our attitude toward others? Or then it's simply the algorithms that make this discourse so talked about. When something is blatantly wrong, it gets a lot of replies of the issue being wrong.

Corvus January 13, 2025 at 11:27 #960310
Quoting ssu
Flat Eartherism is perhaps something similar: if we believe that people are so ignorant and dumb to believe that the Earth is flat, what does that tell of our attitude toward others?


Whether the Earth is flat or round is not really a good question. You will see the Earth round, if you see it from the space. But if you see the Earth from the ground standing in the street of NY or Tokyo, it will appear flat. Hence it depends on where you are seeing the Earth from.

The real point of the question is, how the knowledge of the flat Earth and round Earth came from.
The Flat Earther's knowledge must have come from their own senses i.e. living and working on the Earth, looking at it directly with their own eyes, apprehending and observing it. It appears undoubtedly and conclusively flat.

The Round Earther's knowledge must have come from the Science class, books and media i.e. it is based on the authority of the institution. It is doubtful many of the Round Earthers have gone to the space in person, and peeked into the Earth and making the comments that the Earth is round. There must be only a handful of the rich or astronautical folks who actually have gone to the space and seen the Earth. Why should one trust those handful of folks claims?

Hence the Flat Earthers' knowledge is based on their own experience and observation rather than relying on the popular beliefs based on the authoritarian inculcation and propaganda.

Therefore the Flat Earther's beliefs are more scientific than the Round Earthers?
Gmak January 13, 2025 at 12:06 #960317
Reply to flannel jesus

There is grade in the knowledge. And round Earth is the entry. After that, in the more advanced grade, you discover it's magic. You need to see magic picture to understand.
ssu January 13, 2025 at 12:11 #960319
Reply to Corvus Quoting Corvus
The Round Earther's knowledge must have come from the Science class, books and media i.e. it is based on the authority of the institution.

Hence the Flat Earthers' knowledge is more Scientific than the Round Earthers' in terms of the method of their knowledge acquisition i.e. it is based on their own experience and observation rather than relying on the popular beliefs based on the authoritarian inculcation and propaganda.

Therefore the Flat Earther's beliefs are more scientific than the Round Earthers?

???

Trying to troll me exactly the way I said that Flat Earthers troll us? Or are you really serious? :smirk:

I don't understand your viewpoint. If there are things that puzzle me that I can see with my own eyes that go against Flat Earth idea, where Science (and geometry) gives me a good answer, why would it then be
about authority of institution, propaganda telling me this? Do you think that learning in school is just a form of remembering lines that the teacher tells you? A lot of that learning is things that I can see working in reality. Just as I can believe in arithmetic, because it works, it gives me answers of my surrounding reality. That's the real idea of understanding: you just don't "learn by heart" or accept something as true because an authority figure has said so, you can observe it yourself that it is so.

In fact, the vast majority of "Flat Earth" conspiracy theories start exactly the way you think Science education works. They see a video in YouTube, which gives an argument about a huge conspiracy. Bigger than the so-called "Moon landing hoax". And this is, in fact, it is actually exactly that "relying on the popular beliefs based on the authoritarian inculcation and propaganda", which you talk about. The authoritarians are just the conspiracy theorists themselves.

As I explained before, you can observe from multiple things that show that the Earth is a sphere. I just gave two examples that I myself have experienced. I could give others. I have been in Central America, in Costa Rica (which has been closest to the Equator) and notice that my shadow is quite under me, a thing where my shadow never is where I live. And there I can see new stars and constellations that I couldn't see at any time in Finland. And I've been in Australia and New Zealand and noticed the a totally different star constellations that I've never seen in Finland. So you tell me how all that is possible with in the flat Earth world?
Corvus January 13, 2025 at 12:36 #960324
Quoting ssu
Trying to troll me exactly the way I said that Flat Earthers troll us? Or are you really serious? :smirk:


It is meaningless to continue any kind of conversation with someone who are obsessed with trolling, and brand anyone asking questions or suggesting other ideas.

I hope that you are not the type of folks. :D What would anyone get from trolling the people with the obsession? That would be a total waste of one's life and time.

Well, if you read my post carefully, you would notice that I have not said whether the Earth is flat or round. I have just pointed out the ways they have acquired their knowledge.

Perhaps you were lucky enough to be able to travel all those different countries, and be able to reason and experiment from different part of the world. But there are the majority of the Earth population who have not gone out the place they were born, and seen the Earth only from where they stand. To these folks their own observations and apprehension is the only criteria they could draw their knowledge on the shape of the Earth.

If you accept the fact that philosophy is more than just believing everything you read and see on youtube, internet, and what is told in the classroom, then you would open your mind and listen to the other folks different ideas and methodologies in arriving their own beliefs and claims.

If you don't agree with the other folks ideas, then just use your reasoning and arguments to make your point, and prove your point is right, if you think it is enough worthwhile doing so.
Claiming someone is trolling out of the blue without concrete evidence is not a philosophical statement. Good luck.
Corvus January 13, 2025 at 13:31 #960332
Quoting ssu
And I've been in Australia and New Zealand and noticed the a totally different star constellations that I've never seen in Finland. So you tell me how all that is possible with in the flat Earth world?


My point was that methodologies of arriving at the knowledge is as important as the knowledge itself. Never said, the Earth is flat, round, flatly round or roundly flat.
ssu January 13, 2025 at 13:48 #960338
Quoting Corvus
But there are the majority of the Earth population who have not gone out the place they were born, and seen the Earth only from where they stand.

And this obviously is the reasoning just why not all historical cultures came to the conclusion that Earth is round. Eratosthenes had to have a lot of exact information to calculate the circumference of Earth (which he got nearly right) in 200 BC.

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Quoting Corvus
If you accept the fact that philosophy is more than just believing everything you read and see on youtube, internet, and what is told in the classroom, then you would open your mind and listen to the other folks different ideas and methodologies in arriving their own beliefs and claims.

We help others the best with really thinking about what they say and supporting them we think they correct and also disagreeing with them, when we see something incorrect in their reasoning. I value much about the responses I get in this forum. If someone disagrees with me, that's OK. If many disagree with me and say the similar reason for why I am in error, I do have to look at my reply. That's the best kind of help you can get here.

Quoting Corvus
My point was that methodologies of arriving the knowledge is as important as the knowledge itself.

Then for this topic, the important question here is: Just why some people, if they indeed are have thought about the issue, come to the conclusion that Earth is flat?

Why is there https://theflatearthsociety.org/home/index.php ? Why do they have the mission of:

The mission of the Flat Earth Society is to promote and initiate discussion of Flat Earth theory as well as archive Flat Earth literature. Our forums act as a venue to encourage free thinking and debate.

The Flat Earth Society mans the guns against oppression of thought and the Globularist lies of a new age. Standing with reason we offer a home to those wayward thinkers that march bravely on with REASON and TRUTH in recognizing the TRUE shape of the Earth - Flat.


Are we "free thinkers" if we believe in something that is false? Do we have to be so different, or otherwise we are the sheeple that conspiracy theorists believe others, the mainstream, being?
Corvus January 13, 2025 at 14:13 #960342
Quoting ssu
Then for this topic, the important question here is: Just why some people, if they indeed are have thought about the issue, come to the conclusion that Earth is flat?

Why is there https://theflatearthsociety.org/home/index.php ? Why do they have the mission of:


I am not familiar with either Flat Earthers or Round Earthers claims. But my point is rather, it is interesting to infer how they arrived their knowledge, as I have made out in the post above.

From my own point of view, I am not a Flat Earther, and I am not a Round Earther either. I am an empiricist. Whether the Earth is flat or round depends on what location you are seeing the Earth from.

If you are in the spacecraft outside of the Earth in the space, it will appear round. If you stand on the football stadium in London, the Earth will appear flat. How it appears to your vision, that's what matters.

So, the Earth is flatly round, and at the same time roundly flat would be the answer.
ssu January 13, 2025 at 15:10 #960363
Quoting Corvus
I am not familiar with either Flat Earthers or Round Earthers claims.

How? Seems you value them to be similar, that one isn't better than the other, at least theoretically to make a theoretical argument. And not knowing "their claims" doesn't free you of answering which one you believe to be true, actually, if the you think the World is flat or round.

Quoting Corvus
From my own point of view, I am not a Flat Earther, and I am not a Round Earther either. I am an empiricist. Whether the Earth is flat or round depends on what location you are seeing the Earth from.

That's not at all empiricism or being an empiricist. It's not just our sensory experience makes it true, it's also the empirical evidence that something is so. Roger Bacon himself opposed the older Aristotelian view in this way. And that empirical evidence cannot make both to true.


Corvus January 13, 2025 at 16:31 #960384
Quoting ssu
How? Seems you value them to be similar, that one isn't better than the other, at least theoretically to make a theoretical argument. And not knowing "their claims" doesn't free you of answering which one you believe to be true, actually, if the you think the World is flat or round.

To me, the both claims don't make sense. As I made clear that the shape of the Earth changes depending on where you are looking at it from.

Quoting ssu
That's not at all empiricism or being an empiricist. It's not just our sensory experience makes it true, it's also the empirical evidence that something is so.

How is it not? It is purely empirical for the fact that the knowledge is based on my observations on different locations on the Earth. How more could you get empirical, scientific and logical?

The earth is shaped roundly flat and flatly round is far more scientific in the sense that your claim, which comes from the popular media stories and your imagination disguised as reasoning, whereas my claim comes from the direct observations and apprehensions on the object.

ssu January 13, 2025 at 20:17 #960434
Quoting Corvus
As I made clear that the shape of the Earth changes depending on where you are looking at it from.

Any object looks different from where you look at it. It's called perspective. Perspective doesn't refute truth or falsity of a statement regarding objective truth about the universe. Here even the theoretical model or the axioms you start with can be questioned.

Quoting Corvus
How is it not? It is purely empirical for the fact that the knowledge is based on my observations on different locations on the Earth. How more could you get empirical, scientific and logical?

Do note the implementation of the scientific method. It is far more than just "a perspective" you have. You have this whole methodological process that isn't similar to any random observation I can take by looking at something. It is worth reading Bacon and Locke on this issue (among others) as using the scientific method is far more than just an observation.


Corvus January 13, 2025 at 23:37 #960470
Quoting ssu
Do note the implementation of the scientific method. It is far more than just "a perspective" you have.


The question is not asking how do you know X sounds, smells or feels such and such.
When the question is how do you know X looks such and such, the most important factor for the answer is how X appears to your eyes and visions.

ssu January 14, 2025 at 09:20 #960540
Reply to Corvus Your vision can be deceiving. You aren't using the scientific method if you just assume what you see is true. This is the kind of thinking that actually empiricists like Bacon were against in the first place. Me with my bad eyesight cannot see all the stars in the sky, especially not any galaxies or black holes or what ever. It's not a scientific argument to say that what is in the night sky is only the things I myself can see.
Corvus January 14, 2025 at 10:43 #960553
Quoting ssu
Your vision can be deceiving. You aren't using the scientific method if you just assume what you see is true. This is the kind of thinking that actually empiricists like Bacon were against in the first place. Me with my bad eyesight cannot see all the stars in the sky, especially not any galaxies or black holes or what ever. It's not a scientific argument to say that what is in the night sky is only the things I myself can see.


Yes, there is possibility of deceiving in perception. You are right. However, on the issue of how the Earth looks, and how do you know it looks round, it is a straight process. The fact is that everyone is on the Earth somewhere, so it really depends how the folks see the Earth, and how it appears to them.

It would be nonsense to say the Earth is actually shape of a banana, because of blah blah blah 1000 pages of so called scientific theories, and would be absurd to brand everyone who don't believe in that theory as dumb and idiots.

When the question is how X looks, one can only answer in terms of how it appears to his / her vision directly from real time observations, and that is all one can do.

Another point here is that, the question is not whether the Earth is round or flat, but it is asking how do we know it is round. In this case, it makes sense to explain how folks have arrived at their knowledge on the shape of the Earth, rather than screaming and shouting the Earth is round, and everyone who says otherwise are all dumb and mad. This claim is missing the point of the OP, and being too emotional on the trivial points for no reason, it seems.

MoK January 14, 2025 at 11:42 #960563
Reply to flannel jesus
There is no way to be certain that Earth is round if you are very skeptical!
ssu January 14, 2025 at 14:26 #960589
Quoting Corvus
When the question is how X looks, one can only answer in terms of how it appears to his / her vision directly from real time observations, and that is all one can do.

Empiricism and science goes far further than this, and this was already evident during the time of the first empiricists. Science starts from theories, as it understands that the present ideas can change and we can obtain even better models and theories in the future. Hence rarely do we truly talk about laws of nature and we aren't taught at school laws of nature, laws of physics.

Above all, the scientific method tries to be objective and evade subjectivity. Let's take literally what you said: what X looks like, "can only answer in terms of how it appears to his / her vision directly from real time observations, and that is all one can do." How limiting is that? What then about sounds or radio waves, everything else in the electromagnetic spectrum that we cannot see? Scientific theories here help us to define these, by having a spectrum defined by wavelength or frequency. It helps us to create machines that can use these other frequencies and we can "see" by radio waves (radar) or infrared light etc.

And lastly, if we say that this is our science and the scientific theories we use at the present, it doesn't mean that the theories are less important or less valuable, because they can be replaced in the future. It especially doesn't mean then that a hypothesis like "the Earth is flat" has value, because perhaps in the future there would be a theory that would prove it. Science doesn't work like that. It is built on earlier findings and seldom something is shown to be wrong, but simply not adequate to answer everything. Perfect example of the is Newtonian physics compared to Einsteinian physics. Newton's theories are quite accurate on many occasions, but in some situations Einstein's relativity gives us a better answer.

So in the end, we could say that the theory of Earth being ellipsoid is far more useful to us than the theory that the Earth is flat. And since we can even prove that the Earth isn't flat, but an ellipsoid, the theory of it being flat can be said to be simply false.
flannel jesus January 14, 2025 at 18:05 #960632
Reply to MoK sure, there's no way to be certain of anything if you are very skeptical. But if you're reasonably skeptical, there could still be ways to be justifiably confident.
MoK January 15, 2025 at 09:49 #960761
Reply to flannel jesus
Do you believe in science? If yes, there are scientific reasons why Earth is round.
Corvus January 15, 2025 at 10:53 #960765
Quoting ssu
So in the end, we could say that the theory of Earth being ellipsoid is far more useful to us than the theory that the Earth is flat. And since we can even prove that the Earth isn't flat, but an ellipsoid, the theory of it being flat can be said to be simply false.


For vast majority of the ordinary folks wouldn't care, if the Earth was round or flat. They are busy keep leading their daily lives I would imagine. It would only matter to the rocket sciences folks or world travelers, and the pilots ... really really fraction of the folks would care about the roundness of flatness of the Earth. Hence your claim above seems coming from prejudice and
exaggeration.

Again, the OP is a simple question. How do we know it is round? You don't need much scientific theories to explain the answers as you would on the radio waves, relativity theories or some QM topics.

And most importantly, no one was claiming the Earth was flat in this thread I believe. I never claimed it is flat or round, hence it is odd to ciriticise or talk down on the folks who believe in the flat Earth.
flannel jesus January 16, 2025 at 14:09 #961081
I went on a couple flat earth Discord groups and was quite unpleasantly surprised with the state of their community.

What I thought would be the case is, flat earthers were convinced that they have a better model that makes better predictions than the round earth. (I just thought they'd be wrong about those things for a variety of reasons).

What's actually the case is, most flat earthers don't have a model at all. The reason for that is simple: the ones that DO have a model have an easily falsified model. The "clever" ones have learned from that experience, and just denied having a model at all. They claim nobody knows that hte world is like, they don't have a map because nobody really knows what the continents are shaped like and arranged like.

Now normally, an agnostic position is respectable. We don't know everything, we're all ignorant of some things, so saying "I don't know" should be a respectable answer, right?

But we live in a world where you can take an air plane from just about any part of the world to just about any other part of the world. We have GPS google maps coverage of everywhere. You really expect me to believe those things are true, AND nobody knows anything about the shape and arrangement of continents?

They're not even ashamed of their lack of a model.

So instead of working on a model, they build communities where they allow "globies" to come in, but they dog pile them and then ban them on the premise of misused psychological buzzwords. They basically use these communities as funny little bullying rings, because they don't actually want to seriously investigate the shape of the planet, they just want to get revenge on the globies for their shame.

Apparently.
JustinShin January 21, 2025 at 19:14 #962669
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AmadeusD January 21, 2025 at 19:36 #962675
Trust in the processes which glean the information that I can piece together to understand the curvature, shape and orientation of the Earth in relation to my position on it.

The propensity evidence of the rest of the Solar System being spheroid (generally) is also helpful. I believe it because it would be pointless and time consuming to question generations of astronomy based on the fact that I don't personally know astronomy maths.
BC January 21, 2025 at 20:29 #962679
Quoting flannel jesus
What does any of this have to do with sexual arousal?


Just "Because" by McCarthy and Lennon: Because the world is round it turns me on.

I have no personally obtained evidence that the world is round or that the earth is the third planet from the sun. Various someone elses figured out all this out and I take their word for it. I have experienced gravity first hand, so I am confident it exists. There are a lot of alleged facts about the world which seem to be true, but of which I have not a shred of personal evidence. Somehow atoms manage to produce what we suppose to be substantial matter. Don't ask me how. Somehow electrons manage to move from here to there; are they moving within a field or are they moving within a copper wire? Beats me.

The world seems to work in a particular way for which various people have gathered evidence. I am taking their word for it.
flannel jesus January 21, 2025 at 20:52 #962687
Reply to BC It's actually apparently pretty accessible to prove the world is round. All you need is access to a 600-ft-high view of the sea. They're not exactly EVERYWHERE but you can find it. Go and take a photo of the horizon with a normal rectilinear lens, being sure to keep the horizon as near to center-frame as you can (this is because the edges of lenses tend to have more distortion). Then, you can analyze the picture in some editor for any deviation of the horizon towards a flat line. It won't be obvious to the naked eye, but once you draw a straight line from the left of the horizon to the right, it should stand out - the middle will bulge up.

Here's a similar technique illustrated: https://mctoon.net/left-to-right-curve/

If you don't want to trust these variuos someone elses, and see it for yourself, you can do it! Or just buy a telescope and watch ships disappear past the horizon, bottom-up.
BC January 21, 2025 at 22:11 #962706
Reply to flannel jesus Sure. I'm familiar with these methods of seeing the earth's curve. There's also the curved shadow of the earth during an eclipse.

Several someone elses figured out the earth was round and about 24,000 miles in diameter long time ago. According to NASA:

It has actually been known that the Earth was round since the time of the ancient Greeks. I believe that it was Pythagoras who first proposed that the Earth was round sometime around 500 B.C. As I recall, he based his idea on the fact that he showed the Moon must be round by observing the shape of the terminator (the line between the part of the Moon in light and the part of the Moon in the dark) as it moved through its orbital cycle. Pythagoras reasoned that if the Moon was round, then the Earth must be round as well. After that, sometime between 500 B.C. and 430 B.C., a fellow called Anaxagoras determined the true cause of solar and lunar eclipses - and then the shape of the Earth's shadow on the Moon during a lunar eclipse was also used as evidence that the Earth was round.

Around 350 BC, the great Aristotle declared that the Earth was a sphere (based on observations he made about which constellations you could see in the sky as you travelled further and further away from the equator) and during the next hundred years or so, Aristarchus and Eratosthenes actually measured the size of the Earth!


Once civilization collapses in a few years (or next week) this knowledge will soon be lost and will have to be rediscovered, IF there is anyone around to rediscover anything at all.
Banno January 22, 2025 at 00:52 #962742
User image

Stop motion of lunar eclipse.
flannel jesus January 22, 2025 at 11:00 #962807
Reply to Banno Wonderful. Funnily enough, most flat earthers also believe the moon itself is flat. There's actually another stop-motion you can get of the moon to disprove that.

It's a not-very-well-known fact that the face of the moon kinda wobbles a bit, which allows us to see it from a very slightly different angle at different times. It wobbles enough that if you take frames from various full moons and put them together, you can see the 3d form of it in an animation.

https://www.reddit.com/r/educationalgifs/comments/w7otnc/ive_captured_almost_a_complete_lunar_cycle_to/

https://www.youtube.com/watch?v=FCKmZXhVvkQ
flannel jesus January 22, 2025 at 12:00 #962810
Here's an even better one:
https://www.youtube.com/watch?v=vC7odtQHoPc

Given that you can produce this type of animation using only consumer-available telescopes and cameras, it's pretty hard to deny that the moon is spherical. That looks like a wobbling sphere to me.