I -believe- the earth is round. But the intellectual honesty I’ve taken from The flat earthers tells me I have delegated my source of truth on that topic to others whom I am trusting to relay the truth. Maybe one day I’ll get into orbit and see for myself. With my own eyes. But that is beside the point of what I learned from them. I learned any time I outsource what I think is true to third parties, there is a risk of me believing a lie. Because people lie sometimes. And sometimes they draw conclusions based on assumptions and conjecture. My thought process is non-binary or more honestly, tri-state. I have true, false, and I have not observed that to be either true or false.
1. I regularly do video conferences with friends and colleagues on other continents; I can see if its light or dark in their windows. I have personally verified that some of my friends and colleagues and their places exist.
2. I have seen many ships disappear behind the horizon, and I have seen mountains disappear behind the horizon from ships; I have verified the accuracy of Vesselfinder (by comparing transits through lines in Vesselfinder with what I can see) and checked that it is at the expected distance. (I was curious about the delay.)
3. I have watched the ISS (once even trailed by the ATV) and it was right where HeavensAbove said it would be. And 90 minutes later I did it again. I have personally verified the basic math behind circular orbits.
4. I have experienced changing radio band propagation conditions consistent with a day/night cycle that is different in different places. Such as grayline DX, which is good propagation along the day/night line. Which implies the day/night line is real. And based on the reports I received I know it matches the map. I have built some transmitters and receivers myself.
5. I have flown between continents, been jetlagged and changed my clock's time (or maybe changing my wristwatches time is changing the sun and causing the jetlag?). I have watched the entire flight through windows, so I know I traveled very far.
6. I have seen the motion behind Foucault's pendulum over enough time (I've been to the museum long enough to verify that the pendulum plane rotates as expected, and I saw nobody messing with it in any obvious way.) We also did the same experiment in school. In school, we did the math for the Coriolis force, and talked about how it comes up as a significant factor in unexpected places (e.g. railway). Someone would talk.
7. I've observed the direction of the toilet swirl, and whirlpools in lakes.
8. I've experienced tide levels and swum with/against tide currents (sometimes even in the same place). I have also seen the moon in the sky and I think if it would be inconsistent someone would've noticed by now.
9. I've seen the shape of day/light boundary on the moon. Now that's the moon, but that one's clearly spherical, which is one data point.
10. I had a trusted fried, but he's got a PhD in astrophysics now, so he must be in on it and we cannot be friends anymore. /s
And I'm just some nerd, I haven't done too many experiments. I'm sure I could still extend the list, but of course there's no point since neither of us believe in the flat earth "theory".
There's no intellectual honesty in coming up with fake experiments like flat earthers do (if they even go to the trouble).
Before 2020, I thought flat earth like conspiracies were harmless fun (and I still think that a significant number of flat earthers are just having fun), and maybe they are. But after spending several hundred hours "discussing" many conspiracy theories (people I know and care about started believing very outlandish ones, like chemtrails and 5G causing covid) the last two years, and first hand witnessing intellectual incompentence (complete math illiteracy down to calculating a percentage, complete rejection of the concept of mathematical proofs, zero concept of scale e.g. of organizations and communities, complete refusal to read original research, insisting on "reading between the lines" to interpret texts claims made in texts into the opposite) I have come to see conspiracy theories and fake or un-intellectuality (is that a word?) as very dangerous (the "can cause death" type of danger).
this is not an indication of a round earth. the coriolis effect on this is negligible.
1: There are time zones in the flat earth model. The earth is a flat disc with antarctica (or is it the north pole?) at the center, and the sun moves around it in a circle, so the places opposite the sun are in nighttime
2: Believe it or not, flat-earthers believe light only travels so far, which is why things disappear "over the horizon"
4: I don't actually understand this one, but I suspect they'd handwave and talk about the same point in (1)
5: Same as (1)
I don't think flat-earthers have accounted for Foucalt's pendulum however.
That does not match my experience. I did looked into it and I found no consistent model of a flat earth. Lots and lots of words and sometimes even with consistent logic at times - but build upon completely false assumptions and flawed logic and therefore worthless. (you can proof anything, if your basic assumptions are made up)
"I don't think flat-earthers have accounted for Foucalt's pendulum however. "
And some of them tried and believe they did, but only when ignoring other facts and used twisted logic.
Like some parent poster had said - it is not about proof, but way more about ideology.
Otherwise they could very easily have a real proof, by sending up a weatherballoon, or organise a boat trip to the end of the world. But since they always refuse to do so (I challenged quite some with that concept) or even really think about it - they likely suspect inside that they are wrong, but rather not confirm for real, because then they would have to abolish a lot of their other ideology like chemtrails etc.
1. Find a sufficiently large "shallow" body of water. 2. Build a number a number of masts/poles in a straight line, all with an identical height over the water.
Now when standing at the shore and looking at the masts I predicts one of two things.
a. you can see all masts in their entirety with a telescope, or b. you can see less and less of the masts the further away they are.
There are actual places with power lines that satisfy this requirement. For b. you can use high school math to reason about the curvature needed to explain the results. There is no such sound logic (to my knowledge) explaining this for a flat surface.
I haven't done the experiment, but this brings it back to trusting scientists (light bends just above the water, but doesn't 4m above the water). I would need to do additional experiments to understand the refraction.
The simplified method works by considering two cities along the same meridian and measuring both the distance between them and the difference in angles of the shadows cast by the sun on a vertical rod (a gnomon) in each city at noon on the summer solstice. The two cities used were Alexandria and Syene (modern Aswan), and the distance between the cities was measured by professional bematists.[16] A geometric calculation reveals that the circumference of the Earth is the distance between the two cities divided by the difference in shadow angles expressed as a fraction of one turn.
https://en.wikipedia.org/wiki/Eratosthenes#Measurement_of_Ea...
They found a road that was almost due north and south (US 183 from Bassett, NE to 370 miles south in Coldwater, KS). They measured the elevation of Antares at its zenith one night, then again the next. From that they get the change in latitude. Combined with odometer data and some estimates for wiggles, and end with a result about 5% larger than the best-known solution.
Their measuring instrument was a Ryder van dubbed "The Van of Eratosthenes."
As an aside, later in the same episode is when I learned about GPS. https://youtu.be/yRY2SkMTafc?t=2968 . "This is the future of mapping."
However, there is no predictive value in any of what you've written here, so while they may be, to some, "refutations", they are not in any way useful.
If there were actually any flat earthers who cared about reason, because of the lack of predictive value (not to mention the contradictory/unprovable nature of what you've written here), they would not remain flat earthers for very long.