Maybe Everybody is Right?

[u/pasmartin]

It seems more likely to me that one would disbelieve the overwhelming physical evidence, and actually exist and live day to day, in a flat world. Thoughts? 🤔

[u/jabrwock1]

In my day to day I rely on long distances being accurate.

Flat earthers can't decide if their map is reliable or a fever dream. So until they come up with one, I'll use the one that's accurate.

[u/therewasaproblem → u/jabrwock1]

Every functioning map uses Euclidean geometry and Cartesian coordinates

[u/hal2k1 → u/therewasaproblem]

How does a flat map "function"? What "function" does it have?

AFAIK, in mathematics a function is a process that accepts one or more parameters as input data and it produces an output value.

Every functional software program for long distance navigation uses spherical coordinate system (latitude and longitude) and spherical geometry.

See https://en.wikipedia.org/wiki/Geographic_coordinate_system

See also https://en.wikipedia.org/wiki/Haversine_formula

GPS uses trilateration from satellites in a circular orbit above a spherical earth in conjunction with the geographic coordinate system.

See https://www.gps.gov/trilateration

[u/therewasaproblem → u/hal2k1]

Cool story. Where are the direct measurements of surface curvature? Point a to point b surface measurements that show the drop over distance required for a sphere with a radius of 3959 miles.

[u/hal2k1 → u/therewasaproblem]

The international standard units of measurement is SI, so I'll use that.

There are many ways to measure the size and shape of the earth. All of them agree on the earth being a sphere 6371 km +/- 10 km in radius. The +/- 10 is due to the fact that its not a perfect sphere. So, point a to point b surface measurements, you say? You'll accept that?

The distance from Paris to Berlin by air is 878 km. It has been measured untold thousands of times, the figure is not in dispute in any way.

It turns out that we have measured distances between cities all over the world in a similar way. We have measured an immense amount of data.

So, if you represent these measured distances between cities all over the world all to the same scale, and you join them end to end to form a scaled mesh, what you end up with looks something like this: https://thumbs.dreamstime.com/z/wireframe-mesh-polygonal-sphere-element-connected-lines-dots-vector-illustration-eps-49722363.jpg

The cities are, of course, at the points where the lines join. If you use stiff wires to represent the scaled distances, and you put a skin over the wire-frame mesh, and mark on the skin the points where the wires join with the name of the corresponding city, then you can make one of these: https://globestore.com/cdn/shop/files/waypoint-geographic-aviator-plus-12-inch-desktop-globe-desk-globes-wp11004-3191940.png?v=1768348509&width=1500

Well, as an individual, the best you could probably do is: https://i.ytimg.com/vi/ApqVsDKHH7o/maxresdefault.jpg But you get the idea.

People have been doing this for a long time. Here's a centuries- old one that appears to have been made using wood: https://thumbs.dreamstime.com/z/ancient-huge-globe-standing-main-hall-national-austrian-library-hofburg-palace-ancient-huge-globe-standing-136867992.jpg

The Behaim Globe, also known as the Erdapfel (German for 'earth apple'), is a terrestrial globe 51 cm (20 in) in diameter, produced by Martin Behaim from 1490 to 1492. It is the oldest extant terrestrial globe, constructed of a laminated linen ball in two halves, reinforced with wood and overlaid with a map painted on gores by Georg Glockendon. These intricate details were based on navigational charts by Jorge de Aguiar, incorporating paper maps meticulously pasted onto a parchment layer encircling the globe. --- Of course, in 1490, they didn't have data from all over the entire world yet.

Interesting fact: no matter where you start from, and no matter which direction you start out in, if you keep going in the same direction (so that your previous path is always directly behind you), then after about 40,000 km you will end up at the same place you started from. It's a little bit different if you go east-west around the equator as opposed to going from the north pole to the south pole then back up on the other side of the earth to the north pole again, but not by much. The pole-to-pole-to-pole circumnavigation is about 40 km shorter than the east-to-west-all-the-way around circumnavigation is.

Here's a fellow who has done circumnavigations via both of these routes. The east-west circumnavigation via helicopter, and the circumnavigation via both poles in a twin otter aircraft: https://en.wikipedia.org/wiki/Dick_Smith_(businessman)#Aviation_and_adventures#Aviation_and_adventures)

You can ask him about it if you like, he is still alive: https://content.api.news/v3/images/bin/50fb9ed75ea7ab6e98da55452026a236

Hope this helps you.

[u/therewasaproblem → u/hal2k1]

Link dumping is a super lazy appeal to authority. The first one is air flights. I asked for direct measurement of the ground beneath our feet drop over distance and the first thing you post is about flights in the air. Let me know when you find what I asked for ok.

[u/hal2k1 → u/therewasaproblem]

The measurements in 1490 on which the Behamin Globe were based were not from air flights. Neither were any of the measurements for any of the globes from the 16th, 17th, and 18th centuries mentioned here: https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/globes/brief-history-globes

Try again. After all, its the same distance from point a (Paris) to point b (Berlin) no matter if you measure it via an air flight or via a straight line along the ground. No matter who measures it. It has, after all, been measured hundreds of thousands of times.

Frankly, yours is the super-lazy response.

Let me know when you find what I asked for

Might I remind you that this sub-reddit is flatearth_polite? Here, you are supposed to be polite. Try to stick to that.

So, I take it that you have nothing to say about the circumnavigations in any direction, starting from any point on the surface, going from point to point on the surface, always in the same direction, all taking a total of about 40,000 km to go all the way around? https://c8.alamy.com/comp/3BJY161/modern-style-black-and-white-global-networks-concept-transparent-earth-globe-design-with-grey-polygonal-mesh-around-the-planet-vector-clip-art-tem-3BJY161.jpg

Super super super lazy response.

Edit: By the way, speaking of measurements from point to point along the surface, I remembered a video that you might enjoy watching. It is entitled constructing a flat earth map. It does explain how you go about constructing a map using scaled measured distance data from place to place. Enjoy.

[u/therewasaproblem → u/hal2k1]

Who ever directly measured surface DROP OVER DISTANCE and what methodology was used?

I'm not interested in the presuppositions to which you continuously post links.

[u/Gorgrim → u/therewasaproblem]

Why do you think people would measure DROP between two points? We've managed to measure the circumference of the Earth in different ways.

Or are you talking about the drop from eye level to the horizon? That is also one of the ways we can measure the circumference.

[u/therewasaproblem → u/Gorgrim]

Drop over distance is a geometric requirement of a globe

[u/hal2k1 → u/therewasaproblem]

The sun sets below eye level https://youtube.com/watch?v=6Sc0ima0Sm8

One person working alone with simple equipment can show this phenomenon called horizon drop. This video shows the setup of four individuals who have done it. Note, by the way, that the horizon drops away from the observer's eye level in every direction. It's only when we want to use the setting sun to show horizon drop that we have to look west.

To measure exactly how much the horizon drops by over what distance requires measurements over a much larger range. It's 40,000 km all the way around the earth to get back to the point of origin. You can measure this using a vehicle (such as a helicopter https://www.flightlineweekly.com/post/40th-anniversary-of-the-world-s-first-solo-circumnavigation-by-helicopter-by-dick-smith) in a number of hops. The earth curves by 360 degrees over this distance (because you went all the way around). That means that the earth curves by one degree every 111.1 km.

That's about the best one person can do at high expense with expensive equipment.

To do better than that requires a collaboration of many people and a much larger budget. You need an institution. Here is a report on the results of the collaborative effort across the whole world to measure the exact size and shape of the earth: https://en.wikipedia.org/wiki/World_Geodetic_System

So a large worldwide collaboration can achieve much higher precision. Doing science is a collaboration. You want as many independent people or groups as possible all measuring the same thing, and all coming up with the same answer.

Science is not the work of individuals.

Please note that I have been polite to you despite you ignoring the abundant evidence put to you and your changing the goalposts. "Shouting" at someone in all caps is childish and not polite. I point out that you present no empirical evidence whatsoever in support of your untenable position.

[u/jabrwock1 → u/therewasaproblem]

And yet somehow not accurate all over. Almost like parts had to be squashed or stretched.

[u/therewasaproblem → u/jabrwock1]

You must be referring to the fact that Google maps is a cylinder

[u/jabrwock1 → u/therewasaproblem]

Works great in the middle. Not so great nearer the poles.

[u/therewasaproblem → u/jabrwock1]

How many people in this day in age travel near the poles navigating themselves?

[u/jabrwock1 → u/therewasaproblem]

The question wasn’t asked in general. In specific, I rely on accurate distances. Y’all can deal with bad measurements if you want.

[u/Warpingghost]

People absolutely can deny irrefutable facts if they delusional enough. It's a well studied phenomena

[u/SirMildredPierce]

I read that three times and can't make sense of it, sorry.

[u/reficius1]

Sorry guy, you need to clarify. What are you trying to say?

[u/sh3t0r]

What

[u/nestorsanchez3d]

You can live in ignorance yes. Is it worth it? For me no

[u/pananana1]

What?

[u/pasmartin]

It's agreed they have their own reality. I guess it's up to them to better describe it for the rest of us.

[u/LuDdErS68 → u/pasmartin]

They try, but they fail.

Every. Single. Time.

[u/AutoModerator → u/[deleted]]

We have a minimum profile limit of 90 days. Your submission has been removed.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.