Refuting the Flat-Earth theory

[FlatAssembler]

I am thinking about making a YouTube video refuting the Flat Earth Theory, as a former Flat-Earther. Here are the arguments I am planning to use:

1) The dip of the horizon. Flat-Earthers often claim that the horizon is always at your eye-level, like here:

A fact of basic perspective is that the line of the horizon is always at eye level with the observer.

But that is demonstrably not the case. You can observe that in two ways:
a) You can see the sunset twice if you watch the sunset sitting down and then quickly stand up (the sun stays at your eye level, but the horizon imperceptibly falls).
b) You can measure it directly from an airplane using a device with a camera and a gyroscope (like almost all modern mobile phones):

The formula for the dip of the horizon is easily derived from the Round Earth Theory, as anybody who knows high-school mathematics can confirm:


And here we see how is the Round Earth Theory superior to the Flat Earth Theory: it makes such simple and testable predictions. It seems to me that you can never derive an exact formula for anything from the Flat Earth Theory.

2) Why does the gravitational acceleration (9.8m/s2) decrease measurably when you climb up on a mountain? And how is your answer compatible with the rest of the Flat Earth Theory? You don't get to both claim gravity doesn't exist (and that that's why gravity doesn't cause the Flat Earth to collapse under its own weight) and that stars have a gravitational field.

3) If GPS is land-based, how come are GPS devices capable of telling your location, including your elevation, with just three signals? The simple truth is, when you know distance from three points, you can calculate two points where you might be. Those points will be different, mostly in elevation. If GPS devices receive signals from satellites, they can eliminate the point that's above the satellites as impossible. If they receive signals from land-based emitters, they cannot do that.

4) Polar day and polar night on Antarctica. If time zones work the way you claim they do, they would be impossible.

5) A bit of a soft question: Can you point me to any scientific discovery that was made using anything resembling your methods, by making countless ad-hoc hypotheses and asserting massive conspiracies? Yes, science has been wrong before, but scientists were almost always simply mistaken, not lying. Especially not massively colluding with each other.

Do you think that I should change something or add something?

[arewethereyet]

[The Valkyrie]

If the world was flat cats would have knocked everything off by now.

Theory disproved.

Moving on.

[Angrboda]

For a moment there, I thought you had changed your avatar to that of an armored chicken.

[BrianSoddingBoru4]

I am thinking about making a YouTube video refuting the Flat Earth Theory, as a former Flat-Earther. Here are the arguments I am planning to use:

1) The dip of the horizon. Flat-Earthers often claim that the horizon is always at your eye-level, like here:

A fact of basic perspective is that the line of the horizon is always at eye level with the observer.

But that is demonstrably not the case. You can observe that in two ways:
a) You can see the sunset twice if you watch the sunset sitting down and then quickly stand up (the sun stays at your eye level, but the horizon imperceptibly falls).
b) You can measure it directly from an airplane using a device with a camera and a gyroscope (like almost all modern mobile phones):

The formula for the dip of the horizon is easily derived from the Round Earth Theory, as anybody who knows high-school mathematics can confirm:


And here we see how is the Round Earth Theory superior to the Flat Earth Theory: it makes such simple and testable predictions. It seems to me that you can never derive an exact formula for anything from the Flat Earth Theory.

2) Why does the gravitational acceleration (9.8m/s2) decrease measurably when you climb up on a mountain? And how is your answer compatible with the rest of the Flat Earth Theory? You don't get to both claim gravity doesn't exist (and that that's why gravity doesn't cause the Flat Earth to collapse under its own weight) and that stars have a gravitational field.

3) If GPS is land-based, how come are GPS devices capable of telling your location, including your elevation, with just three signals? The simple truth is, when you know distance from three points, you can calculate two points where you might be. Those points will be different, mostly in elevation. If GPS devices receive signals from satellites, they can eliminate the point that's above the satellites as impossible. If they receive signals from land-based emitters, they cannot do that.

4) Polar day and polar night on Antarctica. If time zones work the way you claim they do, they would be impossible.

5) A bit of a soft question: Can you point me to any scientific discovery that was made using anything resembling your methods, by making countless ad-hoc hypotheses and asserting massive conspiracies? Yes, science has been wrong before, but scientists were almost always simply mistaken, not lying. Especially not massively colluding with each other.

Do you think that I should change something or add something?

I think you should give up on the idea of bothering to refute this particular bit of idiocy. Why would you waste your time on something like this?

Boru

[Nay_Sayer]

Doesn't hurt to have more people debunking this nonsense I suppose.

Professor Dave has excellent videos on the subject.

[Anomalocaris]

I must have been asleep when the plane went over the edge of the flat world the time when I flew around the world for a business trip.

(If your are based in the US and you have an opportunity to take a business trip to the Middle East, take it, you can swindle an itinerary that let’s you brag about having gone around the world)

[Gawdzilla Sama]

Take the morons out to sea. Ships approaching your ship will show their masts first and then the rest of the ship gradually rises over the horizon. If that's an optical illusion the ship's radar is deluded as well, because the radar signature gets larger as more hull appears.

[BrianSoddingBoru4]

Take the morons out to sea. Ships approaching your ship will show their masts first and then the rest of the ship gradually rises over the horizon. If that's an optical illusion the ship's radar is deluded as well, because the radar signature gets larger as more hull appears.

This sort of reasoned, not-sensibly-refutable evidence is one of the reasons why efforts to debunk the Flatties are pointless - they won’t believe it. They’ll either ignore the evidence or claim that you somehow jimmied the radar.

Reasoning with nutters is the equivalent of shouting at the rain.

Boru

[Gawdzilla Sama]

Most of the faithful won't believe anything anyway. You have to speak to the uncertain, the fence sitters. Save a few if you can.