#1 is bullshit. You can go up on a high mountain and CLEARLY see a very gradual curve. Go in a plane and that curve is even more apparent. Go into orbit and its painfully obvious.

#2 relative size blows this out of the water (get it?). Earth very very very big. The centripetal force is not enough to counteract the force of gravity.

#3 see #2

#4 The plane is spinning with the earth at the same time it is also propelling itself foreward. When the plane is standing perfectly still on the runway it is moving at the speed the earth is spinning. Everything on earth is. It then propels itself the speed of the earth's spin plus its thrust speed.

#5 "The cartoon omits the telescope's focusing lens, implying that the photons remain freely propagating particles all the way down the tube. In fact, once the photons impinge on the telescope's lens, they are no longer free entities, but become part of the Earth-system, participating in its motion. The initial tilt -- Bradley's angle of aberration -- insures that the light impinges on the lens at right angles, so there is no additional refraction. The lens then focuses such light onto the telescope's focal point. Filling the telescope with water changes nothing. Airy's failure is in accord with the Earth's orbital motion. It proves nothing."

The top comment said it better than i could. Its essentially the same answer as #4 tweaked slightly.

#6 They arent inaccurate. They are navigation techniques that would work regardless of if it was flat or spherical because theyre essentially using landmarks .

Flat Earth "theory" is nothing but bunk garbage that cannot posit ANY positive evidence for it being true. The only thing flat earthers can do is fail to understand established science and then nitpick at those misunderstandings as if theyve made some profound scientific discovery. That, or they look at clear evidence of a round earth and go "nu uh" with zero sound evidence to disprove it. For instance, a favorite argument of flat earthers is to say that literally every single photo nasa has ever taken is either CGI or taken with a "fish eye lens" despite having ZERO proof that this is the case. And their CGI dispute comes from the fundamental misunderstanding of how earth images are generated because they apparently dont know how relative size works.

It is PRECISELY because it goes against all modern science AND classical science that it should be utterly discounted.

Another couple arguments I previously forgot to mention:

1. "Surveyors' operations in the construction of railroads, tunnels, or canals are conducted without the slightest "allowance" being made for "curvature," although it is taught that this so-called allowance is absolutely necessary! This is a cutting proof that Earth is not a globe."

2. "There are rivers that flow for hundreds of miles towards the level of the sea without falling more than a few feet - notably, the Nile, which, in a thousand miles, falls but a foot. A level expanse of this extent is quite incompatible with the idea of the Earth's "convexity." It is, therefore, a reasonable proof that Earth is not a globe."

https://wiki.tfes.org/AhundredproofstheEarthisnotaglobe

"horizon always appears completely flat, regardless of height or location."

-False. The curvature appears more defined as altitude increases.

"it always rises to eye height"

-What are you using as a reference to determine this? Or are you just parroting?

"If the Earth were a spinning ball, truly, consistently flat water surfaces would not exist."

-What makes you think truly flat surfaces do exist?

"Every time experiments have been conducted to prove this, however, the standing water has been found to be perfectly level."

-Bullshit. There are countless photos of ships, buildings, and land masses, partially obscured by the horizon.

"if the Earth were a spinning globe, airplanes flying west would have to fly faster than the Earth spins to reach their destination, traveling at over a thousand miles per hour"

-This is false, because the Earth's atmosphere is moving with the Earth.

"possibly the strongest proof, is the experiment known as "Airy's Failure".

-I call BS on that one. The speed of light is still very fast. The speed of light traveling through a diamond, is only about half speed.

"If these techniques, which assume the Earth to be a flat plane"

-Citation needed.

Fifth, and possibly the strongest proof, is the experiment known as "Airy's Failure". In short, the man performing the experiment failed to prove motion in the Earth

The "experimenter" is using a logical fallacy derived from Einsteinian physics. Motion can be proven, but since it is always relative to the observer, it can not be proven whether the object or the observer is moving.