Recently I saw a post on the flat earth society forum and I just had to respond. First, here is the post, my answer is below.
Note about point 1-3: Every single one does suffice as a 100% flat earth disprove.
From the north pole, looking straight up, it looks like this
And at the equator like this
On a flat earth, the north star would be visible all the time. Or to go be bit deeper: In theroy, in infinte distance the north star would actually appear to be at ground level. But since earth is not infinite, this cannot be true. Additionally, on the southern hemisphere you can not see the north star at all – impossible, even on a infinite flat earth.
You do not have to rely on those pictures. Travel to those places and capture those images yourselfes.
2. Sunrise and sunset
Notice: The clouds get illuminated from BELOW. On a flat earth, if the sun would just disappear in infinte distance, clouds could be illuminated from straight ahead but never from below.
This is a nice picture of a upward-cast shadow :
This would require a sun below the height of the clouds. Same for this video:
Also, if you watch a sunset, you clearly see how the sun sets behind the horizon instead of actually getting smaller and smaller. If the sun was getting smaller and smaller, with a telescope you could bring it back into view - which you cannot.
You do not have to rely on those pictures - go out and check it yourself.
3. Vanishing behind the horizon
Ships and buildings vanish behind the horizon. Look, for example, at this video:
You do not have to rely on thoes videos. Go out and check it yourself, a telescope helps.
The signal comes from the sky. With "ground-transmitter" / pseudosatellites I could not go onto a 2000m+ high mountain and shield everything but the sky, and still have a GPS reception.
Do not belive me, go out and check it yourself.
This does not directly disprove the flat earth, but as far as I know flat earthers deny the existance of satellites.
5. Size of the sun
On a flat earth with an approaching sun, its size would diffrentiate during the day.
Go out and check it yourself with a camera and suitable filters so it would not overexpose the sun.
Flat earth argument is, that the world is acclereation with 9.81m/s^2. But not all over the world the gravity is equally strong. In case of an acclerating plate, this would be impossible.
Go grab a scale and measure the same object at the equator and the northpole! Or at least at somewhere near the equator and near the north pole.
I do not see a reason for the corioliseffect on flat earth.
8. Ridiculous overall-model
HERE IS MY REPLY
I can't stand pompous posts like this. If the OP really felt this way, if he felt strongly about his "belief"... believe me, he wouldn't be here. None of you who prance around here pretending to have knowledge and facts would be anywhere near this forum. The reason you are here is for self confirmation. That's the only reason. You say, "Flat Earthers must be brain dead liars who simply refuse to accept proofs and scientific facts." Yet, deep down inside everyone (whether anyone will EVER admit it or not) all of us see the absurdity of the globe. Spinning 1040 mph, going 66,000 mph around the sun, 480,000 mph around the galaxy and 2.2 million mph around the "great attractor" which is 100 Quadrillion times the size of the sun. Spinning and twisting and tilting on an ecliptic plane in elliptical fashion which includes the changing of speeds constantly. The crazy notions that are included in a globe belief however are taught to us as children and explained as scientific and mathematical facts. So, as children and many people even as adults, we can easily choose to accept and trust the accepted so-called "proofs."
Well, we are now many years removed from our schooling and now that you have heard someone questioning your deeply held beliefs, it is quite scary because of the implications and the potential of it being true. Everyone knows what it would mean for our view of the world and our opinion of science and schooling if it ever came out that Earth was actually flat. So, OP is just trying to prove it to himself so that he can sleep at night. That is understandable. However, if the flat Earth was as dumb as all you globe believers say it is, then none of you would be here. You wouldn't have ever so much as searched for this website or signed up for this forum. If you aren't into midget porn... you don't seek out midget porn fetish websites and become a member there with your 5000+ posts about how midget porn is not actually arousing or entertaining. You stay as far away from that "group" as possible. If I go on YouTube and see a video making some asinine statement, you can bet your bottom dollar that I would never spend the hour watching it let alone make comments on the video page telling the creator that he is an idiot. I certainly know that I would NEVER seek out the forum where these asinine statements are discussed and then spend the time signing up let alone making a post trying to show how wrong their dumb ideas were. So, before I go through Mr. OP's "proofs" I just wanted to show everyone that there is a reason why all you Globe believers hang out here. It is not because you think you have the proof. If you did, you would have a million other things to do and places to go. You are here because you hope you have proof. You really, really, really hope that you have all the answers because if you don't... it is world and life changing info and many will have to change their lives and most likely say some apologies and stop being such a dick to everyone you meet.
So, that said, let me first start by showing you something about science that you need to understand and I can't wait to see the responses from people who will make excuses galore to try and explain what is really quite obvious here. Science is about knowledge and about the study of the natural world based on facts learned through experiments and observation. It is the state of knowing as distinguished from ignorance or misunderstanding and lastly it is a system of knowledge covering general truths or the operation of general laws especially as obtained and tested through scientific method. I'm sure everyone agrees with that. So, when you do the research and you realize that some of our "facts" actually don't fall into the definition of science, how do you allow that and not start to ask questions? For example, when Hubble saw that all galaxies are moving away from us, he knew that it meant that either we are in the center of the universe or he needed to find another way to explain it. So, clearly here, he has to make a decision... not based off evidence but rather his biased opinions. He states very clearly in his book "The Observational Approach to Cosmology" what he found, he said
"Such a condition would imply that we occupy a unique position in the universe, analogous, in a sense, to the ancient conception of a central Earth...This hypothesis cannot be disproved, but it is unwelcome and would only be accepted as a last resort in order to save the phenomena. Therefore we disregard this possibility.... the unwelcome position of a favored location must be avoided at all costs.... such a favored position is intolerable...Therefore, in order to restore homogeneity, and to escape the horror of a unique position…must be compensated by spatial curvature. There seems to be no other escape."
"People need to be aware that there is a range of models that could explain the observations, for instance, I can construct you a spherically symmetrical universe with Earth at its center, and you cannot disprove it based on observations. You can only exclude it on philosophical grounds. In my view there is absolutely nothing wrong in that. What I want to bring into the open is the fact that we are using philosophical criteria in choosing our models. A lot of cosmology tries to hide that.”
"We know that the difference between a heliocentric theory and a geocentric theory is one of relative motion only, and that such a difference has no physical significance."
"Science today is locked into paradigms. Every avenue is blocked by beliefs that are wrong, and if you try to get anything published in a journal today, you will run up against a paradigm, and the editors will turn you down."