I love a good flat earth debate. Mind if I toss a couple things at you? I'll be respectful towards you, but possibly not towards your sources. Your sources are a mixture of people who don't think things through properly, people who beg the question, fear profiteers, and trolls.

We need solid, definitive experiments that anyone can do to discern the truth.

I'll point you to my post here where I show you some very simple experiments I performed suggesting the Earth is a globe. By no means definitive, but they give great qualitative evidence that the Earth isn't flat.

The only way in which this can make any sense to me, is if the force of gravity applied to an an object was relative to the mass of that object. But, as the aforementioned experiments revealed, we know that this is not the case, and that the same force is applied to everything.

Someone misled you here, I'm afraid. You've been trolled, and I'm sorry to have to be the one to tell you. The fallacy in this argument is that gravity does not apply the same force to everything. Gravitational forces are proportional to mass. The thing that gravity does the same to everything is what's known as the acceleration due to gravity. Let me explain:

Remember F=ma from high school physics? I'll rearrange it to give you a=F/m. This is a special case of Newton's first law of motion, which says that if you apply a constant force F to an object with mass m, it will accelerate with acceleration a. If you drop a hammer with mass 100 and a feather with mass 1 in a vacuum, as you say, experiments show that they both move downward together at the same speed and hit the ground at the same time. That is, they both have the same a. If this is true, but the hammer weighs 100 times more than the feather, then we can deduce that the force applied by gravity is 100x stronger on the hammer than it is on the feather. That is, gravitational forces are proportional to mass. The reason the ocean stays stuck to the earth is that it's very massive; the reason I'm not squished is that I'm not very massive. Done. Someone lied to you with that silliness about gravity being the same force on everything. If gravity were the same force on everything, the hammer would accelerate 100x faster than the feather.

now the astronaut video:

I am convinced that the body language exhibited by Chris Cassidy after stating that they are filming from America, not space, is extremely telling.

What? This, above everything else you've mentioned, has me thinking that you're just trolling us. He didn't say that (as I'll show) and he was acting shifty, nervous, and nauseated throughout the entire video. Not just after he said his piece.

Check out this website, whose authors also claim to believe that Chris said they're in America. Note in the transcript that Chris says "across the United States from where we’re talking to you right now." He does not say "where we're talking to you from right now." If his grammar is correct, the simplest inference we can make here (and you like Occam's razor, right? so let's apply it!) is that the kids he's talking to are on the West Coast of the US. Referring back to the article I linked, it turns out this is correct: they're in Oro Grande, California. Chris was referring to the students, not to himself.

Of course, you're more than welcome to overcomplicate it if you want! That's your prerogative. But don't go around telling people that Occam's razor is important to you without applying it uniformly.

Occam's Razor suggests that the simplest explanation is more often the correct one than not.

I agree! So let's apply it to a flat earth conspiracy, shall we? Here is a list of people who know whether the earth is flat or not. That is, their jobs depend on knowing the truth. Note that this subtlety is important, and strengthens the power of Occam's razor for this situation! Their jobs don't necessarily depend on the truth being one thing or the other, but if the earth is actually flat and they believed it were a globe, they'd do their jobs wrong.

• Navigators
• Cartographers
• Airplane Pilots, even amateur ones
• Anyone who has ever sailed on the open ocean
• Military artillery people
• Physicists
• Astronomers
• Ecologists
• Astronauts
• World heads-of-state

There must be 10's of millions of people in these categories. That is, there are 10's of millions of people who know. If this is a conspiracy, they're all in on it. Occam's razor suggests that a non-negligible fraction of them would have leaked this information. Occam's razor suggests that we should accept the far simpler hypothesis that the Earth really is round and that there aren't 10's of millions of people who are simultaneously living a public lie about it.

So, thanks. Thanks for giving me another great opportunity to argue one of the very few facts that I'm 100% convinced of! It's not often that I can really emotionally commit to one side of an argument, but this is one of them.

If I could give people who are reading this one piece of advice, it's this: apply the scientific method to everything. If you think something might be true, don't go looking for evidence that it's true. Rather, go looking for evidence that it is not true. Be skeptical of what you hear from youtube trolls, and be even more skeptical of yourself. Don't let yourself accept faulty arguments just because they excite some anti-establishment sentiments. Hold yourself to a higher standard.