You cannot prove any of this yourself. You can only base this off the printed findings of others. Then you have to trust that this person was not lying, misinformed, or just barking up the wrong tree themselves.
You can easily prove the earth is a globe yourself without relying on third party information. That is what the OP asked, although we know now he was just trolling.
Sure that's why every amature weather balloon sent up without a fisheye lens camera comes back with a perfectly flat horizon, you're a massive faggot guy.
I often see this video posted as proof for flat earth which is just funny.
The fact that you see a hard line horizon from 121,000 feet proves that the Earth is curved -- only a curved Earth creates such a horizon at that altitude.
Where is the ice wall? or the dome?
''Sure that's why every amature weather balloon sent up without a fisheye lens camera comes back with a perfectly flat horizon''
Does it ever comeback with the ice wall or the dome, though?