The Astronauts presence is paramount, because then I can see these so called brave souls actually go into space and once I knew they were strapped in and into low earth orbit, I can then say I was absolutely wrong.
I think I have about as much chance of seeing this happen as Santa teaming up with Superman and raining presents down onto the world.
So without the astronauts, the space shuttle itself will never convince you that the Earth is round? A shuttle with an empty payload going into orbit doesn't prove this to you unless astronauts are in them? What the actual fuck? Please explain.
To get off a globe, the last thing you would do is arc, think about it.
You're forgetting about gravity and the spinning Earth. To climb up a mountain, would you go directly up the face of the mountain, or would you go along the longer but less steep pathway that circles around it? This concept is even more accentuated by the fact that with no air resistance in orbit, it takes no energy for the shuttle to go around, unlike a person walking along the path.
Also, the fact that the Earth spins needs to be considered too, but explaining it doesn't work with this analogy.