Keep shilling.

The horizon is not always at eye level

On a globe earth the square of the angle between the horizon and a horizontal plane should be proportional to the elevation

Would be a cool experiment to do

And it would give you the radius of the earth

there is no radius, thats the issue

I was supposing a globe earth

thats the issue, you cannot suppose, you should just observe

Suppositions tell you what to observe

You can't just say there is no radius because you say you can't prove the earth is a globe.