I only want a non optical device that measures and shows the curvature of our supposed sphere.
Surely there must be such a structure/ device in 2018 that does not solely rely on visual interpretations.
Simply a hardware structure that ends the whole discussion.
The Globe is HUGE, get used to it!
Here, just an idea:
OK, so you make a covered (to keep out any wind) water trough 4 km long and keep it temperature controlled (to avoid refraction).
Then somehow put
one set of height markers say 1.5 m above the centre water level (nice eye-level) extending in a perfectly straight line every 200 m to each end
and another set of markers 1.5 m above the level local water level every 200 m to each end.
So at each 200 m, the difference between the levels of the two markers is the curvature to that point.
The difference in level would be about 8 cm at each end - real exciting and convincing? I don't think!
Especially as total reliance would still have to be placed on the surveyors that set the display up.
That sort of thing has been done with the water in a (very) long "hose".
There is an ex-flat-earther,
odiupicku who now posts videos debunking
Eric Dubay.
Here is the third of a series:
ERIC DUMBAY's 203rd proof - make it viral or stay dumb - part 1, odiupicku, Published on Oct 19, 2017
.
And
ERIC DUMBAY's 203rd proof - make it viral or stay dumb - part 2, odiupicku, Published on Oct 19, 2017
.
odiupicku is a member here under the name
cikljamas and "changed over" during his time.
He still believes in a
Geocentric Model (Tycho Brahe's version) and is still very
anti-NASA!
In Holland we have an attraction park called 'Corpus' where you enter a huge human body on the inside with plastic organs and somewhat underwhelming other features.
People pay to go there and see what we know is inside our body anyways.
A long enough structure that shows earth's curvature should be a financial benefit in no time.
Schooltrips etc. to the 'curvatureon' 
But it seems that it is THE most difficult piece of mechanics that has ever been created.
It is also contagious like the plague, because it hasn't been tried once by authorities with enough financial means to built something along those lines.
I think they want to ignore the obvious....... that such a device cannot be built, since no curvature as claimed in the current sphere with a circomference of 40.0000 km can be shown through whatever mechanical structure.
No such a thing has not been built for the simple reason that it would be huge, expensive, still reliant on professionals to set up and less exciting than watching paint dry.
There have been a number of attempts to built mechanical structures to do that and some show curvature - either way!
No material is rigid enough, so angle measurement have to be relied on and the
curvature is about 0.05 minutes of arc each 100 m.
I did post a somewhat similar, though accidental demonstration of the earth curve in,
Flat Earth General / Re: Most ridiculous thing a FEer has said to prove a flat earth.I did post the same material in reply to an earlier post of yours, but you ignored it then as you will now.
So like it or not the Globe is HUGE, get used to it!