Having spent 3-1/2 years on a warship, I can assure you that I have seen the phenomena of the curvature of the earth.
I do not believe you. And, the reason I do not believe you is that I believe that you think you have seen 'curvature'
in the direction you are looking - which is about as 'specious' as you can get. It may sound good - but, it is not valid - because it is based on
circular reasoning.
My question to you is - have you ever actually seen 'curvature' in the direction
perpendicular to the direction you are looking?
If a ship disappears over curvature between you and the horizon - in the same distance as it is from you to the horizon - you should see the same curvature fall-off to the left and to the right within that same distance - enough that the entire ship would fall below the horizontal tangent line.
There are no two ways about it - the same curvature would exist in all directions - not just in the direction you are looking.
If you are on a ship out on the open ocean - you see the horizon for 360 degrees around you. If the horizon were 10 miles away, you should see the same amount of curvature drop-off 10 miles to the left and 10 miles to the right of the point on the horizon in the direction you are looking.
There are no two ways about it - the same curvature would exist in all directions - not just in the direction you are looking.
To say you have seen 'curvature'
in the direction you are looking is meaningless.
I believe you
think that you have seen 'curvature'
without really actually having seen it.
Just because it is true that -
if there were curvature - a ship
would disappear over the horizon -
does not mean that - because a ship disappears over the horizon - that there is actually curvature present.
This is faulty thinking, and does not offer any proof of curvature.
Show me a picture with enough drop-off to the left and to the right of the center of the image such that a ship would fall below the horizontal tangent within the same distance from the center image horizon point as the distance from the camera to the horizon.
Your reasoning is specious.
My reasoning is "spot on" - because, I know how it really works - the thing you refuse to even consider.
I was involved in Radar and communications. There is a reason why microwave aerials are mounted as high as possible. Microwaves are line of sight so the higher the aerial, the further away the effective horizon.
I have been in electronics for most of my life - and, know enough about it to agree with what you say here - but, [it is] not because of 'curvature'.