Astronomers, in their consideration of the supposed "curvature" of the Earth, have carefully avoided the taking of that view of the question which - if anything were needed to do so -would show its utter absurdity. It is this: - if, instead of taking our ideal point of departure to be at Valentia, we consider ourselves at St. John's, the 1665 miles of water between us and Valentia would just as well "curvate" downwards as it did in the other case! Now, since the direction in which the Earth is said to "curvate" is interchangeable - depending, indeed, upon the position occupied by a man upon its surface - the thing is utterly absurd; and it follows that the theory is an outrage , and that the Earth does not "curvate" at all: - an evident proof that the Earth is not a globe.
The most commonly accepted explanation of this is that the space agencies of the world are involved in a conspiracy faking space travel and exploration. This likely began during the Cold War's 'Space Race', in which the USSR and USA were obsessed with beating each other into space to the point that each faked their accomplishments in an attempt to keep pace with the other's supposed achievements. Since the end of the Cold War, however, the conspiracy is most likely motivated by greed rather than political gains, and using only some of their funding to continue to fake space travel saves a lot of money to embezzle for themselves.