Besides, why would you even be arguing if you knew for sure that the Earth is round?
It would appear that you have some doubt. Otherwise, what would be the point?
As a round earther, I visit this forum in the (probably vain) hope of educating those flat earthers with a broader perspective on our planet and the cosmos as to the facts and figures established by accredited scientists over the past five centuries or so that prove unequivocally that the planet is indeed an oblate spheroid.
Not all flat earthers on these forums are as delusional or ill-educated as
saros or
sceptimatic, or
cikljamas or
hoppy.
If I can at the very least encourage the better educated and more rational of the flat earthers to even consider for a moment that our planet
could possibly be spherical, then I feel I'm not wasting my time debating with them on this forum.
Personally, I don't have anything to prove, and I've certainly never doubted the planetary scientific
status quo at any time throughout my life. I know that several flat earthers bring up the
argumentum ad populum defence whenever I mention that all the world's estimated 6,000,000 accredited scientists all agree that the earth is spherical, but conversely they're unable to list even 6 scientists who believe the earth is flat—despite being asked numerous times.
And being of an amateur scientific bent, plus having worked in the civil/structural engineering disciplines all my working life, I have not the slightest doubt that the earth is spherical. And why should I... particularly considering that the flat earthers have absolutely
no contradictory evidence that they can bring to the table.