Why do you think the Earth is a Ball ?

[kljesta64]

Dr.Henry_Killinger said:
The temperature gradient between the poles and the equator is caused primarily by the Earth being spherical.
The Sun's rays hit more surface area in the poles because its curved.(near parallel 2 Sun), and less in the equator because its flatter(perpendicular). Since the heat is distributed over less area in the Equator, that heat is concentrated and its hotter. At the poles that heat is distributed over a large area, so it is diffused.

Also lunar eclipses.

i think i get all that ..but still dont see how it proves the earth to be round as you said 'curved' but not a ball not round a flat earth can also be curved.