If we consider that the ancients had the same powers of observation as we
moderns do, then it's reasonable to believe that they knew the earth was a
sphere in that flat circles or disks do not produce crescents such as we see
in the phases of the moon. Only spheres produces cresents. In observing the
moon, the ancients wouldn't have
too much difficulty concluding that the earth, a heavenly body like the sun
and moon, is probably spherical too.
Cliff Moody
[b-hebrew] Circles and spheres,
Cliff Moody, 08/24/2012