more proof of a round earth:
Rotation of the starry sky every 23 hours and 56 minutes, proves Earth moves in relation to the sun. The sun appears to move around Earth in 24 hours. For the stary sky and sun motions to not be an equal time, then it is the Earth moving in relation to the two other references. Repeated for one year, this proves Earth goes around the sun once each year because the starry sky will repeat its patterns once each year.
Sticks of equal lengths perpendicular to the ground have unequal shadows at the same time of day. This proves the world is a sphere.
By measuring the angle of the shadow compared to true north and length of the shadow at noon GMT you can find the latitude and longitude of each stick's location. Collectively, this data proves Earth is a least a half sphere. Repeated on the other side of the world at 12 midnight GMT, you can prove the entire world is a sphere.
The sun rotating around the sky once a day proves rotation of Earth on it's axis if you also know premise 1 and premise 2 as stated above.
haha i love how all the people here that know the earth is round have proof but "flatearthers" or what ever they call themselves have almost none... well none that makes any logical sense