Answer:
well the earth is round known to the scientists but flat to some people as they can believe. humans discovered that the world is round and not flat from the astronauts and scientist as you think of the man who first went to the moon!
While it is true that men were not able to observe the complete globe until they traveled to space, a Greek astronomer calculated that the earth was actually round about 200 B.C.E. However, the fact of it's spherical shape was not generally accepted until almost a 1000 years later.
More fascinating than that though, is the knowledge that the shape of the earth was recorded in the Bible book of Isaiah about 750 B.C.E. He wrote at Isaiah 40:22 "There is One who is dwelling above the circle of the earth." The Hebrew word translated "circle" carries the meaning of a complete, or spherical circle.
Even before that, around 1500 B.C.E. Moses (who recorded the account of Job's trails) quoted Job's observation that God was "Hanging the earth upon nothing." (Job 26:7) This is clearly contrary to the common belief of the time that the earth was not only flat, but had to be supported by something, be it the god Atlas, giant elephants, or what have you.