It's a bit more complicated than most realize. Basically, if you travel South (away from the North Star) you will eventually run into a giant 150+ foot Ice wall. Authorities call this giant ice wall "Antarctica" and it is a fact that Antarctica is made up of 95% Ice wall. If you don't believe me, just ask Wikipedia:
Coastal types around Antarctica:
Ice shelf (floating ice front) 44%
Ice walls (resting on ground) 38%
Ice stream/outlet glacier (ice front or ice wall) 13%
Rock 5%
Total 100%
source:
http://en.wikipedia.org/wiki/Antarctica#GeographyNow whether or not this Ice wall is part of a circular continent at the bottom of a sphere-shaped earth, or a giant ring of ice surrounding a flat disc earth is for you to decide.
According to the Bible, God created a Firmament in the midst of the Great Deep (Waters) to separate Water Above from Water below and He called the Firmament "Sky" or "Heaven". Then God commanded the waters Under the Firmament to be gathered to one place and let Dry Land appear, which He called "Earth".
Here is a picture of Creation according to the Bible:
He sits enthroned above the circle of the earth, and its people are like grasshoppers. He stretches out the heavens like a canopy, and spreads them out like a tent to live in.
Isaiah 40:22
And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so. And God called the firmament Heaven. And the evening and the morning were the second day.
Genesis 6:8
Praise him, you highest heavens and you waters above the skies.
Psalm 148:4
The Hebrew word for Firmament is "Raqiya" which comes from the root word raqa and can be found in several passages including Isaiah 40:19 - "The idol! a workman casts it, and a goldsmith overlays it with gold, and casts for it silver chains." The word "overlay" is the verb root raqa. Raqa is the process of hammering out a piece of gold or other metal into thin plates which was then applied to a carved or molten image.
source:
http://www.ancient-hebrew.org/27_firmament.htmlcan you join him in spreading out the skies, hard as a mirror of cast bronze?
Job 37:18
So to answer your question about what would happen if you reached the edge of the earth? Basically, if you climbed the Ice wall it would be nothing but Flat Ice as far as the eye can see. If you traveled further South it would get colder, darker and windier even pitch black depending which direction you were headed. You may actually reach the ends of the earth where the Firmament rests on the Ground, or where the 4 Portals for the Winds are located. But chances are you will not get that far. There is even a Chasm in the East that separates us from the Garden of Eden and the land lay in Darkness, this is North/East of China.
Here is an ancient map with the Chasm and Wind portals. That is the Mediterranean Sea (Middle of the Earth sea) in the Middle-Left of the Map. The Kaspian Sea leading to the Northern Ocean at the Top. Many ancient maps show the Caspian Sea leading to the Northern Ocean, something that is being covered up/lied about today.