The higher you climb up, the farther you see. Lay your head on a bed. You can see all edges. Lay your head on a exercise ball. As you pull the ball away you can see more of it until half is full exposed to you. It's the effect of round vs flat objects. It's why old ships had crow nests. Wanna see something. Print out a map and cut all the land mass out. Then put them all together. Look at where the gulf of Mexico is on your new pangaea. You think a missile hit or a meteor? Did we destroy ourselves before? Remember this is a rough pangaea map. Because the sizes are altered of the land masses on a map because the Earth is round and the map is flat.