Can we see [blank_start]wheter[blank_end] the earth is a globe? Yes, we can, when we watch a ship that sails out to sea. If we watch closely, we see that the ship begins [blank_start]to disappear[blank_end] . The bottom of the ship disappears first, and then the ship seems to sink lower and lower, [blank_start]until[blank_end] we can only see the top of the ship, and then we see nothing at all. What is hiding the ship from us? It is the earth. Stick a pin most of the way into an orange, and [blank_start]slowly[blank_end] turn the orange away from you. You will see the pin disappear, [blank_start]just as[blank_end] a ship does on the earth.