The origin of the globe can be traced back to more than 2000 BC, but the oldest globe was built in 1504, more than 30 years before Columbus discovered America. This oldest globe is made of two ostrich eggs embedded together, with a metal rod as the axis and a silver coating on the outside, with a diameter of about 26 cm.

According to historical records, this oldest globe was carved by German artist Behaim in 1504. In order to make this globe, Behaim first drew a world map on the surface of two ostrich eggs, and then embedded the two ostrich eggs together to form a complete world map. Then, he put the ostrich egg globe on a circular base with a metal rod as the axis, and coated it with a layer of silver to make it look more beautiful.

The globe shows the function of alternating day and night.

Use electric lights or flashlights to represent the sun so that it is on the same plane as the center of the earth. The earth rotates around its axis from west to east (the northern end of the axis points to the north). The period of the Earth's rotation (360) is a sidereal day, that is, 23 hours, 56 minutes and 4 seconds.

When the earth rotates from west to east, it rotates counterclockwise from the North Pole. Seen from above the Antarctic, the earth rotates clockwise; Seen from above the equator, the earth rotates from west to east. These three statements are consistent. Because the earth (instrument) is an opaque sphere, the sun (electric light or strong flashlight) can only illuminate half of the earth at the same time, that is, the sun is daytime and the back is night. The hemisphere illuminated by the sun (electric light or strong flashlight) is called the daytime hemisphere, and the hemisphere illuminated at midnight is called the night hemisphere.

The dividing line (two lines) between two fighting balls is combined into a circle, which is called the end line (circle). When the earth (instrument) rotates continuously from west to east, we will find that the direct point of the sun sweeps from east to west, and the morning and evening circles move regularly from east to west, so the day and night on the earth will change constantly. The globe has been turning from west to east, which can prove that day and night alternate regularly on the earth.

Baidu Encyclopedia-Global