ASTR 101 Chapter Notes - Chapter Reading: Snow Globe, Mark Sargent, Epicenter
Document Summary
Pythagoras had no evidence, but believed earth was a sphere. Ships sailing out to sea would disappear hull first, appearing as if they were sinking into the ocean on the horizon. A second reasoning was that different constellations are visible at different latitudes, which shows that the sky seen from earth appears as a dome above us. Finally, in a lunar eclipse, the earth casts a round shadow on the moon. Photos of earth weren"t taken until the 20th century. The ability to doctor images easily and growth of conspiracy theories have contributed to the rise of flat-earthers. One of the best documented methods of showing earth as a sphere was performed by the greeks. When the sun was directly overhead in one place, a stick there cast no shadow. At the same time in a city around 500 miles north, a stick there did cast a shadow.