Tag

astronomy

• Disaster means "bad starThe word disaster comes from Italian dis-astro, a bad star, and belongs to a big family of star words.
• Astronaut, nautical and the sailor rootAstronaut means star sailor. The naut- root runs through nautical, nausea and Nautilus.
• King Lear: Edmund's star speech and the scientific methodGloucester blames eclipses; his son Edmund mocks blaming the stars, a modern idea in a play about ancient Britain.
• Eratosthenes measures the EarthAbout 240 BC, one angle (7.2°) and one distance gave the size of the whole planet.
• The shadow stick and why the lines meet at Earth's centerHow the 7.2° was measured at Alexandria, and why a plumb line points to the center of the Earth.
• Why the sun's rays count as parallel (Aristarchus)The Greeks already knew the sun was very far away, so rays reaching two cities 500 miles apart are effectively parallel.
• The flat-Earth myth and ColumbusEducated Europeans never forgot the Earth was round. The argument with Columbus was about its size, and he was wrong.
• Copernicus, 1543Nicolaus Copernicus put the sun at the center and published as he was dying.
• Bruno, Galileo and "Eppur si muoveWere people put to death for saying the Earth isn't the center? Bruno was burned in 1600, mostly for theology; Galileo was convicted in 1633.