ASTR 1102 Lecture : Lecture29
Document Summary
One of the big questions astronomy tries to answer. In 17th century, it was treated as heresy by the catholic church to claim that the earth is not at the center of the universe. Galileo placed under house arrest in 1633 for publishing evidence that the earth moves around the sun. In 19th century, astronomers thought the solar system was at the center of the galaxy. Now in 20th and 21st century we try to fathom our galaxy"s place in bigger universe. Far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the galaxy lies a small unregarded yellow sun. Orbiting this at a distance of roughly ninety-two million miles is an utterly insignificant little blue green planet whose ape- descended life forms are so amazingly primitive that they still think digital watches [iphones] are a pretty neat idea. Douglas adams 1978, the hitchhiker"s guide to the galaxy .
