PHYS 170 Lecture 1: Astronomy week 1
Document Summary
Universe: totality of all space, time, matter and energy. Scales are very large, measured in light-years, the distance light travels in a year is about. Without liquid water there can be no chemical reactions which could create life. Stars that appear close together in the sky does not mean that they are close together in space. Latitude: used to locate things on earth, 0 degrees is located on the equator. Declination: used to locate things in space, horizontal, celestial analog of latitude. Longitude: used to locate things on earth, 0 degrees is located in greenwich, england. Right ascension: used to locate things in space, vertical, celestial analog of longitude. Zodiac: arrangement of stars in the sky. Reason for the seasons: tilt and amount of direct sunlight. Procession: earths axis changing over the course of time. Ecliptic: the sums equator and the plane that the planets are on.
