ASTR 105 Lecture Notes - Lecture 1: List Of Fables Characters, Parsec
Document Summary
The study of the physical universe: scientific method. To figure out how things work, we make an educated guess (hypothesis) Repeat steps 1-3 to reveal a fundamental rule of nature: scientific attitude. When science tells us that such & such is true. Interpret as such and such is true based on our current. Exponent must be a whole number: examples: = 482 x 10 x 10 (12 factors of 10) = 57 10 10 (9 factors of 10) Astronomy distance units: the astronomical unit (au) 1 au ~ 150,000,000 kilometers (a. 1. b. 1) useful for solar system distances (a. 1. b. 1. a) average mars-sun distance ~ 1. 52 au: light year (ly) = the distance light travels in one year. 1 ly ~63,000 au (b. 1. a. 1) useful for stellar distances (b. 1. a. 1. a) distance to proxima centauri (the star closest to our solar system) ~ 4. 2 ly: the parsec (pc) Useful for stellar distances (d. 2. a. 1) distance to proxima centauri ~ 1. 3 pc: the megaparsec (mpc)
