Part a: the sun produces 3.9 ⋅ 1033 ergs of radiant energy per second. how many ergs of radiant energy does the sun produce in 1.55 ⋅ 107 seconds? part b: which is the more reasonable measurement of the diameter of a human hair: 1.8 ⋅ 10−2 mm or 1.8 ⋅ 102 mm? justify your answer.

What is the tychonic system? a. a model of the solar system in which all the planets (including earth) orbit the sun b. a model of the solar system in which the planets, moon, and sun orbit earth c. a model of the solar system where the planets orbit the sun, and this system orbits earth d. a model where all the planets and earth are fixed in space and only the sun and moon move e. a model that expands the system to a vast number of galaxies and star systems