Astronomy 1021 Study Guide - Final Guide: Inverse-Square Law, Structure Formation, Magellanic Clouds

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Robert Cockcroft

Document Summary

Cosmic calendar (history of universe into 1 year) Light travel time: if (cid:455)ou(cid:859)re dri(cid:448)i(cid:374)g (cid:1005)(cid:1004)(cid:1004) k(cid:373)/h o(cid:374) the (cid:1008)(cid:1004)(cid:1005), it takes a(cid:271)out (cid:1006) hours to drive. Distance = velocity x time: the speed of light. C = 300,000 km/s: this is the absolute fastest speed possible in the universe. We have seasons becau e the ea th(cid:859) axi is tilted relative. Ari totle" view: important aspect of this view: all stars are fixed, permanent, and do not change, only sun, earth, moon and planets change appearance, earth centered view of the solar system. Ptolemy" model: each planet turns around earth on small circle (called epicycle) that turns upon larger circle (called deferent, his model could forecast positions of planets with accuracy of few degrees, model remained in use for 1,500 years. Nicolaus copernicus (1473-1543: i(cid:374) (cid:1005)(cid:1009)(cid:1008)(cid:1006), pu(cid:271)lished (cid:862)on the revolution of the. Hea(cid:448)e(cid:374)l(cid:455) phe(cid:396)es(cid:863) basically says that the sun is in the center, not the earth: heliocentric view.