AST-1002 Chapter Notes - Chapter 18: Edwin Hubble, Photon, Strong Interaction
Document Summary
The universe consists of all matter, energy, and spacetime that we can ever detect or that will ever be able to affect us. We use this definition because there may be matter and energy in other dimensions or matter and energy that are moving away from us so quickly that their influence will never reach us. So far in this text, we have explored matter on size scales from atoms to superclusters of galaxies. We also learned in that the superclusters are all moving away from one another, implying that the universe is expanding. Cosmology is the study of the large-scale structure and evolution of the universe. Cosmological constant - a number sometimes inserted in the equations of general relativity that represents a pressure that opposes gravity throughout the universe. Edwin hubble is credited with discovering that we live in an expanding universe.
