expanding universe theory noun the theory, developed from the observed red shifts of celestial bodies, that the space between galaxies is expanding, so that they appear to recede from us at velocities that increase with their distanceSee also
Collins English Dictionary – Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 expanding universe theory in Science expanding universe theory [ĭk-spăn′dĭng] The cosmological theory based on the work of Edwin Hubble that holds that the universe is expanding. Central to the theory is the interpretation of the color shift in the spectra of all observed galaxies as being the result of the Doppler effect, indicating that the galaxies are moving away from one another. According to the theory, galaxies are not moving through space but rather with space as it expands. The expansion of the universe implies that all of the matter of the universe was once concentrated in one place, which lends support to the big bang theory. The cosmogonical theory holding that a violent eruption from a singularity led to the formation of elementary particles, the subsequent formation of hydrogen and helium, and the dispersion of the galaxies from these elements. The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.