PHYS 037 Lecture Notes - Lecture 7: Gravitational Energy, Shape Of The Universe, Dark Energy
18 Oct 2016
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Document Summary
Mass and energy can curve the space around it. Travel in any direction would eventually bring you back to your starting point (closed universe) Space could be at, or have zero curvature. If space is closed, distant galaxies or clumps of mass will appear larger than reality. If at, there will be no apparent distortion in size. If we know density, we can predict gravitational energy. Critical density : when total energy of universe is zero gravitational energy balances other two. M = / c, where is the measured density of the universe. If m > 1, the universe will re-collapse. If m < 1, the universe will expand forever. If m = 1, the universe is exactly at the critical density. Night sky is dark because galaxies" light hasn"t reached us yet. Dark matter > 95% of matter in universe. Dark energy 76% of total content in universe.
