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Refining the Big Bang
•Flatness Problem – why so close to a critical universe?
•Horizon Problem – why is background all same T?
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•SOLVED BY AN “INFLATIONARY UNIVERSE”
–“Grand Unified Theories” of combined Gravity/Weak/Electric/Nuclear forces predict very rapid expansion at very early time:  “inflation”
–When inflation ends, all matter moving away with v=vescape  (flat universe – curvature forced to zero)
–Also solves horizon problem – everything was in causal contact
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