110 likes | 194 Views
Early Universe. Singularity. In the first few seconds of the universe photons outnumbered matter – radiation era . The Planck era existed before 10 -43 seconds. No scientific model to explain Quantum gravity, string theory. -42. -39. -36. -33. -30. -27. -24. -21. -18. -15. -12.
E N D
Singularity • In the first few seconds of the universe photons outnumbered matter – radiation era. • The Planck era existed before 10-43 seconds. • No scientific model to explain • Quantum gravity, string theory -42 -39 -36 -33 -30 -27 -24 -21 -18 -15 -12 -9 -6 -3 0 +3 +6 +9 +12 +15
Inflation • The forces of nature were initially identical. • Split as universe cooled • A period of inflation expanded the universe. • 1050 times in size • Possible confirming disturbance measured? -42 -39 -36 -33 -30 -27 -24 -21 -18 -15 -12 -9 -6 -3 0 +3 +6 +9 +12 +15
Energetic photons created matter-antimatter pairs. Quark epoch Lepton (electron) epoch At 1 microsecond the Universe was too cool to make more pairs. Most matter-antimatter pairs annihilated. Slight excess of matter Asymmetry currently explored in accelerators Creation of Matter -42 -39 -36 -33 -30 -27 -24 -21 -18 -15 -12 -9 -6 -3 0 +3 +6 +9 +12 +15
Exploring Early Times • Particle accelerators can briefly reproduce the temperature of early times. • Fermilab in Illinois • CERN in Switzerland • Equivalent to about 1 picosecond (10-12 s)
Creation of Light Nuclei • During the first few minutes there was fusion as in stars. • proton + neutron deuterium • deuterium + deuterium helium • helium + helium lithium + proton • There are only about 72% protons and 28% neutrons. • Forms 75% hydrogen, 25% helium, trace of lithium • All heavier elements made in stars -42 -39 -36 -33 -30 -27 -24 -21 -18 -15 -12 -9 -6 -3 0 +3 +6 +9 +12 +15
Nucleosynthesis • The density of ordinary matter determines the likely mix of light nuclei. • WMAP measures ordinary matter at 4.6% of the total. • Predicted mix matches other observations
Matter Era • 50,000 years after the big bang matter energy exceeds radiation – matter era. • Matter eliminated by antimatter • Radiation energy decreased by redshift • 400,000 years after the big bang atoms formed. • Proton + electron = hydrogen -42 -39 -36 -33 -30 -27 -24 -21 -18 -15 -12 -9 -6 -3 0 +3 +6 +9 +12 +15