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 -9 -6 -3 +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 +3 +6 +9 +12 +15

Creation of Matter 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 -42 -39 -36 -33 -30 -27 -24 -21 -18 -15 -12 -9 -6 -3 +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 +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 +3 +6 +9 +12 +15