Matter and Anti-matter Anti Protons slightly outnumber anti-protons anti At end of particle era, universe contains some matter! Finally cool enough for electrons to combine with nuclei to form atoms (380,000 yrs) yrs) Photons now “decoupled” = free decoupled” to become CMB of future What is Olber”s paradox? What will be the fate of the universe ? What is the universe made of ? What is the dark matter ? Is the theory of inflation correct ? What is the dark energy ? Which of this, if any, should we believe?