AST201H1 Lecture Notes - Lecture 16: Structure Formation, Nucleosynthesis, Supercomputer

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Michael Reid

Document Summary

As time passes, distant galaxies get farther apart. Rewinding hubble"s law tells us that all galaxies overlapped about 14 billions yrs ago- the beginning of time. Georges lemaitre, the belgian catholic priest who first figured out that hubble"s law implies that the universe began in a hot, dense state. Lemaitre"s idea came to be known as the big bang theory the universe began a in a hot, dense state. Side note: big bang theory describes how our expanding universe must have started out much hotter and denser than it is today bc of the expansion caused matter and energy to cool down and expand with time. Calling something a theory doesn"t mean that it"s tentative or unproven. Hot and very dense should have a black body spectrum. So it must have been a lot denser and hotter in the past. Era of nuclei- the universe consisted a plasma of free electrons & hydrogen nuclei & helium nuclei.