BIO 211 Lecture 2: Lecture 2 (8_29)_ Time Scales & Origin of Life
8 Jan 2019
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Lecture 2 (8/29): time scales & origin of life. Earth formed as part of birth of solar system (after birth of universe) Protoplanetary disk (large rotating cloud of rocks/gas) composed of hydrogen and helium. Around 4. 6bya, star near protoplanetary disk was destroyed in supernova, explosion sent shockwave through proto disk, mass concentrated in the middle began to heat up formation of sun. Other small perturbations (matter, etc) in outer rings of disk became protoplanets. As protoplanets were formed, other huge amounts of heat in solar system led to nuclear fusion of hydrogen and helium. Pressure within central mask of protoplanetary disk triggers nuclear fusion. Gravity causes matter to condense around perturbations (outside of sun"s gravitational grasp) Rest of proto area in disk separate into rings (large fragments collide w each other, create large objects, which create our planets) Precambrian: supereon (since its so big) divided into 3 eons. Differentiate between supereon eons era.
