origin of the universe and the solar system

big bang

began 13.8 bya from 1 hot & dense point that expanded rapidly

cosmic bg radiation & galactic redshift

alan guth

proposed a model based on big bang

incorporated a short period of exponential cosmic inflation to solve horizon & flatness problems of original theory

steady state

no beginning or end, constant avg density over time even thru expansion

alternative for big bang, rejected

inflationary universe

alexei starobinsky & andrei linde

extension of big bang → the first fraction of a second AFTER big bang was exponential expansion

hypothetical energy field, solves the missing details

flat problem

rapid expansion of inflation → curvature stretched dramatically to appear flat

horizon problem

tiny region that was uniform expanded and stretched it into a larger, more uniform cosmos

magnetic monopole problem

dilution of density of any magnetic monopoles made b4 inflation

spreads it out thinly so we can’t detect

oscillating

alexanger friedmann

universe expands and shrinks over and over

big band, big crunch

oscillates forever

multiverse

hugh everett III

our universe is one of many

collection of diff models

creationism

charles darwin

religious belief that supernatural acts made creation

nebular hypothesis

emanuel swedenborg

most widely accepted model, made before by immanuel kant & pierre-simon laplace

sun, planets, and celestial bodies formed a giant rotating cloud called a nebula

protoplanet hypothesis

william hunter mccrea

modern nebular, planets form around a young star dust and gas in a spinning disk, forming planetary embryos called protoplanets

grow into full planets