1.big bang Theory about the origin of the solar system that suggests our Sun and planets formed from a cloud of dust and gas.
2.steady state
Theory about the origin of the universe that suggests the universe is a never-ending cycle of expansion and contraction.
3.oscillating universe
Theory about the origin of the universe that suggests the universe has and will continue to be at a steady, continuous state.
4.nebular
Theory that upholds the big bang Theory but suggests there was an extremely rapid expansion or inflation milliseconds after the big bang.
5.inflation
Theory that suggests the origin of the universe started with an explosion and expansion of a very hot, dense, compact fireball.
6.condensation
Theory about the origin of the solar system that agrees with the nebular theory but stresses the importance of interstellar dust in planet formation.