traced back to proponents such as Emmanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace (PSL has his own version of the theory)
The nebula appeared to be intact at first, but it is speculated that a nearby supernova or a passing star disrupted this stable state
> Gravitational Collapse - materials that made up the nebula were drawn toward the center of the giant gas cloud in a phenomenon
> The Protoplanet Hypothesis
modern version of the nebular hypothesis, which was proposed by C.F. Von Weizsacker and modified by Gerald Kuiper
this is where some materials formed eddies; these eddies are like a blob of materials, where gravity within each eddy causes these materials to combine and form protoplanets
> Protoplanet - the collection of matter that will develop into a planet
> The Encounter Hypothesis - another set of ideas that explains the formation of the solar system is the different theories about the interaction of the sun with a comet, a star, or other celestial body
