Definition of "nebular hypothesis" []

• A hypothesis concerning the origin of the solar system according to which a rotating nebula cooled and contracted, throwing off rings of matter that contracted into the planets and their moons, while the great mass of the condensing nebula became the sun. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "His nebular hypothesis in the last volume of his essays is the most masterly astronomical paper I have ever read, and in his forthcoming volume on Biology he is I understand going to show that there is something else besides Natural Selection at work in nature."