Page 8 - Science E-Book Prep.3 2024-2025 1st term_Neat unit 3,4

Science Department
Prep.3

? Nebular assumption (Laplace 1796):

Scientist : Pierre Simon Laplace
Origin: Nebula

Nebula: a gaseous sphere revolving around itself

This perception is affected by two observations:
1. There is something that looks like a nebula in the space.
2. The rings surrounding some planets such as the rings at Saturn

Theory assumptions:
1. The solar system was a gaseous sphere revolving around itself, this
sphere is called a nebula
2- It gradually lost its heat.
3- Its revolving speed increases.
4- Under the effect of the centrifugal force, the nebula
lost its sphere form and become a flat rotating disk.
5- Parts got separated from this disk and form a gaseous
ring which rotates at the same direction that the nebula
rotates.
6- These gaseous rings got cooled and frozen to form the
planets of the solar system.
7- The flaming mass that remained in the center formed
the sun.

First Term 49