Here are entered theoretical works on the phenomenon of gravitation, i.e. the attraction between masses anywhere in the universe, and on determinations of the constant of gravitation. Works relating to measurement of the resultant effect of the gravitational attraction and centrifugal repulsion between any body and a planet or other celestial body, including works on earth's gravity are entered under the heading Gravity.
Here are entered works on the use of mathematical tools and methods in physics. Works on the use of computers and computational tools and methods in physics are entered under Computational physics.
--subdivision Permeability under individual materials and types of materials, individual chemicals and groups of chemicals, and individual organs and regions of the body, e.g. Concrete--Permeability; Copper--Permeability; Skin--Permeability