Browse Reference Articles
161 to 170 of 195 articles
-
Gravitation
Gravity is a force of attraction that acts between bodies that have mass. Gravity is the reason for the very existence of the earth, the sun and other celestial bodies; without it matter would not ... > more -
Introduction to general relativity
General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1916. It unifies Einstein's earlier special relativity with Sir Isaac Newton's law of universal ... > more -
Lunar space elevator
A lunar space elevator (also called a moonstalk) is a proposed cable running from the surface of the Moon into space. It is similar in concept to the better known Earth space elevator idea (a cable ... > more -
Nuclear fusion
In physics, nuclear fusion is the process by which multiple nuclei join together to form a heavier nucleus. It is accompanied by the release or absorption of energy depending on the masses of the ... > more -
Precession of the equinoxes
The precession of the equinoxes refers to the precession of Earth's axis of rotation with respect to inertial space. The precession of the equinoxes is caused by the differential gravitational forces ... > more -
Interstellar medium
The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. Whilst the ISM refers to the matter (interstellar matter, also abbreviated ... > more
Search ScienceDaily
Number of stories in archives: 138,555

