Gravitation and Celestial Mechanics


Gravitation and celestial mechanics deals with classical Newtonian gravitation and the motion and forces associated with it. This is divided into four realms: Surface gravitation, Particle celestial mechanics, Rigid celestial mechanics, and nonrigid celestial mechanics. These roughly correspond with the divisions of classical mechanics.	Sapience Home Site Map About Sapience Science Physics Mechanics Nonrigid Celestial Mechanics Rigid Body Celestial Mechanics Particle Celestial Mechanics Surface Gravitation

Gravitation and celestial mechanics deals with classical Newtonian gravitation and the motion and forces associated with it. This is divided into four realms: Surface gravitation, Particle celestial mechanics, Rigid celestial mechanics, and nonrigid celestial mechanics. These roughly correspond with the divisions of classical mechanics.

Nonrigid Celestial mechanics

In addition to the rotational effects produced by gravitation, real bodies are elastic or fluid, not rigid. Gravitation then produces tidal effects, which include alteration of orbits and rates of rotation, mechanical stress, a tendency for bodies to become spherical or ellipsoidal, and heat generation due to friction.

Rigid Body Celestial mechanics

Spherical bodies with a uniform distribution of mass can be treated as if all the mass were concentrated at the center. However, most real bodies do not have a completely uniform distribution of mass and they are not perfectly spherical. Gravitation can produce rotational forces on extended bodies.

Particle Celestial Mechanics

Particle celestial mechanics deals with Newton's law of gravitation and its consequences. The important case of systems with two particles can be examined, and includes orbital mechanics and Kepler's laws. It also includes studies of three and more bodies, which resists exact solution in the general case.

Surface Gravitation

Surface gravitation is the simplest division of gravitation, and deals with the gravitational force near the surface of the earth where variations are small and can usually be ignored.


Throughout most of history, during prehistory, antiquity, and classical and medieval periods, the study of gravitation was confined mostly to the observation that unsupported objects fall down to the earth's surface. (What goes up, must come down) In the modern period, knowledge of gravitation has become far more advanced. In the 16th century there was little development, but in the 17th century, this study was advanced substantially with Newton's theory of gravitation, which has formed the foundation of the subject ever since. Further developments in the 18th century, 19th century, and 20th century are related to improved mathematical technique and application of other areas of mechanics. Application of sociology to the study of gravitation, including social structure and change, communities, and peoples of the world, has not yet been examined seriously. Various nations have contributed. This is closely connected to Western civilization, although in recent times Asiatic peoples have also been examining it. There is little progress from African or American Indian peoples. Institutions including families, education, economics, government, and religion will be developed as the site expands. Culture, including material culture, conceptual culture, and behavioral culture will be useful. Anthropology including particular groups, human geography, human ecology, physical anthropology, and demography is indirectly useful. Social foundations can be applied. Connections with personal studies including biographies may be useful in developing this subject. Psychology including social psychology, personality, mental disorders, developmental psychology, behavior patterns, mind, and behavioral elements can be connected. The human body including form and appearance, life cycle, disease, body functions, and body systems illustrates some applications.
Biology including biohistory, ecology, systematics, organism biology, cell biology, and molecular biology also chiefly illustrates applications. Earth science including geohistory, physical geography, atmospheric science, hydrospheric science, and geology may demonstrate some applications. This area is closely connected to astronomy. Cosmology, galactic astronomy, stellar astronoy, and solar system astronomy all provide illustrations. There are few direct applications of chemistry including systems, reactions, and substances.	Links to other sites: Yahoo - Gravity
Theoretical connections with the structure of matter including subatomic physics are being explored. Atomic physics and molecular physics are useful. Properties of bulk matter are indirectly connected to gravitation. There is a quantum theory of gravity, but it has not yet been confirmed by experiment. Celestial mechanics overlaps somewhat with relativistic physics. The special theory of relativity is not as useful, but the general theory of relativity extends gravitation. There are analogies and similarities with electromagnetism, especially including electrostatics. Electric current is not very useful, and there are significant differences with magnetism. Optics does not seem to be well connected to gravitation. Thermodynamics including nonclassical thermodynamics, classical thermodynamics, and statistical mechanics is weakly connected to gravitation. Nonrigid body mechanics including wave mechanics, fluid mechanics, and deformable bodies is also useful. Rigid body mechanics will be important. Dynamic systems, static systems, and rotation can be considered. The discussion of rigid bodies and motion including extended bodies, position and orientation, linear and angular velocity, linear and angular acceleration, and types and cases will be useful. Understanding of gravitation depends in part on particle mechanics. Particle systems including system properties, particle interactions, and simplified systems can be used. Energetics including work, mechanical energy, and power, and Kinetics including types and cases of force, concepts of, force, momentum, and mass is important. Motion due to gravity is described using kinematics with types and cases of motion and concepts of acceleration, velocity, and position. Many physical bodies move as if they were particles.

Throughout most of history, during prehistory, antiquity, and classical and medieval periods, the study of gravitation was confined mostly to the observation that unsupported objects fall down to the earth's surface. (What goes up, must come down) In the modern period, knowledge of gravitation has become far more advanced. In the 16th century there was little development, but in the 17th century, this study was advanced substantially with Newton's theory of gravitation, which has formed the foundation of the subject ever since. Further developments in the 18th century, 19th century, and 20th century are related to improved mathematical technique and application of other areas of mechanics.

Application of sociology to the study of gravitation, including social structure and change, communities, and peoples of the world, has not yet been examined seriously. Various nations have contributed. This is closely connected to Western civilization, although in recent times Asiatic peoples have also been examining it. There is little progress from African or American Indian peoples.

Institutions including families, education, economics, government, and religion will be developed as the site expands. Culture, including material culture, conceptual culture, and behavioral culture will be useful. Anthropology including particular groups, human geography, human ecology, physical anthropology, and demography is indirectly useful. Social foundations can be applied.

Connections with personal studies including biographies may be useful in developing this subject. Psychology including social psychology, personality, mental disorders, developmental psychology, behavior patterns, mind, and behavioral elements can be connected. The human body including form and appearance, life cycle, disease, body functions, and body systems illustrates some applications.

Biology including biohistory, ecology, systematics, organism biology, cell biology, and molecular biology also chiefly illustrates applications. Earth science including geohistory, physical geography, atmospheric science, hydrospheric science, and geology may demonstrate some applications. This area is closely connected to astronomy. Cosmology, galactic astronomy, stellar astronoy, and solar system astronomy all provide illustrations. There are few direct applications of chemistry including systems, reactions, and substances.

Links to other sites:

Yahoo - Gravity

Theoretical connections with the structure of matter including subatomic physics are being explored. Atomic physics and molecular physics are useful. Properties of bulk matter are indirectly connected to gravitation. There is a quantum theory of gravity, but it has not yet been confirmed by experiment. Celestial mechanics overlaps somewhat with relativistic physics. The special theory of relativity is not as useful, but the general theory of relativity extends gravitation. There are analogies and similarities with electromagnetism, especially including electrostatics. Electric current is not very useful, and there are significant differences with magnetism. Optics does not seem to be well connected to gravitation. Thermodynamics including nonclassical thermodynamics, classical thermodynamics, and statistical mechanics is weakly connected to gravitation.

Nonrigid body mechanics including wave mechanics, fluid mechanics, and deformable bodies is also useful.

Rigid body mechanics will be important. Dynamic systems, static systems, and rotation can be considered. The discussion of rigid bodies and motion including extended bodies, position and orientation, linear and angular velocity, linear and angular acceleration, and types and cases will be useful.

Understanding of gravitation depends in part on particle mechanics. Particle systems including system properties, particle interactions, and simplified systems can be used. Energetics including work, mechanical energy, and power, and Kinetics including types and cases of force, concepts of, force, momentum, and mass is important. Motion due to gravity is described using kinematics with types and cases of motion and concepts of acceleration, velocity, and position. Many physical bodies move as if they were particles.