An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A branch of → mechanics based on → variational principle that describes systems by their → Lagrangian or → Hamiltonian. Analytical mechanics provides a formalism that is different from that of Newton and does not use the concept of force. Among other things, analytical mechanics gives a more simple description of continuous and constrained systems. Moreover, its mathematical structure allows it an easier transition to quantum mechanical topics.

→ analytical; → mechanics.

The branch of astronomy that deals with the calculation of motions of celestial bodies under the action of their mutual gravitational attractions.

→ celestial; → mechanics.

Mekânik, → mechanics; âsmâni, → celestial.

The branch of physical science which deals with the motions of bodies travelling at velocities that are very much less than that of light in a vacuum. Same as → Newtonian mechanics.

→ classical; → mechanics.

The branch of physics that extends the ideas developed in → mechanics and → thermodynamics to the study of motion and equilibrium of → fluids.

→ mechanics; → fluid.

A branch of → physics that deals with motion and the → action of → forces on bodies. Mechanics may be divided into three areas, → kinematics, → dynamics, and → statics.

From mechanic, from L. mechanicus, from Gk. mekhanikos "an engineer," also "inventive," literally "pertaining to machines" (adj.), from mekhane, → machine, + → -ics.

Mekânik, loan from Fr. Sâzokârik, from sokâr, → mechanism, + -ik, → -ic.

A system of mechanics based on → Newton's law of gravitation and its derivatives. Same as → classical mechanics.

→ Newtonian; → mechanics.

Mechanics in which the masses under consideration move at speeds much slower than the speed of light.

→ non-relativistic; → mechanics.

A development of Newtonian mechanics based on the discrete character of energy (Planck 1900) and the wave motion of material particles (de Broglie 1924). It is relies on the consideration that energy state of a quantum mechanical system can be derived at a given instant by a function whose square of the modulus gives the probability distribution of the coordinates of the system. Quantum mechanics is essential for the treatment of all atomic processes. It holds also for ordinary large scale processes although in this case the deviations from Newtonian mechanics are negligible.

→ quantum; → mechanics.

A quantum theory that incorporates special relativity, for example, → quantum electrodynamics.

→ relativistic; → quantum mechanics.

The surface area of a black hole's horizon can never decrease.

→ second; → law; → black hole; → mechanics.

→ statistical physics.

→ statistical; → mechanics.

One of the forms of quantum mechanics, due to Louis de Broglie and extended by E. Schrödinger. It originated in the suggestion that light consists of corpuscles as well as of waves and the consequent suggestion that all elementary particles are associated with waves.

→ wave; → mechanics