Conservation of Mass

Conservation Of Mass

The law of conservation of mass, also known as the principle of mass/matter conservation, states that the mass of an isolated system (closed to all transfers of matter and energy) will remain constant over time. This principle is equivalent to the conservation of energy: when energy or mass is enclosed in a system and none is allowed in or out, its quantity cannot otherwise change over time (hence, its quantity is "conserved" over time). The mass of an isolated system cannot be changed as a result of processes acting inside the system. The law implies that mass can neither be created nor destroyed, although it may be rearranged in space and changed into different types of particles; and that for any chemical process in an isolated system, the mass of the reactants must equal the mass of the products.

The concepts of both matter and mass conservation are widely used in many fields such as chemistry, mechanics, and fluid dynamics. Historically, the principle of mass conservation, discovered in chemical reactions by Antoine Lavoisier in the late 18th century, was of crucial importance in progressing from alchemy to the modern natural science of chemistry.

In a thermodynamically closed system (i.e. one which is closed to exchanges of matter, but open to small exchanges of non-material energy (such as heat and work) with the surroundings) mass is only approximately conserved. In this case the input or output of energy changes the mass of the system, according to special relativity, although the change is usually small since relatively large amounts of energy are equivalent to only a small amount of mass. Mass is absolutely conserved in so-called isolated systems, i.e. those completely isolated from all exchanges with the environment. In special relativity, the mass-energy equivalence theorem states that mass conservation is equivalent to total energy conservation, which is the first law of thermodynamics. In special relativity the difference between closed and isolated systems becomes important, since conservation of mass is strictly and perfectly upheld only for isolated systems. In special relativity, mass is not converted to energy, as such, since energy always retains its equivalent amount of mass within any isolated system. However, certain types of matter may be converted to energy, so long as the mass of the system is unchanged in the process. When this energy is removed from systems, they lose mass.

In general relativity, mass (and energy) conservation in expanding volumes of space is a complex concept, subject to different definitions, and neither mass nor energy is as strictly and simply conserved as is the case in special relativity and in Minkowski space. For a discussion, see mass in general relativity.

Read more about Conservation Of Mass:  History, Generalization

Other articles related to "conservation of mass, mass, conservation of, of mass":

Conservation Of Mass - Exceptions or Caveats To Mass/matter Conservation - General Relativity
... In general relativity, the total invariant mass of photons in an expanding volume of space will decrease, due to the red shift of such an expansion (see ... The conservation of both mass and energy therefore depends on various corrections made to energy in the theory, due to the changing gravitational potential energy of such systems ...
Derivation Of The Navier–Stokes Equations - Conservation Laws - Conservation of Mass
... Mass may be considered also ... Taking (no sources or sinks of mass) and putting in density where is the mass density (mass per unit volume), and is the velocity of the fluid ... This equation is called the mass continuity equation, or simply "the" continuity equation ...
Lift (force) - Description of Lift On An Airfoil - Bernoulli's Principle: Lift, Pressure, and Speed - Conservation of Mass
... point, then lift can be explained in terms of pressures using Bernoulli's principle and conservation of mass ... This idea is called "conservation of mass", and for incompressible flow mass is conserved within each streamtube ... Conservation of mass says that the flow speed must increase as the stream tube area decreases ...

Famous quotes containing the words conservation of, mass and/or conservation:

    The putting into force of laws which shall secure the conservation of our resources, as far as they may be within the jurisdiction of the Federal Government, including the more important work of saving and restoring our forests and the great improvement of waterways, are all proper government functions which must involve large expenditure if properly performed.
    William Howard Taft (1857–1930)

    Reduced to a miserable mass level, the level of a Hitler, German Romanticism broke out into hysterical barbarism.
    Thomas Mann (1875–1955)

    A country grows in history not only because of the heroism of its troops on the field of battle, it grows also when it turns to justice and to right for the conservation of its interests.
    Aristide Briand (1862–1932)