Planck momentum
Encyclopedia
Planck Momentum is the unit of momentum
, denoted by
, in the system of natural units
known as Planck units
.
6.52485 kg m/s
where
In SI units Planck momentum is approximately 6.5 kg m/s. It is equal to the Planck mass multiplied by the speed of light
, usually associated with the momentum of primordial photons in some prevailing Big Bang
models. Unlike most of the other Planck units
, Planck momentum occurs on a human scale. By comparison, running with a five-pound object (108×Planck mass) at an average running speed (10-8×speed of light in a vacuum) would give the object Planck momentum. A 70 kg human walking at an average speed of 1 m/s would have a momentum of about 10.7
.
Momentum
In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object...
, denoted by
, in the system of natural unitsNatural units
In physics, natural units are physical units of measurement based only on universal physical constants. For example the elementary charge e is a natural unit of electric charge, or the speed of light c is a natural unit of speed...
known as Planck units
Planck units
In physics, Planck units are physical units of measurement defined exclusively in terms of five universal physical constants listed below, in such a manner that these five physical constants take on the numerical value of 1 when expressed in terms of these units. Planck units elegantly simplify...
.
6.52485 kg m/swhere
is the Planck length
is the reduced Planck's constant
is the speed of lightSpeed of lightThe speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
in a vacuumVacuumIn everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
is the gravitational constantGravitational constantThe gravitational constant, denoted G, is an empirical physical constant involved in the calculation of the gravitational attraction between objects with mass. It appears in Newton's law of universal gravitation and in Einstein's theory of general relativity. It is also known as the universal...
In SI units Planck momentum is approximately 6.5 kg m/s. It is equal to the Planck mass multiplied by the speed of light
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
, usually associated with the momentum of primordial photons in some prevailing Big Bang
Big Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
models. Unlike most of the other Planck units
Planck units
In physics, Planck units are physical units of measurement defined exclusively in terms of five universal physical constants listed below, in such a manner that these five physical constants take on the numerical value of 1 when expressed in terms of these units. Planck units elegantly simplify...
, Planck momentum occurs on a human scale. By comparison, running with a five-pound object (108×Planck mass) at an average running speed (10-8×speed of light in a vacuum) would give the object Planck momentum. A 70 kg human walking at an average speed of 1 m/s would have a momentum of about 10.7
.