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When a pulsar's spin period slows down sufficiently, the radio pulsar mechanism is believed to turn off (the so-called "death line"). This turn-off seems to take place after about 10–100 million years, which means of all the neutron stars born in the 13.6-billion-year age of the universe, around 99% no longer pulsate.
Volume per unit mass (reciprocal of density) m 3 ⋅kg −1: L 3 M −1: intensive Spin: S: Quantum-mechanically defined angular momentum of a particle kg⋅m 2 ⋅s −1: L 2 M T −1: Strain: ε: Extension per unit length unitless 1: Stress: σ: Force per unit oriented surface area Pa L −1 M T −2: order 2 tensor Surface tension: γ ...
electromotive force: volt (V) pi: 3.14159... (irrational number) unitless rho: mass density usually simply called density kilogram per cubic meter (kg/m 3) volume charge density: coulomb per cubic meter (C/m 3) resistivity: ohm meter (Ω⋅m) sigma: summation operator
It is defined as periodic time increase per unit time; it is a dimensionless quantity, but can be given the units of s⋅s −1 (seconds per second). [ 59 ] The spin-down rate ( P -dot) of neutron stars usually falls within the range of 10 −22 to 10 −9 s⋅s −1 , with the shorter period (or faster rotating) observable neutron stars ...
A body force is simply a type of force, and so it has the same dimensions as force, [M][L][T] −2. However, it is often convenient to talk about a body force in terms of either the force per unit volume or the force per unit mass. If the force per unit volume is of interest, it is referred to as the force density throughout the system.
Unlike true orbital velocity, radial velocity can be determined from Doppler spectroscopy of spectral lines in the light of a star, [3] or from variations in the arrival times of pulses from a radio pulsar. [4] A binary system is called a single-lined spectroscopic binary if the radial motion of only one of the two binary components can be ...
In physics, natural unit systems are measurement systems for which selected physical constants have been set to 1 through nondimensionalization of physical units.For example, the speed of light c may be set to 1, and it may then be omitted, equating mass and energy directly E = m rather than using c as a conversion factor in the typical mass–energy equivalence equation E = mc 2.
The slug is a derived unit of mass in a weight-based system of measures, most notably within the British Imperial measurement system and the United States customary measures system. Systems of measure either define mass and derive a force unit or define a base force and derive a mass unit [ 1 ] (cf. poundal , a derived unit of force in a mass ...