gravitational constant
(G, universal gravitational constant, Newtonian gravitational constant)
(indicates how much pull between two masses)
The gravitational constant (G) is an experimentally-determined
value that relates gravitational force between any two objects
to their masses and the distance between them.
The force is proportional to the product of the masses
and inversely proportional to the square of the distance
between them, and the gravitational constant relates
the masses and distances to the magnitude of the force:
F = -Gm1m2/r²
- F - the force on each object (toward the other).
- G - the gravitational constant.
- m1 and m2 - mass of the two objects.
- r - distance between the two objects.
The currently-determined value of the gravitational constant is
6.67430 × 10-11 N·kg-2m2
(i.e., m3 kg-1 s-2),
where:
- N - newtons (force units of 1 kg·m·s-2).
- kg - kilograms.
- m - meters.
- s - seconds.
The Einstein gravitational constant (κ) is:
κ = 8πG/c4
This expresses gravity in a manner convenient to general relativity (GR) equations
and according to GR, is perhaps "more basic". G is referred to
as the Newtonian gravitational constant when there is a need to
distinguish which one is intended.
(constant,gravity,physics)
Further reading:
https://en.wikipedia.org/wiki/Gravitational_constant
https://en.wikipedia.org/wiki/Einstein_field_equations
https://physics.nist.gov/cgi-bin/cuu/Value?bg
https://academic.oup.com/nsr/article/7/12/1803/5874900
Referenced by pages:
chirp mass (Mc)
general relativity (GR)
Hill stability
hydrostatic equilibrium
innermost stable circular orbit (ISCO)
Jeans length
Kelvin-Helmholtz timescale (KH timescale)
mass function
Planck units
Schwarzschild radius (RS)
solar mass (MSun)
standard gravitational parameter (μ)
stellar structure
Toomre Q parameter (Q)
virial parameter
Index