ثابت الجاذبية

ثابت تناسبي γ في قانون نيوتن للجاذبية الكونية. يمكن أن ترتبط قوة الجاذبية F بين نقطتين للكتلة m1 و m2 بالمسافة r بينهما:

$F={\frac {\gamma m_{1}m_{2}}{r^{2}}}$

$\gamma$ has the value $6.67\times 10^{-11}N\cdot m^{2}/kg^{2}$. The force is a vector directed toward the attracting mass. The gravitational field g (also a vector, often called the acceleration of gravity) is the force per unit mass (measured by the force on the mass m₁ in the gravimeter):

$g={\frac {F}{m_{1}}}={\frac {\gamma m_{2}}{r^{2}}}$;

g is the vector sum of the effect of all the masses (e.g., the masses in the Earth).