# Understanding the different kinds of mass in gravity

On this site, the Phys.SE question Is there a fundamental reason why gravitational mass is the same as inertial mass? has been asked. See also this Phys.SE question. The 'answer' provided on this forum has been that the curvature of spacetime explains both. The answer is still cryptic for me as I am more a concrete thinker.

Newton said $F=ma$. I can use this formula to measure inertial mass. Experimentally I can measure the motion of an object while applying a constant force to it. Newton also said $F=\frac{GMm}{r^2}$. In this case, what simple experiment will allow the measurement of gravitational mass?

• thank you qmechanic for 'refining' the question. It's interesting to see that some people here can interpret the meaning of a question in spite of the noise. – aquagremlin Jul 24 '13 at 2:16

What you're probably looking for is something like the famous Eötvös experiment which used a kind of torsion balance to test the equivalence of gravitational and inertial mass.

• thank you. i totally forgot about the torsion balance. but then it's not all that different than using a balance scale. – aquagremlin Jul 23 '13 at 23:02

Mass universe is constituted of micro / macro mass natural bodies/systems. It is known that the mass (micro / macro) natural bodies is concentrated mainly in neutrons, protons and electrons as entities with a certain stability, fig. 3.

Fig. 3. (Electro)convergence of the electron/neutron /proton, )

1- Neutron matrix (local substantial body/ local wave induced environmental, mi); 2 – Neutrino flux, JdV,( cilyndrical cloth neutrinos Mi/H1, penetrated the transverse plane of matrix neutron); 3- Rotation moment of neutron matrix, respectively vortices, mi (with speed v, ω ); Pv’, Pv - electroconvergence vortex magnetic moments (coupling) of underground neutrino, Mi, respectively, neutron/ mi;

Neutrino flux, JdV, (2) unbalanced spatial neutron matrix, (1) and maintains a transport phenomenon (on the environment) and displacement (in counter flow) of entities (pre) mass, mi, (3). For reasons of logical presentation, we associate pulsating neutrino mass rotating blade / spine, mi, (3) respectively neutron mass mN =ρ dV, an electric charge, q = Dm, where D is the constant magnetic universal. To describe the dynamics of (micro) local mass systems, N, with mass, mN =ρ dV , is associated with the force of gravity, dVg , and neutrino flux, JdV, ( mass emerge entities induced environmental) magnetic force, J BdV, so that it follows the equation for mass magnetic interaction between natural bodies:

               F =pdV+JB                                                              (2)


In the event that all substances/neutrino flux, Mi/JdV, of the moving with the same speed v, the resultant current of matter, J = Dv , so that equation (2) can be written as:

                                     F = (g+Dv+B)                                                          (3)


Formula (3) represents the equation of gravity for the mass unit of the substance D crivoi

• Dear crivoi D. Welcome to Phys.SE. It is usually frown upon to directly copy-paste identical answers. (The problem is if everybody start to copy-paste identical answers en mass.) In general in such situations, please consider one of the following options: (i) Delete one of your answers. (ii) Flag for duplicate posts and delete one of your answers. (iii) If you think the two posts are not duplicates, then personalize each answer to address the two different specific questions. – Qmechanic Feb 16 '15 at 13:29

## protected by Qmechanic♦Feb 16 '15 at 13:25

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