Freedom of Science

There is a very nice discussion going on at Physics Forum regarding the Cavendish Experiment. I wrote about the two tests that I want to try here and I really appreciate the thoughtful comments at Physics Forums.

I am arguing that the linear force of the wire cannot balance the dynamic Newtonian force which varies as the inverse square of the distance between weights.

Cavendish never assumed such an unphysical equilibrium to compute the density of the Earth. He did not know about G so he never computed G. The modern derivation which is based on the unphysical equilibrium of a linear force and a dynamical force is a later addition invented in the 19th century by the British Newtonian physicists to define Cavendish experiment as the first posthumous computation of G.

The geometry of the Cavendish experiment is very simple:

AB = the initial position of the pendulum arm
BC = r = the excursion of the arm
AC = the pendulum arm at excursion r
BD = l = the initial distance between weights B and D.
CD = (l - r) = the distance between weights at excursion r

The absurdity of the Cavendish experiment is obvious at once. BC is linear and varies as r; CD is dynamical and varies as 1/(l - r)^2.

The point C cannot move both linearly and dynamically at the same time. BC cannot vary linearly as distance while CD varies as inverse square of the distance. It is unphysical to assume such a motion. This proves that G cannot be computed from the Cavendish experiment by assuming a measurement of an attraction between weights.

What do you think?

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