Apr 042009

The gravitational theory that I’ve been working on for some time with John Moffat is called STVG, or Scalar-Tensor-Vector Gravity. It grew out of Moffat’s investigation of Nonsymmetric Gravity.

There is also a phenomenological formula called MOND (MOdified Newtonian Dynamics) that effectively flattens out the acceleration curve at high radii from a point source. MOND is nothing more than a formula designed by its creator, Mordechai Milgrom, to solve a specific problem, namely the rotation curves of galaxies. It is not rooted in any theory, and in fact, it is known to contradict some; for instance, it violates the law of conservation of energy and momentum. This is why Jacob Bekenstein endeavored to create a relativistic theory called TeVeS, which fixes MONDs problems, while still gives the approximate MOND acceleration formula in the case of weak fields.

Both STVG and TeVeS are gravity theories, and both happen to incorporate tensor, vector, and scalar fields. Beyond that, however, there’s nothing in common between the two theories.

Unfortunately, many Wikipedians don’t know this, and try from time to time to merge the STVG and TeVeS articles. Hopefully not any longer… I just posted a long, fairly complete description of STVG on Wikipedia.

 Posted by at 11:48 pm