Replies

I have talked enough to Robert Bennett by e-mail to be able
to say that he does not even understand physics at the level of a college freshman physics major. He misunderstands basic things. If he has a Ph.D. it cannot be in theoretical physics from any reputable physics department. He uses terms like "inertial frame", and "Lense-Thirring effect" without any understanding. He made arguments to me about stellar parallax that involved elementary blunders. My own credentials? I have a Ph.D. in theoretical physics from Princeton Univ. (1978) and have published over 125 papers in research journals on fundamental physics.

Stephen M. Barr

Are you the author of "Modern Science, Ancient Religion"?

I disagree on Dr. Bennett. His chapter 12 is a pretty significant piece of work.

Mark

Dr. Barr:

I remember you stating in a previous post (last year) that rotation is absolute in general relativity. This is factually untrue. It is absolute in special relativity. Einstein invented general relativity to solve this issue (relativity of rotation).

We can all make errors.

Mark

Re 14: It would be interesting if you could post some of the exchanges.

I engaged Sungenis and Bennett two years ago and soon saw that they were nutters. Bennett has no understanding of a rotating reference frame, no understanding that rotation implies an accelerated system, and his dismissal of the Coriolis "force" was laughable.

The offer of $100k to prove them wrong is laughable. Note that they are the sole deciders and can change the rules at whim. The simplest way for them to always 'win' is: we do not accept your evidence. This parallels the creationist arguments against evolution.

I never got to finish that previous conversation.Here it is:

Sir, I am afriad you don't understand GR correctly. While Einstein was indeed influenced by Mach's ideas, GR is not really a Machian theory, though it predicts some effects that are reminiscent of Machian ideas (like dragging of inertial frames). One can find some books that say that GR is Machian, but the general consensus is that it is not. In GR, uniform motion is relative, but accelerated motion is absolute --- just as in Newtonian physics. The question of whether something is rotating or not is an ABSOLUTE question with one and only one correct answer. Yes, one can go to a frame in which a rotating object looks like it is not rotating --- however, such a frame is not an inertial frame; more specificly, it is a rotating frame. And one can tell that it is so by looking at the "fictitious forces" that appear in that frame. It is absurd to say that the whole universe could be rotating about an axis that goes through the earth. Distant stars could only be kept in circular orbits about such an axis by some centripital force directed toward that axis. Here the people like Sungenis will babble about dragging of inertial frames. They say that the distant matter going around will drag the stars around the axis. Not so. Not least of the problems with this idea is that one cannot write down a global rotating coordinate system, since the time coordinate lines would become superluminal at some finite (and not so large) distance. To put it another way, if all the stars go around the earth every 24 hours, then stars more than a light-year away would be going faster than light. But all this is nonsense anyway. Anyone who has a solid grasp of GR knows that in it accelerated motion is an ABSOLUTE concept. Finally, let me say that I actually do research in areas that require GR. I have refereed papers for journals such as Classical and Quantum Gravity. As I said, I teach GR at the graduate level --- do you?

17 posted on 10/11/2005 6:58:42 AM PDT by smpb (smb)

I agree, there is some controversy as to whether GR is Machian. I should have stated that it contained Einstein's interpertation of Mach.

Still in GR there are no fictitous forces in rotation. They become real forces as described by Thirring, Barbour and Berlotti, Bondi, etc. Einstein invented GR specifically so he could relativize rotation (a shortcoming of SR). When you reduce to the approximation of a Post-Newtonian formulation, then you are more SR-like, but as a general principle, rotation is relative in GR.

As to the point at which velocities of the stars become superluminal, this is the Schwartzchild radius, and Bondi has demonstrated that a shell of matter at this radius represents the effect of the rest of the universe. This lends support to Thirring, Barbour Berlotti, etc.

This also lends support to the ideas that aether theory can reproduce many relativistic effects (i.e, frame dragging). It tends to reduce GR to a more local action as it is usually described. Aether theories, especially with graviton type gravity tend to be more local in action also, while Mach's principle is more universal. Never the less, the matter at the farther reaches of the universe do have an effect at the earth, it is just a matter of how to represent it.

Mark

It wouldn't surprise me to learn Bennett has no such degree. Sungenis doesn't have the PhD he claims, so it would only follow...