On Mar 21, 2007, at 6:53 PM, philip madsen wrote:
In fact most of the selected paragraphs I offer below from Wikipaedia, (admittedly not gospel) merely add more confusion as to what is reality and what is imagination.
Imagine that -- how can it be that paragraphs from Wikipaedia add confusion? Oh, and Sinbad the comedian is dead too -- so reported the Wickipaedia a touch prematurely.
If you're getting the impression I have little faith in the Wikipaedia (or Wickipedia for those who hate dipthongs and digraphs), you'd be right. The place to go for somewhat more useful information on this would be Physical Review D, Nature, and the journal Gravitation and General Relativity.
Let's clear the air about a few things. First, you have a baby-vs- bathwater problem if you tie Lense-Thirring to General Relativity (GR). I'm no fan of GR either: I think it's ripe for overthrow for a host of compelling reasons. But the Lense-Thirring effect also arises out of Mach's Principle, and about half of all informed physicists believe that Mach's Principle is incompatible with GR. So, there's no necessity to tie the Lense-Thirring effect to GR, then pooh-pooh GR, and thus disparage Lense-Thirring for a guilty association. That line of reasoning doesn't fly. Lense-Thirring has been readily defended outside of GR's formalism: the death of one does not entail the death of the other.
There's more reason not to chain Lense-Thirring to GR: the coefficients for the predicted magnitudes differ, based on how you derive Lense-Thirring. You follow the original GR-based derivation, you get one value; you follow Mach's Principle, something different pops up.
Second, the Lense-Thirring effect is important to geocentricity: it has a bearing on Einstein's letter to Ernst Mach where the former explains how the Foucault pendulum's plane of oscillation precesses when a shell of matter surrounding the pendulum is rotated. If the shell is sufficiently massive, the precession period matches the period of the shell's rotation (known as "perfect frame dragging"). It so happens that THIS is the situation the geocentric universe finds itself in: the rotating cosmos causes the Foucault pendulum to move in sync with the universal mass (perfect frame dragging). Throw out Lense-Thirring, and this explanation becomes more than suspect. Throwing out Lense-Thirring is cutting off our nose to spite our face. (Ironically, that means that all the "attempts" to measure Lense-Thirring are missing the 800-pound gorilla sitting in the living room -- the Foucault pendulum is undergoing a huge Lense- Thirring effect, since the rotating mass of the cosmos is causing the entire thing at the macro level to precess.)
So, let's be careful not to inflict damage on some of our best evidence. So-called "friendly fire," where you shoot your own troops inadvertently, should be avoided.*
In no way, however, do I assert that Lense-Thirring, as a physical effect, directly points to GR or spacetime or other non-classical physics models. It can be codified within a more classical regime (including aether-based regimes, depending on the nature of the aether being proposed). So, we need to be discerning enough to discriminate between the baby and the bathwater. Throw out the bathwater all you want: don't kill the baby -- we need this particular baby.
Third, there's a time to demand "direct" proof, and a time to accept sufficient "indirect" proof as adequate warrant. I apply the former to the issue of alleged dark matter and or the alleged existence of black holes (all alleged discoveries are invariably based on "indirect" proof -- the proviso is usually added, if the journalist is forthcoming and honest, that there is no direct proof they exist). In other circumstances, however, an indirect proof can be compelling. Lense-Thirring evidence tends to be in this latter category. The difference is that for black holes, we should have no problem detecting them directly if they exist; but the Lense-Thirring effect is difficult to detect directly. So we cut some provisional slack for the latter, while being hard-nosed over the former.
For what it's worth, Martin* I don't know why, but the idea of shooting your own troops reminds me of some dated dialogue on the old Dragnet TV series, where the detective (named Friday) interviews a woman. I'm paraphrasing from memory here--
Woman to Friday: "You're policemen! Why are you here? Did something happen?"
Friday: "Yes, ma'am. It's about your boyfriend, Paul." Woman: "Something bad happened to Paul?" Friday: "You could say that, ma'am." Woman: "How bad is it?" Friday: "As bad as it can get." Woman: "He's dead?" Friday: "Mmm hmmm. It was a gun that killed him."Woman: "I'm sure it was an accident. You know how it goes with gun collectors like Paul. You're cleaning your gun, and it accidentally goes off."
Friday: "Six times in the back of the head, ma'am?"