There are other books that are possibly better. The one by Wald comes to mind. MTW was just handy at the moment.

Physically, the lowest multipole order that is possible is the quadrapole. This unfortunately lowers the magnitude of any effect enormously. The need for a varying quadrapole moment is a very well known result. Trying to ignore it doesn't do the M-E folks any favours.

Quote from: Cinder on 07/09/2011 08:21 AMExtraordinary, unlike ... which un-extraordinary conjecture for the origins of inertia?According to you, what extraordinary claims result from the theory that inertial mass is the same as gravitational mass?Like I said, you won't be able to directly convince me, because I know I lack sufficient comprehension of theoretical physics to properly evaluate the theory. All I really know is that the mainstream scientific community finds the equivalence of inertial mass and gravitational mass to be uncontroversial and experimentally confirmed. But I don't comprehend the subtleties of the theoretical ramifications or the fine subtleties of the experimental verification.

Extraordinary, unlike ... which un-extraordinary conjecture for the origins of inertia?

Quote from: IsaacKuo on 07/09/2011 10:48 AMQuote from: Cinder on 07/09/2011 08:21 AMExtraordinary, unlike ... which un-extraordinary conjecture for the origins of inertia?According to you, what extraordinary claims result from the theory that inertial mass is the same as gravitational mass?Like I said, you won't be able to directly convince me, because I know I lack sufficient comprehension of theoretical physics to properly evaluate the theory. All I really know is that the mainstream scientific community finds the equivalence of inertial mass and gravitational mass to be uncontroversial and experimentally confirmed. But I don't comprehend the subtleties of the theoretical ramifications or the fine subtleties of the experimental verification.I'm not looking to convince you. That's the second time you say that.I'm asking/putting this to you: what about the current explanation for the origins of inertia makes e.g. Sciama's conjecture extraordinary? From very faint memory reading Feynman's lectures, the "mainstream" conjecture for the origins of inertia are comparably vague and tentative. Hence the "fog" analogy. That we haven't noticed any need to improve on them, to my layman sense of impartiality, seems like people a few centuries ago being skeptical of our modern refinements of the laws of physics.

TBH the only thing I truly believe in myself is that we should build these and see. No simpler way to settle the matter and to Mach Effect Thrusters' credit they sound pretty darn cheap to build proof of concepts for, compared to any potentially revolutionary technologies I can think of.

we have to first acknowledge that there is NO accepted theory of inertia yet per Cinder's fog analogy.

Not sure if you caught it, but Woodward responded to this in an e-mail sent to Paul posted a few pages back.

Quotewe have to first acknowledge that there is NO accepted theory of inertia yet per Cinder's fog analogy.That isn't quite true. General Relativity explains its origins in an indirect manner. Since the equations of motion are derivable from G_ab=8\piT_ab, the amount of acceleration as a function of mass is hidden in there if you want to find it.Woodard and Co. do not have a monopoly in explaining inertia by any means.My point is that it doesn't matter what theory of inertia (or gravity) you take. Try it. No matter which one you choose, you have a choice between allowing/requiring negative mass/energy, or have quadrupole radiation as the lowest order coupling. (Or have a theory of gravity that doesn't gravitate... but we'll ignore those.)If you allow the creation of negative energy, it is trivially easy to make a propulsion device. No need to use oscillators at all. All you need is a rigid rod to separate equal masses of opposite sign.

Due toconservation of energy/momentum, monopole and dipole mass/energyfluctuations do not exist in General Relativity. If you wish toradiate gravitational waves, you need to have a varying quadrapolemoment. If a theory of gravity predicts dipole (or the requiredmonopole) radiation, then it has been ruled out by experimentalgravity wave searches.

What I'm trying to get to here is the following:- Is there a something that says that negative mass is forbidden (natural phenomena / experiments)? Then the ME-teory goes down the drain as I understand you.

Is there a particular reason why negative mass isn't allowed (causality problems that may arise)?

As is the reminder that Woodward isn't the only one thinking about the origin of inertia.

Inertia is implicit within the equations of motion. If your theory of gravity (whatever it is) predicts equations of motion, then your theory also describes inertia.

Quote from: Cinder on 07/10/2011 08:36 AMTBH the only thing I truly believe in myself is that we should build these and see. No simpler way to settle the matter and to Mach Effect Thrusters' credit they sound pretty darn cheap to build proof of concepts for, compared to any potentially revolutionary technologies I can think of. Cinder:"Simple" devices often turn out NOT to be as simple in practice as Woodward and his Crew have found out to their chagrin over the last 20 years. If you need another example of this, just look at the Cold Fusion fiasco where a lot of unprepared folks thought that the 1988 Ponds and Flashmann experiment was "simple" to replicate, but then found out that it wasn't. However if you are willing to EXACTLY duplicate the best example of the experiment in question, you have a shot of duplicating the results. And that takes some inital and detailed collaboration with the original experimenter. Best, Paul M.

As previously said I'm a newb to GRT/SRT, but I always thought that equations of motion don't "describe" inertia; they rather require a priori, a particular understanding of inertia,that every action has an equal and opposite reaction.

If the error in ME conjecture is so well defined, shouldn't that help in identifying what is producing the false positive signal in the experiments?

QuoteIf the error in ME conjecture is so well defined, shouldn't that help in identifying what is producing the false positive signal in the experiments?Not really. The real world is messy, and there are all sorts of non-ideal behaviour you need to worry about. You are better off designing an experiment that avoids as many of the issues as possible.Unfortunately for the ME conjecture, the cleanest idea of using a battery powered device surrounded by a Faraday Cage didn't yield any thrust. This strongly hints that what some of the experiments are measuring isn't what they hope it is.