Author Topic: Propellantless Field Propulsion and application  (Read 690264 times)

Offline Star-Drive

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Re: Propellantless Field Propulsion and application
« Reply #1420 on: 07/10/2011 04:11 AM »
There are other books that are possibly better.  The one by Wald comes to mind.  MTW was just handy at the moment.

Steve & Cuddihy:

When it comes to books on gravity, my preference is for Ciufolini and Wheeler's "Gravitation and Inertia".

http://www.amazon.com/Gravitation-Inertia-Ignazio-Ciufolini/dp/0691033234/ref=pd_sim_b_5 
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Offline GeeGee

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Re: Propellantless Field Propulsion and application
« Reply #1421 on: 07/10/2011 06:02 AM »
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.

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

"What von Feurst says to you about gravity waves is, of course, correct.  In the standard calculation the lowest order freely propagating at infinity term is the quadrupole term.  And it is minuscule.

The "problem" here is that in standard GR, inertial reaction forces are not considered to be gravitational in origin, notwithstanding that Sciama's calculation (and one done by Nordtvedt in the 1980s on "linear accelerative frame dragging") show that when the universe is taken to be "rigidly" accelerating in some direction past a local object, it exerts a force on the object (if it is constrained to not participate in the acceleration) that is just the inertial reaction force when phi/c^2 is roughly one.

Since inertial reaction forces are acceleration dependent, a radiative process is involved.  And since inertial reaction forces are decades of orders of magnitude larger than the sort of radiation reaction forces of standard gravity wave analysis, the source of von Feurst's comments is straight-forward.  "Mach effects" are just Newtonian order tansients in the much larger inertial reaction force picture, as you note."

Also just a suggestion but I think it would be best to state your objections directly to Woodward since he is the one who derived the M-E.
« Last Edit: 07/10/2011 07:06 AM by GeeGee »

Offline Cinder

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Re: Propellantless Field Propulsion and application
« Reply #1422 on: 07/10/2011 06:15 AM »
Extraordinary, 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. 
« Last Edit: 07/10/2011 06:16 AM by Cinder »
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Offline 93143

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Re: Propellantless Field Propulsion and application
« Reply #1423 on: 07/10/2011 06:37 AM »
Not only that, but my comment that was being responded to (regarding separating different types/definitions of mass) was just a dredged-up half-memory, likely mistaken; it really shouldn't be used as a point of attack...

In fact, I'll remove it, since it seems to have done more harm than good.
« Last Edit: 07/10/2011 06:38 AM by 93143 »

Offline Cinder

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Re: Propellantless Field Propulsion and application
« Reply #1424 on: 07/10/2011 08:36 AM »
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.
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Offline Star-Drive

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Re: Propellantless Field Propulsion and application
« Reply #1425 on: 07/10/2011 03:06 PM »
Extraordinary, 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. 

Folks:

Steve F. may not see this yet, but IMO his concentration on monopole, dipole or quadrupole radiation is missing the point that if we are to explain the origins of inertia, and the possible transient effects that appear to surround it, we have to first acknowledge that there is NO accepted theory of inertia yet per Cinder's fog analogy.  And depending on the inertia model we pick, that model could drastically affect how inertia effects are created, conveyed and/or transmitted throughout the cosmos.  We also have to acknowledge the fact that inertial reaction forces are only expressed under an acceleration of a confined volume of mass/energy, and that the onset of these inertial reaction forces are instantaneous, as expressed by Newton's third law.  The latter point is not an opinion, but an observed fact. 

Based on the work of Newton, Mach, Einstein, Sciama, Nordtvedt and more current contributors, Woodward posits that Newtonian inertial reactions forces have to be based on Mach’s principle and that these effectively instantaneous inertial radiation reactions forces are developed in the universe's causally connected gravitational field.  These assumptions demands that we finally accept the reality of J. C. Maxwell’s E&M propagation equation’s plus AND minus in time solutions, and by analogy, in gravitation based effects as well.  Now I won’t go into the dither that the practioners of the mainstream physics community go into whenever they discuss cause and effect issues surrounding Maxwell’s plus & minus E&M propagation solutions as well as the related Wheeler/Feynman Absorber Theory, other than to say they both provide a possible means to accomplish “Spooky Action at a Distance” that is demanded by the expression of inertia in a Machian Universe.   However that still leaves the problem that Steve F. raised, and that is what should the characteristics of a tensor based, gravitational radiation be that are generated by accelerated quantities of mass/energy?  Especially when considering that their backwards AND forward in time propagation solutions have to be taken into account as well.  A solution that has to provide us the observed instantaneous AND large reaction forces we experience every time we make something move?

I don’t have an immediate answer to this question, but I do know that Woodward is working on one as I type this.  If I have to take a guess at his answer though, I’ll bet that it is wrapped around the atemporal nature of inertial reaction forces.  This implies that the very small and retarded quadrupolar gravitational radiation “pilot wave” emitted by a local chunk of accelerated mass/energy will have to be summed with the very large advanced quadrupolar gravitational return wave coming back from all the rest of the mass/energy in the causally connected universe.  Hmmm, and I’m now wondering what the antenna pattern would be of such an atemporal quadrupolar gravity wave interaction…

Best,

Paul M.
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Offline Star-Drive

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Re: Propellantless Field Propulsion and application
« Reply #1426 on: 07/10/2011 03:18 PM »
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.

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.
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Offline sfuerst

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Re: Propellantless Field Propulsion and application
« Reply #1427 on: 07/10/2011 04:25 PM »
Quote
we 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.

Trying to split the coupling into a sum of advanced and retarded waves is pointless.  The mathematical results are the same, just your interpretation of those results differs.  It becomes a matter of philosophy rather than science.  (You can't determine locally which direction in time a null-wave is travelling, since it experiences no time.)

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

Actually, I did catch it, and did respond to that point.  Dragging of inertial frames in GR is extremely well known.  I used to model photons within the Kerr space-time, where the ergosphere contains extreme frame-dragging. 

The problem is that the issue with M-E propulsion is gravity theory agnostic.  It is step 1 (initial gravitational mass/energy distribution) that is broken, we don't even get to step 2 (applying a gravity theory).

Offline Eric_S

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Re: Propellantless Field Propulsion and application
« Reply #1428 on: 07/10/2011 08:43 PM »
Quote
we 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.


First of all, thank you for your insight sfuerst!

Is there a particular reason why negative mass isn't allowed (causality problems that may arise)? Is there some phenomenon that should exist given that negative mass is allowed, but be can't see signs of it and thus ==> we are forced to use a quadropole ==> ME theory falls (sadly).

Copys of Gravitation by MTW and GR by Wald are on my to buy list for my little science, engineering and maths library. But that won't be untill my salary rolls in the 25th, and then shipping, taking the time to read and understand them.

Offline Eric_S

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Re: Propellantless Field Propulsion and application
« Reply #1429 on: 07/10/2011 09:09 PM »
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 it forbiden due to causality? Then there _may_ still be room for it, as long as it doesn't have the chance of actually transmitting information faster than light? Ie the creepier parts of ME-theory; that states that you can drain the universe of energy if a certain term grows large enough and allows for spacedrives to be made, are rendered invalid by some intrinsict protection mechanism of the universe. But the parts that allow you to make "hoverboards" and hovercars" may still work.

The explanations on why it isn't a mathematical necessity are much apreciated. As is the reminder that Woodward isn't the only one thinking about the origin of inertia.

[ed]

Thought that this might needed to be reposted (from sfuerst):

Quote
Due to
conservation of energy/momentum, monopole and dipole mass/energy
fluctuations do not exist in General Relativity.  If you wish to
radiate gravitational waves, you need to have a varying quadrapole
moment.  If a theory of gravity predicts dipole (or the required
monopole) radiation, then it has been ruled out by experimental
gravity wave searches.

[/ed]
« Last Edit: 07/10/2011 10:47 PM by Eric_S »

Offline GeeGee

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Re: Propellantless Field Propulsion and application
« Reply #1430 on: 07/10/2011 09:20 PM »
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.

There is something called the quantum inequalities conjecture that apparently limits how much exotic matter you can produce, but I've seen a couple papers on this that show this isn't true, i.e.

http://arxiv.org/abs/gr-qc/0207057

Offline sfuerst

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Re: Propellantless Field Propulsion and application
« Reply #1431 on: 07/10/2011 09:21 PM »
Quote
Is there a particular reason why negative mass isn't allowed (causality problems that may arise)?

The problem isn't that negative mass isn't allowed.  The problem is that we don't know how to make any.  The closest we have is the Casimir effect, where the vacuum between the conducting plates has a lower energy than normal.  However, the mass-energy in the plates themselves greatly outweighs any negative energy between them, so the total is always positive. :-/

If you could make matter with negative energy, all sorts of things would be possible.  Wormholes, warp drives, ftl communication, time machines...  M-E propulsion would look absolutely tame compared to all the other breakthroughs.

Negative-energy (gravitational wave) radiation is a different story though.  If it existed, then the vacuum state would be unstable.  This is the reason why Einstein moved to a tensor rather than vector theory of gravity when creating GR.  Gravitational waves in GR have positive energy.

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

The problem here is that Woodward is asking the wrong question.  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.  The real questions are "what are the equations of motion?", and "how well do they match with experiment?".

Currently, the simplest theory of gravity that matches all observations is GR.  This isn't for the lack of trying though.  There are many other theories that have failed to live up to expectations.

Offline cuddihy

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Re: Propellantless Field Propulsion and application
« Reply #1432 on: 07/10/2011 10:15 PM »

  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.


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.

From what I've seen, both the conventional understanding of inertia (that it is a basic and intrinsic property of matter) and Woodward's (that is is an "observed" or "effectively" instantaneous gravitational radiation reaction to the rest of the matter in the universe) have this same understanding.

Even without yet understanding the quadropole / dipole issue yet, I would still disagree that asking what the origin of intertia is, is "the wrong question," any more than asking what the nature of the relationship between energy and mass is, was asking the wrong question for Einstein.

Prior to SRT didn't most people think that energy and mass were fundamentally unrelated phenomena?

Woodward may be wrong about the existence of an easily exploitable "Mach effect," or his inertial flux ideas may also be mistaken, but I still think it's an important question to ask (the origin and possible modifyability of inertia.)

Offline Cinder

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Re: Propellantless Field Propulsion and application
« Reply #1433 on: 07/10/2011 10:54 PM »
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.

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.
Yes, that's what I'm saying... The experimental setups in question here are on that order.  It's skepticism that keeps more replications from taking place, not affordability.  We're in the table-top ballpark, not so much particle accelerator or even few- but multiple-room setups' order.

Even if the conjecture's definitely wrong, it'll be that much easier in terms of money, to demonstrate it.  And to me the experimental expense in time and effort is worthwhile - with proper records, the how-to lessons wouldn't ever be un-learned and in the big picture this would be one more pair of "concentration" cards excluded representing all possible laws of nature, to narrow down where/what are the "laws" of inertia.

Even if straight forward building and testing approach, rather than theorizing, necessarily includes lots of theorizing to make any progress in figuring out just what needs to be built and how, it's fortunate that ME experiments so far seem to be as affordable as they are.
« Last Edit: 07/10/2011 10:58 PM by Cinder »
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Offline sfuerst

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Re: Propellantless Field Propulsion and application
« Reply #1434 on: 07/10/2011 10:57 PM »
Quote
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.

In Newtonian physics, that is correct.  In that context, it is quite mysterious why inertial mass and gravitational mass have any connection since gravity is just one force amongst many.

GR is different.  It models the behaviour of all mass/energy in the universe in a self-consistent manner.  It handles the effects of every other force by modelling their stress-energy content.  By using calculus of variations on the Einstein equation, the effects of inertia neatly pop out due to conservation of stress-energy.

Offline Cinder

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Re: Propellantless Field Propulsion and application
« Reply #1435 on: 07/10/2011 11:09 PM »
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?
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Offline sfuerst

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Re: Propellantless Field Propulsion and application
« Reply #1436 on: 07/10/2011 11:35 PM »
Quote
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?

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.

Offline cuddihy

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Re: Propellantless Field Propulsion and application
« Reply #1437 on: 07/11/2011 12:20 AM »
Quote
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?

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.

Wow. First time I've heard of that.

When was that done & by who?

Offline sfuerst

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Re: Propellantless Field Propulsion and application
« Reply #1438 on: 07/11/2011 12:25 AM »
Yesterday Duncan Cumming emailed everyone on Woodward's list saying that his battery-powered device didn't work.

Offline cuddihy

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Re: Propellantless Field Propulsion and application
« Reply #1439 on: 07/11/2011 01:17 AM »
At last, some actual yay/nay evidence!

Nay. Can't wait to see the data. That's the first clear yay /nay evidence I've seen either way, and given he's on the email list it's clear he's not open to the same "didn't do it right" charge the Oak Ridge experiment was labeled with.

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