Author Topic: EM Drive Developments Thread 1  (Read 794256 times)

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #1340 on: 10/03/2014 08:41 PM »
Its been many years since I studied this myself, but I think Forward generally gets credit for the drive concept because he noted the backward inertial contribution first.  OTOH, I do recall it being called a "Bondi propeller" as well, so who gets credit for it I'm not certain.  Woodward mentions this in his book but doesn't take sides.  He just notes that indeed, even physicists neglect the fact the negative inertia reverses the reversed gravity and makes negative mass fall toward rather than away from positive mass.

Offline Rodal

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Re: EM Drive Developments
« Reply #1341 on: 10/03/2014 08:45 PM »
Its been many years since I studied this myself, but I think Forward generally gets credit for the drive concept because he noted the backward inertial contribution first.  OTOH, I do recall it being called a "Bondi propeller" as well, so who gets credit for it I'm not certain.  Woodward mentions this in his book but doesn't take sides.  He just notes that indeed, even physicists neglect the fact the negative inertia reverses the reversed gravity and makes negative mass fall toward rather than away from positive mass.

You wrote that many Physicists make an error concerning negative mass and positive mass in reference to  my explanation of what Bondi wrote.  I thought you were saying that Bondi had made an error concerning how negative and positive masses would interact.

By the way, Bondi was a renowned physicist, he developed a steady state theory with Fred Hoyle and had  important contributions to the theory of general relativity.  I can't comment on Forward, from the paper you cite it looks like he is explaining Bondi's results to an aerospace engineering audience and discussing Bondi's interaction as a propulsion model. (This was not Bondi's intention, to my knowledge.  In the paper I quoted Bondi uses General Relativity just to predict how they would interact).
« Last Edit: 10/03/2014 09:35 PM by Rodal »

Offline Rodal

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Re: EM Drive Developments
« Reply #1342 on: 10/03/2014 09:03 PM »
HELP:

I'm modeling the coupled nonlinear differential equations of NASA's Eagleworks inverted torsional pendulum with Mathematica.  One important value needed is the damping constant provided by the magnetic damper.  I can't find this among the data provided either in the "Anomalous Thrust ..." report or the data given by Paul March.

I found that LIGO ( Laser Interferometer Gravitational Wave Observatory) performed an engineering analysis for their pendulum (a completely different type of pendulum) looking at different types of dampers, including magnetic dampers in the range of

Damping ~ 6 kg/s = 6 N s/m

Please let me know whether any of you can suggest a better value or has an idea of the damping coefficient used for the experiments at NASA Eagleworks.  Of course magnetic dampers for industrial applications can go up to values of 210 000 N s/m but they are much larger than what the NASA Eagleworks report shows.
« Last Edit: 10/03/2014 09:10 PM by Rodal »

Offline JasonAW3

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Re: EM Drive Developments
« Reply #1343 on: 10/03/2014 09:37 PM »
In the case as presented, it sort of appears that the electron stream, may be being concentrated and accelerated to increse their effective mass.

They are not claiming that mass, regardless of its elemental particle composition, including electrons, is coming out of the device.

Ok,

As far as I can tell then, it simply shouldn't work.

If you're using RF frequencies, then they are transmitting an electron stream, but where is the stream going?  Unless they have figured out some way of converting electrons into kenitic energy, I can't with any conventional physics, see how this could work.
My God!  It's full of universes!

Offline Mulletron

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Re: EM Drive Developments
« Reply #1344 on: 10/03/2014 09:51 PM »
http://arxiv.org/abs/1302.2775

This paper is compelling in my view. It is written from the point of view of spherical shapes so keep that in mind if you read this. At the conclusion factor in the conical shape of the emdrive and remember the stuff I posted earlier concerning casimir energies and 3d shapes and cavities. Spheres attract externally but repulse internally across a diameter. Cones do the same but scatter because of their asymmetry, causing an imbalance.
« Last Edit: 10/03/2014 09:58 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Mulletron

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Re: EM Drive Developments
« Reply #1345 on: 10/03/2014 09:55 PM »
In the case as presented, it sort of appears that the electron stream, may be being concentrated and accelerated to increse their effective mass.

They are not claiming that mass, regardless of its elemental particle composition, including electrons, is coming out of the device.

Ok,

As far as I can tell then, it simply shouldn't work.

If you're using RF frequencies, then they are transmitting an electron stream, but where is the stream going?  Unless they have figured out some way of converting electrons into kenitic energy, I can't with any conventional physics, see how this could work.
I just want to say that rf is photons.
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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Re: EM Drive Developments
« Reply #1346 on: 10/03/2014 10:14 PM »
http://arxiv.org/abs/1302.2775

This paper is compelling in my view. It is written from the point of view of spherical shapes so keep that in mind if you read this. At the conclusion factor in the conical shape of the emdrive and remember the stuff I posted earlier concerning casimir energies and 3d shapes and cavities. Spheres attract externally but repulse internally across a diameter. Cones do the same but scatter because of their asymmetry, causing an imbalance.
The paper's title:  Inertia from an asymmetric Casimir effect.  It does not mention Sciama's explanation for inertia.

Abstract:

The property of inertia has never been fully explained. A model for inertia
(MiHsC or quantised inertia) has been suggested that assumes that
1) inertia is due to Unruh radiation and 2) this radiation is subject to
a Hubble-scale Casimir effect. This model has no adjustable parameters
and predicts the cosmic acceleration, and galaxy rotation without dark
matter, suggesting that Unruh radiation indeed causes inertia, but the
exact mechanism by which it does this has not been specified. The mechanism
suggested here is that when an object accelerates, for example to
the right, a dynamical (Rindler) event horizon forms to its left, reducing
the Unruh radiation on that side by a Rindler-scale Casimir effect whereas
the radiation on the other side is only slightly reduced by a Hubble-scale
Casimir effect. This produces an imbalance in the radiation pressure on
the object, and a net force that always opposes acceleration, like inertia



Pendry et al. (2006) and Leonhardt (2006).. have demonstrated theoretically
that radiation of a given wavelength can be bent around an object
(which must be smaller than the wavelength) using a metamaterial, making that
object invisible to an observer at that wavelength. It may be possible instead,
to set up a metamaterial to reflect radiation in such a way that an artificial
event horizon is formed. Then according to the model discussed here, this will
damp Unruh radiation on one side of the object which would then be accelerated
towards the metamaterial.
« Last Edit: 10/03/2014 10:22 PM by Rodal »

Offline Rodal

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Re: EM Drive Developments
« Reply #1347 on: 10/03/2014 10:25 PM »
http://arxiv.org/abs/1302.2775

This paper is compelling in my view. It is written from the point of view of spherical shapes so keep that in mind if you read this. At the conclusion factor in the conical shape of the emdrive and remember the stuff I posted earlier concerning casimir energies and 3d shapes and cavities. Spheres attract externally but repulse internally across a diameter. Cones do the same but scatter because of their asymmetry, causing an imbalance.

I noticed that somebody (you ?) invited him to this forum. I applaud the invitation.  Hopefully he comes.  He is definitely welcome  :)
« Last Edit: 10/03/2014 10:41 PM by Rodal »

Offline Mulletron

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Re: EM Drive Developments
« Reply #1348 on: 10/03/2014 10:45 PM »
Gravitation hasn't been shown to communicate outside its local spacetime curvature or even proven it is field theoretic. No gravity waves. Einstein said it was local curvature in spacetime. No ripples to communicate via in spacetime have been found. Find one gravity wave and gravitational Inertia will work. Even non locally across the cosmos because phase velocities are superluminal. Gravity is a how not a why. I'm surprised Feynman invented mathematical time travel to shoehorn that view of Inertia. This is fun.

Also wmap has shown a lumpy cosmos with a dipole anisotropy. Here at home we are dominated by the mass of a planet moon and star and a supermassive blackhole, none of which contribute to any inertial dipole moments.

I invited him. I hope he gets over here. His credentials and willingness to communicate leveraging the Internet are awesome.

Edit: I want to clarify my comments above about gravity being a field. I clearly was in error saying this. What I'm unsuccessfully trying to communicate is that locally, gravity doesn't appear as a force, but from a distance where the curve of space time in which mass "falls" is visible and so it an object's motion along it, a force is apparent. I shouldn't have used the word field.
« Last Edit: 10/04/2014 09:11 AM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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Re: EM Drive Developments
« Reply #1349 on: 10/03/2014 11:15 PM »
Scheme to detect Unruth Radiation by

SLAC National Accelerator Laboratory (operated by Stanford University on behalf of the DOE)
« Last Edit: 10/03/2014 11:47 PM by Rodal »

Offline Mulletron

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Re: EM Drive Developments
« Reply #1350 on: 10/03/2014 11:31 PM »


Easier to just accelerate a thermometer.
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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Re: EM Drive Developments
« Reply #1351 on: 10/03/2014 11:40 PM »
Scheme for Detecting Unruth Radiation (Stanford)

Easier to just accelerate a thermometer.
You are going to need an extremely high acceleration:

2.5 10^20 m/s^2 corresponds to a temperature of 1 K

for comparison, the Space Shuttle acceleration was only 29 m/s^2

and/or an extremely precise thermometer....

with the most precise thermometer you may be able to measure to a precision of  ~10 X 10^(-9) of a degree K.
« Last Edit: 10/03/2014 11:55 PM by Rodal »

Offline Mulletron

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Re: EM Drive Developments
« Reply #1352 on: 10/03/2014 11:49 PM »
Scheme for Detecting Unruth Radiation (Stanford)

Easier to just accelerate a thermometer.
You are going to need an extremely high acceleration:

2.5 10^20 m/s^2 corresponds to a temperature of 1 K

for comparison, the Space Shuttle acceleration was only 29 m/s^2

and/or an extremely precise thermometer....

I agree. Thanks for the math.
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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Re: EM Drive Developments
« Reply #1353 on: 10/03/2014 11:58 PM »
Scheme for Detecting Unruth Radiation (Stanford)

Easier to just accelerate a thermometer.
You are going to need an extremely high acceleration:

2.5 10^20 m/s^2 corresponds to a temperature of 1 K

for comparison, the Space Shuttle acceleration was only 29 m/s^2

and/or an extremely precise thermometer....

I agree. Thanks for the math.

Interesting to notice the following in Unruth radiation:

temperature/acceleration =h / (2 Pi c kB ),

Planck constant, Pi,  Speed of Light, Boltzmann constant,  all together.  I find that very neat !

same as in Hawking radiation (with acceleration=g for a black hole)
« Last Edit: 10/04/2014 12:26 AM by Rodal »

Online RotoSequence

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Re: EM Drive Developments
« Reply #1354 on: 10/04/2014 12:05 AM »
Scheme for Detecting Unruth Radiation (Stanford)

Easier to just accelerate a thermometer.
You are going to need an extremely high acceleration:

2.5 10^20 m/s^2 corresponds to a temperature of 1 K

for comparison, the Space Shuttle acceleration was only 29 m/s^2

and/or an extremely precise thermometer....

with the most precise thermometer you may be able to measure to a precision of  ~10 X 10^(-9) of a degree K.

Railguns come a little closer. At 32 megajoules, BAE's prototype pushed ~588,000 m/s. ;)

Offline frobnicat

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Re: EM Drive Developments
« Reply #1355 on: 10/04/2014 12:09 AM »
For two positive masses, nothing changes and there is a pull on each other causing an attraction. Two negative masses would produce a pull on one another, but would repel because of their negative inertial masses. For different signs there is a push that repels the positive mass but attracts the negative mass.

Bondi pointed out that two objects of equal and opposite mass would produce a constant acceleration of the system towards the positive-mass object.[citation needed] However, the total mass, momentum and energy of the system would remain 0.

This behavior is completely inconsistent with a common-sense approach and the expected behaviour of 'normal' matter; but is completely mathematically consistent and introduces no violation of conservation of momentum or energy. If the masses are equal in magnitude but opposite in sign, then the momentum of the system remains zero if they both travel together and accelerate together, no matter what their speed:


And equivalently for the kinetic energy :


Forward extended Bondi's analysis to additional cases, and showed that even if the two masses m(-) and m(+) are not the same, the conservation laws remain unbroken. This is true even when relativistic effects are considered, so long as inertial mass, not rest mass, is equal to gravitational mass.

This behaviour can produce bizarre results: for instance, a gas containing a mixture of positive and negative matter particles will have the positive matter portion increase in temperature without bound. However, the negative matter portion gains negative temperature at the same rate, again balancing out. Geoffrey A. Landis pointed out other implications of Forward's analysis,[2] including noting that although negative mass particles would repel each other gravitationally, the electrostatic force would be attractive for like-charges and repulsive for opposite charges.

Forward used the properties of negative-mass matter to create the diametric drive, a design for spacecraft propulsion using negative mass that requires no energy input and no reaction mass to achieve arbitrarily high acceleration.

mm, from your understanding (or maybe stated by Forward himself ?) such a diametric drive is a cheap energy generator ? Not free as total mass-energy would be kept constant at 0, but cheap as locally unlimited steady power source.
If such arrangement can accelerate, surely it can push at no acceleration (no ?) : push at constant speed (relative to a massive ground) can create energy. Make it on a circular track around the earth for instance, store the recovered energy : this mass equivalent output of this generator must be compensated by an increase (in absolute value) of the negative mass that is chasing the positive one ? Or the positive mass decreased ? What that theory would have to say as to how mass is kept constant overall in this thought experiment ? I suspect this leads us to a possibility of a device that can forever radiate both negative and positive mass, the later could be converted to energy while the former would just be let free to escape far away. Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.


Offline Rodal

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Re: EM Drive Developments
« Reply #1356 on: 10/04/2014 12:18 AM »
...Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.
Or another way to show to people that negative mass is not likely to exist in reality.

We can still enjoy it virtually in science-fiction plots  :)
« Last Edit: 10/04/2014 12:28 AM by Rodal »

Online Stormbringer

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Re: EM Drive Developments
« Reply #1357 on: 10/04/2014 12:43 AM »
any wormhole that you can poke a single electromagnetic wave or (for negative mass) a massive particle of any type through will do for demonstrating negative mass or energy is real. Cosmic back reaction. the ultimate (nearly) free lunch.
When antigravity is outlawed only outlaws will have antigravity.

Offline aceshigh

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Re: EM Drive Developments
« Reply #1358 on: 10/04/2014 01:21 AM »
Getting unlimited energy source by just radiating away tons of negative mass as debt never to be paid. This is brilliant ! That should easily find some financial backer.

 Interesting, but how about energy from other universes? How about setting up an Electron Pump, by sending tungsten to paramen in a parallel universe with stronger Strong Nuclear Force, and getting Plutonium 186 in return? You know, because in the alternate universe with stronger strong nuclear force, the protons are held together against their own electrostatic force, needing less neutrons to do so. As soon as Plutonium 186 arrives in our universe, with a weaker strong nuclear force, it has an "scarcity of neutrons" and it will start irradiating positrons, liberating energy in the process... to each positron released, a proton is turned into a neutron.

After some time, 20 protons will have turned to neutrons and Plutonium 186 will become Tungsten 186. And all those positrons will annihilate some electrons creating even more energy!

Its interesting for the paramen (the inhabitants of the parallel universe) because our Tungsten 186 sent there is also unstable... too many neutrons, or too few protons. The Tungsten 186 neutrons will start releasing electrons, creating energy, as neutrons turn into protons.

Thus, the cycle can go on forever, as we send them Tungsten 186 which becomes Plutonium 186 there and gives them energy, and they send us the Plutonium 186 which releases energy as it turns into Tungsten 186 here. FREE ENERGY!

Of course, this leak between the different laws in the two universes will tend to stabilize both universes to a thermodynamic equilibrium. And even small changes in the strong nuclear force in OUR universe would cause small stars as our sun to go supernova... and very soon!

edit: in case you guys never read Isaac Asimov, thats the basic plot behind the novel The God's Themselves.

Offline Mulletron

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Re: EM Drive Developments
« Reply #1359 on: 10/04/2014 01:23 AM »
Given what I've researched today (linked to earlier) I'm predicting it is easier to accelerate a conductive cone (pointy end first) than a sphere under very high energy conditions and acceleration. I think that under normal every day conditions the effect would be insignificant. Both internal and external boundary conditions are important to emdrive. Seems logical to me that the Nasa test article would produce more thrust while rotated pointy end up than down due to acceleration of gravity, barely. I need help formalizing this. Prove me wrong.
« Last Edit: 10/04/2014 01:34 AM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

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