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#260 by Peter Lauwer on 15 Jun, 2017 14:50
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An improved method to perform EmDrive experiments
Dear NSF members,
I think to have developed an alternative method to perform measurements with EmDrives on torsion balances and weighing scales. I found it to be possible to supply microwave signals contactless to these devices. This has te following advantages:
– The heat generation on the measurement device will be one to even two orders of magnitude smaller;
– No DC currents (Lorentz forces), except for the microwave power detector,
– No need for magnetic materials (e.g., a microwave circulator) on the balance;
– A substantial reduction of the mass, by several kg’s, which improves the response time of the measurement device;
– Easier control of the frequency and power (no need for wireless control);
– No need for special amplifiers when measuring in a vacuum.
I have uploaded a technical report to Researchgate today: https://www.researchgate.net/publication/317600132_An_improved_method_to_measure_microwave_induced_impulsive_forces_with_a_torsion_balance_or_weighing_scale
(also to arxiv: https://arxiv.org/abs/1706.04999).
Yes, my real name is on it, Peter Lauwer is my pseudonym (but Peter is my second name), I had my reasons.
If you have any remarks, questions, suggestions, etc., please let me know.
I will be on holiday 17-27 June (and part of the time hiking&camping in England, so not everyday able to respond during that period).
Best regards,
Peter
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#261 by OnlyMe on 15 Jun, 2017 19:04
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….
There is another issue that just occurred to me that makes Wheeler's statementQuote from: WheelerSpacetime tells matter how to move; matter tells spacetime how to curve
particularly true, now that we know for a fact (from cosmological measurements) that the expansion of the universe is accelerating and that the cosmological constant is real (and so is dark energy).
Referring again to the General Relativity's field equation:
A spacetime completely free of any matter sources (Tμν=0) with a positive cosmological constant Λ>0 must always be curved , because for Tμν=0, the Ricci tensor Rμν will not vanish.
For Tμν=0, we have
Rμν - ½ R g μν = - Λ g μν
In essence, you can think of the cosmological constant Λ as a source of energy, by bringing this Λ term to the right hand side. That is one of the reasons is it called dark energy, it curves space.
Thus Wheeler was right once again, considering dark energy, spacetime tells matter how to move: it tells matter to move as spacetime accelerates its expansion and carries matter with it.
General Relativity is not just a geometric description of gravity: spacetime itself has energy (both dark energy and is capable of having gravitational waves carrying energy). That is why Wheeler, Kip Thorne and others refer to General Relativity as "Geometrodynamics". Spacetime without matter in General Relativity is not empty (it has gravitational waves and dark energy). Spacetime tells matter how to move [due to dark energy and due to gravitational waves]; and matter tells spacetime how to curve as well (gravitation due to matter).
Dr. Rodal,
The following portions of your above comment concern me, in that they represent assertions of certainty or fact, based on inherently theoretical conclusions and/or interpretations. And please accept that I am not challenging here whether these conclusions and/or interpretations represent reality, just that they should not be represented as having attained the status of facts.
“… now that we know for a fact (from cosmological measurements) …”
“… A spacetime completely free of any matter sources … must always be curved , …”
First, and without comment on validity of those conclusions and interpretations.., as I am sure your know, virtually all of cosmology is, or at least at present is, inherently theoretical and relies heavily on the interpretation and projection of locally defined understanding of gravitation and the propagation of light, both of which occur within an essentially flat Spacetime, to the larger context of galaxies and the universe which can only be thought of and evaluated within the variable time and spacial scales, of GR and its associated 4D Spacetime metric. What we believe to be true, even if it is true should not be referred to as having attained the status of fact, until it has been directly observe to be fact.
In the second, instance noted above, when you reference, “A spacetime completely free of any matter sources…” you stear the discussion into an area that is inherently beyond our ability to ever test and confirm the theoretical assertion and perhaps, since it is understood that a gravitational field, propagating at the speed of light, extends at least to the light horizon beyond the location of any massive object, there is and can be no space within our observable universe completely free of any matter source. The argument is based on a theoretical extension of a portion of the involved math, to a hypothetical space or Spacetime, which cannot exist within the observable universe. Again though exploring the implications this portion of your comments can and almost certainly has value, in our attempts to understand the physical reality of the universe around us, it should not be thought of even approaching the status of a fact, or that it provides a basis to assert that this interpretation of General Relativity's field equation, represents reality.., as a matter of fact.
Setting my above interpretation (comments about what may or may not be fact) aside and attempting to return to my original intent…
In your later or following comments (quoted above), you seem to equate the existence of dark energy and gravitational waves with evidence that Spacetime exists as a causative component of gravitation. In response I would assert that whether we are talking about the presence of, matter, dark energy, gravitational waves or even the quantum vacuum or vacuum energy, a ZPF etc., we are talking about things that exist or may exist in space over time, and whose dynamic interaction can be or is described by the Spacetime model. It is the distribution of matter and energy that are at least a causative component of gravitation, not the Spacetime model that describes that distribution.
Step back for a moment and imagine a room containing a clock which can be seen from anywhere in the room. The clock represents an indication of the progression of time and the length, width and height of the room establish a 4D special frame of reference. Since the room is small relative to the speed of light both with respect to time and the 4 spatial dimensions the room can be treated as defining a flat Minkowski spacetime. It is unlikely that anyone would assert that by describing the location or motion of any object inside the room as being the result of the time and spatial measurements. In effect when one asserts that Spacetime, within the context of GR, is the cause of the location of or how an object moves, they are asserting that just because the time and spatial dimensions involved are variable, endows that Spacetime with causative attributes.
My assertion has been and remains that, it is the effect of the distribution of matter and energy that affects how an object will move through a gravitational field and what the location specific potential of the gravitational field may be… And that GR and Spacetime are descriptive of just how the distribution of matter and energy affect both the location specific potential and the motion over time, of matter and perhaps even energy, due to a gravitational field. In a lay context the words, "Spacetime tells matter how to move..." seems to suggest that Spacetime itself has some physical or sudo-physical property that allows it to directly affect the path of an object through a gravitational field, it is the distribution of matter and energy, rather than a description of its distribution that affects the path of an object through a gravitational field.
I believe that when WarpTech says,….
... The very notion that spacetime is more than a mathematical convenience, seems to me to be absurd.
….
he goes a little to far, only in his assertion that Spacetime is reduced to a mathematical convenience. I do agree that both GR and spacetime are descriptive rather than causative, but more than just convenient, they have proven to be both descriptive and predictive, useful and powerful tools.
I don't believe that most of this discussion would be important if the discussion were not open to the lay public. Though theoretical physicists of differing views may use these terms and arguments without detailed clarifications, they generally understand the differing definitions and interpretations of one another, at least to a greater extent than the lay reader. Where the discussion is being held in a open forum some greater clarity of the difference between what has been proven and what remains a matter of interpretation is more important.
You are correct when you list physicists who share the interpretation you have presented. It is not a perspective I have not shared in the past. What I would say today is that, that perspective/interpretation is one that is generally made while interpreting the world through rose colored glasses, in that the interpretations and conclusions seem limited to evaluation within the context of a modern interpretation of GR, and without care as too lay interpretations.
One further point, it seems to me that if one accepts GR and Spacetime as descriptive rather than causative it does nothing to undermine the success of GR and Spacetime. What it might do is open the way to the possibility of, if not a unification of GR and quantum mechanics, at lest the inclusion of mechanisms originating within some part of quantum mechanics, as functional components of an underlying mechanism, resulting in what we experience as gravitation. IOW as a desiptive model Spacetime could incorporate mechanisms originating as quantum phenomena, as sources of the energy component of the field equations. The equations of the quantum mechanisms do not have to lead to or even be consistent with the field equation of General Relativity, as long as the energy associated with the quantum mechanism can be incorporated. -
#262 by Rodal on 15 Jun, 2017 20:03
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...
Since you still disagree with Wheeler's statement
My assertion has been and remains that, it is the effect of the distribution of matter and energy that affects how an object will move through a gravitational field and what the location specific potential of the gravitational field may be… And that GR and Spacetime are descriptive of just how the distribution of matter and energy affect both the location specific potential and the motion over time, of matter and perhaps even energy, due to a gravitational field. In a lay context the words, "Spacetime tells matter how to move..." seems to suggest that Spacetime itself has some physical or sudo-physical property that allows it to directly affect the path of an object through a gravitational field, it is the distribution of matter and energy, rather than a description of its distribution that affects the path of an object through a gravitational field.
I believe that when WarpTech says,….
... The very notion that spacetime is more than a mathematical convenience, seems to me to be absurd.
….
he goes a little to far, only in his assertion that Spacetime is reduced to a mathematical convenience. I do agree that both GR and spacetime are descriptive rather than causative, but more than just convenient, they have proven to be both descriptive and predictive, useful and powerful tools.
I don't believe that most of this discussion would be important if the discussion were not open to the lay public. Though theoretical physicists of differing views may use these terms and arguments without detailed clarifications, they generally understand the differing definitions and interpretations of one another, at least to a greater extent than the lay reader. Where the discussion is being held in a open forum some greater clarity of the difference between what has been proven and what remains a matter of interpretation is more important.
...QuoteSpacetime tells matter how to move; matter tells spacetime how to curve.
let me make one last attempt
at convincing you how correct Wheeler is (co-author of -arguably- the most highly regarded textbook in General Relativity https://en.wikipedia.org/wiki/Gravitation_(book); and everybody would agree.. the heaviest text 
).
Try to put yourself in the shoes of somebody trying to solve Einstein's field equations:
These equations contain covariant derivatives and other tensor expressions containing the spacetime metric gμν.
But for a yet unsolved problem, you do not know at all what the spacetime metric gμν is. The spacetime metric is a function of the energy-momentum. You do not know the structure of spacetime before solving the field equation ! And this structure of spacetime may change dynamically, as a function of time, as in gravitational waves
It is therefore in principle impossible first for you to specify the spacetime distribution of matter and from this to calculate the spacetime structure. The structure of space (curvature) and the motion of any matter in this space constitutes a dynamical system whose elements are so closely coupled with one another that they can only be solved simultaneously !.
The space is not the stage for the physical event, but rather an aspect of the interaction and motion of matter in General Relativity.
(Stephani)
It is inaccurate to assert thatQuote from: OnlyMe"Spacetime describes how matter moves"
in General Relativity. You cannot solve problems in General Relativity that way, because you would be ignoring the close coupling.
How do you know what is the structure of spacetime? what is the metric of spacetime? It is not a matter of description. Spacetime itself is deformed by matter, and this curvature of spacetime is unknown ahead of solving the field equation.
In General Relativity one is not describing something in terms of a known geometry. The geometry itself is unknown, and this geometry has to be solved in a highly coupled nonlinear differential equation.
Think for a moment about the following fact:
The stress-energy-momentum tensor Tμν which you may regard as the source of the curvature of spacetime, itself contains the unknown spacetime metric gμν
What Wheeler is talking about when he wrote:QuoteSpacetime tells matter how to move; matter tells spacetime how to curve.
is this dynamic close coupling of all terms in the GR equations: the structure of spacetime is itself unknown prior to solving the problem.
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#263 by Monomorphic on 15 Jun, 2017 20:24
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I think to have developed an alternative method to perform measurements with EmDrives on torsion balances and weighing scales. I found it to be possible to supply microwave signals contactless to these devices.
This would be best performed in a vacuum. Since the coupling cavity has one end-plate that is free-floating, I would bet the air inside the cavity expands - simply because the antennas will heat up - pushing on the scale or torsional pendulum, which would obscure and/or cast doubts on the results.
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#264 by M.LeBel on 15 Jun, 2017 20:41
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Todd,
A clock is not different from any other measuring instrument, like a voltmeter for example. It has to interact with or be “affected” in some way by what it measures. A clock will do so when moved up or down in a gravitational field where it is “affected” by the local rate of time where it is placed. That is logical. Otherwise, we are talking Magic.
“Logically, Space is what we measure with our ruler and Time is what we measure with our clock.” Practical, not logical.
Seriously, Todd. These are all place names; energy, mass, time, gravity, the quantum, etc. We measure and calculate them all to the highest precision but no one knows exactly what energy is, what mass is or even how gravity really works etc. We create “definitions” in order to make their meaning as “finite” as we can, but they are just restraining orders, not understanding.
Take E=MC2 for example. A magic formula? No, but it works! Although it apparently is illogical by equating different things, it is accepted as “logical” under the unspoken understanding that all these things are in fact, deep down, different forms of a single type of stuff that can operate logically on each other. Without this admission, the empiricism of physics is no different from believing in magic, and its stubbornness is akin to a dogmatic religion.
The above equation is one of the great steps in reductionnism that science has made in the last 300 years. Logically we already know where it is going to end, only one type of stuff. But physics can’t go there because being an observer based science, the observer and its contribution will always be part of it. The “space” and “time” as defined above are true and choiceless in the observer’s reality which is its own and ultimate barrier. If we could just get out of the way for a moment, we would understand this underlying reality.
I don’t call for any change, removal of anything in physics. This is a necessary add on. Just to be conscious of the real limits of physics and to advance knowingly beyond them. And, maybe, we won’t have to sit good men and women anymore on tons of explosives to send them into space and casually expect them to return as burning meteor or crashing in Kazakhstan,...... and still think we are smart.
Yes, this discourse has its place with the EM drive development. Keep pounding at it! Per aspera ad astra!
Marcel,
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#265 by Peter Lauwer on 15 Jun, 2017 20:56
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I think to have developed an alternative method to perform measurements with EmDrives on torsion balances and weighing scales. I found it to be possible to supply microwave signals contactless to these devices.
This would be best performed in a vacuum. Since the coupling cavity has one end-plate that is free-floating, I would bet the air inside the cavity expands - simply because the antennas will heat up - pushing on the scale or torsional pendulum, which would obscure and/or cast doubts on the results.
I have tested it on a scale, like described in the article, and found no sign of pushing. I will further test it on my torsion balance (next month). It is quite easy to test, you just put a dummy load on the balance and see whether there is any deflection if it is powered.
Also, the mantle (cavity wall) can easily be cooled with water flow. -
#266 by Monomorphic on 15 Jun, 2017 21:33
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I have tested it on a scale, like described in the article, and found no sign of pushing. I will further test it on my torsion balance (next month). It is quite easy to test, you just put a dummy load on the balance and see whether there is any deflection if it is powered.
Also, the mantle (cavity wall) can easily be cooled with water flow.
I was able to roughly simulate your coupling cavity/waveguide. With the coax and connectors in the cavity, which are hard to quantify since I don't have exact dimensions, it won't be exact. I'm pretty sure the second image below shows TM011. I'm not sure about the first, but it looks like the two antennas are coupling better with that mode. I would need to do more setup to run a proper S21.
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#267 by Space Ghost 1962 on 15 Jun, 2017 21:39
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...
One of the most enduring works in physics, with the pithy statements that convey so much, so accurately.
What Wheeler is talking about when he wrote:QuoteSpacetime tells matter how to move; matter tells spacetime how to curve.
is this dynamic close coupling of all terms in the GR equations: the structure of spacetime is itself unknown prior to solving the problem.
While the mathematics expresses this deftly, the way we express mathematics to convey it says as much about the way we represent mathematics itself. Often disagreement here is more about form than substance, because there are many that either are distracted by the form and miss the substance, or because the way they "understand" the substance puts them at odds with the form it is expressed with.
In abstract mathematics one considers numerous different ways to represent the same thing, yet some of them hold unique advantages in form, a simple example is that of operators like Hamiltonian's.
In mathematical physics, developments of consistent systems/geometries/other retain these as advantages, often to consider unifying disparate areas. Huge arguments erupt from this kind of work.
So its fine to "have issues". As long as you can work, like these above cited disciplines, in "equivalence" to the same work.
Which in the case of Wheeler is a hard act to top. It still ends up:QuoteSpacetime tells matter how to move; matter tells spacetime how to curve.
Now, keep in mind, that "move" and "curve" here to an abstract mathematician or in the field of mathematical physics ... are of enormous scope and effect, non trivial. -
#268 by zen-in on 16 Jun, 2017 06:58
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A friend suggested the following experimental method to me when I told him about the EM drive research using torsion pendulums. I don't know if he has done any tests with a torsion pendulum.
One way to cancel out DC biases due to heating, Lorentz forces etc. is to drive the torsion pendulum so that it oscillates with a constant amplitude. The driving force has to be closely regulated and angular displacement data vs time would be collected. According to my friend this is the method used by present day researchers who attempt to measure small forces with a torsion pendulum. He worked at HP for most of his career (when it really was HP) and has always had good technical insight. I asked him if he would like to join this forum and explain this idea but he declined. -
#269 by Peter Lauwer on 16 Jun, 2017 09:31
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A friend suggested the following experimental method to me when I told him about the EM drive research using torsion pendulums. I don't know if he has done any tests with a torsion pendulum.
One way to cancel out DC biases due to heating, Lorentz forces etc. is to drive the torsion pendulum so that it oscillates with a constant amplitude. The driving force has to be closely regulated and angular displacement data vs time would be collected. According to my friend this is the method used by present day researchers who attempt to measure small forces with a torsion pendulum. He worked at HP for most of his career (when it really was HP) and has always had good technical insight. I asked him if he would like to join this forum and explain this idea but he declined.
This usually applies to very small torsion balances. The balances we are working with, have periods of several minutes. I don't think it is useful to operate these in oscillating mode (yes, for veééérrrryyyy small forces, like when measuring the gravitational constant, a few orders of magnitude smaller forces then we are talking about, then you usually measure in the free swinging mode).
But measuring these small forces is not the problem (mine has a threshold of the order of 0.2 micronewton), it are the disturbing influences (heat, currents) that are the problem.
So when I wrote 'Improved method to measure...' I meant the whole setup (and mainly having the disturbing components (rf amplifier etc.) outside the measurement device.
Cheers, 'Peter' -
#270 by Peter Lauwer on 16 Jun, 2017 09:32
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Fantastic, Jamie! I will come back to this later.I have tested it on a scale, like described in the article, and found no sign of pushing. I will further test it on my torsion balance (next month). It is quite easy to test, you just put a dummy load on the balance and see whether there is any deflection if it is powered.
Also, the mantle (cavity wall) can easily be cooled with water flow.
I was able to roughly simulate your coupling cavity/waveguide. With the coax and connectors in the cavity, which are hard to quantify since I don't have exact dimensions, it won't be exact. I'm pretty sure the second image below shows TM011. I'm not sure about the first, but it looks like the two antennas are coupling better with that mode. I would need to do more setup to run a proper S21. -
#271 by Quantum Gravity on 16 Jun, 2017 15:01
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All:
I ran across a paper on the unification of GRT and QM this morning
that IMO we all need to consider in regards to what is real
and what is mathematics devoid of physical content.
Best, Paul M.
On the unification of GRT and QM :
Gravity is neither a fundamental force, nor a spacetime curvature.
There are no physical, empirically detectable graviton particles,
for the same reason that there are no magneton particles
of the magnetic field. Magnetons and gravitons are at best
virtual particles only.
As we shall see below, quantum gravity and quantum antigravity
are essentially not so much different from electromagnetism.
This would explain the reason why there has not been a successful
unification of Einsteinian gravity with electromagnetism.
Well, it is simply impossible to unify electromagnetism,
or quantum mechanics, with gravity,
when gravity is not properly understood.
The theoretical basis for quantum gravity
and quantum antigravity are the Minkowski’s equations :
https://quantumantigravity.wordpress.com/quantum-gravity/
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#272 by Monomorphic on 16 Jun, 2017 17:40
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Fantastic, Jamie! I will come back to this later.I have tested it on a scale, like described in the article, and found no sign of pushing. I will further test it on my torsion balance (next month). It is quite easy to test, you just put a dummy load on the balance and see whether there is any deflection if it is powered.
Also, the mantle (cavity wall) can easily be cooled with water flow.
I was able to roughly simulate your coupling cavity/waveguide. With the coax and connectors in the cavity, which are hard to quantify since I don't have exact dimensions, it won't be exact. I'm pretty sure the second image below shows TM011. I'm not sure about the first, but it looks like the two antennas are coupling better with that mode. I would need to do more setup to run a proper S21.
Having the RF source and main power off the test rig may solve some of my noise issues. We could simplify your coupling cavity to a rectangular waveguide with E-probe. That way only a small hole is required. And that small hole is small enough that 2.45Ghz barely leaks out. This is a simplified sim of the concept that seems to check out. In reality, the waveguide and E-probe would be located at the center of the torsional pendulum, feeding RF through the bottom to a SMA cable that leads to the frustum. There wouldn't even be the need for battery operated power detectors as reflected power could be monitored off-rig by using a circulator before the waveguide.
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#273 by Peter Lauwer on 16 Jun, 2017 18:12
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Fantastic, Jamie! I will come back to this later.I have tested it on a scale, like described in the article, and found no sign of pushing. I will further test it on my torsion balance (next month). It is quite easy to test, you just put a dummy load on the balance and see whether there is any deflection if it is powered.
Also, the mantle (cavity wall) can easily be cooled with water flow.
I was able to roughly simulate your coupling cavity/waveguide. With the coax and connectors in the cavity, which are hard to quantify since I don't have exact dimensions, it won't be exact. I'm pretty sure the second image below shows TM011. I'm not sure about the first, but it looks like the two antennas are coupling better with that mode. I would need to do more setup to run a proper S21.
Having the RF source and main power off the test rig may solve some of my noise issues. We could simplify your coupling cavity to a rectangular waveguide with E-probe. That way only a small hole is required. And that small hole is small enough that 2.45Ghz barely leaks out. This is a simplified sim of the concept that seems to check out. In reality, the waveguide and E-probe would be located at the center of the torsional pendulum, feeding RF through the bottom to a SMA cable that leads to the frustum. There wouldn't even be the need for battery operated power detectors as reflected power could be monitored off-rig by using a circulator before the waveguide.
Briljant!
[edit: it was a hasty reply just before I went of for holiday. I see you already mentioned thisBut depends a bit on how much you want the pendulum arm allow to move.]
If you apply this at the center of the pendulum, disturbing (electromagnetic) forces may be less. -
#274 by TheTraveller on 16 Jun, 2017 21:50
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Guys,
Email from Roger Shawyer and Power Point presentation as received.
Please circulate as per Roger's request.
Enjoy,
Phil
---------- Forwarded message ----------
From: <[email protected]>
Date: Sat, Jun 17, 2017 at 12:04 AM
Subject: Defence Academy EmDrive presentation
To: [email protected]
Hi Phil
Thought you might like to see an edited version of an EmDrive presentation that I made in Feb this year to the UK Defence Academy at Shrivenham. Some slides describing defence applications of second and third generation EmDrive technology have been removed.
I have recently been given clearance to put this version of the presentation into the public domain, so feel free to forward this to anyone who may be interested.
Note that in slide 12, I have revealed that a representative of your RAAF was present at the Pentagon briefing.
Best regards
Roger
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#275 by TheTraveller on 16 Jun, 2017 22:19
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Guys,
Email from Roger Shawyer and Power Point presentation as received.
Please circulate as per Roger's request.
Enjoy,
Phil
Guys,
Interesting image in the presentation which may indicate why Prof Tajmar build the EmDrive he did?
Question is did Prof Yang build this or did Roger? From what looks like stepbacks on each end plate and the signs of high heating, it may be the 1st public image of a Prof Yang EmDrive?
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#276 by Monomorphic on 16 Jun, 2017 22:40
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Question is did Prof Yang build this or did Roger? From what looks like stepbacks on each end plate and the signs of high heating, it may be the 1st public image of a Prof Yang EmDrive?
The way the slide is written and the image placed, it definitely looks like Prof Yang's. This would be the first public image and one I have been waiting for a long time.
I also noticed one of my renderings made it into Roger's presentation on slide 13!
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#277 by Flyby on 16 Jun, 2017 23:02
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Although there are some minor differences in details and dimensions, the general buildup of the device does indeed match best with Yang's first experiment.
(fe the 2 regulator screws on the wave guide)
and if it is not Yang's device, it sure bears a striking resemblance...
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#278 by Rodal on 16 Jun, 2017 23:02
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Shawyer should have given you and NasaSpaceFlight.com forum credit for using your image !Question is did Prof Yang build this or did Roger? From what looks like stepbacks on each end plate and the signs of high heating, it may be the 1st public image of a Prof Yang EmDrive?
The way the slide is written and the image placed, it definitely looks like Prof Yang's. This would be the first public image and one I have been waiting for a long time.
I also noticed one of my renderings made it into Roger's presentation on slide 13! -
#279 by TheTraveller on 16 Jun, 2017 23:05
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Although there are some minor differences in details and dimensions, the general buildup of the device does indeed match best with Yang's first experiment.
(fe the 2 regulator screws on the wave guide)
and if it is not Yang's device, it sure bears a striking resemblance...
Agree.
At least we probably now know why Prof Tajmar built what he did.
at convincing you how correct Wheeler is (co-author of -arguably- the most highly regarded textbook in General Relativity 
).