-
#2140 by TheTraveller on 28 Oct, 2016 14:21
-
The confusing thing is that, however EW reported zero thrust without dielectric
That is not correct. -
#2141 by bad_astra on 28 Oct, 2016 14:49
-
Nice video of the Flight Thruster which shows the "Tuning Port":
https://www.youtube.com/watch?v=KUX8EWxmS3k&feature=youtu.be&t=553
Seems to be very light, so it is probably Aluminum based.
Thanks. His comments also are, to me, the best most simple explanation of how the EmDrive works (if indeed, this is how it works, and if, of course, it works) -
#2142 by Rodal on 28 Oct, 2016 15:09
-
To be rigorous , the AIAA July 28-30, 2014, Cleveland, OH, NASA Brady et.al report reportedThe confusing thing is that, however EW reported zero thrust without dielectric
That is not correct.Quoteand measured no significant net thrust.
my recollection is that later discussion by Star-Drive at NSF was to the effect that later measurements in another measuring device, in another mode shape (not the TE012 mode shape discussed in that paragraph in the Brady report), under ambient pressure, may have resulted in a force measurement without a dielectric, but that the measurements with a dielectric still gave greater force/inputPower measurements than without the dielectric, at NASA.
Nobody else, to my knowledge (neither Shawyer, Tajmar, Yang, etc.) has formally reported in a published paper a comparison using the same dielectrics (extruded HDPE and PTFE) as NASA, with and without them, under similar geometry and mode shapes.
To understand what is going on, similar comparisons have to be formally published (Shawyer did not use these polymer dielectrics, instead he used inorganic dielectrics).
-
#2143 by TheTraveller on 28 Oct, 2016 18:12
-
my recollection is that later discussion by Star-Drive at NSF was to the effect that later measurements in another measuring device, in another mode shape (not the TE012 mode shape discussed in that paragraph in the Brady report), under ambient pressure, may have resulted in a force measurement without a dielectric, but that the measurements with a dielectric still gave greater force/inputPower measurements than without the dielectric, at NASA.
Excited mode is not relevant. EW has observed force generation without a dielectric. -
#2144 by RotoSequence on 28 Oct, 2016 18:20
-
my recollection is that later discussion by Star-Drive at NSF was to the effect that later measurements in another measuring device, in another mode shape (not the TE012 mode shape discussed in that paragraph in the Brady report), under ambient pressure, may have resulted in a force measurement without a dielectric, but that the measurements with a dielectric still gave greater force/inputPower measurements than without the dielectric, at NASA.
Excited mode is not relevant. EW has observed force generation without a dielectric.
It might be relevant; we still don't know why dielectrics are important in some builds, in some geometries, and in specific input frequencies. -
#2145 by X_RaY on 28 Oct, 2016 18:39
-
Could you quote a specific post regarding your statement please? Maybe I missed the one or other post along the thread history.my recollection is that later discussion by Star-Drive at NSF was to the effect that later measurements in another measuring device, in another mode shape (not the TE012 mode shape discussed in that paragraph in the Brady report), under ambient pressure, may have resulted in a force measurement without a dielectric, but that the measurements with a dielectric still gave greater force/inputPower measurements than without the dielectric, at NASA.
Excited mode is not relevant. EW has observed force generation without a dielectric.
My statement was based on the NASA EW report about the Brady et al frustum as due to the emdrive.wiki information. As far as I know this information is popularly accepted till now and based on proved data.
Is there any more information, for example which direction of thrust was observed or the thrust level without dielectric insert? Especially is there any official publication in a physical meaning manner other than a short statement like "Yah, I beleve I have seen..."?
Thanks
-
#2146 by Rodal on 28 Oct, 2016 18:47
-
my recollection is that later discussion by Star-Drive at NSF was to the effect that later measurements in another measuring device, in another mode shape (not the TE012 mode shape discussed in that paragraph in the Brady report), under ambient pressure, may have resulted in a force measurement without a dielectric, but that the measurements with a dielectric still gave greater force/inputPower measurements than without the dielectric, at NASA.
Excited mode is not relevant. EW has observed force generation without a dielectric.
All of this is relevant, until the EM Drive is better understood, and these issues are clarified:
* measured in another measuring device instead of the torsional pendulum used previously by NASA Eagleworks,
* measured in another mode shape (not the TE012 mode shape discussed in that paragraph in the Brady report),
* measured under ambient pressure, (not in partial vacuum)
* Star-Drive emphasized the word "may" in "may have resulted in a force measurement without a dielectric"
(Statistical considerations are important in assessing the relevance of any experimental measurement being discussed)
* nobody else, other than NASA has published results comparing the use of HDPE and PTFE dielectrics in a truncated cone and without using them. In particular Shawyer used very different dielectrics: stiff inorganic dielectrics rather than compliant extruded polymers
* the figure of merit for the EM Drive is the force/PowerInput, not just the force
==> the point being, if the force is thrust that can be used for Space Propulsion and not an experimental artifact, is thrust/PowerInput greater with HDPE and PTFE and if so, under what conditions ?
EDIT: Obviously, I would think that if the results with the HDPE and PTFE dielectric would result in smaller force/InputPower, than with it, the logical course of action for NASA would be to get rid of the dielectrics, as suggested by Shawyer, so if NASA keeps them one would think it is for a good reason
-
#2147 by X_RaY on 28 Oct, 2016 19:06
-
I am Looking forward to future reports of SeeShells, Monomorphic, Paul Kocyla, EW and others.my recollection is that later discussion by Star-Drive at NSF was to the effect that later measurements in another measuring device, in another mode shape (not the TE012 mode shape discussed in that paragraph in the Brady report), under ambient pressure, may have resulted in a force measurement without a dielectric, but that the measurements with a dielectric still gave greater force/inputPower measurements than without the dielectric, at NASA.
Excited mode is not relevant. EW has observed force generation without a dielectric.
All of this is relevant, until the EM Drive is better understood, and these issues are clarified:
* measured in another measuring device instead of the torsional pendulum used previously by NASA Eagleworks,
* measured in another mode shape (not the TE012 mode shape discussed in that paragraph in the Brady report),
* measured under ambient pressure, (not in partial vacuum)
* Star-Drive emphasized the word "may" in "may have resulted in a force measurement without a dielectric"
(Statistical considerations are important in assessing the relevance of any experimental measurement being discussed)
* nobody else, other than NASA has published results comparing the use of HDPE and PTFE dielectrics in a truncated cone and without using them. In particular Shawyer used very different dielectrics: stiff inorganic dielectrics rather than compliant extruded polymers
* the measurements with a dielectric at NASA still gave greater force/inputPower measurements than without the dielectric, at NASA.
* the figure of merit for the EM Drive is the force/PowerInput, not just the force
==> the point being, if the force is thrust that can be used for Space Propulsion and not an experimental artifact, is thrust/PowerInput greater with HDPE and PTFE and if so, under what conditions ?
The more data we have the better. It will give us new chances, to test the different suggested theories. -
#2148 by Star One on 28 Oct, 2016 20:01
-
I keep coming up against people st the moment saying it cannot work because it's a closed system.
-
#2149 by X_RaY on 28 Oct, 2016 20:14
-
I keep coming up against people st the moment saying it cannot work because it's a closed system.
That's not the case! Most here have an open mind for the possibility that it may work. This hope is the main reason why we are here. Nevertheless due to the available data we have, we have to accept that it may be due to experimental artefacts. Or can you report some new upcoming data?
Add
"Closed system" depends on definitions and the related dependencies.
Better I am skeptic than a fanatic blind believer, I "believe" in provable experimental data/informations
https://en.wikipedia.org/wiki/Scientific_method
-
#2150 by Star One on 28 Oct, 2016 20:15
-
I keep coming up against people st the moment saying it cannot work because it's a closed system.
That's not the case! Most here have an open mind for the possibility that it may work. This hope is the main reason why we are here. Nevertheless due to the available data we have, we have to accept that it may be due to experimental artefacts. Or can you report some new upcoming data?
I am engaged in discussions online elsewhere that I was referring to. -
#2151 by RonM on 28 Oct, 2016 21:20
-
I keep coming up against people st the moment saying it cannot work because it's a closed system.
Well, that is conventional wisdom. Unless the EM drive works due to some strange quirk of bouncing microwaves around, it has to be interacting with something (virtual particles, gravity, etc.) and therefore isn't a closed system. What proponents need is experimental evidence of a force well above the signal to noise ratio. Then people will take the results seriously even if they don't understand how it works. -
#2152 by WarpTech on 29 Oct, 2016 00:53
-
...Energy density in the EM drive oscillates at 2 omega, since it is a scalar magnitude. The E, B and S vectors oscillate at omega. So the 2 omega effect is present in the EM Drive too. The effect of energy density on matter is similar to electrostriction. It contracts as the magnitude of energy density increases, but the effect is negligible small I think....
Yes, the energy density, and the Maxwell stress, and the Poynting vector are all oscillating at 2 omega where omega is the frequency of the electromagnetic fields. The E field at omega produces an electrostrictive strain (and hence an elastic stress) on the HDPE or the PTFE also at frequency 2 omega.
Both the electromagnetic forces (Maxwell stress and Poynting vector) and the electrostrictive forces are all acting at the same frequency 2 omega.
The electrostrictive force is out of phase with the electromagnetic force (due to tan delta) a very small amount (delta), which does give a small effect
Tan delta
PTFE ("Teflon") 0.00028 @ 3 GHz
HDPE 0.00031 @ 3 GHz
So delta is only 0.016 degrees (1/62 of a degree), 0.018% of 90 degrees
If my equations are correct, and Q is an effective refractive index, K. Then momentum that moves from low potential to higher potential, will gain momentum due to the increase in Q, and vise versa as the reflection moves back to the lower Q at the back. This change in momentum is a force acting at omega!
-
#2153 by Monomorphic on 29 Oct, 2016 01:04
-
Shawyer's recent patent can be more than a truncated cone. I found "TE014" using this "bell-wedge geometry", looking for "TE013" now.
-
#2154 by Rodal on 29 Oct, 2016 01:08
-
...Energy density in the EM drive oscillates at 2 omega, since it is a scalar magnitude. The E, B and S vectors oscillate at omega. So the 2 omega effect is present in the EM Drive too. The effect of energy density on matter is similar to electrostriction. It contracts as the magnitude of energy density increases, but the effect is negligible small I think....
Yes, the energy density, and the Maxwell stress, and the Poynting vector are all oscillating at 2 omega where omega is the frequency of the electromagnetic fields. The E field at omega produces an electrostrictive strain (and hence an elastic stress) on the HDPE or the PTFE also at frequency 2 omega.
Both the electromagnetic forces (Maxwell stress and Poynting vector) and the electrostrictive forces are all acting at the same frequency 2 omega.
The electrostrictive force is out of phase with the electromagnetic force (due to tan delta) a very small amount (delta), which does give a small effect
Tan delta
PTFE ("Teflon") 0.00028 @ 3 GHz
HDPE 0.00031 @ 3 GHz
So delta is only 0.016 degrees (1/62 of a degree), 0.018% of 90 degrees
If my equations are correct, and Q is an effective refractive index, K. Then momentum that moves from low potential to higher potential, will gain momentum due to the increase in Q, and vise versa as the reflection moves back to the lower Q at the back. This change in momentum is a force acting at omega!
Can you show that with more detail?
Electromagnetic momentum is given by Poynting vector which goes like 2*omega because it is a quadratic function of the fields.
Ditto in General Relativity with the stress-energy-momentum tensor: the momentum density and the momentum flux are a function of the square of the fields:
How come your momentum is a linear function of the fields instead of the square of the fields? -
#2155 by WarpTech on 29 Oct, 2016 01:40
-
...Energy density in the EM drive oscillates at 2 omega, since it is a scalar magnitude. The E, B and S vectors oscillate at omega. So the 2 omega effect is present in the EM Drive too. The effect of energy density on matter is similar to electrostriction. It contracts as the magnitude of energy density increases, but the effect is negligible small I think....
Yes, the energy density, and the Maxwell stress, and the Poynting vector are all oscillating at 2 omega where omega is the frequency of the electromagnetic fields. The E field at omega produces an electrostrictive strain (and hence an elastic stress) on the HDPE or the PTFE also at frequency 2 omega.
Both the electromagnetic forces (Maxwell stress and Poynting vector) and the electrostrictive forces are all acting at the same frequency 2 omega.
The electrostrictive force is out of phase with the electromagnetic force (due to tan delta) a very small amount (delta), which does give a small effect
Tan delta
PTFE ("Teflon") 0.00028 @ 3 GHz
HDPE 0.00031 @ 3 GHz
So delta is only 0.016 degrees (1/62 of a degree), 0.018% of 90 degrees
If my equations are correct, and Q is an effective refractive index, K. Then momentum that moves from low potential to higher potential, will gain momentum due to the increase in Q, and vise versa as the reflection moves back to the lower Q at the back. This change in momentum is a force acting at omega!
Can you show that with more detail?
Electromagnetic momentum is given by Poynting vector which goes like 2*omega because it is a quadratic function of the fields.
Ditto in General Relativity with the stress-energy-momentum tensor: the momentum density and the momentum flux are a function of the square of the fields:
How come your momentum is a linear function of the fields instead of the square of the fields?
What you say is true in a space where the refractive index is a constant, or where the metric is Minkowski's. In the PV Model E and H fields are unaffected or "invariant" with respect to K transformations. However, D and B are not.
S = E x H => S(K) = E x H
Pd = D x B => Pd(K) = (K*D) x (K*B) = K2Pd
where S is the Poynting vector and Pd is the Momentum density vector. This comes from the fact that,
(c/K)2 = 1/(K*ε0*K*μ0)
In PV, Power and Area are covariant with the speed of light, so S is unaffected by K, but momentum density is strongly affected. Now, replace K with Q and...
Edit: Due to the gradient in the potential Q, the energy is either going up-hill or down-hill, and oscillates at omega. There is no way to full-wave rectify this such that up = down. -
#2156 by Rodal on 29 Oct, 2016 02:23
-
what is a linear function of the frequency omega of the electric fields there ?...Energy density in the EM drive oscillates at 2 omega, since it is a scalar magnitude. The E, B and S vectors oscillate at omega. So the 2 omega effect is present in the EM Drive too. The effect of energy density on matter is similar to electrostriction. It contracts as the magnitude of energy density increases, but the effect is negligible small I think....
Yes, the energy density, and the Maxwell stress, and the Poynting vector are all oscillating at 2 omega where omega is the frequency of the electromagnetic fields. The E field at omega produces an electrostrictive strain (and hence an elastic stress) on the HDPE or the PTFE also at frequency 2 omega.
Both the electromagnetic forces (Maxwell stress and Poynting vector) and the electrostrictive forces are all acting at the same frequency 2 omega.
The electrostrictive force is out of phase with the electromagnetic force (due to tan delta) a very small amount (delta), which does give a small effect
Tan delta
PTFE ("Teflon") 0.00028 @ 3 GHz
HDPE 0.00031 @ 3 GHz
So delta is only 0.016 degrees (1/62 of a degree), 0.018% of 90 degrees
If my equations are correct, and Q is an effective refractive index, K. Then momentum that moves from low potential to higher potential, will gain momentum due to the increase in Q, and vise versa as the reflection moves back to the lower Q at the back. This change in momentum is a force acting at omega!
Can you show that with more detail?
Electromagnetic momentum is given by Poynting vector which goes like 2*omega because it is a quadratic function of the fields.
Ditto in General Relativity with the stress-energy-momentum tensor: the momentum density and the momentum flux are a function of the square of the fields:
How come your momentum is a linear function of the fields instead of the square of the fields?
What you say is true in a space where the refractive index is a constant, or where the metric is Minkowski's. In the PV Model E and H fields are unaffected or "invariant" with respect to K transformations. However, D and B are not.
S = E x H => S(K) = E x H
Pd = D x B => Pd(K) = (K*D) x (K*B) = K2Pd
where S is the Poynting vector and Pd is the Momentum density vector. This comes from the fact that,
(c/K)2 = 1/(K*ε0*K*μ0)
In PV, Power and Area are covariant with the speed of light, so S is unaffected by K, but momentum density is strongly affected. Now, replace K with Q and...
Edit: Due to the gradient in the potential Q, the energy is either going up-hill or down-hill, and oscillates at omega. There is no way to full-wave rectify this such that up = down. -
#2157 by WarpTech on 29 Oct, 2016 03:08
-
what is a linear function of omega there ?...
If my equations are correct, and Q is an effective refractive index, K. Then momentum that moves from low potential to higher potential, will gain momentum due to the increase in Q, and vise versa as the reflection moves back to the lower Q at the back. This change in momentum is a force acting at omega!
Can you show that with more detail?
Electromagnetic momentum is given by Poynting vector which goes like 2*omega because it is a quadratic function of the fields.
Ditto in General Relativity with the stress-energy-momentum tensor: the momentum density and the momentum flux are a function of the square of the fields:
How come your momentum is a linear function of the fields instead of the square of the fields?
What you say is true in a space where the refractive index is a constant, or where the metric is Minkowski's. In the PV Model E and H fields are unaffected or "invariant" with respect to K transformations. However, D and B are not.
S = E x H => S(K) = E x H
Pd = D x B => Pd(K) = (K*D) x (K*B) = K2Pd
where S is the Poynting vector and Pd is the Momentum density vector. This comes from the fact that,
(c/K)2 = 1/(K*ε0*K*μ0)
In PV, Power and Area are covariant with the speed of light, so S is unaffected by K, but momentum density is strongly affected. Now, replace K with Q and...
Edit: Due to the gradient in the potential Q, the energy is either going up-hill or down-hill, and oscillates at omega. There is no way to full-wave rectify this such that up = down.
In the attached image, P is momentum density, Q = K is the refractive index AND a Quality factor whose stored energy and dissipation vary within the cavity wrt "r". (This actually makes a lot of sense in terms of the Quantum Gravity of harmonic oscillators.)
-
#2158 by Rodal on 29 Oct, 2016 04:02
-
...
But if P is momentum and P is a function of Q2, and Q is a function of omega, then that means that momentum is a function of omega2, instead of a linear function of omega ...
In the attached image, P is momentum density, Q = K is the refractive index AND a Quality factor whose stored energy and dissipation vary within the cavity wrt "r". (This actually makes a lot of sense in terms of the Quantum Gravity of harmonic oscillators.) -
#2159 by WarpTech on 29 Oct, 2016 04:36
-
...
But if P is momentum and P is a function of Q2, and Q is a function of omega, then that means that momentum is a function of omega2, instead of a linear function of omega ...
In the attached image, P is momentum density, Q = K is the refractive index AND a Quality factor whose stored energy and dissipation vary within the cavity wrt "r". (This actually makes a lot of sense in terms of the Quantum Gravity of harmonic oscillators.)
Q is not a constant. The "force density" is a function of r, and dQ/dr is not zero. As the wave, P moves from back to front, it completes 1/2 cycle of omega. It's value changes as a linear function of omega. It gains momentum as it moves to the front where Q is higher (down-hill), and it loses momentum as it moves to the back where Q is lower (up-hill). As it goes up and down the hill the "force density" oscillates at frequency omega, not 2 omega. You said we needed a "force" acting at omega, not momentum.
