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#880 by Rodal on 22 Dec, 2016 18:38
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I don't know if this question has already been asked : Why does the paper "Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum" from NASA Team edited in the "Journal of Propulsion and Power" does not mention the name of Roger Shawyer as the person who discovered the EMDrive effect nor the name of James Woodward for its theoretical analysis and demonstration of the similar device : the Mach Effect Thruster (MET) ?
concerning shawyer: the nasa EMdrive has nothing to do with shawyer, especially from the theoretical perspective (that is where you cite things). Shawyer's results are uncorfirmed, unvalidedated, and unpublished. So no reason to bother citing them.
I do not agree. The fact only told us EW was not professional and nothing else.
Not true! If you read the requirements to publish in AIAA, they do not allow you to use references that are unpublished, or email conversations, etc... They have very strict rules.Roger, did have a lot of documentation on his cite, but nothing that appeared to me to have been peer reviewed by a major journal.
Roger Shawyer has published one peer-reviewed paper that would have satisfied this rule:
Shawyer, Roger (1 November 2015). "Second generation EmDrive propulsion applied to SSTO launcher and interstellar probe" (PDF). Acta Astronautica. 116: 166–174. doi:10.1016/j.actaastro.2015.07.002.
But with "first generation specific force of 300 mN/kW" and talks to push the efficiency "to a target of 10 kN/kW" with future superconducting versions, the NASA paper and its thrust-to-power ratio of 1.2 mN/kW may have looked off beam in comparison. Although Eagleworks campaign focused on tests in a vacuum and Shawyer never reported such tests. Whatever, it is common practice to cite prior work, especially from the inventor, when one publishes a paper....
The EW paper was submitted more than a year ago. It may have been an issue at the time, that Shawyer's paper was not published.... Yet?
White et.al. could/should have published Shawyer's patents among the references for their AIAA JPP paper, as UK patents are certainly legitimate references for publication in JPP AIAA, and such patents would have provided useful information to interested readers of the AIAA, Journal of Propulsion and Power.
Judging from the fact that Brady et.al.'s 2014 AIAA conference paper had only two references (and one of them was to Cannae website, so in reality only one reference, to one of Yang's papers), it looks like the emphasis was not on Bibliography. Most of the bibliography for the JPP AIAA paper seems to be around defending their QV pilot wave theory conjecture, one presumes as a result of interaction with the JPP referees.
Also the previous mentioned statement in the AIAA JPP paper that there are no analytical solutions to a truncated cone cavity, indicates that the emphasis was not on Bibliography.
But, as I keep pointing out at NSF to people that keep posting that nobody had done any investigation of truncated conical cavities and waveguides prior to Shawyer, this is also incorrect (see Schelkunoff in the 1930's as well as other references I previously posted).
No published article can reach perfection... -
#881 by X_RaY on 22 Dec, 2016 18:48
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Very rightI don't know if this question has already been asked : Why does the paper "Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum" from NASA Team edited in the "Journal of Propulsion and Power" does not mention the name of Roger Shawyer as the person who discovered the EMDrive effect nor the name of James Woodward for its theoretical analysis and demonstration of the similar device : the Mach Effect Thruster (MET) ?
concerning shawyer: the nasa EMdrive has nothing to do with shawyer, especially from the theoretical perspective (that is where you cite things). Shawyer's results are uncorfirmed, unvalidedated, and unpublished. So no reason to bother citing them.
I do not agree. The fact only told us EW was not professional and nothing else.
Not true! If you read the requirements to publish in AIAA, they do not allow you to use references that are unpublished, or email conversations, etc... They have very strict rules.Roger, did have a lot of documentation on his cite, but nothing that appeared to me to have been peer reviewed by a major journal.
Roger Shawyer has published one peer-reviewed paper that would have satisfied this rule:
Shawyer, Roger (1 November 2015). "Second generation EmDrive propulsion applied to SSTO launcher and interstellar probe" (PDF). Acta Astronautica. 116: 166–174. doi:10.1016/j.actaastro.2015.07.002.
But with "first generation specific force of 300 mN/kW" and talks to push the efficiency "to a target of 10 kN/kW" with future superconducting versions, the NASA paper and its thrust-to-power ratio of 1.2 mN/kW may have looked off beam in comparison. Although Eagleworks campaign focused on tests in a vacuum and Shawyer never reported such tests. Whatever, it is common practice to cite prior work, especially from the inventor, when one publishes a paper....
The EW paper was submitted more than a year ago. It may have been an issue at the time, that Shawyer's paper was not published.... Yet?
White et.al. could/should have published Shawyer's patents among the references for their AIAA JPP paper, as UK patents are certainly legitimate references for publication in JPP AIAA, and such patents would have provided useful information to interested readers of the AIAA, Journal of Propulsion and Power.
Judging from the fact that Brady et.al.'s 2014 AIAA conference paper had only two references (and one of them was to Cannae website, so in reality only one reference, to one of Yang's papers), it looks like the emphasis was not on Bibliography. Most of the bibliography for the JPP AIAA paper seems to be around defending their QV pilot wave theory conjecture, one presumes as a result of interaction with the JPP referees.
Also the previous mentioned statement in the AIAA JPP paper that there are no analytical solutions to a truncated cone cavity, indicates that the emphasis was not on Bibliography.
But, as I keep pointing out at NSF to people that keep posting that nobody had done any investigation of truncated conical cavities and waveguides prior to Shawyer, this is also incorrect (see Schelkunoff in the 1930's as well as other references I previously posted).
No published article can reach perfection...
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#882 by Mezzenile on 22 Dec, 2016 20:23
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The WEB site https://sputniknews.com/science/201612211048838113-china-emdrive/ which reports the in-orbit testing by Chinese of an EMDrive device, acknowledges in these terms the pioneer role of the British engineer Roger Shawyer in this probable revolution for space travel :Quote
The EmDrive, first proposed by British engineer Roger Shawyer, allegedly uses only electricity to generate movement simply by bouncing microwaves around a cone-shaped copper chamber and creating radiation pressure. No propellant goes in, no exhaust comes out. Even though the idea garnered headlines in the science press globally and even hit the the cover of New Scientist magazine, most scientists were, and still are, extremely skeptical.
QuoteA researcher from the UK has put forward a theory for how the EmDrive, an electromagnetic propulsion drive, might work, a question which has puzzled scientists since Roger Shawyer first designed the system in 2001.
Read more: https://sputniknews.com/environment/201604301038891179-emdrive-inertia-propulsion-physics/
We should not have to only rely on Russia informations to know the truth !
It is a pity to see on one side the silence of the NASA paper on the prophetic role of Roger Shawyer in this story and on the other side this wonderfull Forum of the same NASA where all is openly discussed and shown.
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#883 by Donosauro on 22 Dec, 2016 20:30
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There are, it seems, a lot of NASA restrictions imposed on EW. EW could not even accept any private contribution of funds or equipment. Probably 2-3 threads back someone asked about contributing funds and.., I believe Paul posted it was not allowed under NASA regulations.
IIRC, I have read that, while private citizens can make contributions to NASA, they cannot specify how the contributions are to be used. It may be, in fact, that contributions can be made only to the government itself, and that the contributors cannot even specify that they are for NASA: http://fms.treas.gov/faq/moretopics_gifts.html.
In any case, I doubt the restrictions single out EW. -
#884 by M.LeBel on 22 Dec, 2016 21:13
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...
Yes, the possibility of path-dependent, Non-Conservative fields was brought up several threads ago, for example by Mulletron, who posted repeatedly about it.
This effect pointed out in the video that is mysterious I believe is the time retarded EM field of an accelerated charge. page 31 http://physics.weber.edu/schroeder/mrr/MRRnotes.pdf . The notes are similar to Edward Purcell's book "electricity and magnetism". That curling electric field I believe is the dynamic part of the magnetic field -dB/dt=curlE that deposits the static magnetic flux over space. That is if you integrate all the magnetic field over space from infinity to the point of the disturbance that is yet to be deposited, and assume it travels at velocity c, you get the electric field of light. You can actually derive it from the Biot-Savart equation and get the same e-field for light from an accelerated charge as Purcell gets. I did this in my thesis, appendix A page 122. Determining if an axially rotated solenoid will induce a radial EMF I thought it was a neat twist.
That is, the mystery in the video is in a current loop all the accelerated charges accelerated in a circle, make a curling electric field that is non-conservative. You can integrate around the loop and continuously work against the electric field generated. Different integral paths differ in energy required. It isn't path independent, unlike a gravity well or a charge which appear to come from a point source.
There are many types of path-dependent problems (elastic-plastic deformation in solids is path-dependent, so are follower-forces in nonlinear dynamics, etc.) Foucault's pendulum is nonholonomic.
The question is: what would make the EM Drive path-dependent ? what non-conservative field is there in the EM Drive?
Conservative field, non-conservative field? Does it matter? These concepts are about knowing something and ignoring other things. Shoot a rocket from the moon’s surface one kilometer high and let it fall back on the launch pad. Circular integral ... work done = zero! Guess what? The rocket is in pieces and you don’t get back the rocket fuel you spent. Knowing start and finish point and ignoring anything in between. This is hardly a realistic concept, considering the kw/h (our rocket fuel) injected into the cavity.
Normally, energy is spent to go against the natural flow of entropy in the form of a field or differential that is already present; we swim up the gravity field in a rocket, we swim up a thermodynamic flow in a fridge. We create a situation (upstream) where a spontaneous event (entropy) will happen; falling back to the ground or evaporation of the refrigerant.
In the emdrive we spend energy to do what? Go upstream of a field? There are no field or differential already present to climb up or fight against! (Assuming free space) Then, we use the energy, not to go against the entropy of a field, but rather to create the entropy field in which the cavity will fall spontaneously.
The field will be gravitational, essentially a time rate differential in which existents tend to exist more where the time rate is slower....because they ARE there longer .... because they fall into larger space.. [ c= m/s slower time = longer seconds which equally requires larger space in order to keep the ratio of c... falling into larger space is ... entropy]
The size of the field must extend beyond the cavity walls for it to “fall” into the gradient. The shape of the gradient must at least present a lower time rate in front of the direction of motion i.e. an existential differential. At best, also a higher time rate at the back. The pair of higher and lower time rate fields are probably easier to produce as some sort “conserved” imbalance or displacement.
(I do realize that this is a very different and unfamiliar way to consider the problem)
Food for thought...
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#885 by flux_capacitor on 22 Dec, 2016 21:37
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COUNTER EXAMPLE: The scalar tensor theory used by Minotti predicts a force for the EM Drive. He has conducted numerical experiments showing this. Yet Minotti's scalar tensor theory results in solutions between coupling of electricity and magnetism (for NON EM Drive problems) that are known to result in unphysical result at the Earth's surface and at LEO, and at GEO. So Minotti has conducted numerical test #2 (discussed above) and he himself disclosed that his scalar tensor theory is not yet a valid physical explanation for the claimed EM Drive experimental results.
What I am suggesting is that you follow a similar approach as Minotti: examining what your theory predicts for well known NON-EM Drive problems involving electromagnetism and gravity.
Fernando Minotti has precisely completed a revaluation of the scalar-tensor theory as applied to the EmDrive, fixing some inconsistencies noted in his previous paper.
The basic equations are essentially the same, only that they are now derived without ad hoc conditions, like keeping some magnitudes of the scalar source terms fixed in the action variation. The only condition now imposed is that the correct Maxwell equations are obtained in the weak field approximation.
The reason for the anomalous effects by the Earth's magnetic field not being observed are the same as before, that the linear terms are zero in that case, and that the equations are satisfied by the non-linear terms. In this case the original analysis by Mbelek has to be redone employing now the solution for the scalar φ with no anomalous effects, which results in a new value of the coupling constant, which is about four orders of magnitude smaller, compatible with White's et al results.
Minotti, F. O. (21 December 2016). "Revaluation of Mbelek and Lachièze-Rey scalar tensor theory of gravitation to explain the measured forces in asymmetric resonant cavities".
Attached below. It should be on the ArXiv soon.
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#886 by Rodal on 22 Dec, 2016 22:21
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It is great news that the theory, using nonlinear terms, does not lead to anomalous results and that it gives reasonable results.COUNTER EXAMPLE: The scalar tensor theory used by Minotti predicts a force for the EM Drive. He has conducted numerical experiments showing this. Yet Minotti's scalar tensor theory results in solutions between coupling of electricity and magnetism (for NON EM Drive problems) that are known to result in unphysical result at the Earth's surface and at LEO, and at GEO. So Minotti has conducted numerical test #2 (discussed above) and he himself disclosed that his scalar tensor theory is not yet a valid physical explanation for the claimed EM Drive experimental results.
What I am suggesting is that you follow a similar approach as Minotti: examining what your theory predicts for well known NON-EM Drive problems involving electromagnetism and gravity.
Fernando Minotti has precisely completed a revaluation of the scalar-tensor theory as applied to the EmDrive, fixing some inconsistencies noted in his previous paper.
The basic equations are essentially the same, only that they are now derived without ad hoc conditions, like keeping some magnitudes of the scalar source terms fixed in the action variation. The only condition now imposed is that the correct Maxwell equations are obtained in the weak field approximation.
The reason for the anomalous effects by the Earth's magnetic field not being observed are the same as before, that the linear terms are zero in that case, and that the equations are satisfied by the non-linear terms. In this case the original analysis by Mbelek has to be redone employing now the solution for the scalar φ with no anomalous effects, which results in a new value of the coupling constant, which is about four orders of magnitude smaller, compatible with White's et al results.
Minotti, F. O. (21 December 2016). "Revaluation of Mbelek and Lachièze-Rey scalar tensor theory of gravitation to explain the measured forces in asymmetric resonant cavities".
Attached below. It should be on the ArXiv soon.
A scalar tensor theory of gravitation is more solid physics foundation for explanation than most other explanations given so far. It is interesting that he calculates a small for TE012 with the NASA geometry.
Please observe that Minotti's theory uses spherical ends rather than the flat ends used by NASA's experiments and hence the somewhat smaller natural frequency than experiment. -
#887 by drakend on 23 Dec, 2016 06:31
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Bob,
Hello,
Have been told by a source I consider as my most reliable that the Chinese observed their EmDrive test unit to self accelerate while in space.
Doubt Dr Chen would have made his EmDrive announcement before he had that data.
I'm a first time poster but an half month lurker. I've been following this thread very closely on a daily basis and related news around the web. I'm already really impressed by the possibility of having a propellantless drive, but here you stated that the Chinese observed that the drive accelerates by itself?!? Is this what you meant?
If I've understood well what you wrote and it's confirmed then the EM Drive would be even more revolutionary than what I've thought. It would become a power generator, not only a "simple" propellantless drive!
Another thing: I read some posts ago that Shawyer and other people are working to an optimized version of the EM Drive using superconductors and they aim to reach the 10 kN/kW. Do you think this is a realistical goal?
If this is true then a 200 kW electrical generator would be more than enough to lift from Earth the corresponding payload of the SLS... it would cost far less than 1% of the single launch costs of SLS!
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#888 by TheTraveller on 23 Dec, 2016 06:45
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Demonstrator EmDrive dimensions solved:
From Roger's Demonstrator EmDrive technical paper, as attached, we now know:
1) Big diameter: 280mm
2) Df: 0.844
3) Freq: 2.45Ghz
4) Mode TE012
By using this data with my spreadsheet that calculates the Df and using Goal Seek it was possible to find the Small diameter as 0.1486202937m to obtain a Df = 0.844.
Then knowing the Mode as TE012 and the Freq as 2.45GHz, the spacing between the end plates was calculated as 0.2192470000m
Which gives us:
Big Diameter: 0.280m
Small Diameter: 0.1486202937m
Length: 0.2192470000m
Freq: 2.45GHz
Mode: TE012
As the Df equation only involves the mode, freq and end plate diameters, the small and big end plate diameters are set to generate the Df of 0.844.
What is uncertain is the length to obtain TE012 mode resonance at 2.45Ghz.
Should point out that Pauls copy of the Demonstrator was off a little bit but he did measure it via pixel counting so would expect it to be off a bit.
Now that the big and small diameters are known, others here can calculated the necessary length.
Have at look at the attached, especially the Guide Wavelength vs axial position vs Radiation Pressure curves to see what a Shawyer Designed frustum signature should look like. There is virtually NO Radiation Pressure on the small end.
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#889 by TheTraveller on 23 Dec, 2016 06:58
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Bob,
Hello,
Have been told by a source I consider as my most reliable that the Chinese observed their EmDrive test unit to self accelerate while in space.
Doubt Dr Chen would have made his EmDrive announcement before he had that data.
I'm a first time poster but an half month lurker. I've been following this thread very closely on a daily basis and related news around the web. I'm already really impressed by the possibility of having a propellantless drive, but here you stated that the Chinese observed that the drive accelerates by itself?!? Is this what you meant?
If I've understood well what you wrote and it's confirmed then the EM Drive would be even more revolutionary than what I've thought. It would become a power generator, not only a "simple" propellantless drive!
Another thing: I read some posts ago that Shawyer and other people are working to an optimized version of the EM Drive using superconductors and they aim to reach the 10 kN/kW. Do you think this is a realistical goal?
If this is true then a 200 kW electrical generator would be more than enough to lift from Earth the corresponding payload of the SLS... it would cost far less than 1% of the single launch costs of SLS!
Highest unconfirmed specific force achieved to date is from Cannae in an email to Paul March as he disclosed in his SSI conference video being 50N/kW or ~5kg/kW, with a loaded Q of 60 million or 6x10^7.
There are a LOT of engineering issues using HTS to make high Q EmDrive cavities.
As such I expect the 1st use of EmDrives in space will be to replace stored gas and Ion based attitude control thrusters. But they will need to be proven to be VERY RELIABLE before any satellite manufacturer and satellite buyer will trust them to deliver a very long and reliable service life for their on orbit satellite. -
#890 by drakend on 23 Dec, 2016 07:09
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Highest unconfirmed specific force is from Cannae in an email to Paul March as he disclosed in his SSI conference video was 50N/kW or ~5kg/kW, with a loaded Q of 60 million or 6x10^7.
Hello,
There are a LOT of engineering issues using HTS to make high Q EmDrive cavities.
As such I expect the 1st use of EmDrives in space will be to replace stored gas and Ion based attitude control thrusters. But they will need to be proven to be VERY RELIABLE before any satellite manufacturer and satellite buyer will trust them to deliver a very long and reliable service life for their on orbit satellite.
is the 50N/kW referred to the EM Drive version using superconductors in its cavity?
The post where I read the 10kN/kW is this one. It mentions explicitly Shawyer working on a new version using superconductors. -
#891 by TheTraveller on 23 Dec, 2016 07:15
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Highest unconfirmed specific force is from Cannae in an email to Paul March as he disclosed in his SSI conference video was 50N/kW or ~5kg/kW, with a loaded Q of 60 million or 6x10^7.
Hello,
There are a LOT of engineering issues using HTS to make high Q EmDrive cavities.
As such I expect the 1st use of EmDrives in space will be to replace stored gas and Ion based attitude control thrusters. But they will need to be proven to be VERY RELIABLE before any satellite manufacturer and satellite buyer will trust them to deliver a very long and reliable service life for their on orbit satellite.
is the 50N/kW referred to the EM Drive version using superconductors in its cavity?
The post where I read the 10kN/kW is this one. It mentions explicitly Shawyer working on a new version using superconductors.
Cannae's web site says they use a 450nm thin film layer of YBCO in their thrusters. Normal room temperature copper EmDrive cavity can achieve a Q loaded of around 50,000 or Q unloaded of 100,000. To achieve a Q loaded of 60,000,000, as I quoted Cannae stated, needs a superconducting cavity. -
#892 by Flyby on 23 Dec, 2016 08:49
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There is a big difference between "having the intend" and achieving the result...Highest unconfirmed specific force is from Cannae in an email to Paul March as he disclosed in his SSI conference video was 50N/kW or ~5kg/kW, with a loaded Q of 60 million or 6x10^7.
Hello,
There are a LOT of engineering issues using HTS to make high Q EmDrive cavities.
As such I expect the 1st use of EmDrives in space will be to replace stored gas and Ion based attitude control thrusters. But they will need to be proven to be VERY RELIABLE before any satellite manufacturer and satellite buyer will trust them to deliver a very long and reliable service life for their on orbit satellite.
is the 50N/kW referred to the EM Drive version using superconductors in its cavity?
The post where I read the 10kN/kW is this one. It mentions explicitly Shawyer working on a new version using superconductors.
Until proven by a real experiment, the intend is nothing more a wishful thinking based upon very crude extrapolations. Personally, i don't believe they will ever get that force range, but hey, even 1N/kW would already dramatically change spaceflight as we know it.
The 50N/kW are rumors based upon 1 email. They could be true, but no evidence has been made public of that result yet, so approach it with the proverbial grain of salt (read "mountain of")...
Needs to be said that the Cannae drive is not the same thing as Shawyer's EMdrive, but supposedly, they use a similar EM effect...
If the EMdrive finally gets confirmed in space (by the Chinese experiment) i suspect focus will shift towards finding an appropriated theory that explains the effect and further research in optimization and scale ability of the effect...
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#893 by drakend on 23 Dec, 2016 09:41
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Cannae's web site says they use a 450nm thin film layer of YBCO in their thrusters. Normal room temperature copper EmDrive cavity can achieve a Q loaded of around 50,000 or Q unloaded of 100,000. To achieve a Q loaded of 60,000,000, as I quoted Cannae stated, needs a superconducting cavity.
I'm not a very technical person so can you clarify the meaning of Q reaching 60 milions? Is it the same as stating 10kN/kW?
Anyway in a previous post you mentioned that, according to your Chinese sources, Chinese researchers noted that the EM Drive, tested in space, produced a self acceleration... does it mean they measured a thrust coming from the EM Drive without even powering the magnetron?There is a big difference between "having the intend" and achieving the result...
Hello Flyby,
Until proven by a real experiment, the intend is nothing more a wishful thinking based upon very crude extrapolations. Personally, i don't believe they will ever get that force range, but hey, even 1N/kW would already dramatically change spaceflight as we know it.
The 50N/kW are rumors based upon 1 email. They could be true, but no evidence has been made public of that result yet, so approach it with the proverbial grain of salt (read "mountain of")...
Needs to be said that the Cannae drive is not the same thing as Shawyer's EMdrive, but supposedly, they use a similar EM effect...
If the EMdrive finally gets confirmed in space (by the Chinese experiment) i suspect focus will shift towards finding an appropriated theory that explains the effect and further research in optimization and scale ability of the effect...
I totally agree with you of course. Before experimental evidence nothing can be called a fact, but the goal of 10kN/kW doesn't come from an email, or at least not only from that as far as I know. I encountered this goal in a previous post made by flux_capacitor, which refers to a paper (page 2) published by Shawyer on his emdrive.com website. I think he should know the real potential capabilities of what he has invented, even if it will be real when he will make the optimized version of the EM Drive and peer reviewed of course.
As an aside can someone explain me why scientists are so fixated with theory? I mean understanding how and why something works is nice and all, sure, but not to the point of dismissing or slowing down real world experiments which apparently contradicts the theory. For the theory there is always time I believe, efforts should be directed at optimizing the EM Drive and getting something viable for space travel as soon as possibile.
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#894 by TheTraveller on 23 Dec, 2016 09:49
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I'm not a very technical person so can you clarify the meaning of Q reaching 60 milions? Is it the same as stating 10kN/kW?
Anyway in a previous post you mentioned that, according to your Chinese sources, Chinese researchers noted that the EM Drive, tested in space, produced a self acceleration... does it mean they measured a thrust coming from the EM Drive without even powering the magnetron?
Hi Drakend,
As per the SPR equation for the thrust generated, Thrust = (2 Qu Pwr Df) / c so increasing power and/or Q should generate increased thrust.
Self acceleration means the EmDrive, when powered, moved by itself.
I'm not aware of any existing EmDrive work using magnetrons as they are generally not compatible with very high Q cavities that need the freq to vary to track changes in the cavity. -
#895 by Mezzenile on 23 Dec, 2016 10:05
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As an aside can someone explain me why scientists are so fixated with theory? I mean understanding how and why something works is nice and all, sure, but not to the point of dismissing or slowing down real world experiments which apparently contradicts the theory. For the theory there is always time I believe, efforts should be directed at optimizing the EM Drive and getting something viable for space travel as soon as possibile.
One great advantage to have a theory or a modelisation of a phenomena is that it may help you to optimize a design where the phenomena is involved without having to perform cost and time consuming hardware tests. If you try to optimize an EMDrive device without having a knowledge of its sensitivity to the various parameters it relies on, it may take a never ending test process to converge towards an optimal design.
Of course this is different from saying I will deny to this phenomena the right to exist if I don't have a theory explaining it in term of concepts of "basic physic". -
#896 by Flyby on 23 Dec, 2016 11:17
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As an aside can someone explain me why scientists are so fixated with theory? I mean understanding how and why something works is nice and all, sure, but not to the point of dismissing or slowing down real world experiments which apparently contradicts the theory. For the theory there is always time I believe, efforts should be directed at optimizing the EM Drive and getting something viable for space travel as soon as possibile.
The main problem with the EMdrive is its APPARENT conflict with the Newton's 3rd law : conservation of momentum.(CoM)
As we currently understand our world, we are used to see action followed by a reaction.
Fe a normal rocket engine perfectly illustrates that: the action is the gasses that are expelled at one side, the reaction is the movement of the rocket. The problem with the EM drive is that we only see the reaction (movement) and do not understand where the action comes from.
This makes a lot of physicists believe that the movement of the EMdrive is a measurement error or that it has a thermal cause.
I cringe each time i see an populist article that states "the EMdrive brakes laws of physics" or "new physics are needed". This is exactly what generates a lot of irritation among scientists, as it is NOT so, of course, that all our science is to be thrown away...
Bombastic statements like that also delivers munition for conspiracy nuts, anti-science movements, religious fundamentalists, basically every silly, shortsighted organization that gains by discrediting science.
Hence why so few serious scientists risk touching the subject, because it could cause serious reputation damage...
Personally, I believe CoM is not violated, but that for the moment we simply fail to understand how it is conserved.
I'm unable to generate proof for that ofc, but consider this analogy :
Looking at a fully loaded 747 airplane, weighing 377 tons, it doesn't seem possible to get it airborne, because it is not lighter then air, hence will never float like a hot air balloon.
Yet, if you then start to learn about aerodynamics and airpressure on the wings in relation to horizontal movement, you suddenly understand why it is possible to get a 377ton plane airborne.
I suspect the apparent violation of CoM will be similar...
The search on how the EMdrive works is motivated to give an answer to that question. The moment it is fully understood how/why an EMdrive works (assuming the chines spaceflight tests are positive) it will also give engineers a better understanding on how to further improve the device, instead of poking in the dark. (trial and error method)
So while experiments ARE important, they would be considerably more efficient if there is a fully developed theory that explains the EMdrive behavior.
Myself, I'm like you, a layman in high end physics, but i'm trying to keep up with the discussions inhere on a daily basis and trying my best to understand what is being discussed. I might not catch the finer details of the discussions between some of the professionals inhere, but I do get a good feeling on what's being talked about and why it is talked about. -
#897 by Mezzenile on 23 Dec, 2016 13:35
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Today to refer to Newton"s 3rd law i.e the conservation of momentum (CoM) is a bit dated at least since Albert Einstein has replaced the Newton concept of absolute space time by his far more elaborated theory : The General Relativity.
The main problem with the EMdrive is its APPARENT conflict with the Newton's 3rd law : conservation of momentum.(CoM)
As we currently understand our world, we are used to see action followed by a reaction.
This makes a lot of physicists believe that the movement of the EMdrive is a measurement error or that it has a thermal cause.
I cringe each time i see an populist article that states "the EMdrive brakes laws of physics" or "new physics are needed". This is exactly what generates a lot of irritation among scientists, as it is NOT so, of course, that all our science is to be thrown away...
Personally, I believe CoM is not violated, but that for the moment we simply fail to understand how it is conserved.
In General Relativity, the so-called laws of conservation of momentum and conservation of energy are only limit cases where the system under observation is "closed". But in fact the universe itself is not closed and any subsystem of the universe which is in gravitationnal interaction with the whole universe cannot be considered as closed.
So General Relativity does not impose as general laws nor the conservation, of momentum, nor the conservation of energy. To be allowed to apply these laws of conservation on a subsystem, you must before be convinced that your subsystem is closed and you cannot be convinced of that when gravitational waves are present.
As a consequence a device as the Mach Effect Thruster (MET) which is very similar to the EMDrive for its capacity to move just using energy, is analysed by James Woodward (its inventor) as interacting via gravitational waves with the future of the whole universe to explain the fluctuations of its inertia. So the MET is potentially able to violate the so-called rule of conservation of momentum and this is apparently not in contradiction with General Relativity.
A possible analysis of the EMDrive at the light of the Mach effect or something equivalent, in the spirit of what James Woodward has done for his device, would certainly explain why it can also escape the contradiction with the false laws of conservation. The true heritage of Newton to keep is the capability he had to change his way of thinking and not rules we should obey forever. -
#898 by oyzw on 23 Dec, 2016 14:05
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According to the latest hearsay, the Chen Yue team Emdrive test is not too smooth, what are the specific problems is not clear, but the test work will continue.
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#899 by Rodal on 23 Dec, 2016 14:12
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According to the latest hearsay, the Chen Yue team Emdrive test is not too smooth, what are the specific problems is not clear, but the test work will continue.
That's why it would be very interesting to see somebody with the knowledge and professional reputation of Physics Professor Wang Xiaogang of highly ranked Peking University question the experimental protocol and results of the claimed EM Drive test in Space by the Chen-Yue team: what was the test? what was measured? is it a valid test? are there any possible experimental artifacts?, and hear the answers in the exchange. It would be great if such discussion takes place at the upcoming Dec 24-25 Chinese Electric Propulsion conference. Are you planning to attend and inform us ?
