Last night I drove to the big out of town TESCO on a mercy mission to buy some fish food and I was glad I did because while walking in the fresh air into the shop, what I have been thinking about, and doing messy calculations on, over the past few days, suddenly became clear. It is a clearer way to explain my MiHsC-emdrive paper. I laughed out loud in the entrance to TESCO, but luckily they didn't lock me up.
In the emdrive the magnetron puts microwaves into the cavity. MiHsC allows more Unruh waves (greater photon inertial mass) at the wide end, so as new microwave energy is put into the cavity its centre of mass is continually being shifted by MiHsC towards the wide end (see diagram). To conserve momentum the cavity has to move the other way towards the narrow end (note: this needs new physics, MiHsC, not standard).
In the emdrive the magnetron puts microwaves into the cavity. MiHsC allows more Unruh waves (greater photon inertial mass) at the wide end, so as new microwave energy is put into the cavity its centre of mass is continually being shifted by MiHsC towards the wide end (see diagram). To conserve momentum the cavity has to move the other way towards the narrow end (note: this needs new physics, MiHsC, not standard).
But hang on!: MiHsC is causing a huge acceleration of the microwaves of 10^18 m/s^2 (~c^2/L). The cavity is not accelerating that much the other way? Why?
Because the cavity is so much more massive. The microwaves in the cavity have a mass (given m=E/c^2) of 10^-20 kg (roughly), whereas the cavity may be 10 kg, so the acceleration of the cavity to conserve momentum can be 10^-21 times smaller, which is about 10^-3 m/s^2, implying a force (F=ma) of a few microNewtons. This is the same process as in my paper but this explanation is different and hopefully much clearer.
An analogy to this would be a small 'magic' boat that everyone is puzzled about, because when it rains it always moves forwards. How is this possible? If you look at the boat from a different angle, from the side, you become aware of the slope in its bottom which pushes rainwater to the back and moves the boat forwards. Similarly, look at the emdrive with MiHsC and the slope is a gradient in the zero point field.
The moral of this piece is clear - when I get rid of the flu I should go for more walks!
26 comments:
Does the cavity Q factor magnify this effect?
Yes, in this explanation the higher the Q value, the longer the microwave energy stays in the cavity so the microwave-mass at any one time (acting like an internal propellant) increases.
Hi,
Why does the microwave present increase Unruh radiation "availability"?
Alain: it doesn't, but more microwave energy increases the overall mass of photons whose centre of mass gets pushed towards the wide end by MiHsC, thus increasing the thrust the other way.
If I understand correctly increasing microwave energy and increasing system Q increases the inertial mass of the photons in the cavity providing the 'reaction mass' to use a rocket analogy, and Unruh radiation provides the energy to accelerate the mass? I am aware I may be stretching an analogy too far.
Steve: Yes, that is correct. Unruh radiation is the source of the new energy needed to do this.
It's long been noted that a good walk is fantastic for theorists wanting to make a breakthrough. Seems it worked for you :-)
"MiHsC makes photons at one end heavier - it gives them acceleration - it creates a a gradient in the zero point field - allows more Unruh waves at the wide end"
IMO these are four potentially unrelated physical concepts. At the end we can read about the boat in the rain, which is the fifth one. How these concepts are related each other?
BTW MiHsC cannot make anything, being a physical theory - only physical process can be responsible for physical action. Which process it is? What makes the photons at one end heavier? What accelerates them, etc?
Hi Mike,
Are there any issues with re-writing this in terms of momentum instead of mass, and center of momentum instead of center of mass?. In this post: http://forum.nasaspaceflight.com/index.php?topic=39772.msg1534977#msg1534977 I re-wrote this in terms of "center of momentum" instead of "center of mass", and "momentum with mass units" (instead of photon mass, a concept which makes some people uneasy because of photons having no rest mass, and having a relativistic mass that is undefined since it is zero times infinity).
Hope you get over the flu soon.
Best regards,
Jose' Rodal, Ph.D.
PS: I still need to think why the Unruh effect would become significant for the EM Drive. If so, shouldn't the Unruh effect also be measurable for many other phenomena?
I think that to improve your explanation you need to include 2 more things. 1)How and where is the Unruh radiation generated 2)How does the Unruh radiation change the inertial mass of the microwaves.
Dear Jose,
I'm using the relativistic mass that forms part of the photon momentum. I can't say that the centre of momentum is shifting since I assume in my paper (eq. 3) that momentum is conserved along the long axis, it has to be the centre of mass that shifts. You are right that you can write m=p/c and get a mass unit, but this is a mass, and shouldn't be called a momentum. The photon-inertial mass has never been properly thought through, and now we have a chance to clear it up.
Why does the Unruh effect suddenly appear in the emdrive? I'd say it's everywhere, but attributed to fudges. Normally, the Unruh effect on inertia is tiny, being affected by the distant Hubble horizon, but it can be seen in systems that are slow moving anyway, eg: the galaxy rotation problem, attributed to dark matter, that MiHsC solves more simply. Often the effect is larger, due to Rindler horizons, but in the past that was just attributed to 'inertia'. In the emdrive the Hubble horizon has been made much smaller and asymmetric, so the effect is boosted. You're right it should happen for other asymmetric shapes too.
Best regards,
Mike
Dear Mike,
Thank you very much for your answer. When you have a chance, I like you to think about this, in light that Prof. Yang at NWPU in China, just nullified all her prior tests that were conducted using power cords (also all of Shaywer test were done using power cords) by using batteries self-integrated in the moving platfrom:
1) Power cords introduce both energy and momentum into the EM Drive. This cannot be ignored: if the power is not on, there is no anomalous force. The anomalous force is, as shown by experiments, due to the power being on.
2) The feeding point of the energy and momentum also cannot be ignored: experiments have shown that it makes a difference whether the energy and momentum are fed in the middle of the EM Drive vs. being fed at one end or the other.
3) An experiment run with batteries in the moving platform has the center of energy and the center of momentum in the moving platform. Conversely, an experiment run with power cords with energy from a stationary supply does not have the center of energy and the center of momentum at the same place as the center of mass of the EM Drive: the center of energy and momentum may be outside the moving platform.
4) Coaxial power cables do not at all solve this issue. On the contrary coaxial cables deliver practically 100% of the electromagnetic momentum along their length. Running the coaxial cable from different directions does not make a difference to this argument, because the electromagnetic momentum gets delivered along whatever path you use. Once the coaxial cable RF momentum is fed, for example at the middle of the EM Drive, then that electromagnetic momentum and power become the photons that have increased momentum towards the big end and decreased momentum towards the small end. For these purposes (center of energy-momentum) it does not matter how you run the coaxial cable from one end to the other. What matters is whether the power source is stationary, with respect to the moving EM Drive, and where in the EM Drive is the RF energy and momentum injected. Because that affects the center of energy/momentum.
5) Running an experiment with a power cord is therefore similar to running an experiment with a normal rocket using propellant coming from a stationary source. Such a test may be OK once one knows that rockets work, and one just wants to test their thrust, but it is unsatisfactory for a propellant-less device that is very much under question whether it can work in Space to self-accelerate.
No propellant ejection for a normal rocket = no thrust
No RF power fed into an EM Drive = no anomalous force
6) To conclusively show that rockets worked, Goddard conducted experiments with the propellant and everything else self-integrated in the rocket and showed lift-off in his experiments. Similarly, to conclusively show that an EM Drive, that works with photons that do not have mass, and only have energy and momentum, can work in outer space, the most conclusive test is the one where batteries and everything else are self-integrated in the moving platform, and not one where electromagnetic energy and momentum are fed from a stationary source.
An experiment with a power cord from a stationary source can perhaps show that one can create an anomalous force on a tapered resonant cavity being fed from a stationary source. It does not prove that there is an anomalous force acting on the whole integrated system (battery+EMDrive+etc.) when the energy and momentum are self-integrated together.
And this is why I think that the center of momentum becomes relevant once one considers that both electromagnetic energy and electromagnetic momentum are being fed into the EM Drive. It seems to me that one should look at the whole system: power source+power cables+EM Drive to address conservation of momentum and conservation of energy, and hence the importance of center of momentum for this whole system.
Thanks for your consideration of this very long post
Jose' Rodal, Ph.D.
Dr Rodal please excuse an interested laymans question. Taking the Goddard example you have provided it is certainly true that a self contained system demonstrated the practicality of a rocket motor with no room for error. However, given a suitably designed umbilical to supply propellent and oxidiser, would the rocket motor have failed to work? I am mindful of the demands that the mass of a suitably large battery would place on a system where the thrust is , currently, very small. The thrust available from Goddards rocket was orders of magnitude greater than the thrust measured from Emdrive experiments to date. I understand your argument, but wonder if a battery based system would not increase the measurement demands beyond a practicality. Is not the requirement to test and characterise in a complete manner any electromagnetic effect of an umbilical supply?
Please forgive the intrusion in this fascinating exchange. If I am out of order please do say and I will observe without comment.
Regards to all
Steve Kelsey
Dear Steve,
At the moment we don't know enough. Electromagnetic systems are unique in a sense because they have what has been called "hidden momentum" by Nobel Prize winner William Shockley (inventor of the transistor). Feynman described some interesting paradoxes, including one where a cylinder will start to rotate (as if magically) once power is cut-off, in order to satisfy conservation of momentum. Concerning "if a battery based system would not increase the measurement demands beyond a practicality" I can make a definite statement: no I don't think that using batteries is any problem for any of the EM Drive experiments performed up to now: 1) Yang had performed the experiments that had claimed the highest forces and the highest force/InputPower of any EM Drive experiment. She nullified all her previous experiments by conducting her experiments with batteries instead of using power cables: if she can do it, everybody else that has performed EM Drive experiments can do it too. and 2) NASA reported the highest force/InputPower with an experiment that used only 2.6 watts of power, which is NO problem to supply with batteries.
Regards,
J.R.
Thank you Dr Rodal for such a detailed reply. Trust Feynman to introduce apparent paradox as a method of explanation. I am intruiged and will look further into 'hidden momentum', it sounds fascinating. My concerns about battery power sources are fully retired.
Best regards to all
Steve
I have been attempting to follow the story of the em-drive and I'm a bit confused. If Mike is correct, which wouldn't surprise me in the least, then the effect only manifests at extremely low acceleration. And this is some kind of space drive? Sounds like it would take a week to get to the corner store.
Roy: MiHsC usually causes a minimum acceleration of 2c^2/HubbleScale ~ 10^-10 m/s^2 (cosmic acceleration). This acceleration is tiny because the Hubble Scale on the denominator is ~10^26m. In the emdrive, the cavity is now doing the job of the Hubble horizon so the acceleration is 2c^2/CavitySize. The denominator, CavitySize, is a factor of 10^27 smaller so the effect is far bigger, and different at either end..
As a layman it seems to me that an emdrive would or could create dark matter as a side effect. (pollution?) The effect of this would only last as long as the drive was on? Getting weird- could you measure the net average use of emdrives by measuring their effect on a larger system? Galaxy?
It would be this dark matter that would conserve momentum by transferring it to other mass via gravitation?
Bud MiHsC theory removes the need for dark matter. It is a self consistent theory that explains many observed anomalies that mainstream cosmology cannot explain without the need for the ad hoc addition of invisible masses.
Ok but.. If an emdrive worked wouldn't it require the transfer of momentum to the external vicinity?
If a object it accelerating as it passes you and there isn't an equal mass flying it the other direction, wouldn't you feel a pull indistinguishable from gravity?
Hi,
the discussion on a null result reemerge on Qtruster reddit
https://www.reddit.com/r/QThruster/comments/50zrhq/emdrive_null_experiment/
it was discussed on EmDrive reddit
https://www.reddit.com/r/EmDrive/comments/4ng2ow/new_emdrive_paper_null_result_for_prediction_of/
paper is
http://vixra.org/pdf/1603.0153v1.pdf
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