Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1882096 times)

Offline deltaMass

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A question popped into my head today - can photons collide/interfere, and if so,...

I can't answer your latter questions, but I can answer this one.

Yes, photons can collide and interfere.  One of the really fascinating things about light is that it can, in photon-photon interactions, behave as if it has no mass, positive mass, or negative mass.  For all of these cases, F=mA still applies.  If you interact a photon in positive mass mode with a photon in negative mass mode then you can have two photons exit the collision moving in the same direction.  This is real, measurable, and breaks the symmetry of Newtons 3rd law [1].

(end of facts, beginning wild supposition here)

The above effect leads directly to my theory du jour for the operating principle of the emDrive.  The asymmetric resonator is creating a standing wave of photons producing identical radiation pressure on the front and rear endplates.  Some light is leaking into the space at the small end and is trapped bouncing back and forth between the standing waves (no radiation pressure) and the small end (radiation pressure).  This latter light is what moves the drive.  The reflectivity of the small end and the strength of the standing wave determine the "lifespan" of the trapped light and explain the correlation between Q and thrust.

I have a few ideas on proving this, but nothing substantial yet.

[1] Optical diametric drive acceleration through action–reaction symmetry breaking - Martin Wimmer, Alois Regensburger, Christoph Bersch, Mohammad-Ali Miri, Sascha Batz, Georgy Onishchukov, Demetrios N. Christodoulides & Ulf Peschel
http://www.nature.com/nphys/journal/v9/n12/full/nphys2777.html
(If your local library has ebscohost, it is available there in full text.)
Yabut, this is lattice optics. It requires the presence of a medium in order to get these funky effects. For every apparent violation of conservation laws, there is a compensating dynamic invoked on the medium itself, so that the system as a whole is well-behaved. This cannot happen inside an empty cavity.

Offline rq3

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I posted a Danger alert and it went poof. Summary as I'll try again, weird.

I asked why the shape of the calculated stress values were shaped around the antenna like they were, squeezed in the forward accelerating direction and flattened out to the sides.
It reminds me of Einstein effects for an object approaching the speed of light. Interesting all other meep views were of this nice round antenna shape.

Just wondering how that compressed stress took that shape.

Shell

I don't recall Meep views of a round antenna shape.   
The antenna is much longer in one direction and has a "thickness" of only 2 Finite Difference nodes.
So, viewed from one side the antenna looks like a line, and when looked from the perpendicular view it looks like a point (or a very small circle of just 2 Finite Difference nodes).
When plotting the stress as the height of the "line antenna" the stress looks like a plate with rounded corners at the top.

Could you please link to the message, or even better copy and paste the round antenna image in your response ?

I need to see the 2 images you are referring to as a picture is worth a thousand words.

Thanks
You 're quite right the antenna is being shown in the horizontal plane not the vertical. I asked the question nicely and did say it was a danger alert. It is the exact way it should be and nothing is funny about it.

Edit: added the picture of the vertical antenna of the poynting vector you calculated associated the 2 and did a divide by 0.

Why are all of these new plots looking more and more like those for the Alcubierre metric?

Rip
« Last Edit: 07/13/2015 09:29 PM by rq3 »

Offline tchernik

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A question popped into my head today - can photons collide/interfere, and if so,...

I can't answer your latter questions, but I can answer this one.

Yes, photons can collide and interfere.  One of the really fascinating things about light is that it can, in photon-photon interactions, behave as if it has no mass, positive mass, or negative mass.  For all of these cases, F=mA still applies.  If you interact a photon in positive mass mode with a photon in negative mass mode then you can have two photons exit the collision moving in the same direction.  This is real, measurable, and breaks the symmetry of Newtons 3rd law [1].

(end of facts, beginning wild supposition here)

The above effect leads directly to my theory du jour for the operating principle of the emDrive.  The asymmetric resonator is creating a standing wave of photons producing identical radiation pressure on the front and rear endplates.  Some light is leaking into the space at the small end and is trapped bouncing back and forth between the standing waves (no radiation pressure) and the small end (radiation pressure).  This latter light is what moves the drive.  The reflectivity of the small end and the strength of the standing wave determine the "lifespan" of the trapped light and explain the correlation between Q and thrust.

I have a few ideas on proving this, but nothing substantial yet.

[1] Optical diametric drive acceleration through action–reaction symmetry breaking - Martin Wimmer, Alois Regensburger, Christoph Bersch, Mohammad-Ali Miri, Sascha Batz, Georgy Onishchukov, Demetrios N. Christodoulides & Ulf Peschel
http://www.nature.com/nphys/journal/v9/n12/full/nphys2777.html
(If your local library has ebscohost, it is available there in full text.)
Yabut, this is lattice optics. It requires the presence of a medium in order to get these funky effects. For every apparent violation of conservation laws, there is a compensating dynamic invoked on the medium itself, so that the system as a whole is well-behaved. This cannot happen inside an empty cavity.

As far as I understand, the cavity is not empty. It has air.

Have we ruled out that the gases inside the cavity have something to do with any potential thrust?

Yes, I'm aware that something that works only with air inside and outside sounds bad, by implying this only works like a lifter. But has anyone tested if having air inside an air tight cavity running with vacuum outside changes anything?
« Last Edit: 07/13/2015 09:22 PM by tchernik »

Offline Rodal

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....
Why are all of these new plots looking more and more like those for the Alcubierre metric?

Rip
Because man/woman is a being who rose among all others on Earth by his/her ability to see patterns.  So we see patterns everywhere (the face on Mars, canals on Mars, trees on Mars, etc.) even when those patterns are just a mirage.

Offline rfmwguy

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A question popped into my head today - can photons collide/interfere, and if so,...

I can't answer your latter questions, but I can answer this one.

Yes, photons can collide and interfere.  One of the really fascinating things about light is that it can, in photon-photon interactions, behave as if it has no mass, positive mass, or negative mass.  For all of these cases, F=mA still applies.  If you interact a photon in positive mass mode with a photon in negative mass mode then you can have two photons exit the collision moving in the same direction.  This is real, measurable, and breaks the symmetry of Newtons 3rd law [1].

(end of facts, beginning wild supposition here)

The above effect leads directly to my theory du jour for the operating principle of the emDrive.  The asymmetric resonator is creating a standing wave of photons producing identical radiation pressure on the front and rear endplates.  Some light is leaking into the space at the small end and is trapped bouncing back and forth between the standing waves (no radiation pressure) and the small end (radiation pressure).  This latter light is what moves the drive.  The reflectivity of the small end and the strength of the standing wave determine the "lifespan" of the trapped light and explain the correlation between Q and thrust.

I have a few ideas on proving this, but nothing substantial yet.

[1] Optical diametric drive acceleration through action–reaction symmetry breaking - Martin Wimmer, Alois Regensburger, Christoph Bersch, Mohammad-Ali Miri, Sascha Batz, Georgy Onishchukov, Demetrios N. Christodoulides & Ulf Peschel
http://www.nature.com/nphys/journal/v9/n12/full/nphys2777.html
(If your local library has ebscohost, it is available there in full text.)
Yabut, this is lattice optics. It requires the presence of a medium in order to get these funky effects. For every apparent violation of conservation laws, there is a compensating dynamic invoked on the medium itself, so that the system as a whole is well-behaved. This cannot happen inside an empty cavity.

As far as I understand, the cavity is not empty. It has air.

Have we ruled out that the gases inside the cavity have something to do with any potential thrust?

Yes, I'm aware that something that works only with air inside and outside sounds bad, by implying this only works like a lifter. But has anyone tested if having air inside an air tight cavity running with vacuum outside changes anything?
Discussed in threads 1 & 2...

Offline ElizabethGreene

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Yabut, this is lattice optics. It requires the presence of a medium in order to get these funky effects. For every apparent violation of conservation laws, there is a compensating dynamic invoked on the medium itself, so that the system as a whole is well-behaved. This cannot happen inside an empty cavity.

In what way is intersecting beams of collimated light different from the interaction between different modes of standing waves within the same optical cavity?

(Yes, this is a real question, and please let me be the first to admit that I don't know what I don't know.)

Offline SeeShells

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....
Why are all of these new plots looking more and more like those for the Alcubierre metric?

Rip
Because man/woman is a being who rose among all others on Earth by his/her ability to see patterns.  So we see patterns everywhere (the face on Mars, canals on Mars, trees on Mars, etc.) even when those patterns are just a mirage.
Internet is very touchy today grrrr.

Or like highly visual Engineers (me) who see patterns and sometimes it supersedes all else. No, there is no Santa Claus bearing gifts in these pictures. What we are looking for is such a small effect it would really be hard to pick out in a visual anyway. Raw numbers will speak louder.

Popped off again... grrr. Be back on later folks.

Shell

Offline Rodal

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As far as I understand, the cavity is not empty. It has air.

Have we ruled out that the gases inside the cavity have something to do with any potential thrust?

Yes, I'm aware that something that works only with air inside and outside sounds bad, by implying this only works like a lifter. But has anyone tested if having air inside an air tight cavity running with vacuum outside changes anything?
Discussed in threads 1 & 2...
Discussed but never resolved.  The fact is that those with the highest thrust claims: Shawyer and Yang have never reported a single test in vacuum.  This is particularly concerning regarding the inventor, whose first patent on the EM Drive goes back to the late 1980's and whose present company was started 15 years ago.  Why never a single test in vacuum reported?

On the other hand testers from prestigious institutions : first NASA and now Prof. Tajmar at TU Dresden University, Germany, tested in vacuum and obtained thrust that is orders of magnitude smaller than those reported by Shawyer and Yang.  Very concerning as to whether Shawyer and Yang's numbers are achievable in a vacuum...

Still some thrust in vacuum is better than nothing...
« Last Edit: 07/13/2015 10:21 PM by Rodal »

Offline apoc2021

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2) Is user apoc2021's generous offer to donate server time still open?

Yes - will just need to figure out the required services and details. I'll PM you and aero now.

Thanks,
Dan

Offline leomillert

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I have just installed MEEP and NSF-1701.ctl is sitting here on my hard drive.
How can I help?

Offline Dortex

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On the other hand testers from prestigious institutions : first NASA and now Prof. Tajmar at TU Dresden University, Germany, tested in vacuum and obtained thrust that is orders of magnitude smaller than those reported by Shawyer and Yang.

Let's not forget NASA used the "wrong" frequencies and had failing equipment in the vacuum tests.

Offline deltaMass

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Give me one microNewton of genuine propellantless thrust and I will give you the stars.

Offline wallofwolfstreet

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Resolution of the Space-Drive Energy Paradox  (version 6)

Have at it @deltaMass and @wallofwolfstreet. I'm looking forward to your responses.

https://www.dropbox.com/s/p86dvc8733h9iph/Desiato-Energy_Paradox-v6.pdf?dl=0

Todd

<<crickets>>


LOL you crack me up.  I don't know how many times people have corrected your math now, only for you to throw a new version back at them as though nothing even happened, not even the slightest acknowledgement of error or miscalculation.  I take a day to respond to a post and you're gloating already.  I do have a day job to attend, commenting on NSF doesn't pay bills (to my knowledge). 

Rather than addressing each issue one by one in posts back and forth, I'll just lay them all out here:

1)  In equation ( 8 ), Eout is equal to the invariant rest mass-energy of the vehicle and battery minus Pin* time*gamma?  How do you figure that?  No KE dependence?  As time goes on, Eout will monotonically decrease?  If we let the drive run forever, using an external power source, to what value does Eout go?  To negative infinity?  Sorry, but this expression for Eout doesn't make sense.       

2)  Equation (9), the function for v, is for the "maximum velocity ... limited by the amount of energy stored in the battery", correct? If so, you've lost track of your own variable names.  You then say "Thrust is dependent on the instantaneous velocity at time t", without ever showing it.  equation (10) shows k=1/v, which isn't the instantaneous velocity at all, but the limiting velocity you just derived one equation up.   

3)  Two issues with equation (11).  No idea how you move from the second last line to the last line (=Pin).  As before, you misapply equation (9).  If equation (9)  is the maximum velocity, how is it you are able to sub it in to v(t)?   

4)  Most obvious issue, k has a v dependence.  I can't copy all the relevant text, but you seem to think this is a-okay:  "I believe the argument originates in the way Lorentz Transforms and the symmetry of two inertial
reference frames is taught. In addition to, a failure to correctly learn and understand the effects of an
accelerated reference frame, or its equivalence to a gravitational field." - Maybe the failure to understand is on your part?  Like it or not, you are now claiming the emdrive is a velocimeter, because k can easily be measured with an accelerometer and a multi-meter.  My professors told me such a velocimeter, independently measuring absolute velocity in a closed system, was impossible.  Maybe you know more than them, and they are the ones with the misunderstanding.     

5)  As I mentioned in this post, you are oversimplifying the "Energy paradox" to instances with acceleration and onboard power supplies.  A free energy machine needs neither, and so even if you dismiss all of the above, paradox still stands firm.

Conclusions?  Swing and a miss.  Can't imagine why you've gotten so hung up on this thing.     
« Last Edit: 07/13/2015 11:55 PM by wallofwolfstreet »

Offline aero

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I have just installed MEEP and NSF-1701.ctl is sitting here on my hard drive.
How can I help?

Good! Run it and see how the data compares to posted data. In particular, generate some csv files, then "diff" them with the "identical" data on Google drive. If you haven't changed any settings, the data should be there. If you change anything at all, chances are your data will be different. If that is the case post a copy of your file to me and I'll run it as is then post a some csv files back to you.

I think that is probably the most straight forward way to check installations. Of course your computer word length may be different so that might not work either.

aero

« Last Edit: 07/14/2015 12:01 AM by aero »
Retired, working interesting problems

Offline deltaMass

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@WarpTech: I haven't yet found time to read your paper, but it seems from what @wallofwolfstreet says in his review that you're up to your same old tricks - ignoring prior criticism without comment, and still maintaining that there is an absolute reference frame. And then blaming this on teaching methods? Really, old chap.

Offline Notsosureofit

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Resolution of the Space-Drive Energy Paradox  (version 6)

Have at it @deltaMass and @wallofwolfstreet. I'm looking forward to your responses.

https://www.dropbox.com/s/p86dvc8733h9iph/Desiato-Energy_Paradox-v6.pdf?dl=0

Todd

Looks like you are getting there...keep at it!  (I'll nitpick if I get some time)

Offline rq3

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Why are all of these new plots looking more and more like those for the Alcubierre metric?

Rip
Because man/woman is a being who rose among all others on Earth by his/her ability to see patterns.  So we see patterns everywhere (the face on Mars, canals on Mars, trees on Mars, etc.) even when those patterns are just a mirage.

Cute. Now answer the question. Is there any possible correlation? You folks are chasing what appears to be impossible physics, why get snooty when someone sees an apparent correlation to other apparently impossible physics? I've already posted an observation that the devices described so far seem to be Q switched resonators, with no coherent (pardon the pun) response.

Rip

Offline Rodal

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Ar SeeShells request, here is the stress tensor (previously shown in http://forum.nasaspaceflight.com/index.php?topic=37642.msg1403629#msg1403629, at the same previous locations, this time all shown to the same scale and from the same viewpoint.

I made an avi movie with Wolfram Mathematica but it is 150 megabytes (so I'm not posting it :)  ), so perhaps someone else can attempt to make a good fidelity movie that takes less bandwidth :-)

We start by showing the stress component sigma xx in the circular cross-sectional yz plane at  x=38, located on the interior, closest to the big end

______________________
The actual stress and the actual Poynting vector in the previously presented images are actually higher than the units shown, as the units are predicated (as I understand from aero) taking the default Meep value for current Io of 1 rather than the actual power input into the antenna.
Therefore to get the actual values for a particular antenna power input, the values have to be scaled up as a function of the actual power input from the antenna.
« Last Edit: 07/14/2015 02:50 AM by Rodal »

Offline Rodal

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We continue by showing the stress tensor component sigma xx at the circular cross-sectional yz plane at  x=97, located on the interior, between the big end and the middle of the frustum
« Last Edit: 07/14/2015 02:28 AM by Rodal »

Offline Rodal

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We continue by showing the stress tensor component sigmaxx at a most important circular cross-sectional yz plane at  x=149, located on the interior, between the  middle and the antenna
« Last Edit: 07/14/2015 02:31 AM by Rodal »

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