Author Topic: EM Drive Developments Thread 1  (Read 765320 times)

Offline frobnicat

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Re: EM Drive Developments
« Reply #1080 on: 09/28/2014 09:34 PM »
I think I see.   

I can get on a railroad flat car, and jerk backwards.  The car will move forward.  If I coast with it, gradually bringing my body forward at a rate of less than the "sticky friction", I will get to a point where I can jerk backwards again, and I can thus "propel" the railroad flat car forward.

Is this correct?

Exactly, this is not efficient with good free wheels but there is no such thing as perfect wheels without friction and non linearities, such imperfections that allow to communicate some momentum from mobile to road. Those mechanical devices can't work in vacuum free floating or free falling 0G and no contact with support : by the book the centre of mass of device is always following a perfect inertial trajectory. Now if the device is big enough (has enough span) so that different parts of it taste different gravity gradients, like with rotating tethers, then by the book it could be possible to have some slingshot effect to exchange some momentum with some nearby massive body without expelling anything, my guess, at least you can't approximate the whole system by only its centre of mass and need to see the details.

guys you are typing too fast !

Offline frobnicat

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Re: EM Drive Developments
« Reply #1081 on: 09/28/2014 10:03 PM »
So far my feeling is that the "propellantless propulsion proponents" are doing a really great job at NOT convincing an (admittedly already reluctant) mainstream science community that there is any effect at all. ...
I agree, that is my reaction as of late, with many exceptions.  Notably, Paul March


coincidentally, the only one who posts here who directly works on propellantless propulsion and the only one who can address the questions raised. I wonder how Frobnicat expects propellantless propulsion proponents here to answer the questions raised when only people directly working with those experiments can answer such questions.

It´s a bit unfair of Frobnicat to demand specific answers from us that only a few people WORKING on those experiments can effectively give, and then say we are not helping the cause.

Answers to this by other contributors suit me.
Just to add (shouldn't) I'm a bit harsh yes, I wouldn't say unfair but you could say "it's easy". Yes it's easy, I recognize having become accustomed to some pretty high standards when it comes to reading and learning from research, from the comfort of my armchair. I'm not demanding to enthusiasts answers they don't have. Just sharing thoughts. Expressing views: beware of borderline methodology, we (sceptics) beg you (enthusiasts) not to dive into black science, for your own sake.
http://www.nerdcoremovement.com/wp-content/uploads/2014/07/Black-Science-1-6.jpg

« Last Edit: 09/28/2014 10:04 PM by frobnicat »

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #1082 on: 09/28/2014 10:17 PM »
"Exactly, this is not efficient with good free wheels but there is no such thing as perfect wheels without friction and non linearities, such imperfections that allow to communicate some momentum from mobile to road. Those mechanical devices can't work in vacuum free floating or free falling 0G and no contact with support : by the book the centre of mass of device is always following a perfect inertial trajectory. Now if the device is big enough (has enough span) so that different parts of it taste different gravity gradients, like with rotating tethers, then by the book it could be possible to have some slingshot effect to exchange some momentum with some nearby massive body without expelling anything, my guess, at least you can't approximate the whole system by only its centre of mass and need to see the details."

Yah, rotating in a grav/gradient allows you to tranfer angular momentum anget a sort of "lift"    ala the "spindizzy"

Online Rodal

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Re: EM Drive Developments
« Reply #1083 on: 09/28/2014 10:34 PM »
Expressing views: beware of borderline methodology, we (sceptics) beg you (enthusiasts) not to dive into black science, for your own sake.
http://www.nerdcoremovement.com/wp-content/uploads/2014/07/Black-Science-1-6.jpg

So, we started by considering the quantum vacuum which leads to dark energy (the cosmological constant), while others proposed dark matter (axons), and now we are warned about staying away from dark science  :D

To me this points to the "Light side of the force" --> classical physics, and stay away from the Dark Side  :D for an explanation.
« Last Edit: 09/28/2014 10:50 PM by Rodal »

Online Rodal

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Re: EM Drive Developments
« Reply #1084 on: 09/28/2014 10:55 PM »
Friction not as easy as some may think



 Prof. Walter Lewin  MIT

8.01 is the introductory freshman Physics course at MIT.  There are many flavors of it.
« Last Edit: 09/28/2014 11:28 PM by Rodal »

Online Rodal

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Re: EM Drive Developments
« Reply #1085 on: 09/28/2014 11:21 PM »
Did you see the "dry ice" floating device at the end of that MIT lecture?  It would be interesting to challenge inventors that have devices like that contraction (rotating chaotically) that John was interested in (that I think relies on friction), to have them run on such a single omnidirectional low-friction support  point instead of several wheels on a track.  Of course, twice the weight of the device should not exceed the max weight allowed for a film to exist for the dry ice to work.

I write "twice the weight" to take into account dynamic (inertial) effects.

Only one "dry ice" support.  The contraction should sit on top.  Let's see whether it moves without any external force.

********
Did you see the experiment at the end with the insect pulling the book, etc ?

I wonder how many microNewtons force is that insect able to pull
« Last Edit: 09/28/2014 11:32 PM by Rodal »

Offline ThinkerX

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Re: EM Drive Developments
« Reply #1086 on: 09/29/2014 12:04 AM »
Ok...

1) This Biefield-Brown effect appears legitimate...at least in an atmosphere.  From some of the terms employed in the Wiki, it seems almost like some of the experimenters are attempting to get this effect to work in a vacuum, with ambiguous results at best.

2) Something that has been brought up a couple times before on this thread yet never really looked into:  Apparently - according to a print article I read some years ago, Shawyer (Sp?) became interested in this class of drive upon being hired to investigate why satellites were consuming far more thruster fuel than they should have trying to maintain their correct orbits.  He concluded the cause was microwave devices on board these satellites that were generating actual thrust.  This might be worth taking a peek at again.  Rodal, any thoughts here? 

3) I have brought this up before, but...could 'dark matter' or 'dark energy' be at play here?  From what I have read, most efforts to investigate dark matter or dark energy involve microwaves.  Hence, if microwaves are deemed useful to detect these phenomena, then perhaps microwaves could influence/excite/interact with them somehow to produce the observed thrust?  Or does this cause as many issues with the laws of physics as the other explanations?

And as to the various tests and devices, it seems to me the researchers are making an impressive effort to counter testing artifacts, as well as testing out different classes of device to see which one works best.   Of course, their best efforts might not be good enough. 


Online Rodal

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Re: EM Drive Developments
« Reply #1087 on: 09/29/2014 12:17 AM »
...

3) I have brought this up before, but...could 'dark matter' or 'dark energy' be at play here?  .explanations?

...

I will answer your question #3 for now.

Dr. White's explanation (pumping "the quantum vacuum") can be interpreted as using dark energy because in some theories the cosmological constant is related to both dark energy and the quantum vacuum.  Not enough is known yet about dark energy to say much more than that.

*********
My personal opinion for whatever it's worth, is that the  (few watts) microwave devices (Cannae and Frustum-type) cannot make real the virtual particles of the quantum vacuum.  One needs a petawatt laser to be able to make real electron/positron virtual pairs.  A petawatt is 10^15 watts, that is:
1000000000000000 watts.

« Last Edit: 09/29/2014 12:24 AM by Rodal »

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #1088 on: 09/29/2014 12:43 AM »
But that is enough to make extremely long wavelength "dark matter" particles, always assuming they exist of course.

Online Rodal

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Re: EM Drive Developments
« Reply #1089 on: 09/29/2014 12:53 AM »
But that is enough to make extremely long wavelength "dark matter" particles, always assuming they exist of course.

Good point.  But aren't they supposed to be "weakly interacting"?

On the other hand "weakly interacting" dark matter may be more likely to interact than a non-real-in-a-microwave (virtual) particle pair from the quantum vacuum. 

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #1090 on: 09/29/2014 12:55 AM »
Esp in a 2-photon interaction.

Edit : still need a non-linear GR term.

(I know I'm crossing GR and StdM here but that's what has to happen for EM to do anything)

(beats the rest-mass-changes foolishness)
« Last Edit: 09/29/2014 01:05 AM by Notsosureofit »

Online Rodal

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Re: EM Drive Developments
« Reply #1091 on: 09/29/2014 01:01 AM »
Esp in a 2-photon interaction.

Edit : still need a non-linear GR term.

<<First calculations of rate of e+–e− pair production in photon-photon collision was done by Lev Landau in 1934.[1] It was predicted that the process of e+–e− pair creation (via collisions of photons) dominates in collision of ultra-relativistic charged particles—because those photons are radiated in narrow cones along the direction of motion of original particle greatly increasing photon flux.

In high-energy particle colliders, matter creation events have yielded a wide variety of exotic heavy particles precipitating out of colliding photon jets (see two-photon physics). Currently, two-photon physics studies creation of various fermion pairs both theoretically and experimentally (using particle accelerators, air showers, radioactive isotopes, etc.).
>>

http://en.wikipedia.org/wiki/Matter_creation

http://en.wikipedia.org/wiki/Two-photon_physics
« Last Edit: 09/29/2014 01:04 AM by Rodal »

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #1092 on: 09/29/2014 01:07 AM »
Exactly !

Online Rodal

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Re: EM Drive Developments
« Reply #1093 on: 09/29/2014 01:10 AM »
Esp in a 2-photon interaction.

Edit : still need a non-linear GR term.

(I know I'm crossing GR and StdM here but that's what has to happen for EM to do anything)

Is this a theoretical possibility, or is there any experimental evidence of such nonlinear GR term?

If only a theoretical possibility has anyone looked at whether such a nonlinear GR term could be introduced without producing other effects that would run contrary to the Universe as we know it?

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #1094 on: 09/29/2014 01:18 AM »
Still looking, but hints would be things like tapered cavities and asymmetric dielectrics which would add dispersion to the cavity photons, hence the nonlinear term.  (you'll be the first to know if I find something while digging)

Online Rodal

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Re: EM Drive Developments
« Reply #1095 on: 09/29/2014 01:23 AM »
Still looking, but hints would be things like tapered cavities and asymmetric dielectrics which would add dispersion to the cavity photons, hence the nonlinear term.  (you'll be the first to know if I find something while digging)

Excellent statement <<that's what has to happen for EM to do anything)>>   :)
« Last Edit: 09/29/2014 01:30 AM by Rodal »

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #1096 on: 09/29/2014 01:46 AM »
You could compare to wave-tank model w/ a slope and a step wall.  The nonliniarity comes in at the liquid drop formation.  But where do you get the value for this case ?  Plank drops ?

(notice there is a classical static force in these cases, shock waves etc etc)
« Last Edit: 09/29/2014 01:53 AM by Notsosureofit »

Online Rodal

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Re: EM Drive Developments
« Reply #1097 on: 09/29/2014 01:54 AM »
My mind can't get around the energy required

<< To create an electron-positron pair the total energy of the photons must be at least 2mec2 = 2 × 0.511 MeV = 1.022 MeV (me is the mass of one electron and c is the speed of light in vacuum), an energy value that corresponds to soft gamma ray photons. The creation of a much more massive pair, like a proton and antiproton, requires photons with energy of more than 1.88 GeV (hard gamma ray photons).>>

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #1098 on: 09/29/2014 01:56 AM »
Not as long as you keep asking for electron/positron pairs (real), not gonna happen.

Same problem w/ creating "Plank drops" if they were to exist, way to much energy.

If the effect is real you need a large momentum to energy ratio so c is way too big but a plank mass would be nice if you could couple to it.

Leaving now, but I may have to think about the water drop analogy.  The nonlinearity (in the dispersion curve) is present before the drop "breaks" (is created ?) 
« Last Edit: 09/29/2014 02:21 AM by Notsosureofit »

Online Rodal

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Re: EM Drive Developments
« Reply #1099 on: 09/29/2014 02:22 AM »
Not as long as you keep asking for electron/positron pairs (real), not gonna happen.

Same problem w/ creating "Plank drops" if they were to exist, way to much energy.

If the effect is real you need a large momentum to energy ratio so c is way too big but a plank mass would be nice if you could couple to it.

Leaving now, but I may have to think about the water drop analogy.  The nonlinearity (in the dispersion curve) is present before the drop "breaks" (is created ?)

A Planck mass as in a Micro black hole ? 



EDIT:  Wait, only now I saw <<You could compare to wave-tank model w/ a slope and a step wall.  The nonliniarity comes in at the liquid drop formation.  But where do you get the value for this case ?>>

I have to think about that....
« Last Edit: 09/29/2014 02:26 AM by Rodal »

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