Author Topic: EM Drive Developments Thread 1  (Read 764626 times)

Online Rodal

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Re: EM Drive Developments
« Reply #1040 on: 09/28/2014 01:48 PM »
(how is it possible to include a video directly inside the post ?)

it works automatically by copying the link, as in this video:



or the video you posted:



Do not use the  "Insert Hyperlink" key
Do enter a "carriage return" also known as "Enter" key right after the video link.
« Last Edit: 09/28/2014 02:02 PM by Rodal »

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #1041 on: 09/28/2014 01:52 PM »
Progress in publishing ?

Online Rodal

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Re: EM Drive Developments
« Reply #1042 on: 09/28/2014 02:04 PM »
Progress in publishing ?
You noticed (at the end of the demonstration) that the presenter was holding for the audience an Antigravity Propulsion book.
« Last Edit: 09/28/2014 02:06 PM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1043 on: 09/28/2014 02:19 PM »
Does this merit a bottle of Scotch? John, when you wrote <<Rodal has repeatedly asserted that the "scientific controls" of the inverted pendulum are not satisfactorily removing >>: the issues I raised are endemic, and known, with inverted pendulums and magnetic dampening.  They are not due to scientific controls.

Huh?

Maybe run this thru yer grammar checker, kemosabe?  I am using the term "scientific controls" in its plain English sense, which  in this case, may not include the stricter scientific sense that you might be referring to.  Here's what I think you are saying:

The "endemic issues" of inverted pendulums, which include magnetic damping and such should not be confused with "scientific controls" pertaining to differentiating null results from detected results.  I just lumped the endemic issues into the subject of scientific controls.

Howzabout sharing your definition of "scientific controls"?

And one more thing.  I remember only promising a drink, not the whole bottle.  Or was that the Lapfrog speaking?

... but the will to log and communicate every possible detail on a stable reference experiment is lacking.

I admire your style of writing.

It is indeed the case that the "will to log and communicate every possible detail" is lacking.  With the experimental results reported in the "apparently endless series of various devices" as a basis, one reads posts like the "#1020 'you' post", and finds no corroborating information nor pragmatically useful explanation of either the underlying theory nor of the experimental apparatus.  The methodology of theory and experiment is simply not served.

...there seems to be an assumption that Eagleworks or Dr. Woodward have something that could be so easily reproduced that a complete description is all that is needed for someone else to reproduce it.

It is not so much as an assumption, by my take.  It is more that questions are simply not being answered, and what appear to be objections to theory and experiment are not being countered.

I think that they are trying too hard to see something, and not hard enough to see nothing. ... If effect is impossible, any progress is illusory.

And.  Some of the enthusiasts are getting far too emotional about it.
« Last Edit: 09/28/2014 02:20 PM by JohnFornaro »
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1044 on: 09/28/2014 02:24 PM »
Progress in publishing ?
You noticed (at the end of the demonstration) that the presenter was holding for the audience an Antigravity Propulsion book.

Well, of course they're going to try and sell the book.

If we can tentatively accept that the stage floor is the "scientifically controlled" equivalent of the conference room table, what made that device hover?

The whirly bird thing was converting electrically caused rotary action into forward momentum.  He needs to tighten up the mechanism, since it would be a bumpy ride, but it looks like it works.

What say you to those two devices?
« Last Edit: 09/28/2014 02:24 PM by JohnFornaro »
Sometimes I just flat out don't get it.

Online Rodal

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Re: EM Drive Developments
« Reply #1045 on: 09/28/2014 02:36 PM »

Maybe run this thru yer grammar checker, kemosabe?  I am using the term "scientific controls" in its plain English sense, which  in this case, may not include the stricter scientific sense that you might be referring to.  Here's what I think you are saying:

The "endemic issues" of inverted pendulums, which include magnetic damping and such should not be confused with "scientific controls" pertaining to differentiating null results from detected results.  I just lumped the endemic issues into the subject of scientific controls.

Howzabout sharing your definition of "scientific controls"?
I was interpreting "scientific controls" with emphasis on "controls" and "scientific" just being a modifier.  I wanted to emphasize that what I am questioning is not anything to do with automatic http://en.wikipedia.org/wiki/Automatic_control or human control http://www.bartlett.psychol.cam.ac.uk/human%20control%20systems.html of the experimental setup.  One of the responders seems to have addressed this as finding "fault" with the experimenter in having made some mistake during the experiments, which is not at all what I question.  What I questioned is the use of a magnetically damped inverted pendulum because it is subject to self-excitation and mode coupling of swinging with torsional modes.

Having said that, I see that Wikipedia has a different view of the meaning of "scientific controls" http://en.wikipedia.org/wiki/Scientific_control  as <<an experiment or observation designed to minimize the effects of variables other than the single independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements. >>, so yes, kernosabe, according to this definition, your use of "scientific control" was well utilized.

Online Rodal

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Re: EM Drive Developments
« Reply #1046 on: 09/28/2014 02:48 PM »
...there seems to be an assumption that Eagleworks or Dr. Woodward have something that could be so easily reproduced that a complete description is all that is needed for someone else to reproduce it.

Huh?, reproduction of results by independent scientists is what I always understood to be the definition of the scientific method.

Does @birchoff or Prof. Woodward have a different definition of the scientific method?
« Last Edit: 09/28/2014 03:03 PM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1047 on: 09/28/2014 02:51 PM »
...

Having said that, I see that Wikipedia has a different view of the meaning of "scientific controls" http://en.wikipedia.org/wiki/Scientific_control  as <<an experiment or observation designed to minimize the effects of variables other than the single independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements. >>, so yes, kernosabe, according to this definition, your use of "scientific control" was well utilized.

Thanks, kemosabe, since the oracle's daffynition more or less agrees with mine..
« Last Edit: 09/28/2014 02:52 PM by JohnFornaro »
Sometimes I just flat out don't get it.

Online Rodal

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Re: EM Drive Developments
« Reply #1048 on: 09/28/2014 03:03 PM »
...there seems to be an assumption that Eagleworks or Dr. Woodward have something that could be so easily reproduced that a complete description is all that is needed for someone else to reproduce it.

Do the Eagleworks or Prof. Woodward's experiments to be easily reproduced elsewhere, in addition to "a complete description," need  a "personal touch" that only Prof. Woodward and/or a few other special people can provide?

I hope that the implication is not that Prof. Woodward's experiments are akin to experiments that need a "personal touch", for example http://en.wikipedia.org/wiki/Spoon_bending.

Certainly not.  If the experiments cannot be easily reproduced by other scientists at other locations, they cannot  be considered part of the scientific progress.
« Last Edit: 09/28/2014 03:19 PM by Rodal »

Offline frobnicat

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Re: EM Drive Developments
« Reply #1049 on: 09/28/2014 03:04 PM »
What say you to those two devices?

- Offboard high voltage generator + light construction + ionic wind, basically same effect as developed for "no moving parts" cooling fans. Interesting but irrelevant for space propulsion (needs an atmosphere to push on). Might learn something for ion thrusters (but then mass has to be expelled). Low or high altitude propulsion possible with generators of high enough power/mass ratio (as a lot of other schemes...). Don't know how it compares to usual propellers. Sure that no anti-gravity or beyond standard physics are involved.

-  "Unsymmetrical frictional resistance" of some sort. Net forward momentum effect will vanish as soon as in 0G and not in contact to any exterior mass : irrelevant for space propulsion. No beyond standard physics are involved, though it might be tricky to explain precisely the apparent forward momentum, given complex mechanical coupling and, er, somehow chaotic modes of giggling. Even with low friction bearings, one does get a force component tangential to the rail when the bearing is rolling, this tangential component's magnitude depends on the normal components. By wriggling the centre of mass and the rotational momentums in such a way that the normal component is not symmetrical relative to periodic forward/backward movements, like for instance being light when forward and stomping when backward, you can get a net forward momentum. That and possibly a small help by "accompanying" the device's wires.

thanks for the video posting tip Rodal

Online Rodal

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Re: EM Drive Developments
« Reply #1050 on: 09/28/2014 03:11 PM »
Progress in publishing ?
You noticed (at the end of the demonstration) that the presenter was holding for the audience an Antigravity Propulsion book.

Well, of course they're going to try and sell the book.

If we can tentatively accept that the stage floor is the "scientifically controlled" equivalent of the conference room table, what made that device hover?

The whirly bird thing was converting electrically caused rotary action into forward momentum.  He needs to tighten up the mechanism, since it would be a bumpy ride, but it looks like it works.

What say you to those two devices?

The first device is presented almost like a magician's trick, and saying what made it hover is like trying to ascertain what trick did a magician use.  I suspect ionic wind and the visible wires.

For the second device I suspect "Dean drive" effect (observe the frictional stick-slip and jumping in the tracks) plus the (unconscious guiding) influence of the cables held by the person.
« Last Edit: 09/28/2014 03:13 PM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1051 on: 09/28/2014 03:16 PM »
One of the responders seems to have addressed this as finding "fault" with the experimenter in having made some mistake during the experiments, which is not at all what I question.

It is always clear that a person's moral character is not defined by whatever mistakes that person might make in an experiment.  Cognitive infiltration, as I use the term, comes into play when the hominem is deliberately substituted for the criticism of the experimental or theoretical setup.

Also, I was using the term "control" loosely to refer to experimental controls.  Kinda like the placebo effect.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1052 on: 09/28/2014 03:20 PM »
In the ionic wind device, one would be able to feel the "breeze", then.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1053 on: 09/28/2014 03:24 PM »

The whirly bird thing was converting electrically caused rotary action into forward momentum.  He needs to tighten up the mechanism, since it would be a bumpy ride, but it looks like it works.

For the second device I suspect "Dean drive" effect (observe the frictional stick-slip and jumping in the tracks) plus the (unconscious guiding) influence of the cables held by the person.

The cables trail the device and appear more to be an actual drag or load that the device must carry.  It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.

Why couldn't this be done?
Sometimes I just flat out don't get it.

Online Rodal

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Re: EM Drive Developments
« Reply #1054 on: 09/28/2014 03:25 PM »

Online Rodal

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Re: EM Drive Developments
« Reply #1055 on: 09/28/2014 03:34 PM »
It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.
Why couldn't this be done?

I was given this windup toy by a Swiss friend  :) years ago that demonstrates a chaotic walking motion produced by an off-center-of-rotation CG of rotating mass:



It also relies on stick-slip friction at the legs.  Also observe that it is important to have long lightweight legs in order to maximize the motion.

The chaotic, limit-cycle motion results in a "walking motion".  One can derive the equations of motion (using the Lagrangian and the non-conservative term due to stick-slip friction).  It is an interesting example of nonlinear equations of motion resulting in this "walking motion".  It is a very inefficient and difficult to control motion, so it is of no practical use for walking robots.
« Last Edit: 09/28/2014 05:02 PM by Rodal »

Online Rodal

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Re: EM Drive Developments
« Reply #1056 on: 09/28/2014 04:59 PM »
It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.
Why couldn't this be done?

Think of how you move your body to roller skate.

It can only work when there is stick-slip friction against a surface, just like you need friction to roller skate.  Devices like this that need stick-slip friction against a surface cannot work in outer space. No frictional surface on outer space.

For motion on the surface of our planet, relying on stick-slip friction motion is much more inefficient than, for example, a Tesla using an electric motor to directly drive its wheels, relying on rolling friction of its tires.
« Last Edit: 09/28/2014 05:01 PM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1057 on: 09/28/2014 05:10 PM »
It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.
Why couldn't this be done?

Think of how you move your body to roller skate.

Ima good skater on ice and roller blades.  The secret is pushing on your blade at right angles to its axis, so that you don't roll or slide.  That's the friction.  Which you know.  As an aside, one of the things I still can't really do is jump into a right angled dramatic brake in either medium. 

Unless the wheels of the whirly bird device were frictionally directional, it appears to move forward without canting its wheels along their vertical axis, and developing friction in the same way as ice skating or roller blading.
Sometimes I just flat out don't get it.

Online Rodal

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Re: EM Drive Developments
« Reply #1058 on: 09/28/2014 05:27 PM »
It does look to be, if I imagine the device to be made to a tighter specification, that he is converting rotary motion into forward motion.
Why couldn't this be done?

Think of how you move your body to roller skate.

Ima good skater on ice and roller blades.  The secret is pushing on your blade at right angles to its axis, so that you don't roll or slide.  That's the friction.  Which you know.  As an aside, one of the things I still can't really do is jump into a right angled dramatic brake in either medium. 

Unless the wheels of the whirly bird device were frictionally directional, it appears to move forward without canting its wheels along their vertical axis, and developing friction in the same way as ice skating or roller blading.
Look at the critter wind-up toy motion for the rest of the story. 
« Last Edit: 09/28/2014 05:27 PM by Rodal »

Online Rodal

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Re: EM Drive Developments
« Reply #1059 on: 09/28/2014 05:32 PM »
The frictional rolling of a driven wheel against a surface always comprises a "stick" region at the leading side of rolling motion and a sliding region behind it.  The sliding is due to the shear stress exceeding the friction times the normal load.  The extent of stick and sliding in a rolling wheel is governed by the amount of normal force, the amount of shear force and the coefficient of friction.  The coefficient of friction is nonlinear: it is lower for sliding motion than for sticking motion.   
« Last Edit: 09/28/2014 05:34 PM by Rodal »

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