Quote from: DrBagelBites on 07/06/2015 11:22 pmQuote from: Rodal on 07/06/2015 11:08 pm...Is there one question in particular you would like me to ask? Not sure if I would be able to ask all of them or even more than one. -IAs it gets closer to the date of the presentation, I will re-post all the questions in order of importance. As there are going to be more questions posed, it is too early to rank the questions at this point in time. What is the deadline by which you would like to have the list of questions ranked by importance?
Quote from: Rodal on 07/06/2015 11:08 pm...Is there one question in particular you would like me to ask? Not sure if I would be able to ask all of them or even more than one. -I
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Quote from: DrBagelBites on 07/06/2015 11:42 pmThat is one thing I am going to definitely try and avoid: "EmDrive". It is a controversial name, and referring to it by a more generic "electromagnetic, propelantless engine" might incite more of a response. I'll let you know what each company says based off of the question!I'll probably ask those questions during the time of visiting booths, or if I am lucky enough, to sit next to a key player during the luncheons. I am very excited. You might like to try the "Field Effect Propulsion" angle as well. I think your assumption is correct in that "emdrive" will just result in rapidly closed doors.Perhaps also mention the "Hypothetical concepts surrounding proposals such as present thoughts on the 4 main contenders; Bias Drive: Works with the properties of space itself, Altering/adjusting the local properties,Diametric Drive: Works with field sources, diametrically opposed sources reating upon the mass,Disjunction Drive: Works with the properties of matter that create and react to a field, Pitch Drive: Works With the field itself. a slope in scalar potential. The common theme between them all is the asymemtric field.
That is one thing I am going to definitely try and avoid: "EmDrive". It is a controversial name, and referring to it by a more generic "electromagnetic, propelantless engine" might incite more of a response. I'll let you know what each company says based off of the question!I'll probably ask those questions during the time of visiting booths, or if I am lucky enough, to sit next to a key player during the luncheons. I am very excited.
Only useful posts please. I notice the main detractors (four of them) who claim this thread (with 460,000 views on this one thread alone) has no place on here are always on this thread too. Do not respond to posts that have no value. Do not quote them. Report them because they, and your response, will be removed.And yes, to quote a removed post, I too think this is "all bollocks" but unlike those I referenced, I don't judge my own world view as the law of the land.
While I feel those are very interesting topics, and could definitely warrant a question, I feel these are still very very close to "warp drive" and the associations that come with it. I am not saying they are the same at all, but to elicit a response that would really give some new insight as to what is happening, I feel it would be in our best interests to at least phrase it so that there isn't that connection that can completely dismantle the validity of the question.
Quote from: DrBagelBites on 07/07/2015 12:10 amWhile I feel those are very interesting topics, and could definitely warrant a question, I feel these are still very very close to "warp drive" and the associations that come with it. I am not saying they are the same at all, but to elicit a response that would really give some new insight as to what is happening, I feel it would be in our best interests to at least phrase it so that there isn't that connection that can completely dismantle the validity of the question.I agree, wording and timing is crucial. I also admit to feeling a certain amount of both frustration and disappointment with the whole field as these things were Hot news way back in the mid 1990's. I remember M.G.Millis, Then of NASA Lewis Research Center presented papers on these same topics... I think it was about 1996-1997 from memory?.
Quote from: DrBagelBites on 07/07/2015 12:10 amWhile I feel those are very interesting topics, and could definitely warrant a question, I feel these are still very very close to "warp drive" and the associations that come with it. I am not saying they are the same at all, but to elicit a response that would really give some new insight as to what is happening, I feel it would be in our best interests to at least phrase it so that there isn't that connection that can completely dismantle the validity of the question.I agree, wording and timing is crucial. I also admit to feeling a certain amount of both frustration and disappointment with the whole field as these things were Hot news way back in the mid 1990's. I remember M.G.Millis, Then of NASA Lewis Research Center presented papers on these same topics... I think it was about 1996-1997 from memory?. Dr Whites (and others) findings would naturally follow as ongoing consequences of such things.
Quote from: arc on 07/07/2015 12:21 amQuote from: DrBagelBites on 07/07/2015 12:10 amWhile I feel those are very interesting topics, and could definitely warrant a question, I feel these are still very very close to "warp drive" and the associations that come with it. I am not saying they are the same at all, but to elicit a response that would really give some new insight as to what is happening, I feel it would be in our best interests to at least phrase it so that there isn't that connection that can completely dismantle the validity of the question.I agree, wording and timing is crucial. I also admit to feeling a certain amount of both frustration and disappointment with the whole field as these things were Hot news way back in the mid 1990's. I remember M.G.Millis, Then of NASA Lewis Research Center presented papers on these same topics... I think it was about 1996-1997 from memory?. Fwiw, would not announce ur an experimenter. When I did booth duty (abt 30 years worth), off the wall claims by visitors got a chilly reception. Lots of booth critters are looking for their next sales opportunity. Best to ask a question relevant to their company and if answer not known, ask for a name and is that person available at the show. Also, have a biz card...a title of consultant was pretty commonplace. Trade shows are a blast, always had to stick close to my booth, so never roamed much...that is a privledge...
Quote from: Rodal on 07/06/2015 10:25 pmQuote from: WarpTech on 07/06/2015 10:20 pm...Also, did Dr. Tajmar treat his EM Drive as a thruster or a ratchet? According to SPR and TheTraveler, if he was expecting it to thrust, he probably got Null results as is to be expected, since it is not intended to thrust without some outside influence to make it ratchet.ToddWell, I understand that Tajmar will not present his results under vacuum as "null results" but as valid results.As to the outside influence to motivate the EM Drive, how did Yang motivate her EM Drive to thrust?and more generally, can you think of a question we could ask Tajmar along these lines? (I have tried to construct such a question and it is difficult to do in a few words, without appearing unintelligible, as first one has to describe what one means by "as a ratchet under outside influence". I have enough trouble understanding what Shawyer may mean by that, much less how to construct such a question in an intelligible manner)It would be great if you and others could think of how to ask such a question to Tajmar, with a minimum of words and in a way that he understands what the question is about.Perhaps the "Ratchet Question" could best be phrased as to whether Prof. Tajmar saw the "EM drive" as a purely closed system or an open one that interacted with its environment. If Tajmar saw "EM drives" as closed, then did they have their own inertial frame of reference.Does this work?
Quote from: WarpTech on 07/06/2015 10:20 pm...Also, did Dr. Tajmar treat his EM Drive as a thruster or a ratchet? According to SPR and TheTraveler, if he was expecting it to thrust, he probably got Null results as is to be expected, since it is not intended to thrust without some outside influence to make it ratchet.ToddWell, I understand that Tajmar will not present his results under vacuum as "null results" but as valid results.As to the outside influence to motivate the EM Drive, how did Yang motivate her EM Drive to thrust?and more generally, can you think of a question we could ask Tajmar along these lines? (I have tried to construct such a question and it is difficult to do in a few words, without appearing unintelligible, as first one has to describe what one means by "as a ratchet under outside influence". I have enough trouble understanding what Shawyer may mean by that, much less how to construct such a question in an intelligible manner)It would be great if you and others could think of how to ask such a question to Tajmar, with a minimum of words and in a way that he understands what the question is about.
...Also, did Dr. Tajmar treat his EM Drive as a thruster or a ratchet? According to SPR and TheTraveler, if he was expecting it to thrust, he probably got Null results as is to be expected, since it is not intended to thrust without some outside influence to make it ratchet.Todd
I thought I would chime in with questions for the AIAA conference. I am going to be attending the event, so I will be able to report back to you guys about what happens, other questions that were asked, etc. Let me know of a couple of definite questions that anyone would want me to ask during the Q and A, and I'll be sure to ask them and report back the answers. -I
I have, from aero's csv files,1) Calculated the Poynting vector component in the longitudinal direction (the components in the transverse direction are self-cancelling, since they point in opposite directions away from the axis)2) Determined the location of the local maximum on the wave-pattern immediately downstream (towards the big base) from the antenna location: it is column (x location) 1493) calculated the time fluctuation of the Poynting vector component in the longitudinal direction at that local maximum location. It is attached below.We see that:1) The average over an integer number of periods is not zero. It is negative, meaning that it points from the small base towards the big base. (We had previously shown this with 3D and also with vector field plots)2) The magnitude of the Poynting vector (averaged over integer time periods) grows with timeThis is all fully consistent with a force acting (to balance momentum) pointing towards the small base. Although consistent, not yet a proof, since:1) We only have available data for the last 13 steps out of ~325 time steps. We don't know whether this is a transient or how representative it is from the long-term response.2) This flux (power/area) may get dissipated into heat. It has to be shown why is the Poynting vector growing with time, how long does this go on for, and whether this all goes into losses at the walls or whether (and if so how) this Poynting vector gets converted into a force.Units are in Meep units. [Have to take into account also aero's scale factor to figure out SI units]The dots represent the data point. The smooth curves between the points are interpolated. We should also be able from these data to calculate the frequency if we knew the time step (the frequency of the Poynting vector should be twice the frequency of the microwave field) and we should also be able to calculate the rate of growth per unit time.
Background: previous post with Poynting Vector Field plots for time steps 03 through 13: http://forum.nasaspaceflight.com/index.php?topic=37642.msg1399795#msg13997952) The magnitude of the Poynting vector (averaged over integer time periods) grows with timeThis is all fully consistent with a force acting (to balance momentum) pointing towards the small base. Although consistent, not yet a proof, since:It has to be shown why is the Poynting vector growing with time, how long does this go on for, and whether this all goes into losses at the walls or whether (and if so how) this Poynting vector gets converted into a force.
Quote from: Rodal on 07/07/2015 01:26 amBackground: previous post with Poynting Vector Field plots for time steps 03 through 13: http://forum.nasaspaceflight.com/index.php?topic=37642.msg1399795#msg13997952) The magnitude of the Poynting vector (averaged over integer time periods) grows with timeThis is all fully consistent with a force acting (to balance momentum) pointing towards the small base. Although consistent, not yet a proof, since:It has to be shown why is the Poynting vector growing with time, how long does this go on for, and whether this all goes into losses at the walls or whether (and if so how) this Poynting vector gets converted into a force.At what rate do you see the poynting vector grow?Shell
Quote from: SeeShells on 07/07/2015 02:05 amQuote from: Rodal on 07/07/2015 01:26 amBackground: previous post with Poynting Vector Field plots for time steps 03 through 13: http://forum.nasaspaceflight.com/index.php?topic=37642.msg1399795#msg13997952) The magnitude of the Poynting vector (averaged over integer time periods) grows with timeThis is all fully consistent with a force acting (to balance momentum) pointing towards the small base. Although consistent, not yet a proof, since:It has to be shown why is the Poynting vector growing with time, how long does this go on for, and whether this all goes into losses at the walls or whether (and if so how) this Poynting vector gets converted into a force.At what rate do you see the poynting vector grow?ShellDid not get the Finite Difference data to calculate that until a few minutes ago (message from aero just above yours ) . Will need to convert units and calculate. Got some $$$ paying work to do now, maybe I'll calculate it tomorrow
I don't know whether this is stating the obvious, but one of the TheTraveller's recent posts made me go ahh. With Shawyer's experiments, if the drive is stationary in a low noise environment and switched on, it does not move. Well, it may generate some thrust, but not enough to overcome any friction in the test equipment. It needs an external stimulus or acceleration to get moving. Once moving, and free to accelerate, the drive will generate thrust and continue to accelerate. A sort of feed back loop as it were. Which explains Shawyer's rotating test rig. With a balance scale, when the drive's velocity falls to zero when it is at the top/bottom, the thrust should drop off. However, having a balance scale with a way to inject a known initial acceleration to the drive might be a good way to test.To my somewhat limited understanding, this looks like some kind of relativity problem. When stationary, or at constant velocity, photons are hitting the walls in the same reference frame. However, with the drive under acceleration, photons will be hitting the walls in different frames, and in some fashion generating thrust.For the EM drive theories currently being discussed, do they require an initial impetus or acceleration to get the drives to move or not. If not, then this goes against what Shawyer is saying.Similarly, for analysis being done. Is this assuming a drive at zero or constant velocity, or a drive under acceleration.It may also be that the earth's rotation is going to have an effect upon the EM drive as the photons bounce around inside.And if EM drives do work, perhaps they'll have an analogue to the car choke, which gives them a shake to get them started.
Quote from: SeeShells on 07/07/2015 02:05 amQuote from: Rodal on 07/07/2015 01:26 amBackground: previous post with Poynting Vector Field plots for time steps 03 through 13: http://forum.nasaspaceflight.com/index.php?topic=37642.msg1399795#msg13997952) The magnitude of the Poynting vector (averaged over integer time periods) grows with timeThis is all fully consistent with a force acting (to balance momentum) pointing towards the small base. Although consistent, not yet a proof, since:It has to be shown why is the Poynting vector growing with time, how long does this go on for, and whether this all goes into losses at the walls or whether (and if so how) this Poynting vector gets converted into a force.At what rate do you see the poynting vector grow?ShellDid not get the Finite Difference data to calculate that until a few minutes ago (message from aero just above yours ) . Will need to convert units and calculate. Got some $$$ paying work to do now, maybe I'll calculate it tomorrow Also have to find previous posts from aero with link to Meep units conversion.QUESTION TO AERO: is the scale factor the same in all the runs ?
...;Meep progress: 13.054/13.052188647619047 = 100.0% done in 6479.3s, -0.9s to go;run 0 finished at t = 13.054 (6527 timesteps)It looks to me like the number you want is dt = 13.054/6527 which equals 0.002, a nice number. Or maybe you want to use the 100% done numbers. Anyway, you should be able to use this dt for any of the csv files from the h5 files with dimensions 247x264x264 or any run of 32 cycles with resolution =250 and frequency = 2.45 GHz. That is, they should have those dimensions.
So I've just had the cops at the door saying the neighbors are complaining about the noise coming from this thread I see mod notes all over the place, so here's the deal.1) Always, always, always remember this thread has to be about space flight applications. That's because we're a space flight site. You'd get away with talking about how this is the key to your plans to create an anti-gravity device that you're going to sell on Ebay over at the www.superwackyphysics.net forum, but not here.2) Lots and lots of people read the threads here (all threads - this isn't some special "everyone's reading it, you should change the name of the site" thread. This is a pretty busy site. Heck if you sneeze SpaceX, hoards of people start mashing their F5 keys like a global event is about to occur). As such, your posts need to be worthwhile, otherwise all those people *reading the thread* sigh with disappointment...and some write me a 20 page e-mail about how I should read every post and personally edit them to fit the site's "tone" (that has happened a few times! ) I don't get paid enough for that (I don't get paid).Remember, this isn't some chat where only the people posting are reading. You can see from the view count those posting are less than 0.1 percent of those reading this thread. You wouldn't stand in the middle of a busy street and say something silly....same deal in a thread like this.3) Loooooooooooong threads wander. It's natural. So I think we'll look to start a Thread 4 for this subject this week.So let's all focus, be civil, be productive and we can all get on with our business