Quote from: aero on 11/04/2014 06:42 pmThanks. But we need to explain this video before we can attribute the EM Drive thrust in general to chamber wall/cavity interactions.http://emdrive.com/dynamictests.htmlVideo clips are near the bottom of the page. I don't see anything in the video that the EM Drive could interact with.After all this lengthy discussion I have been tracking for a while, what stays with me is the absolute need of more experimental results to talk about. More data points, more confirmations (or refutations).And the video you bring, while enticing, is alas not enough. I can imagine several ways to trick a video like that, just requiring enough willingness and lack of a consciousness to do it.Don't get me wrong. I like visual demonstrations as the next guy, it's that we only have this one so far.But if more people replicated that... we could start becoming really intrigued.
Thanks. But we need to explain this video before we can attribute the EM Drive thrust in general to chamber wall/cavity interactions.http://emdrive.com/dynamictests.htmlVideo clips are near the bottom of the page. I don't see anything in the video that the EM Drive could interact with.
Quote from: Rodal on 11/03/2014 11:16 pmQuote from: frobnicat on 11/02/2014 11:33 pmNext batch of scraped data from figure 19 page 15 of "anomalous thrust..." from Brady et al. The top (result1.txt) and middle (result2.txt) graphs are scraped. Same caveats as previously posted. For first curve (top figure 19) I removed the (non existent) flat last sampled data of the previous version to avoid artefacts when analysing with filters.Each line of those files is the value in µN at each .1 s interval (linearly interpolated from manual reconstruction). The vertical scale were roughly given by the calibration pulses at about 30µN (expect no more than 5% precision). Absolute values are arbitrary (because of the drifting baseline). Horizontal scale given by the indication of 196 s for the whole display graph window of the pictures.Will proceed with other graphs when time permits. Will post attempts at original signal reconstruction : thrust(t) while what we see is only balance displacement(t). Since the balance is underdamped, a lot can hide behind those oscillations and drifts in position.Frobnicated Top of Fig. 19 page 15 of anomalous (Mean and Linear Least Squares Fit)Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue)Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Linear LS (Red)Power Spectral Density (from FFT) on raw data detrended by Linear LS (Red)horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*94.6Peaks Period (seconds)3 1/(3/(94.6)) = 31.53 s Pulse period5 1/(5/(94.6)) = 18.92 s 4*Pendulum Period7 1/(7/(94.6)) = 13.51 s10 1/(10/(94.6)) = 9.46 s 2*Pendulum Period15 1/(15/(94.6)) = 6.31 s <---- This unidentified frequency appears on both Top and Middle18 1/(18/(94.6)) = 5.26 s20 1/(20/(94.6)) = 4.73 s Pendulum Period25 1/(25/(94.6)) = 3.78 s41 1/(41/(94.6)) = 2.31 s 1/2 Pendulum PeriodFrobnicated Middle of Fig. 19 page 15 of anomalous NASA report (Mean, Linear Least Squares Fit and Quadratic Least Squares Fit)Autocorrelation of Middle of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue), by Linear LS (Red) and by Quadratic LS (Green)Power Spectral Density of Middle of Fig. 19 page 15 (from FFT) on raw data detrended by Quadratic LS (Red)horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*98Peaks Period (seconds)3 1/(3/(98)) = 32.67 s Pulse period5 1/(5/(98)) = 19.60 s 4*Pendulum Period7 1/(7/(98)) = 14..00 s12 1/(13/(98)) = 7.54 s 16 1/(16/(98)) = 6.13 s <---- This unidentified frequency appears strongly on both Top and Middle22 1/(22/(98)) = 4.45 s Pendulum Period29 1/(29/(98)) = 3.38 s 34 1/(34/(98)) = 2.88 s36 1/(36/(98)) = 2.72 s 40 1/(40/(98)) = 2.45 s 42 1/(42/(98)) = 2.33 s 1/2 Pendulum Period
Quote from: frobnicat on 11/02/2014 11:33 pmNext batch of scraped data from figure 19 page 15 of "anomalous thrust..." from Brady et al. The top (result1.txt) and middle (result2.txt) graphs are scraped. Same caveats as previously posted. For first curve (top figure 19) I removed the (non existent) flat last sampled data of the previous version to avoid artefacts when analysing with filters.Each line of those files is the value in µN at each .1 s interval (linearly interpolated from manual reconstruction). The vertical scale were roughly given by the calibration pulses at about 30µN (expect no more than 5% precision). Absolute values are arbitrary (because of the drifting baseline). Horizontal scale given by the indication of 196 s for the whole display graph window of the pictures.Will proceed with other graphs when time permits. Will post attempts at original signal reconstruction : thrust(t) while what we see is only balance displacement(t). Since the balance is underdamped, a lot can hide behind those oscillations and drifts in position.Frobnicated Top of Fig. 19 page 15 of anomalous (Mean and Linear Least Squares Fit)Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Mean (Blue)Autocorrelation of Top of Fig. 19 page 15 (from FFT) on raw data detrended by Linear LS (Red)Power Spectral Density (from FFT) on raw data detrended by Linear LS (Red)horizontal scale = frequency(Hz) * 0.1 * (DataLength/2) = frequency(hz)*94.6Peaks Period (seconds)3 1/(3/(94.6)) = 31.53 s Pulse period5 1/(5/(94.6)) = 18.92 s 4*Pendulum Period7 1/(7/(94.6)) = 13.51 s10 1/(10/(94.6)) = 9.46 s 2*Pendulum Period15 1/(15/(94.6)) = 6.31 s <---- This unidentified frequency appears on both Top and Middle18 1/(18/(94.6)) = 5.26 s20 1/(20/(94.6)) = 4.73 s Pendulum Period25 1/(25/(94.6)) = 3.78 s41 1/(41/(94.6)) = 2.31 s 1/2 Pendulum Period
Next batch of scraped data from figure 19 page 15 of "anomalous thrust..." from Brady et al. The top (result1.txt) and middle (result2.txt) graphs are scraped. Same caveats as previously posted. For first curve (top figure 19) I removed the (non existent) flat last sampled data of the previous version to avoid artefacts when analysing with filters.Each line of those files is the value in µN at each .1 s interval (linearly interpolated from manual reconstruction). The vertical scale were roughly given by the calibration pulses at about 30µN (expect no more than 5% precision). Absolute values are arbitrary (because of the drifting baseline). Horizontal scale given by the indication of 196 s for the whole display graph window of the pictures.Will proceed with other graphs when time permits. Will post attempts at original signal reconstruction : thrust(t) while what we see is only balance displacement(t). Since the balance is underdamped, a lot can hide behind those oscillations and drifts in position.
Quote from: tchernik on 11/04/2014 07:52 pmQuote from: aero on 11/04/2014 06:42 pmThanks. But we need to explain this video before we can attribute the EM Drive thrust in general to chamber wall/cavity interactions.http://emdrive.com/dynamictests.htmlVideo clips are near the bottom of the page. I don't see anything in the video that the EM Drive could interact with.After all this lengthy discussion I have been tracking for a while, what stays with me is the absolute need of more experimental results to talk about. More data points, more confirmations (or refutations).And the video you bring, while enticing, is alas not enough. I can imagine several ways to trick a video like that, just requiring enough willingness and lack of a consciousness to do it.Don't get me wrong. I like visual demonstrations as the next guy, it's that we only have this one so far.But if more people replicated that... we could start becoming really intrigued.No question that we need more data and more replication.Operating on the assumption that there is a real force generated by the EM Drive precludes the need to speculate that the data is somehow faked. If we assume that the data is faked and the force is not real then that's the end of the story. No need to go any further.We here are operating on the assumption that the measurements are real and that the force is from a real EM Drive effect or else it is from an experimental artifact. We are pursuing both lines of investigation so the story ends when we find either the cause of the EM Drive effect or the experimental artifact that fits all of the data we have. Or when we have exhausted the data available. Without more data the latter seems likely at this point.
Ok, Admittedly, the math for this a\has finally gotten WAY beyond me. Could someone give me an idea of the power to motion ratio that seems to be being generated with this system, verses, say, a regular chemical rocket? What I am trying to find out is simple; Is this system somehow generating more motion than should be possible, assuming a direct conversion of energy to motion? In other words, is 1 calorie of energy somehow rasing 1 cubic centimeter of water's temprature higher than 1 degree celcius, or is the amount of power being used within a reasonable ratio of energy effecient conversion, say, 70% of power applied is being converted to motion, as an example? For the moment, set aside HOW it appears to be doing what it is doing, and let's see if it violates any of the Laws of Thermodynamics. Sorry, but you guys have gone so far beyond me mathematically, (plus, I think I may have missed a couple of equations that would have made it simpler to follow) that I am having the devil's own time trying to keep up with this thread.
@momerathe.... Momentum is a form of energy. Let's not split hairs here.
Quote from: Mulletron on 11/04/2014 08:39 pm@momerathe.... Momentum is a form of energy. Let's not split hairs here. No, it really isn't. They may be mathematically similar concepts, but they are not the same. This is not splitting hairs; without precision of expression we're not going to get anywhere.
Quote from: momerathe on 11/04/2014 09:12 pmQuote from: Mulletron on 11/04/2014 08:39 pm@momerathe.... Momentum is a form of energy. Let's not split hairs here. No, it really isn't. They may be mathematically similar concepts, but they are not the same. This is not splitting hairs; without precision of expression we're not going to get anywhere.Fine let's split hairs. If an object has momentum, then it is moving. If it is moving, then it has kinetic energy. And if an object has kinetic energy, then it definitely has mechanical energy... Kinetic energy is a form of energy.
Quote from: Mulletron on 11/04/2014 03:58 pm....More info on the Feigel Effect:http://rspa.royalsocietypublishing.org/content/early/2011/10/06/rspa.2011.0481.full.pdf (A peer review with surprising results!)http://physics.aps.org/story/v13/st3The anomalous thrust production from an RF test device was due to the Feigel–van Tiggelen effect.Interesting paper. Some thoughts occur:* the dielectric constant in the can will be very low. it's meant to be evacuated, after all.* the ExB fields in the Feigel effect are steady, those in an EM wave oscillate sinusoidally. Thus the force would be continually swapping direction, and average to zero.* If you are right, it spells the death-knell for this device as a form of propulsion. From the paper:QuoteFeigel considers the following situation: a region of a dielectric fluid far fromthe boundaries of its container is initially at rest (t = 0). Subsequently, strongelectrical and magnetic fields crossed at right angles to each other are appliedto the region. As the fields reach their constant final values, Eext and Bext forelectrical and magnetic fields, respectively, the fluid is accelerated by the Lorentzforces (FLorentz ∝ vt(Eext × Bext)) to a final velocity v.It's a one-off impulse. It can't provide a steady thrust (again, I'm not saying that you're one of the people saying it does) unless you can keep increasing the field forever. When you turn the field off, the dielectric will stop moving. Kind of how the casimir effect provides a one-off energy gain when you bring the two plates together.
....More info on the Feigel Effect:http://rspa.royalsocietypublishing.org/content/early/2011/10/06/rspa.2011.0481.full.pdf (A peer review with surprising results!)http://physics.aps.org/story/v13/st3The anomalous thrust production from an RF test device was due to the Feigel–van Tiggelen effect.
Feigel considers the following situation: a region of a dielectric fluid far fromthe boundaries of its container is initially at rest (t = 0). Subsequently, strongelectrical and magnetic fields crossed at right angles to each other are appliedto the region. As the fields reach their constant final values, Eext and Bext forelectrical and magnetic fields, respectively, the fluid is accelerated by the Lorentzforces (FLorentz ∝ vt(Eext × Bext)) to a final velocity v.
Good catch. Gotta see what changed their mind. Good thing emdrive only works when it is switched on.
Question - Has anyone thought of looking for correlations between Shawyer's thrust profile and Brady's? Be very interesting if something showed up.The attached plots are from Shawyer's CEAS 2009 paper.
Momerathe, a warm welcome to this forum !
You are pre-supposing.Who knows what energy actually is?
Relating to this is that it turns out that even macro objects have a very small hard to measure wave function.