The cat is ok btw.Just slightly singed.
Quote from: Rodal on 10/19/2014 08:32 pmTaking into account the frequency drift and bandwidth issues that the researchers have tuning the device under resonance, with concomitant drift in Q (which therefore cannot be a constant during the measurements) these results are quite interesting!More on that later please, as relation of resonance with Q not clear to me (higher Q => narrower bandwidth not the point, that's perfectly clear). Needs time to think of a clear enough way to express what's not clear, that's difficult.
Taking into account the frequency drift and bandwidth issues that the researchers have tuning the device under resonance, with concomitant drift in Q (which therefore cannot be a constant during the measurements) these results are quite interesting!
I don't know what is an inch or a foot.
1) Both inner surface ends of the truncated cone must have been made out of copper. Otherwise the cavity would not have the correct boundary conditions to be a resonant cavity: it would be a waveguide. One wouldn't be able to have high Q and resonance if the inner surface of the ends wouldn't be copper.2) The inner surface of the copper must have been pretty well polished, in order to get Q~50 000, given the calculated skin depths3) There cannot be any significant irregularities on the inside surface of the truncated cone.
Ok, that's good. Basically anything sensible we come up with can be computed then for this small data set.Yes. I looked at some articles on PSP, its just another way of doing beamed propulsion. Since the photons within the resonance cavity (between the mirrors) actually are pushing, all of them count to give thrust. In the EM drive case, it seems that all of the photons are counting to give thrust but they are not leaving the cavity of the engine. I guess that is the trick and the problem. How can the momentum of the photons in the cavity be separated from the photons themselves? Momentum departs, photons remain.
Ok I'm aware that I'm the stick in the mud here, but not by virtue of being intentionally obtuse here. I believe I have things in the right perspective. Let me state this another way:Now you can dump rf energy into a cavity all day long, and that rf cavity is going to eventually absorb (as a function of Q) and re-radiate that energy right back to the universe in which it resides. Given the cavity has a big end and a small end, you have more surface area on the big end in which to radiate heat, giving the illusion of thrust by new science. This isn't new science. I don't need a page long series of equations to characterize this. It is just thermodynamics.
Also it is well known that if an electric current flows through anything, wires, cavity walls, whatever... the result is a perpendicular magnetic field around the conductor. Now pulse that current, you get a pulsating magnetic field.
The NASA test campaign is very telling compared to the other tests, because the NASA tests were low power tests. This allowed them to effectively separate out artifact modes of thrust from the dominant mode of thrust. They concluded, all things considered that the dielectric was important to measured thrust. If you dump hundreds watts into an empty sealed test article, yep, you're gonna measure some thrust. The thrust you get doesn't need new science to explain.
One can try to get famous by writing page long formulas to explain the obvious, but there is no need.Empty cavities providing thrust isn't anomalous thrust.Cavities with dielectric present providing thrust is anomalous thrust. And when you remove the dielectric, the thrust goes away.......that is anomalous.
Quote from: frobnicat on 10/20/2014 12:19 amQuote from: aero on 10/19/2014 10:43 pmHave we exceeded a million equation search yet?No but 21769 is already quite a lot. The data set is sparse and with some uncertainties : the risk is overfitting. Scanning on more than 15 bits (32768 combinations) worth of explanation could easily bring up more perfect formula for the specific available data but with less generalisation power : worse at predicting next data points to come. Need more data points before it's worth looking at much more formulas. Not a problem of computing power, not before reaching many billions of formulas. At this stage with 7 data points, from a "phenomenological theoretically agnostic" point of view, simpler is better, and there is not that much simple equations.Note : the number of combinations of exponents and added terms were 94 millions but of those only 21769 unique representations (discarding equivalents) made sense in dimensional analysis (kg m s).Not quite there yet. The theoretical geometrical variable for a resonant cavity box is Sqrt[a^-2+L^-2] and we didn't have square roots of additions allowed, is that right?Moreover we had a number of formulas very close: [a^-2+L^-2] and [a^-1+L^-1] So the data was telling us we need to allow Sqrt[a^-2+L^-2] We had these square roots but they are missing the plus sign:a^-2 b^-2 L^2 Q^1 P^1 F^-1 c^-1 sqrt(a^-2 L^-2)^-1 1.02 0.58a^-1 b^-2 L^2 Q^1 P^1 F^-1 c^-1 sqrt(a^-1 L^-1)^-1 1.32 0.58
Quote from: aero on 10/19/2014 10:43 pmHave we exceeded a million equation search yet?No but 21769 is already quite a lot. The data set is sparse and with some uncertainties : the risk is overfitting. Scanning on more than 15 bits (32768 combinations) worth of explanation could easily bring up more perfect formula for the specific available data but with less generalisation power : worse at predicting next data points to come. Need more data points before it's worth looking at much more formulas. Not a problem of computing power, not before reaching many billions of formulas. At this stage with 7 data points, from a "phenomenological theoretically agnostic" point of view, simpler is better, and there is not that much simple equations.Note : the number of combinations of exponents and added terms were 94 millions but of those only 21769 unique representations (discarding equivalents) made sense in dimensional analysis (kg m s).
Have we exceeded a million equation search yet?
6 entriesThresholds : mean=2.00 stddev=1.35 a b L Q P F c mean stddev--------------------------------------------------------------------- a b L Q P F c exterm mean stddev---------------------------------------------------------------------a^2 b^-2 L^-2 Q^2 P^2 F^-2 c^-2 (a^-2 + b^-2)^-1 1.42 1.34a^0 b^0 L^2 Q^2 P^2 F^-2 c^-2 (a^-2 + b^-2)^1 1.76 0.93a^2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 (a^ 2 + b^ 2)^-1 1.42 0.68a^0 b^-2 L^0 Q^2 P^2 F^-2 c^-2 (a^-2 + L^-2)^-1 1.31 0.77 *a^-2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 (a^-2 + L^-2)^-1 0.09 1.00 *a^-2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 (a^ 2 + L^ 2)^1 1.87 0.84 *a^2 b^-2 L^-2 Q^2 P^2 F^-2 c^-2 (b^-2 + L^-2)^-1 1.23 1.21a^0 b^0 L^2 Q^2 P^2 F^-2 c^-2 (b^-2 + L^-2)^1 1.95 1.06 a^-2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 (b^ 2 + L^ 2)^1 0.72 1.35 a^2 b^2 L^-2 Q^2 P^2 F^-2 c^-2 |a^-2 - b^-2|^1 1.34 1.25a^0 b^0 L^2 Q^2 P^2 F^-2 c^-2 |a^-2 - b^-2|^1 1.34 0.60a^2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 |a^ 2 - b^ 2|^-1 1.84 1.02a^-2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 |a^-2 - L^-2|^-1 0.79 1.22a^-2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 |a^ 2 - L^ 2|^1 1.16 0.79a^2 b^2 L^-2 Q^2 P^2 F^-2 c^-2 |b^-2 - L^-2|^1 0.66 0.62a^2 b^0 L^0 Q^2 P^2 F^-2 c^-2 |b^-2 - L^-2|^1 1.88 0.88a^0 b^2 L^0 Q^2 P^2 F^-2 c^-2 |b^-2 - L^-2|^1 -0.57 0.83a^0 b^0 L^2 Q^2 P^2 F^-2 c^-2 |b^-2 - L^-2|^1 0.65 0.51a^-2 b^2 L^2 Q^2 P^2 F^-2 c^-2 |b^-2 - L^-2|^1 -1.79 1.19a^-2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 |b^ 2 - L^ 2|^1 -0.57 0.43a^0 b^-2 L^0 Q^2 P^2 F^-2 c^-2 sqrt(a^-2 b^-2)^-1 1.59 1.13a^-2 b^-2 L^2 Q^2 P^2 F^-2 c^-2 sqrt(a^-2 L^-2)^-1 0.98 0.91a^0 b^-2 L^0 Q^2 P^2 F^-2 c^-2 sqrt(b^-2 L^-2)^-1 0.98 1.26a^2 b^0 L^2 Q^2 P^2 F^-2 c^-2 (a^-2 * b^-2)^1 1.59 0.80Checked : 1581201Validated : 972
Here is the PDF mentioned above.http://www.emdrive.com/iac2014presentation.pdf
Quote from: Star One on 10/20/2014 11:17 amHere is the PDF mentioned above.http://www.emdrive.com/iac2014presentation.pdfIs there a paper with more details to be published ?"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?...
Quote from: Star One on 10/20/2014 11:17 amHere is the PDF mentioned above.http://www.emdrive.com/iac2014presentation.pdfIs there a paper with more details to be published ?"4 independent organisations, in 3 different countries" : what organisations ? with what kind of balance ? Someone present at the conference to take notes and give some context ?
Woah:On page 7 of that PDF, they've already got a design for an all electric SSTO! They can't put that in a paper and post it on the intertubes unless it was true!I didn't read any further, so I may have missed the fine print regarding ticket prices and carry on baggage.Hey! Mucho thankso for the Hendrix clip!Do you do yoga? After a weekend of log splitting, I'm looking forward to Hillary's class this PM at 5:30, Downtown. See ya there?