Quote from: Flyby on 07/31/2015 02:20 pmIt is deceptive to use the efficiency parameter (N/kW) when you see on Yang's graph's that when you increase power you end up with a way lower efficiency (720mN/2.5kW).What this shows that the thermal impact has a far bigger impact then you assume and that with and increased Q you're massing up gigantic power intensities in the resonance patterns.With needed Q's in the order of 10^10 i really doubt if cooled nitrogen will be able to keep the frustum walls cooled...IIRC, Shawyer talked about 17MW of stored energy in the cavity, by only using "700W to 1kW-ish" microwave generators and with a Q of barely 50k....Agreed, i'm no specialist in the matter, but it looks to me a near impossible engineering challenge, to pack all that in a minimal configuration, with a low enough weight to power ratio, so it can fly...IF the EMdrive ever turns out to be something (no hard evidence till today), it will be usable for orbit positioning, interplanetary travel and maybe interstellar probes...but terrestrial liftoff vehicles ? nah...The thermal degeneration on the Q is only going to grow the more power you put into it...at certain point, even supercooled liquids wont be enough to handle the thermal issues....Just adding on to this, does anyone have any idea (@rfmqguy in particular) what the highest Q ever obtained by an electromagnetic resonator (whether a cavity or circuit) is? Ie. in the actual physical world, what is the best Q ever obtained?
It is deceptive to use the efficiency parameter (N/kW) when you see on Yang's graph's that when you increase power you end up with a way lower efficiency (720mN/2.5kW).What this shows that the thermal impact has a far bigger impact then you assume and that with and increased Q you're massing up gigantic power intensities in the resonance patterns.With needed Q's in the order of 10^10 i really doubt if cooled nitrogen will be able to keep the frustum walls cooled...IIRC, Shawyer talked about 17MW of stored energy in the cavity, by only using "700W to 1kW-ish" microwave generators and with a Q of barely 50k....Agreed, i'm no specialist in the matter, but it looks to me a near impossible engineering challenge, to pack all that in a minimal configuration, with a low enough weight to power ratio, so it can fly...IF the EMdrive ever turns out to be something (no hard evidence till today), it will be usable for orbit positioning, interplanetary travel and maybe interstellar probes...but terrestrial liftoff vehicles ? nah...The thermal degeneration on the Q is only going to grow the more power you put into it...at certain point, even supercooled liquids wont be enough to handle the thermal issues....
Our final tapered cavity design had an internal top radius of 38.5 mm, a bottom radius of 54.1 mm and a height of 68.6 mm
Quote from: rfmwguy on 07/31/2015 01:42 pmI tried this yesterday, but failed miserably...here is the google+ page where you can see all my videos:https://plus.google.com/102151053813184986030/videosWhen ?, what is the latest estimated date for the first experiment measuring thrust?Where is going to be the RF feed located during the first experiment? (big base or small base?)
I tried this yesterday, but failed miserably...here is the google+ page where you can see all my videos:https://plus.google.com/102151053813184986030/videos
I asked Martin Tajmar directly by email about cavity dimensions that would be off by a factor 2, and he replied confirming the numbers were indeed radii instead of diameters.He added he already uploaded a revised manuscript altogether with some other typo corrections and some additional clarifications at the AIAA website, but revisions from the conference will appear only after 21st of August.For now, the updated paper is online on the UD-Dresden website.In the updated paper the height is still confirmed to be 68.6 mm.
Awesome, I guess we know that the high Q's needed have at least been obtained before
Quote from: flux_capacitor on 07/31/2015 02:54 pmI asked Martin Tajmar directly by email about cavity dimensions that would be off by a factor 2, and he replied confirming the numbers were indeed radii instead of diameters.He added he already uploaded a revised manuscript altogether with some other typo corrections and some additional clarifications at the AIAA website, but revisions from the conference will appear only after 21st of August.For now, the updated paper is online on the UD-Dresden website.In the updated paper the height is still confirmed to be 68.6 mm.That height (68.6mm) does not result in resonance at 2.44 GHz. Did you discuss the height with him as well?
Quote from: X_RaY on 07/31/2015 02:05 pm...http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404523#msg1404523Why is vacuum Energie ^120 times to big? Because of the mathematical singularities associated with Quantum Mechanics, and the inability up to now to come up with a unified theory of Quantum Gravity. So, I take the ^120 problem as a symptom of the fact that we don't yet have a satisfactory theory of Quantum Gravity. I would rather rely on the astronomical measurements pointing towards the value of the cosmological constant than relying on Quantum Mechanics calculations for the vacuum energy. I would not rely on Quantum Mechanics calculations of the vacuum energy until we have a theory of Quantum Gravity. We were able to explain inflation without a theory of Quantum Gravity.
...http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404523#msg1404523Why is vacuum Energie ^120 times to big?
Quote from: Rodal on 07/31/2015 02:56 pmQuote from: flux_capacitor on 07/31/2015 02:54 pmI asked Martin Tajmar directly by email about cavity dimensions that would be off by a factor 2, and he replied confirming the numbers were indeed radii instead of diameters.He added he already uploaded a revised manuscript altogether with some other typo corrections and some additional clarifications at the AIAA website, but revisions from the conference will appear only after 21st of August.For now, the updated paper is online on the UD-Dresden website.In the updated paper the height is still confirmed to be 68.6 mm.That height (68.6mm) does not result in resonance at 2.44 GHz. Did you discuss the height with him as well?I know. I will ask him in return if this value of 68.6 mm is the external height, or the internal maximal height, and what is exactly the final internal height at resonance after the tuning screw was fixed.
To @Rodal, @TheTraveller and others: can you try to find resonances and modes with your COMSOL and spreadsheets programs with those dimensions?
Quote from: rfmwguy on 07/31/2015 01:36 pmFor conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo. The balancing force to gravity is labeled dark matter to explain the imbalance of forces.I'm not sure how that follows. Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive? Dark matter behaves just like regular matter gravitationally. What imbalance of forces are you referring to specifically here? There is no imbalance of forces in gravity from a Newton's 3rd law perspective.
For conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo. The balancing force to gravity is labeled dark matter to explain the imbalance of forces.
So TT is deluding himself when he quotes 6-figure Q values from Yang because they are unrealistic (and wrong).
Quote from: wallofwolfstreet on 07/31/2015 02:29 pmQuote from: rfmwguy on 07/31/2015 01:36 pmFor conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo. The balancing force to gravity is labeled dark matter to explain the imbalance of forces.I'm not sure how that follows. Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive? Dark matter behaves just like regular matter gravitationally. What imbalance of forces are you referring to specifically here? There is no imbalance of forces in gravity from a Newton's 3rd law perspective.Sloppily saying gravity is the only know force without a repulsive condition, thus an imbalance in the big scheme of things.
Quote from: rfmwguy on 07/31/2015 03:45 pmQuote from: wallofwolfstreet on 07/31/2015 02:29 pmQuote from: rfmwguy on 07/31/2015 01:36 pmFor conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo. The balancing force to gravity is labeled dark matter to explain the imbalance of forces.I'm not sure how that follows. Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive? Dark matter behaves just like regular matter gravitationally. What imbalance of forces are you referring to specifically here? There is no imbalance of forces in gravity from a Newton's 3rd law perspective.Sloppily saying gravity is the only know force without a repulsive condition, thus an imbalance in the big scheme of things.There is some indication of balance that the mainstream currently espouses - the inflaton and dark energy. Both act in an anti-gravitic sort of way. But as you probably know, the inflaton ran out of gas very quickly, and dark energy is yet to truly come into its own. So yes, gravity wins for now.
Quote from: rfmwguy on 07/31/2015 03:45 pmQuote from: wallofwolfstreet on 07/31/2015 02:29 pmQuote from: rfmwguy on 07/31/2015 01:36 pmFor conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo. The balancing force to gravity is labeled dark matter to explain the imbalance of forces.I'm not sure how that follows. Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive? Dark matter behaves just like regular matter gravitationally. What imbalance of forces are you referring to specifically here? There is no imbalance of forces in gravity from a Newton's 3rd law perspective.Sloppily saying gravity is the only know force without a repulsive condition, thus an imbalance in the big scheme of things.Haven't you heard of Exotic Matter? It represents repulsive gravity and causes inflation. The ZPF is the driving force, setting the scale of protons and sub-atomic particles which are in equilibrium with it. Where the ZPF power is decreasing, we have gravity and gravitational length contraction and time dilation as matter deflates. Where the ZPF is increasing (think, going up-hill) the opposite is true. The ZPF is gaining power and matter is inflated in the process of lifting it. (The opposite of length contraction and time dilation.)Exotic Matter, is simply normal matter immersed in a more powerful ZPF. The ZPF increases the energy stored but it also inflates the volume of that matter, such that the equilibrium energy density is lower than it would be in a less powerful ZPF, or in a gravity well. It is the ZPF that is responsible for gravity, it doesn't gravitate, it inflates.Todd
Exotic Matter, is simply normal matter immersed in a more powerful ZPF. The ZPF increases the energy stored but it also inflates the volume of that matter, such that the equilibrium energy density is lower than it would be in a less powerful ZPF, or in a gravity well. It is the ZPF that is responsible for gravity, it doesn't gravitate, it inflates.Todd