Yep, Horizon episodes should make hard things easy to chew, otherwise someone may get it wrong, like: "they said that some new conical microwave ovens will no longer fry chicks, it will make them fly!" A bit of humor, but on the other hand, I feel disapointed because so many possible new "magical" technologies are still in the domain of "magical" and not real. (Cold fusion, for example). You watch a nice documentary about it and start dreaming, and then you realize that it is slowly but surely being pushed towards "fairy tales" category and will never become real...
As has been pointed out before, this is a sci-fi-esque energy to momentum drive being discussed. A pretty big signal is going to be needed to get more than niche interest. How "big" of a signal do you think is needed?
Now that the thread is back on track, I think I want to pose a question I haven't seen asked so far. I think its an important question because of how easy it is to move the goalposts for success after experiments have been run.What would count as "strong" evidence for an anomalous result from these force measurement experiments, assuming a reasonably well-designed experiment?Personally I think a test in a clean (no hot soft parts) microtorr environment which shows something like 10-100 mN of thrust (which would be about 1000 times the environmental gas pressure on the faces of the device) would be very interesting and hard to dismiss as a thermal effect. In the air its hard for me to say, but for me I think something in the range of one to ten newtons would be needed to really get me interested (flying off the table levels of force).
Shell, Aero & Crew:The manufacturing tolerances for building these EMDrive based room-temp copper frustums does not have to be very good to get Q-factor results that are quite usable in obtaining interesting thruster performance. Our unloaded, (-7dB down from the VNA S11 amplitude reference plane assuming near optimal antenna coupling using a magnetic loop antenna), with no dielectric discs, the TE012 resonance at 2,167 MHz per our 2014 AIAA/JPC paper's copper frustum came out to be ~54,000. Considering our garage construction crew used a civil war vintage bending mill to form the copper sheet into a cone, which was then lead/tin soldered together with two half inch wide exterior flanges butted together, and pulled together using 0.050" thick by 1/2 inch wide copper hoops that I hand routered out of copper sheets, which were then lead/tin soldered to the cone, should tell you that great precision for your first frustum prototypes is not required. And since I also just used semi-flat 1/16" thick FR4 printed circuit boards with one side plated with 1.0 oz (34.8 microns thick) copper with the copper side towards the inside of the cavity, super parallel surfaces on the end caps is not required either. BTW, since the wave-length of ~2.0 GHz RF is 5.906" (0.1500m), keeping within 1/100th of a wavelength (0.0591") tolerance of your design in your first build as the telescope builders do, one should just use moderate (0.03") shop tolerances for your first prototype builds and go from there.Best, Paul March
I was thinking the same thing here, Shell...It shows how much weight they all carry to steer and lead a topic as this one. Sad to say, but you only realize what they mean and how important they are to keep this topic going, once they're "gone". (not for real ofc).As for speculations...Most of us know there is a white elephant in the room... I'm quite sure we have similar ideas about their disappearance(s)...Anyway, I'm very glad Paul March pops up from time to time now, to give you DIY builders some guidelines.Gives some extra food for the brain...and to ponder about...
Quote from: Chrochne on 10/19/2015 06:56 am BBC would not make a document on just "some" technology. Compare Horizon episodes from 30 years ago (they're on youtube) to an episode you get today. Today, all you'll get is a lot of inspiring music and a contentless narrative about how 'the world may never be the same again'. The information density in a typical Horizon episode is so low because they need to fill the air time with shots of scientists looking wistfully at the skies.This will hurt, rather than hinder the efforts to get to the bottom of this issue.
BBC would not make a document on just "some" technology.
Episodes vary from each as with all shows, some are better than others but to paint them all with the same brush, unless you have an outside agenda, serves no purpose.
Quote from: Tetrakis on 10/19/2015 04:22 amAs has been pointed out before, this is a sci-fi-esque energy to momentum drive being discussed. A pretty big signal is going to be needed to get more than niche interest. How "big" of a signal do you think is needed?Proving there is a signal, from a scientific point of view, is one step, but an EMdrive will only get "meaning" if it finds a real world application that affects us all in a direct or indirect way. I'm not very qualified to establish what the content would be for a 5 sigma, but i know that 5_sigma is what most scientist will accept for the effect being "true". How do you quantify the odds of 1:3.5mil that the signal you see is not thermal or random noise? Beats me...So, I'd like to flip and invert the question by wondering what is needed to make a real world application with a "working EMdrive" (on the assumption it does).I believe the real world application with the least needed thrust force would be satellite/space station positioning. I think it was in topic#3 that there was somebody that took the time and effort to calculate what was needed to counter the orbital decay of a satellite.To have meaning, that is the minimum expectation for the thrust that the EMdrive should develop...I'll try to locate that post and add it inhere.anything higher will only boost the importance of an EMdrive.with 0.4N/kW, several articles start -rightfully- talking about interplanetary space exploration...
Quote from: Flyby on 10/19/2015 03:14 pmQuote from: Tetrakis on 10/19/2015 04:22 amAs has been pointed out before, this is a sci-fi-esque energy to momentum drive being discussed. A pretty big signal is going to be needed to get more than niche interest. How "big" of a signal do you think is needed?Proving there is a signal, from a scientific point of view, is one step, but an EMdrive will only get "meaning" if it finds a real world application that affects us all in a direct or indirect way. I'm not very qualified to establish what the content would be for a 5 sigma, but i know that 5_sigma is what most scientist will accept for the effect being "true". How do you quantify the odds of 1:3.5mil that the signal you see is not thermal or random noise? Beats me...So, I'd like to flip and invert the question by wondering what is needed to make a real world application with a "working EMdrive" (on the assumption it does).I believe the real world application with the least needed thrust force would be satellite/space station positioning. I think it was in topic#3 that there was somebody that took the time and effort to calculate what was needed to counter the orbital decay of a satellite.To have meaning, that is the minimum expectation for the thrust that the EMdrive should develop...I'll try to locate that post and add it inhere.anything higher will only boost the importance of an EMdrive.with 0.4N/kW, several articles start -rightfully- talking about interplanetary space exploration...I suspect none of us can image eventual "real world" application that might come from the drive itself or, more likely, the results of the underlying principles.I remember reading somewhere that nearly one-third of the US economy can be attributed to technology that directly utilizes the principles of quantum mechanics - probably one of the most esoteric fields to non-physicists.
Quote from: Flyby on 10/19/2015 01:54 pmI was thinking the same thing here, Shell...It shows how much weight they all carry to steer and lead a topic as this one. Sad to say, but you only realize what they mean and how important they are to keep this topic going, once they're "gone". (not for real ofc).As for speculations...Most of us know there is a white elephant in the room... I'm quite sure we have similar ideas about their disappearance(s)...Anyway, I'm very glad Paul March pops up from time to time now, to give you DIY builders some guidelines.Gives some extra food for the brain...and to ponder about...I call it a 800 pound gorilla, I miss wrestling with it sometimes. lolI'm glad for Paul's clarification as well, very smart man, dang good engineer. Shell
Quote from: Prunesquallor on 10/19/2015 04:42 pmQuote from: Flyby on 10/19/2015 03:14 pmQuote from: Tetrakis on 10/19/2015 04:22 amAs has been pointed out before, this is a sci-fi-esque energy to momentum drive being discussed. A pretty big signal is going to be needed to get more than niche interest. How "big" of a signal do you think is needed?Proving there is a signal, from a scientific point of view, is one step, but an EMdrive will only get "meaning" if it finds a real world application that affects us all in a direct or indirect way. I'm not very qualified to establish what the content would be for a 5 sigma, but i know that 5_sigma is what most scientist will accept for the effect being "true". How do you quantify the odds of 1:3.5mil that the signal you see is not thermal or random noise? Beats me...So, I'd like to flip and invert the question by wondering what is needed to make a real world application with a "working EMdrive" (on the assumption it does).I believe the real world application with the least needed thrust force would be satellite/space station positioning. I think it was in topic#3 that there was somebody that took the time and effort to calculate what was needed to counter the orbital decay of a satellite.To have meaning, that is the minimum expectation for the thrust that the EMdrive should develop...I'll try to locate that post and add it inhere.anything higher will only boost the importance of an EMdrive.with 0.4N/kW, several articles start -rightfully- talking about interplanetary space exploration...I suspect none of us can image eventual "real world" application that might come from the drive itself or, more likely, the results of the underlying principles.I remember reading somewhere that nearly one-third of the US economy can be attributed to technology that directly utilizes the principles of quantum mechanics - probably one of the most esoteric fields to non-physicists.I believe this is very true, considering the nature of computing in todays economy. An elephant in the room is the scaling, can it provide a platform for earth-bound transport as well as space. Scaled up EMDrive "levitation" is a big possibility for rail transport, not to mention everything else.If I put an objective hat on, power consumption of heavy lift drives would probably mean commercial transport would be first. However, this could be decades in the future and Space Flight seems the best short term application.I am hoping last year's rumors of NASA testing this past summer are correct and peer review is underway. Once this opens up, I would envision more labs and even NASA themselves jump-start the small effort to date and its possible a smallsat could be built within a short time frame.Regardless, times are pretty exciting for a change and we may have more to celebrate than speed and memory in computers which have taken center stage for years.
Quote from: Star One on 10/19/2015 03:05 pmEpisodes vary from each as with all shows, some are better than others but to paint them all with the same brush, unless you have an outside agenda, serves no purpose.Outside agenda? Please. Everything I mentioned in my previous post is present within every current Horizon episode. It will muddy the waters considerably.
...If I put an objective hat on, power consumption of heavy lift drives would probably mean commercial transport would be first. However, this could be decades in the future and Space Flight seems the best short term application.I am hoping last year's rumors of NASA testing this past summer are correct and peer review is underway. Once this opens up, I would envision more labs and even NASA themselves jump-start the small effort to date and its possible a smallsat could be built within a short time frame.Regardless, times are pretty exciting for a change and we may have more to celebrate than speed and memory in computers which have taken center stage for years.
Quote from: rfmwguy on 10/19/2015 05:18 pm...If I put an objective hat on, power consumption of heavy lift drives would probably mean commercial transport would be first. However, this could be decades in the future and Space Flight seems the best short term application.I am hoping last year's rumors of NASA testing this past summer are correct and peer review is underway. Once this opens up, I would envision more labs and even NASA themselves jump-start the small effort to date and its possible a smallsat could be built within a short time frame.Regardless, times are pretty exciting for a change and we may have more to celebrate than speed and memory in computers which have taken center stage for years.The thing that was driving everyone nuts a couple of threads back was the implication of a rotary EMDrive driving an alternator and producing more power than it consumed. The CoM and CoE angst seems to have diminished, but not because the conundrum was "solved", it just led to so many paradoxes that everyone threw up their hands and gave up (or used it as evidence the EMDrive was impossible).That contradiction still exists as far as I can see - the only way out is to assume energy and momentum are exchanged with "non-traditional" sources. If this is true, we would be tapping into a new energy supply. I think space applications probably pale in comparison with the implication of that.