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.
...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: Prunesquallor on 10/19/2015 07:24 pmQuote 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.It's going to be very interesting to see the endgame. I'm making sure I stay tuned.Shell
I'm still having trouble visualizing how it can get more power out of an alternator than the power it takes to spin it. This overunity still makes me think of the questionable claims of one motor driving another motor/generator and that assembly being a perpetual motion machine.Lets say 1200 Watts of energy is firing an emdrive that sits on a rotary table with the friction of an alternator which in turn powers the emdrive...doesn't seem to me it can work. Its like a garden hose shooting into a water pump which then pumps more water into the hose...system losses overcome energy and CoE is maintained.
QuoteI'm still having trouble visualizing how it can get more power out of an alternator than the power it takes to spin it. This overunity still makes me think of the questionable claims of one motor driving another motor/generator and that assembly being a perpetual motion machine.Lets say 1200 Watts of energy is firing an emdrive that sits on a rotary table with the friction of an alternator which in turn powers the emdrive...doesn't seem to me it can work. Its like a garden hose shooting into a water pump which then pumps more water into the hose...system losses overcome energy and CoE is maintained.Which is where Doctor David Bae's bouncing laser (photon recycling) scheme comes in. A 5000 fold increase in power without violating CoE. I still maintain a really clever engineer could probably finagle the static version of his setup into a free energy device, in which case, lots of fun and games ensue. I also maintain his scheme is an insight or clue as to what is going on with the EM Drive.
Quote from: SeeShells on 10/19/2015 07:55 pmQuote from: Prunesquallor on 10/19/2015 07:24 pmQuote 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.It's going to be very interesting to see the endgame. I'm making sure I stay tuned.ShellI'm still having trouble visualizing how it can get more power out of an alternator than the power it takes to spin it. This overunity still makes me think of the questionable claims of one motor driving another motor/generator and that assembly being a perpetual motion machine.Lets say 1200 Watts of energy is firing an emdrive that sits on a rotary table with the friction of an alternator which in turn powers the emdrive...doesn't seem to me it can work. Its like a garden hose shooting into a water pump which then pumps more water into the hose...system losses overcome energy and CoE is maintained.I did not jump in on those threads a while back, because my synapses we not yet firing on all cylinders ;^)
Roger has emailed he will probably appear on the Horizon episode about his EMDrive. Seems details about how far the BBC will be allowed to penetrate into the EMDrive world and what they will be shown are still being worked out.I would speculate this process may also involve the next NASA EW paper and their findings.
The classical equations for rotational kinetic energy guarantee that if you assume constant thrust at constant power for the EMDrive, energy out will eventually exceed energy in. You can assume friction will always deplete enough energy to prevent torque from increasing enough to produce energy in excess of the input, but it's an arbitrary assumption and doesn't balance the books. I don't want to start up the old CoE/CoM arguments again. During all the DiY excitement, I just think we need to keep in mind that we are still talking about a device that, if it produces thrust in excess of a photon rocket, currently defies explanation.
Quote from: Prunesquallor on 10/20/2015 04:59 amThe classical equations for rotational kinetic energy guarantee that if you assume constant thrust at constant power for the EMDrive, energy out will eventually exceed energy in. You can assume friction will always deplete enough energy to prevent torque from increasing enough to produce energy in excess of the input, but it's an arbitrary assumption and doesn't balance the books. I don't want to start up the old CoE/CoM arguments again. During all the DiY excitement, I just think we need to keep in mind that we are still talking about a device that, if it produces thrust in excess of a photon rocket, currently defies explanation.Just as rfmxguy, I'm having difficulties to visualize and "see" how that would be possible.How can you possibly build a dynamo that delivers more electricity then what the EMdrive needs?Friction and heat grow exponential with speed. From what I can find, the best dynamo's have an efficiency of 72%.. It puzzles me how you can achieve over-unity devices with that?Although I lack the skills to actually calculate the results, my feeling is that the over-unity calculations result in a COE violation due to an oversimplification of the used formula(s). Blame my pragmatism, but i don't see any COE violation from my perspective. Maybe there is a violation in the abstract world, on paper, but out there ? in the real world?
Roger told me SPR have confirmed experimentally, using the rotary test rig, that neither CofM nor CofE are violated. As I see it, in effect, the EMDrive creates an internal larger EM wave momentum gradient toward the big end. The EMDrive moves externally toward the small end or opposite to the internal momentum gradient increasing toward the big end.As the EMDrive accelerates, Q drops as the EM wave momentum converts into opposite direction EMDrive momentum. This drops stored cavity energy, dropping Q and Force generated. Also causes a replacement amount of energy to flow into the cavity, which restores Force generation.
Quote from: Flyby on 10/20/2015 10:36 amQuote from: Prunesquallor on 10/20/2015 04:59 amThe classical equations for rotational kinetic energy guarantee that if you assume constant thrust at constant power for the EMDrive, energy out will eventually exceed energy in. You can assume friction will always deplete enough energy to prevent torque from increasing enough to produce energy in excess of the input, but it's an arbitrary assumption and doesn't balance the books. I don't want to start up the old CoE/CoM arguments again. During all the DiY excitement, I just think we need to keep in mind that we are still talking about a device that, if it produces thrust in excess of a photon rocket, currently defies explanation.Just as rfmxguy, I'm having difficulties to visualize and "see" how that would be possible.How can you possibly build a dynamo that delivers more electricity then what the EMdrive needs?Friction and heat grow exponential with speed. From what I can find, the best dynamo's have an efficiency of 72%.. It puzzles me how you can achieve over-unity devices with that?Although I lack the skills to actually calculate the results, my feeling is that the over-unity calculations result in a COE violation due to an oversimplification of the used formula(s). Blame my pragmatism, but i don't see any COE violation from my perspective. Maybe there is a violation in the abstract world, on paper, but out there ? in the real world?Friction doesn't "destroy energy", it transforms energy (e.g. Kinetic energy to heat). It's easier to go back to the frictionless, linear kinetic energy example of an accelerating spacecraft:1) By assumption, EMDrive spacecraft thrust is constant with power. For constant power, energy input increases linearly with time (by definition, delta_energy = power*delta_time). 2) Since there is no mass depletion (reactionless drive) acceleration is constant (acceleration = thrust/mass) and velocity increases linearly with time (delta_velocity=acceleration*delta_time). 3) Change in kinetic energy (by definition delta_KE = 0.5*mass*delta_velocity ^2) increases as the square of delta_velocity, therefore as the square of time. Hence the dilemma using classical physics: input energy increases linearly with time and resultant kinetic energy increases as the square of time. Eventually, change in KE will always exceed the energy input to the drive. Immersing this spacecraft in an atmosphere so that drag (friction) limits the delta_velocity does not solve the dilemma - some of the kinetic energy will be changed into heat, sound, etc. but the books still will not balance. Folks have tried to invoke general relativity and preferred frames to "fix" this dilemma, but I have not seen any success so far. I always think it is interesting that everyone abhors the idea of a violation of classical conservation of energy, but embraces a violation of conservation of momentum - the very underlying assumption of the EMDrive. (TT, I hear you, I just do not believe there is currently a classical set of equations that support what you say. It seems to me the photon rocket is as far as you can take what you are saying. I could be wrong). Anyway, sorry I brought it up again. This was hashed to death several threads back without resolution. Don't get me wrong, I'm now more convinced than ever that the thrust generation is real and that it does violate our classical understanding of conservation of momentum and energy (I suspect something like Dr. White's mutable quantum vacuum is going on). My original point was that the implications, if true, may go far beyond a nifty space drive.
If Dark Mass can bend light in a gravitational lens it means that it also can be effected by a similar effect caused within the drive cavity itself. What if this drive acted as a captured lens of photons to accelerate dark matter just like a jet engine? We can pull the dark matter particles into and through the drive and focus them out the back accelerating them and creating thrust.
Your attempt to work around conservation of momentum with the em wave explanation does not work. The drive can temporarily appear to move externally due to em waves internally traveling in the opposite direction, but long before the drive could move one cavity length, the photons would hit the other end with the same momentum (and then reflect reversing the total motion). If you claim the em stored momentum changes due to cavity shape, this still means that they either broke conservation of momentum, transferred it to the something outside the system somehow, or (according to how physics probably works) transferred the momentum to the walls of the cavity. The photons are part of the EM drive system, and the center of energy of the system can't move to the left if they are storing momentum to the right equal to the rest of the system's momentum to the left.tl;dr Current experiments cannot show an em drive conserving momentum without either an explanation of what the drive interacts with outside itself, or demonstrating that the drive doesn't work.
Quote from: SeeShells on 10/20/2015 01:41 pmIf Dark Mass can bend light in a gravitational lens it means that it also can be effected by a similar effect caused within the drive cavity itself. What if this drive acted as a captured lens of photons to accelerate dark matter just like a jet engine? We can pull the dark matter particles into and through the drive and focus them out the back accelerating them and creating thrust.Geeze, well there's a lot of leaps of faith for this to happen.Dark matter, if it exists, appears to have mass, creating gravity, so it bends the path that light follows. It does not automatically follow that light can change the path of dark matter. Dark matter would seem to be gravitationally affected but by definition, it is dark matter because it only responds to gravity.A photon (even a microwave photon) is defined as having zero mass, however, an interesting thought experiment goes like this.Imagine you have a perfectly reflecting sphere in a vacuum with mass M.Imagine that inside you have 1 mass of matter (m1) and an equal mass of anti-matter (m2). The total mass of this system M + m1 + m2.Now imagine that you bring the matter and antimatter together so that all the matter and anti-matter is annihilated releasing photons as the energy, which because the sphere is perfectly reflecting is totally contained within the sphere forever.The question is, is the mass of the system still equal to M + m1 + m2? It would seem the answer is both yes and no, depending on your preferred framework.If you choose the side that says the answer is yes, then a frustum in resonance would have a mass gradient that over time is running from one end to the other, at least according to your meep simulations, which could in principle direct dark matter in one direction.However, the effect would be so small in this case that it probably couldn't be measured with today's technology. The math on this is non-trivial, but the result would be > 0. Barely.But as a conjecture, it should lead to more discussion.
Plug in relativistic mass increases and show me that you reach over unity before you reach the speed of light. You don't actually have constant acceleration. As the energy in the system increases so does its relativistic mass. More mass means less acceleration. This isn't an issue in the every day world as we don't have macro objects that go a substantial percentage of c.
Quote from: meberbs on 10/20/2015 01:30 pmYour attempt to work around conservation of momentum with the em wave explanation does not work. The drive can temporarily appear to move externally due to em waves internally traveling in the opposite direction, but long before the drive could move one cavity length, the photons would hit the other end with the same momentum (and then reflect reversing the total motion). If you claim the em stored momentum changes due to cavity shape, this still means that they either broke conservation of momentum, transferred it to the something outside the system somehow, or (according to how physics probably works) transferred the momentum to the walls of the cavity. The photons are part of the EM drive system, and the center of energy of the system can't move to the left if they are storing momentum to the right equal to the rest of the system's momentum to the left.tl;dr Current experiments cannot show an em drive conserving momentum without either an explanation of what the drive interacts with outside itself, or demonstrating that the drive doesn't work.Well Shawyer has started putting opening in his drive, and before that EM waver were leaking from the device. It could well be that the rotary table tests established that leakage caused the reported momentum, so that the next version was decide to intentionally "leak" (i.e. expel) photons.BTW the waves hitting one side are not the same as the waves hitting the other. The bounces causes the light to redshift, meaning less energy is hitting side A than side B. Think about the implications of the force on the two sides not being the same.