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#480 by glennfish on 21 Dec, 2015 11:29
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Trillions of confined photons,
Reminds me of a sci-fi novel I wrote, sadly unpublished. Mix in a little of Everett's many worlds view with sprinkling of Tegmark, Each of the trillions of photons traversing multiple universes taking all possible paths, where in this universe, it is absorbed at one location. I guess with that model, in some Universes, Shell turned it on, and it went pfft without generating any thrust....
Glad to be in one where the story continues. -
#481 by glennfish on 21 Dec, 2015 11:45
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I have been noodling away on my Meep program, simplifying the input format and improving the reports it generates. I just finiahed a part that computes various dimensions of the frustrum in both meters and wavelengths. Relationships to wavelengths are always interesting when looking at the pictures. Here is some output for Shell's frustrum:
Height 0.248m 2.06w
BigDia 0.295m 2.45w
SmlDia 0.170m 1.41w
Side 0.256m 2.13w
HalfAn 14.2 deg
I will be happy to add any more derived dimensions that people think might be interesting. I will be adding the distance of the feedline attachment from the small end, and the diameter of the frustrum at that point, once I get the code added for feedlines.
In looking at Shell's thermals, I have a question for you and your royal MEEPness.
Can you add shell's waveguide to the simulation and if so, here's what would be helpful to understand.
Assume 100 joules of RF power enters the frustum.
Is there any way to see how many joules exit back through the waveguide?
If so, is there any way to see if that would change depending on whether the frustum had a high Q vs the lowest possible Q?
Such a simulation would be very helpful in predicting and thereby eliminating thermal effects from measurements. -
#482 by Paul451 on 21 Dec, 2015 11:48
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The reason why so many people have said the em-drive violates conservation of energy is really quite simple. One central claim of the em-drive is that the force it produces is constant and requires only a constant input of energy. If you plotted the energy that was input over time it would be a straight line with a positive slope; ie EI = kt, where k = the input energy/ Sec. However the kinetic energy would be a square function, EK = MV2/2. It wouldn't take very long for the kinetic energy curve to achive a higher value than the input energy curve. Where does this excess energy come from?
I don't see how that is a convincing argument, because you would wind up with the same situation even using conventional chemical rockets... Given an unlimited fuel supply,
And there's your problem. You need to define an impossible thing in order for a conventional system to mimic a reactionless thruster. Without that, no conventional device can achieve constant force/power, there will always be some kind of limit. For any kind of rocket, it's finite propellant. For any kind of external propulsion or interactions, it's change in efficiency due to velocity relative to the outside factor. But there's always something.
(With one exception, photon drives. Your photon emitter effectively manufactures its "propellant". But the critical velocity is greater than the speed of light, so it quite neatly sorts itself out.) -
#483 by OnlyMe on 21 Dec, 2015 12:35
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The reason why so many people have said the em-drive violates conservation of energy is really quite simple. One central claim of the em-drive is that the force it produces is constant and requires only a constant input of energy. If you plotted the energy that was input over time it would be a straight line with a positive slope; ie EI = kt, where k = the input energy/ Sec. However the kinetic energy would be a square function, EK = MV2/2. It wouldn't take very long for the kinetic energy curve to achive a higher value than the input energy curve. Where does this excess energy come from?
I don't see how that is a convincing argument, because you would wind up with the same situation even using conventional chemical rockets... Given an unlimited fuel supply,
And there's your problem. You need to define an impossible thing in order for a conventional system to mimic a reactionless thruster. Without that, no conventional device can achieve constant force/power, there will always be some kind of limit. For any kind of rocket, it's finite propellant. For any kind of external propulsion or interactions, it's change in efficiency due to velocity relative to the outside factor. But there's always something.
(With one exception, photon drives. Your photon emitter effectively manufactures its "propellant". But the critical velocity is greater than the speed of light, so it quite neatly sorts itself out.)
Even with the EMDrive you have a finite energy source, so there is no difference other than how long it takes to deplete your energy reserve. Best case would seem to be some sort of nuclear reactor, whose fuel even so would be depleted at some point. You have to have power to generate the microwaves that the EMDrive runs on. Even an EMDrive or photon drive is dependent on available energy.
This of course all depends on inertia being an inherent property of mass/matter. If it turns out to be emergent and the result of an interaction between an accelerating object and vacuum energy, relativistic conditions could become far more complicated. But for that discussion to have any merit one first would have to clearly define the characteristics of the vacuum. On that there is no consensus. It is not even certain that it exists and there are those who would argue that it does not, at least in the way it has been being discussed.
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#484 by rfmwguy on 21 Dec, 2015 13:23
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Probably people always feel that they are living in a time of transition, but we can hardly be mistaken perhaps in thinking that this is an era of particularly momentous change, rapid and proceeding at an ever quickening rate. - Emily Greene Balch
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#485 by VAXHeadroom on 21 Dec, 2015 13:28
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...
p.s. I'll be in dc later this week vax, perhaps there will be enough time to have a beer or two. Holiday travels to see the kids in MD.
DUDE. I'm off all week. THIS NEEDS TO HAPPEN
I'll PM with phone number.
-- Emory -
#486 by rfmwguy on 21 Dec, 2015 13:41
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PM'd you w/my cell in anticipation of the 1st Annual East Coast Emdrive Conference....
p.s. I'll be in dc later this week vax, perhaps there will be enough time to have a beer or two. Holiday travels to see the kids in MD.
DUDE. I'm off all week. THIS NEEDS TO HAPPEN
I'll PM with phone number.
-- Emory
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#487 by SteveD on 21 Dec, 2015 14:17
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What constitutes violations of CoE ("Conservation of Energy") and/or CoM ("Conservation of Momentum")?
The reason why so many people have said the em-drive violates conservation of energy is really quite simple. One central claim of the em-drive is that the force it produces is constant and requires only a constant input of energy. If you plotted the energy that was input over time it would be a straight line with a positive slope; ie EI = kt, where k = the input energy/ Sec. The constant force, F, produces a constant acceleration, a = F/M, where M = the mass being accelerated (em-drive + hypothetical space ship, lol). Since the velocity, V, after time t is: V = a*t the velocity increases linearly. However the kinetic energy with respect to time is a square function, EK = MV2/2. It wouldn't take very long for the kinetic energy curve to achieve a higher value than the input energy curve. Where does this excess energy come from?
Then why are some saying that for the EM Drive to do what it maybe doing, would in fact need to violate CoE and/or CoM to do so?
The equation for thrust from a photon rocket is N=W/C where N is newtons and W is watt seconds of energy. Doesn't that equation also imply constant thrust from constant power? Doesn't a photon rocket suffer from the same problem? Remember, photon rockets have been experimentally observed. -
#488 by rfmwguy on 21 Dec, 2015 14:24
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You need to publish this book. Createspace.com is a print on demand service owned by amazon. I self-published my last 2 books with them and avoided the publishing house tricksters.Trillions of confined photons,
Reminds me of a sci-fi novel I wrote, sadly unpublished. Mix in a little of Everett's many worlds view with sprinkling of Tegmark, Each of the trillions of photons traversing multiple universes taking all possible paths, where in this universe, it is absorbed at one location. I guess with that model, in some Universes, Shell turned it on, and it went pfft without generating any thrust....
Glad to be in one where the story continues.
Regarding photons...I'm still leaning towards them as being the leading candidate for kinetic energy output, especially in a resonance mode of some sort. Shell and aero have been diligently studying this for a while now and perhaps their efforts will yield results.
Hey, the way I figure it, anything that can act as both a wave and a particle depending on the observation method has my attention
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#489 by SteveD on 21 Dec, 2015 14:27
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Quote
The reason why so many people have said the em-drive violates conservation of energy is really quite simple. One central claim of the em-drive is that the force it produces is constant and requires only a constant input of energy. If you plotted the energy that was input over time it would be a straight line with a positive slope; ie EI = kt, where k = the input energy/ Sec. The constant force, F, produces a constant acceleration, a = F/M, where M = the mass being accelerated (em-drive + hypothetical space ship, lol). Since the velocity, V, after time t is: V = a*t the velocity increases linearly. However the kinetic energy with respect to time is a square function, EK = MV2/2. It wouldn't take very long for the kinetic energy curve to achieve a higher value than the input energy curve. Where does this excess energy come from?
Except then you have Doctor David Bae's photon bouncing scheme. Yes, it requires two platforms, but the force produced by those recycled photons is 2000+ times greater than the energy input. Which sounds like a violation of Conservation of Energy, and maybe violation of Conservation of Momentum as well. Yet the consensus is, with this scheme, CoE and CoM are not violated.
I have wondered on these threads multiple times in the past that if the EM Drive is somehow valid, then a clue as to why it is valid might be somewhere in Bae's research.
Well with Bae's setup, each time the photon bounces it gets redshifted a little bit. Energy is being conserved, but we've trained ourselves to think that amplitude = energy and frequency = invariable in the rf spectrum. With Bae's stuff frequency = energy and amplitude = well he'd very much like it to be invariable.
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#490 by Paul451 on 21 Dec, 2015 14:32
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Even with the EMDrive you have a finite energy source, so there is no differenceGiven an unlimited fuel supply,
And there's your problem. You need to define an impossible thing in order for a conventional system to mimic a reactionless thruster. Without that, no conventional device can achieve constant force/power
There really is. Solar panels or some other transfer of power is fundamentally different from the transfer of fuel, or some other transfer of force.
For example: Someone on this thread (or rather the last version of this thread) talked of a rocket on an arm with fuel being pumped down the arm (ie, from the axis to the tip) and claimed that this proved that conventional systems were the "same" as a reactionless thruster such as the EMDrive. But, of course, the propellant has momentum, it needs to be spun up to speed to reach the rocket (say by using the centripetal force from the rotation to draw it "down" the arm), that acts as a continuous brake which increases in proportion to the velocity of the arm. The efficiency of the system thus is velocity dependent.
However, a reactionless system only requires electricity (or even microwaves themselves, if you're particularly clever) transmitted down the arm. There's very little momentum exchanged, small enough (given the efficiencies proposed for EMDrives/METs/etc) that it can be safely ignored. That means that the efficiency of the system is velocity independent. And that's where the free-energy fun happens.The equation for thrust from a photon rocket is N=W/C where N is newtons and W is watt seconds of energy. Doesn't that equation also imply constant thrust from constant power? Doesn't a photon rocket suffer from the same problem? Remember, photon rockets have been experimentally observed.
When calculating "overunity", the critical cross-over velocity occurs when Velocity = Power / Force, where velocity is in m/s, power in watts, force in newtons. Try working out the critical velocity for a photon emitter. (Hint: Don't solve the equations numerically. Only cancel like-terms.) -
#491 by rfmwguy on 21 Dec, 2015 15:13
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Housekeeping note FYI only -
So...I get notices on reported posts from most other NSF threads, not just this one. While I don't act on the others, I do read them out of curiosity. This leads me to compliment all posters here on EmdriveT6.
Well done, group. Keep it up.
Limiting long thread length on "quotes" really helps. That seems to be a typical concern. Just move up your post and insert (...) in place of some text from another poster(s) where appropriate. Vids and pics, once posted can be (...) in most cases...thanks! -
#492 by rfmwguy on 21 Dec, 2015 15:44
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Interesting, so if I follow this correctly, there is a terminal velocity or point of diminishing returns?
Even with the EMDrive you have a finite energy source, so there is no differenceGiven an unlimited fuel supply,
And there's your problem. You need to define an impossible thing in order for a conventional system to mimic a reactionless thruster. Without that, no conventional device can achieve constant force/power
There really is. Solar panels or some other transfer of power is fundamentally different from the transfer of fuel, or some other transfer of force.
(...)The equation for thrust from a photon rocket is N=W/C where N is newtons and W is watt seconds of energy. Doesn't that equation also imply constant thrust from constant power? Doesn't a photon rocket suffer from the same problem? Remember, photon rockets have been experimentally observed.
When calculating "overunity", the critical cross-over velocity occurs when Velocity = Power / Force, where velocity is in m/s, power in watts, force in newtons. Try working out the critical velocity for a photon emitter. (Hint: Don't solve the equations numerically. Only cancel like-terms.)
I think an assumption many are grappling with is that its likely an open system of some sort. Would the definition of the "open" be required to calculate T.V.? Photon mass doesn't seem to cut it, given the micronewton force measurements...therefore, we're dealing with Xem for lack of a better term. -
#493 by Notsosureofit on 21 Dec, 2015 15:58
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... if it really is a GR effect, there is no velocity dependence. Newtonian and SR will always lead to an "impossible" solution.
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#494 by frobnicat on 21 Dec, 2015 16:02
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The reason why so many people have said the em-drive violates conservation of energy is really quite simple. One central claim of the em-drive is that the force it produces is constant and requires only a constant input of energy. If you plotted the energy that was input over time it would be a straight line with a positive slope; ie EI = kt, where k = the input energy/ Sec. However the kinetic energy would be a square function, EK = MV2/2. It wouldn't take very long for the kinetic energy curve to achive a higher value than the input energy curve. Where does this excess energy come from?
I don't see how that is a convincing argument, because you would wind up with the same situation even using conventional chemical rockets... Given an unlimited fuel supply,
And there's your problem. You need to define an impossible thing in order for a conventional system to mimic a reactionless thruster. Without that, no conventional device can achieve constant force/power, there will always be some kind of limit. For any kind of rocket, it's finite propellant. For any kind of external propulsion or interactions, it's change in efficiency due to velocity relative to the outside factor. But there's always something.
(With one exception, photon drives. Your photon emitter effectively manufactures its "propellant". But the critical velocity is greater than the speed of light, so it quite neatly sorts itself out.)
Even with the EMDrive you have a finite energy source, so there is no difference other than how long it takes to deplete your energy reserve. Best case would seem to be some sort of nuclear reactor, whose fuel even so would be depleted at some point. You have to have power to generate the microwaves that the EMDrive runs on. Even an EMDrive or photon drive is dependent on available energy.
This of course all depends on inertia being an inherent property of mass/matter. If it turns out to be emergent and the result of an interaction between an accelerating object and vacuum energy, relativistic conditions could become far more complicated. But for that discussion to have any merit one first would have to clearly define the characteristics of the vacuum. On that there is no consensus. It is not even certain that it exists and there are those who would argue that it does not, at least in the way it has been being discussed.
This has been explained again and again. Try to make your system a stationary process : from a given "ground" inertial frame, sustain a thruster with all the flow(s) it needs to keep thrusting at constant velocity V (relative to said ground) at constant thrust F vector (same direction as velocity). Recover on ground a raw mechanical power of Prmp=FV (F times V) by letting the thruster push on a linear generator that's calibrated such as opposing a force F (hence the thruster as 0 acceleration, hence the velocity is constant). The raw mechanical power is converted by the generator (on ground) as a fraction of electrical power, a fraction of this electrical power is sent back to the moving thruster. The thruster system receives from this feedback loop a power Pfl=ηPrmp=ηFV where η is efficiency : η<1
Wheels on ground, electrical vehicle.
Needed flow of power (from ground), Pnf>FV
And so Pfl<Pnf
Overall the system needs a constant power input Pnf-Pfl>0 to remain in a stationary situation.
Ion thruster
With Vej the ejection velocity (relative to thruster) of propellant, and μ the mass flow rate (kg/s)
F=μVej
Needed flow of power (from ground), Pnf>0.5μVej²
Needed flow of matter (from ground), μ
The flow of propellant lost by the ion thruster can conceivably be recovered by the ground system to be fed back, overall the system can be a closed cycle for matter and yet remain in a stationary situation.
But this flow of matter (propellant) needs to be put from ground to thruster's velocity
This requires an added power of constant "in flight refueling" Pifr>0.5μV²
Overall the system consumes Pnf+Pifr>0.5(Vej²+V²)F/Vej
This latest expression has a minimum (i.e. the system consumes the least overall power) for Vej=V (that is, the propellant is expelled at such a velocity wrt. thruster as it is at rest wrt. ground). At such best case the expression takes value FV, hence Pnf+Pifr>FV
And so Pfl<Pnf+Pifr
Overall the system needs a constant power input Pnf+Pifr-Pfl>0 to remain in a stationary situation.
Chemical thruster
-> refer to ion thruster (the mass flow rate of "in flight refueling" will give the fed power as power=mass_flow*energy_density)
-> same conclusion
emdrive with "figure of merit" φ (in Newtons per electrical Watt)
Needed flow of power (from ground), Pnf=F/φ
Feedback loop power Pfl=ηFV
Whenever V>1/(ηφ) we have Pfl>F/φ
And so for such V>1/(ηφ) : Pfl>Pnf
Overall the system acts as a constant power output Pfl-Pnf>0 while remaining in a stationary situation.
With φ=.1 N/kW and η=.1 the overunity appear above 100km/s
With φ=1 N/kW and η=.5 the overunity appear above 2km/s, this is in the ballpark of energy storage flywheels tangential velocities...
Only a φ<3.33 µN/kW (photon rocket) can guarantee that such V>1/(ηφ) can never be exceeded (even with ideally rigid materials and asymptotically close to one efficiency) because that would make V>c
Conclusion, it is simply wrong to say that conventional proven propulsive schemes suffer from the same apparent conservation of energy issue as the propellantless schemes claiming above 3.33 µN/kW "figure of merit". Only propellantless schemes claiming above 3.33 µN/kW have this problem. It is "instantaneous", it appears on any (non 0) arbitrarily small delta time interval. At a minimum, such propellantless schemes shouldn't be longer qualified as drives, but rather as sails or generators, i.e. systems which are known to exhibit net power output production while remaining in a stationary situation (because fed by an "infinite" or huge enough reserve of energy).
To comment, please refer only to units of power(W), force(N), relative velocities(m/s), mass flow rates (kg/s), as nothing else is needed and those eschew the problems with arbitrary choices of reference frames.
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#495 by X_RaY on 21 Dec, 2015 16:07
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Sounds like great news Shell, congratulations.Whatever comes of this em-drive business, whatever that means, I am fascinated as well. In fact, because of the em drive I am now getting interested in physics. I've always loved computer science, but thanks to everybody here I am now deeply interested in physics. Its definitely not a boring subject, nor is it confusing. It just seems that way at first.
Thanks.
Rodal should be a professor and teach his stuff if he hasn't in the past or doesn't currently. And Shell is a great engineer, also very inspirational. rfmwguy sticks his neck out there and gets to business, so we can all benefit. Nice job guys and keep up the good work.
You all are simply incredible! I'm not throwing that word out here lightly and this even goes for the ones who are just tuning in to see this unfold, I urge you all to please stay tuned.
I'm reminded every day now of the father who said he had a daughter and she said she wanted to grow up to become to be a scientist like me. What a proud dad he must be. Hearing that gives me hope and faith in the fathers and mothers and the children who will walk in our shoes.
Things are happening. EagleWorks has a paper in peer review and I'm restoring my lab into my home and the frustum antennas I fried. I'll say it. I got thrust and yes it was above EagleWorks and rfmwguy's and several others. It was a O. M.G. moment. Honestly, I got so excited I was shaking, it was like a new hot rod car and I regressed turning up the power. I didn't record any of it as it was just a preliminary test to see if everything worked. I got more thrust and as the digital scales were climbing it went pffft. That wasn't good.
For those of you that are wondering what I have in plans right now (other than getting things set up in the home) is to test two different antennas, one being a cone style and the other being a ball on the end of the antennas (like your car antenna) to see if I can negate some of the coronal discharges from the points of the antennas that it had to see to fry itself into a match. I've vowed it will not happen again at greater power.
Don't ask what levels I got, all I'll say they were out of the noise and error IMHO. We will revisit it all again when I get set up. I'll post all the data I get for everyone to see. Yes, rfmwguy I'll post some pics.
Everyone have a great Sunday. I'm back to rebuilding a waveguide that wasn't as good as it needed to be the first time and may have caused my antennas to matchstick.
Shell
PS: Dad, you tell your daughter that you're proud of her, as am I.
I'm very curious about your data next time with all the details of the experiment.
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#496 by OnlyMe on 21 Dec, 2015 16:14
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... if it really is a GR effect, there is no velocity dependence. Newtonian and SR will always lead to an "impossible" solution.
As long as the evaluation remains strictly confined to GR correct. However, is that any longer realistic?
If the quantum vacuum is real in any incarnation and interacts with matter, things become far more complex. -
#497 by Rodal on 21 Dec, 2015 16:17
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...
As many times as it has been explained before, new people to the thread keep bringing this up. I can only say thank you to Frobnicat and Paul451 to take their time to explain this once again.
This has been explained again and again. Try to make your system a stationary process : from a given "ground" inertial frame, sustain a thruster with all the flow(s) it needs to keep thrusting at constant velocity V (relative to said ground) at constant thrust F vector (same direction as velocity). Recover on ground a raw mechanical power of Prmp=FV (F times V) by letting the thruster push on a linear generator that's calibrated such as opposing a force F (hence the thruster as 0 acceleration, hence the velocity is constant). The raw mechanical power is converted by the generator (on ground) as a fraction of electrical power, a fraction of this electrical power is sent back to the moving thruster. The thruster system receives from this feedback loop a power Pfl=ηPrmp=ηFV where η is efficiency : η<1
...
Conclusion, it is simply wrong to say that conventional proven propulsive schemes suffer from the same apparent conservation of energy issue as the propellantless schemes claiming above 3.33 µN/kW "figure of merit". Only propellantless schemes claiming above 3.33 µN/kW have this problem. It is "instantaneous", it appears on any (non 0) arbitrarily small delta time interval. At a minimum, such propellantless schemes shouldn't be longer qualified as drives, but rather as sails or generators, i.e. systems which are known to exhibit net power output production while remaining in a stationary situation (because fed by an "infinite" or huge enough reserve of energy).
To comment, please refer only to units of power(W), force(N), relative velocities(m/s), mass flow rates (kg/s), as nothing else is needed and those eschew the problems with arbitrary choices of reference frames. -
#498 by Paul451 on 21 Dec, 2015 16:25
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Interesting, so if I follow this correctly, there is a terminal velocity or point of diminishing returns?
Other way around.
The critical velocity is the point where kinetic energy is being produced at a higher rate than (electrical) energy is consumed by the thruster. Conveniently, it happens to be when Velocity = Power/Force (normal units).
Below that velocity, the device is mundane (from a conservation of energy point of view), it consumes more energy than it produces. At the critical velocity, the energy produces equals the energy consumed, and the device is at unity. Above the critical velocity, the device will be producing more energy than it consumes. And you've broken the laws of physics. (Hurrah!)
Conventional devices always conspire the stay below their critical velocity, usually be changing the thrust/power ratio.
A theoretically perfect photon emitter happens to have a critical velocity of "c", and so can never reach overunity. A realistic photon drive has a critical velocity above "c", and really can't reach overunity.
A device with a constant thrust to power ratio, and a thrust to power ratio higher than a theoretically perfect photon emitter, has a critical velocity that can be reached by a real system. It can therefore be used to violate CoE. Even these lab-scale result are much greater than the thrust of a photon drive, and so if it's a genuine propellantless/reactionless effect, such devices can violate CoE.
[frobnicat covered it better, of course.] -
#499 by rfmwguy on 21 Dec, 2015 16:55
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Thanks, Paul451...I've reached no theories on what is happening, so my eyes are wide open. Buts lets speculate just a bit. A photon rockets is limited by c...understood.
An emdrive is reportedly several factors above an emdrive, thus the assumption is made that it is over-unity and violates CoE/M...this is where classical scientists' eyes explode, I understand that as well.
Sooo, consider the possibility that it is manipulating/focusing/expelling/attracting/interacting with XEM...a natural condition of the universe, perhaps part of the theory of an ever-expanding universe...a driving force...lets even say it could be the new LHC particle, call it unicorn dust...doesn't matter for this thought experiment.
Suppose a natural condition, a zero frame of reference, of which we are never a part of (as we fly thru the cosmos) does exist and somehow we are putting on the brakes, attaching to it/countering it/repelling it, whatever...
Are we really at an over-unity, CoM/E violating condition? I am tending to believe it is not and something hasn't been fully understood by our ancestral scientist friends and their legions of followers.
After all, as others have said before, how much stranger is this than the big bang when all the matter and energy in the universe simply appeared out of nothingness...
