Quote from: HMXHMX on 11/16/2015 10:09 PMWoodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.It answers the question raised by Mezzenile a few pages ago. I attach Woodward's document "Over-Unity Argument & Mach Effect Thrusters" to this message for more convenience.It is worth noting besides that Woodward & Fearn are also currently working on a theoretical explanation for EmDrive's thrust.

Woodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.

Quote from: flux_capacitor on 11/17/2015 08:14 AMQuote from: HMXHMX on 11/16/2015 10:09 PMWoodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.It answers the question raised by Mezzenile a few pages ago. I attach Woodward's document "Over-Unity Argument & Mach Effect Thrusters" to this message for more convenience.It is worth noting besides that Woodward & Fearn are also currently working on a theoretical explanation for EmDrive's thrust.They are working on a refutation of the quantum vacuum explanation for any putative EMdrive thrust, not a theoretical explanation of EMdrive, just to be clear.

Quote from: HMXHMX on 11/17/2015 04:39 PMQuote from: flux_capacitor on 11/17/2015 08:14 AMQuote from: HMXHMX on 11/16/2015 10:09 PMWoodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.It answers the question raised by Mezzenile a few pages ago. I attach Woodward's document "Over-Unity Argument & Mach Effect Thrusters" to this message for more convenience.It is worth noting besides that Woodward & Fearn are also currently working on a theoretical explanation for EmDrive's thrust.They are working on a refutation of the quantum vacuum explanation for any putative EMdrive thrust, not a theoretical explanation of EMdrive, just to be clear.Ok that makes a WHOLE lot more sense.Since you wrote the update on SSI any predictions on when we will see any additional information from Woodward and Fearn? to my knowledge the next thing to look forward to would be the replication results from Austria and Canada. But it sounds like Woodward and Fearn are already way into testing new devices. Is that accurate?

Quote from: HMXHMX on 11/16/2015 10:09 PMWoodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.That paper: http://ssi.org/epi/Over-Unity_Argument_&_Mach_Effect_Thrusters.pdf, shows an embarrassing lack of understanding of classical Newtonian physics. It's difficult to have respect for any more advanced physics derivations (which I haven't spent much time looking into), if he is promoting basic Newtonian physics equations that are flawed at a very fundamental level. He says, "Now we have done something stupid and wrong," but it isn't in the place he attempts to demonstrate. The physics mistake is when he DEFINES the physics "figure of merit" (ratio of force to input power) as something that is time invariant and assumes that non-physical condition for his calculations. Having a constant force for a given input power in a closed system guarantees problems according to Newtonian physics (in any reference frame), and, of course that eventually results in a violation of conservation of energy. It doesn't occur in any known physical machine. That doesn't mean the calculations of input or output energy are wrong. It means you can't talk about a constant ratio of force to input power in a time invariant fashion for a closed system if you want to respect conservation of energy over time, which the Mach Effect Thruster papers purport to do. His arguments regarding varying reference frames once again show profound ignorance of conservation of energy under special relativity and his pointing to the definition of velocity as the "likely source of the error," is both alarmingly vague and dangerously misleading.At this point, he seems so confident of his results as to be completely impervious to well-intentioned criticism and peer review, because any physicist trained in classical mechanics would shake their heads at those arguments and clearly some people have brought the correct derivations to his attention. His arguments are something I worked through both in my freshman physics class and later on in mechanics classes many years ago. He would be better off to not address the over-unity argument at all than to point at that paper.

Quote from: gargoyle99 on 11/17/2015 08:21 PMQuote from: HMXHMX on 11/16/2015 10:09 PMWoodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.That paper: http://ssi.org/epi/Over-Unity_Argument_&_Mach_Effect_Thrusters.pdf, shows an embarrassing lack of understanding of classical Newtonian physics. So Woodward takes the time and effort to put together a complete write up arguing against COE violations math included and the the best criticism you have to offer is personal ad hominem attacks, with vague points thrown in? I mean either give a well reasoned critique of what is said in the monograph or don't bother saying anything at all.

Quote from: HMXHMX on 11/16/2015 10:09 PMWoodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.That paper: http://ssi.org/epi/Over-Unity_Argument_&_Mach_Effect_Thrusters.pdf, shows an embarrassing lack of understanding of classical Newtonian physics.

Quote from: birchoff on 11/18/2015 12:21 AMQuote from: gargoyle99 on 11/17/2015 08:21 PMQuote from: HMXHMX on 11/16/2015 10:09 PMWoodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.That paper: http://ssi.org/epi/Over-Unity_Argument_&_Mach_Effect_Thrusters.pdf, shows an embarrassing lack of understanding of classical Newtonian physics. So Woodward takes the time and effort to put together a complete write up arguing against COE violations math included and the the best criticism you have to offer is personal ad hominem attacks, with vague points thrown in? I mean either give a well reasoned critique of what is said in the monograph or don't bother saying anything at all.In between the ad hominem and personal attacks, I pointed out what was wrong with the physics. But, if that was not sufficiently clear, I can go into more detail.(Also, I see that at the beginning of this thread, other people have brought up the correct physics and provided references, but I can review.)Professor Woodward considers a Newtonian system with constant thrust F and constant input power P.Total Input Energy = P tTotal Output Energy = Kinetic Energy = 1/2 mv^{2} = 1/2 ma^{2}t^{2}So far, Woodward's derivation is correct. Here he points out, correctly, that this system appears to violate conservation of energy, because input energy scales with time t and output energy scales with t^{2}, so for ANY such system, there is a time after which the output energy exceeds the input energy.This derivation applies to not only the alleged Mach Effect Thruster (MET), but any system with constant thrust and constant input power. Next he makes the first elementary mistake. He claims that because other systems with constant thrust and constant input power besides the MET also follow Newtonian physics and everybody knows that they observe the conservation of energy, therefore there must be some mistake in this calculation and really, the MET also follows conservation of energy, despite the glaring error demonstrated in the above equations.After discussing with a dismissive tone how this is all elementary and basic physics, he goes on to state vaguely that the mistake "likely" is in the definition of "velocity."Actually, the mistake is in the original conjecture. There are NO closed Newtonian systems that have constant acceleration and constant input power. They would all violate conservation of energy.If there is constant acceleration (consider an ideal weight hanging from a pulley accelerating another mass across a frictionless table), then the input power will scale linearly with time (the falling weight increases in speed as it falls).Likewise, consider the Newtonian system of the car you drive to work. If you accelerate at a constant rate, the engine consumes more gasoline to go from 50 mph to 60mph than it did to go from 0 mph to 10 mph, even though the delta-V is the same.Alternatively, if you have a system with constant power input, then the acceleration drops off over time. For example, a model RC electric car with a small battery will accelerate very fast from an initial stop, but then quickly slow its acceleration after a few seconds. This is without regard to any friction losses.To summarize, in a Newtonian world, there are NO physical closed systems with a constant acceleration and a constant input power and so his argument that dragons must exist because they are no more illogical than unicorns is badly flawed. A closed system can either have constant acceleration, or constant input power, but not both without violating conservation of energy. (An open system also follows conservation of energy, but you also have to take into account what is being added or removed from the system.)Then Woodward attempts to work around the issue by arbitrarily limiting the amount of time that the system can run:We know that, starting from t = 0, if we let the integration interval t get very large, the work equation integral will first equal and then exceed the energy calculated by the figure of merit equation. So we require that t be sufficiently small that this obvious violation of energy conservation does not happen. You can't work around this problem by arbitrarily limiting the time that the system runs. What happens when that much time actually passes? The problem is with the initial conjecture, not with the physics equations and it is an elementary error.This is a forum for professionals and serious space flight enthusiasts. Participants regularly calculate bi-elliptic and Hohmann orbital transfers and that math is just Newtonian physics but it's a lot harder than this!Nobody who has passed a Newtonian mechanics college course could read that paper without wincing at the naive physics. I hope that Professor Woodward gets some peer review from somebody knowledgeable and straightens out his misconceptions, because otherwise he will have considerable difficulty getting credibility from any physicist who reads that paper, whether or not the Mach Effect Thruster generates thrust.

Quote from: gargoyle99 on 11/18/2015 12:12 PMQuote from: birchoff on 11/18/2015 12:21 AMQuote from: gargoyle99 on 11/17/2015 08:21 PMQuote from: HMXHMX on 11/16/2015 10:09 PMWoodward Lab update at http://www.ssi.org includes a monograph on "over-unity" controversy as it relates to propellantless propulsion.That paper: http://ssi.org/epi/Over-Unity_Argument_&_Mach_Effect_Thrusters.pdf, shows an embarrassing lack of understanding of classical Newtonian physics. So Woodward takes the time and effort to put together a complete write up arguing against COE violations math included and the the best criticism you have to offer is personal ad hominem attacks, with vague points thrown in? I mean either give a well reasoned critique of what is said in the monograph or don't bother saying anything at all.In between the ad hominem and personal attacks, I pointed out what was wrong with the physics. But, if that was not sufficiently clear, I can go into more detail.(Also, I see that at the beginning of this thread, other people have brought up the correct physics and provided references, but I can review.)Professor Woodward considers a Newtonian system with constant thrust F and constant input power P.Total Input Energy = P tTotal Output Energy = Kinetic Energy = 1/2 mv^{2} = 1/2 ma^{2}t^{2}So far, Woodward's derivation is correct. Here he points out, correctly, that this system appears to violate conservation of energy, because input energy scales with time t and output energy scales with t^{2}, so for ANY such system, there is a time after which the output energy exceeds the input energy.This derivation applies to not only the alleged Mach Effect Thruster (MET), but any system with constant thrust and constant input power. Next he makes the first elementary mistake. He claims that because other systems with constant thrust and constant input power besides the MET also follow Newtonian physics and everybody knows that they observe the conservation of energy, therefore there must be some mistake in this calculation and really, the MET also follows conservation of energy, despite the glaring error demonstrated in the above equations.After discussing with a dismissive tone how this is all elementary and basic physics, he goes on to state vaguely that the mistake "likely" is in the definition of "velocity."Actually, the mistake is in the original conjecture. There are NO closed Newtonian systems that have constant acceleration and constant input power. They would all violate conservation of energy.If there is constant acceleration (consider an ideal weight hanging from a pulley accelerating another mass across a frictionless table), then the input power will scale linearly with time (the falling weight increases in speed as it falls).Likewise, consider the Newtonian system of the car you drive to work. If you accelerate at a constant rate, the engine consumes more gasoline to go from 50 mph to 60mph than it did to go from 0 mph to 10 mph, even though the delta-V is the same.Alternatively, if you have a system with constant power input, then the acceleration drops off over time. For example, a model RC electric car with a small battery will accelerate very fast from an initial stop, but then quickly slow its acceleration after a few seconds. This is without regard to any friction losses.To summarize, in a Newtonian world, there are NO physical closed systems with a constant acceleration and a constant input power and so his argument that dragons must exist because they are no more illogical than unicorns is badly flawed. A closed system can either have constant acceleration, or constant input power, but not both without violating conservation of energy. (An open system also follows conservation of energy, but you also have to take into account what is being added or removed from the system.)Then Woodward attempts to work around the issue by arbitrarily limiting the amount of time that the system can run:We know that, starting from t = 0, if we let the integration interval t get very large, the work equation integral will first equal and then exceed the energy calculated by the figure of merit equation. So we require that t be sufficiently small that this obvious violation of energy conservation does not happen. You can't work around this problem by arbitrarily limiting the time that the system runs. What happens when that much time actually passes? The problem is with the initial conjecture, not with the physics equations and it is an elementary error.This is a forum for professionals and serious space flight enthusiasts. Participants regularly calculate bi-elliptic and Hohmann orbital transfers and that math is just Newtonian physics but it's a lot harder than this!Nobody who has passed a Newtonian mechanics college course could read that paper without wincing at the naive physics. I hope that Professor Woodward gets some peer review from somebody knowledgeable and straightens out his misconceptions, because otherwise he will have considerable difficulty getting credibility from any physicist who reads that paper, whether or not the Mach Effect Thruster generates thrust.Before I say anything else. Thanks for putting much more effort into the critique.That said I am not sure we are reading the same paper. Because I do not see anywhere in the paper where woodward says anything to the effect of the "first elementary mistake" you pointed to.I re read the monograph this morning and my interpretation is that Woodwards argument is an attempt of proof by definition.paraphrasing....Given all newtonian systems obey conservation of energy, and the figure of merit equation describes a newtonion system. the equation derived from the stated Figure of Merit equation cannot be valid for all values of t. Otherwise a newtonian system would violate conservation of energy.Now towards the end he seems to arbitrarily limit final t in the integral and my suspicion is he believes that the limit on t isn't arbitrary because of the boundaries placed on t from the definition of a newtonian system.Now I dont know if I completely agree with the argument made in the monograph because upon second reading the first question that jumped out at me after seeing the last critique you made is that I dont see where he proved that a MET is a newtonian device (granted he is probably depending on the work Fearn and Watsner did to show that HN Theory of Gravitation is a super set of GR).P.S. please be aware my physics neurons are severely rusted and my interpretations and word choice may be very poor.

...paraphrasing....Given all newtonian systems obey conservation of energy, and the figure of merit equation describes a newtonion system. the equation derived from the stated Figure of Merit equation cannot be valid for all values of t. Otherwise a newtonian system would violate conservation of energy.That is an excellent paraphrase. One of the given axioms is not correct and that leads to the contradiction. The problem is that the figure of merit equation as he used it does NOT describe a Newtonian system, because the force of merit equation describes the measured force per input power ONLY at a specific point in time and he is assuming that the force will be invariant over all time for a constant input energy. Such a system will not be Newtonian, as demonstrated above.Of course, the hope of the MET is that it might accelerate a spacecraft for long journeys. That's why understanding and resolving the conservation of energy question is important. Is conservation of energy violated? Otherwise, how does the force change over time and what mechanism, if any, does the system use to interact with the external Universe? The Mach conjecture is very interesting to me and I, admittedly, don't understand all the ways it could affect General Relativity theory. However, the math for GR is so much more sophisticated that I will be very skeptical of anyone's GR interpretation if they don't demonstrate knowledge of the simpler (though not trivial!) conservation of energy in a strictly Newtonian system. As a space enthusiast, I strongly support research into exotic space propulsion systems, but I think you should understand Newtonian physics if you're going to show how you can bypass it.

...So far this is all just elementary mechanics. We have not yet done anything stupid or wrong (or both). As long as we don’t mess with the math, we’re OK (and energy conservation is not violated). How then do some argue that in this simple system – and METs in particular – energy conservation is violated?Simple. By [Some, where some are the critics arguing that MET's violate COE because it provides constant thrust for constant power] doing something stupid and wrong. In particular, by [the over unity critics] taking the “figure of merit” of a thrust (force) generator – by definition, the number of Newtons of thrust produced per watt of input power to the thrust generator – and treating it as a dynamical equation that can be used to calculate the energy input to a motor that acts for some length of time; that is:F_{m} = F / P (10)where F_{m} is the figure of merit and P the input power to the motor that produces the thrust F. ...

...t = (F_{m}a / 2)t^{2} (15)which is obviously wrong. For some values of t, the coefficient of t^{2} on the right hand side of Equation (15) (a constant by the way) may make this equation valid. [That is, it can be treated as a simple quadratic equation and solved by the usual techniques.] As a continuous evolution equation, however, it is nonsense. But this is the mathematics of those who make the “over unity” energy conservation violation argument about the operation of METs. The real question here is how could anyone, having done this calculation or its equivalent, think that they had made a profound discovery about anything? [Or METs in particular?] After all, it is universally known that energy conservation is not violated in classical mechanics....

As I understand it. Woodward isn't the one claiming that the Figue of merit equation represents a newtonian system. He is claiming that the critics arguing that constant thrust for constant power propulsion devices are over unity devices are the ones incorrectly treating the Figure of merit equation as if it represents a newtonian system. But instead of simply stating that is the problem. He takes the reader through the problem with the incorrect assumption starting with eqn 10 all the way through to eqn 15 finally concluding the following:Quote from: Mach Effect Thrusters (Mets) And “Over-Unity” Energy Production(http://ssi.org/epi/Over-Unity_Argument_&_Mach_Effect_Thrusters.pdf)...t = (F_{m}a / 2)t^{2} (15)which is obviously wrong. For some values of t, the coefficient of t^{2} on the right hand side of Equation (15) (a constant by the way) may make this equation valid. [That is, it can be treated as a simple quadratic equation and solved by the usual techniques.] As a continuous evolution equation, however, it is nonsense. But this is the mathematics of those who make the “over unity” energy conservation violation argument about the operation of METs. The real question here is how could anyone, having done this calculation or its equivalent, think that they had made a profound discovery about anything? [Or METs in particular?] After all, it is universally known that energy conservation is not violated in classical mechanics....As a resultparaphrasing....Given all Newtonian systems obey conservation of energy, and the figure of merit equation describes a Newtonian system. the equation derived from the stated Figure of Merit equation cannot be valid for all values of t. Otherwise a Newtonian system would violate conservation of energy.should have beenGiven all Newtonian systems obey conservation of energy and the figure of merit equation does not describe a Newtonian system; since equation (15), which was derived from the figure of merit equation, cannot be valid for all values of t. Then the assertion that constant thrust for constant power results in over unity for a MET cannot be valid. Since an MET is a valid Newtonian device.

Quote from: birchoff on 11/18/2015 08:49 PMAs I understand it. Woodward isn't the one claiming that the Figue of merit equation represents a newtonian system. He is claiming that the critics arguing that constant thrust for constant power propulsion devices are over unity devices are the ones incorrectly treating the Figure of merit equation as if it represents a newtonian system. But instead of simply stating that is the problem. He takes the reader through the problem with the incorrect assumption starting with eqn 10 all the way through to eqn 15 finally concluding the following:Quote from: Mach Effect Thrusters (Mets) And “Over-Unity” Energy Production(http://ssi.org/epi/Over-Unity_Argument_&_Mach_Effect_Thrusters.pdf)...t = (F_{m}a / 2)t^{2} (15)which is obviously wrong. For some values of t, the coefficient of t^{2} on the right hand side of Equation (15) (a constant by the way) may make this equation valid. [That is, it can be treated as a simple quadratic equation and solved by the usual techniques.] As a continuous evolution equation, however, it is nonsense. But this is the mathematics of those who make the “over unity” energy conservation violation argument about the operation of METs. The real question here is how could anyone, having done this calculation or its equivalent, think that they had made a profound discovery about anything? [Or METs in particular?] After all, it is universally known that energy conservation is not violated in classical mechanics....As a resultparaphrasing....Given all Newtonian systems obey conservation of energy, and the figure of merit equation describes a Newtonian system. the equation derived from the stated Figure of Merit equation cannot be valid for all values of t. Otherwise a Newtonian system would violate conservation of energy.should have beenGiven all Newtonian systems obey conservation of energy and the figure of merit equation does not describe a Newtonian system; since equation (15), which was derived from the figure of merit equation, cannot be valid for all values of t. Then the assertion that constant thrust for constant power results in over unity for a MET cannot be valid. Since an MET is a valid Newtonian device.Umm. That still isn't quite right. You've changed the logic to be circular. Rather, MET (or any other device) is not a valid Newtonian device if it claims to have constant force for constant power (i.e. obeys the figure of merit equation over time), because that is what leads to the violation of CoE. Are you suggesting the Professor Woodward is claiming that the MET force is not a constant for a given input power? If so, he should state that explicitly, because that could solve the question immediately. I haven't seen that, but maybe I missed it somewhere. Also, as I read Professor Woodward's final derived equations, they contain no terms that are non-local and they have terms for constant power and constant acceleration and appear to be time-invariant. That certainly implies that a figure of merit equation DOES apply to the MET. If the author thinks that it does not, I suggest he state so clearly as well as explain how it doesn't. I just came across this in one of his early papers:http://physics.fullerton.edu/~jimw/nasa-pap/The appearance of momentum conservation violation in our impulse engine doesn't mean that momentum isn't conserved. It means that we can't treat the impulse engine as an isolated system. Since the effect responsible for the apparent violation of the conservation principle is inertial/gravitational, this should come as no surprise at all. As Mach's principle makes plain, anytime a process involves gravity/inertia, the only meaningful isolated system is the entire universe. Since inertial reaction forces appear instantaneous [see Woodward, 1996a and Cramer, 1997 in this connection], evidently our impulse engine is engaging in some "non-local" momentum transfer with the distant matter in the universe. With suitable choice of gauge, this momentum transfer can be envisaged as transpiring via retarded and advanced disturbances in the gravitational field that propagate with speed c.As previously noted, having a non-isolated system is another way to get out of the conservation of energy conundrum. If that's the ace he wants to play, he should make that clear right away, because the example he chose in the paper we are discussing was an isolated system. (Also, it's not at all clear to me how the MET would be interacting with external gravitational fields/waves to maintain conservation of energy, but I'm willing to listen to ideas.)Even more helpful would be a description of what the time dependent force on the MET should be according to his theory. If it isn't constant acceleration for constant power, then WHAT IS IT?Most helpful of all, would be to demonstrate an MET accelerating for a significant period of time in an environment free of other experimental errors and measure what it does, although I am aware of the experimental challenges in measuring such low levels of thrust over time.

this may be topical:http://nextbigfuture.com/2015/11/theory-and-experiments-suggest-space.html