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#760 by OnlyMe on 20 Sep, 2016 14:56
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As long as I am on a rant here.., the idea of unlimited acceleration is almost laughable. There has been a lot of discussion about the Quantum Vacuum (QV), but not a great deal of clear description of just what that means. Still there is a growing consensus that the QV does exist, even where agreement on just what it is, is lacking. In any event, without a warp drive or some sub space engineering, that could take whatever QV model you believe in out of the picture, any object composed of atoms does not appear to be able to exceed something between 20-30% the speed of light before the atoms begin to ionize. (Which would result in the spaceship coming apart.) At least not in our labs or anything we can observe with any degree of certainty.., cosmologically.
Since, in GR, as in Newtonian physics, there is no local difference between uniform motion, and immobility, I do not see why this limit to 20-30% of C.
In it's own referential, the speed of any ship will always be zero.
At the opposite, the most distant galaxies are moving away from us at 90% of C. Also, in the referential of one of them, the earth is moving to 90% of C, and I am still no totally ionized
Since the speed is only relative to a referential (as it was told for Kinetic Energy in thread 7) and since there is no absolute referential in GR, there is no speed limit other than C. There is no ionisation or coming apart. But, of course, micrometeorites become very dangereous, if their speed is high relatively to the ship
In the Newtonian sense the vacuum is an empty space. There is no quantum structure or element to it. As such there is no possible interaction between a moving object and the empty vacuum.
Within the context of GR things are not quite as clear cut. While we have no conclusive evidence that the spacetime of GR has any independent substance, that we could describe as a QV, experiments like the Gravity Probe B experiment and its confirmation of the frame dragging effect, tend to support.., or at least open the door to this kind of interpretation. If, in any model of the QV a physical object interacts with the QV to any degree, we are no longer dealing with a vacuum we can think of as Empty Space.., and we can no longer discount the possibility that that interaction has consequences, on either the QV or the physical object.
The 20-30% c limit I used, just comes from the fact that in accelerators and in nature, detectable atoms exceeding this range seem to be fully ionized bare nuclei. Mostly protons and alpha particles in nature and up to gold and lead nuclei in accelerators.
While as I mentioned aspects of and even perhaps the existence of a/the QV remains controversial, Unruh Radiation is generally accepted. While at classical velocities the impact of Unruh Radiation is generally insignificant to atomic stability, it is not unreasonable to expect that at relativistic velocities, the situation may be different.
Both the potential existence of Unruh Radiation and any interaction between a physical object and Spacetime, as suggested by the frame dragging effect, open the door to the potential that, relativistic velocities may result in the ionization of atomic structures.
All of this leads to, at least the potential that the idea that all things in motion tend to stay in motion may not be entirely accurate beyond the classical environments and conditions, that it has been proven. -
#761 by OnlyMe on 20 Sep, 2016 15:06
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For the same builds what is important is the same thrust from the same frustum and antenna design for the same RF input properties. For the rest of the setup, the more different the better as long as measurement sensitivity and accuracy is maintained. Otherwise it still could be a systematic error in the measurement. Also specific modifications showing predictable changes in thrust would be useful as well (e.g. a coating to deliberately reduce Q by a factor of 2 also reducing thrust by that factor) Of course that is the second step, after a reliable signal is found to begin with.
We will never know for certain from any of the null result tests. Only when experiments that have returned thrust have been independently repeated with the same EXACT builds, and all systemic and other variables have been ruled out or identified as the source of the thrust, will any of us know anything with any certainty. BTW while Prof. Yang has every right to modify her conclusions, there is nothing about her second experiment and paper that nullifies the first. The two were far different in to many ways to be thought of as anything but different experiments with different builds, and I never saw anything published with enough detail that anyone could reproduce either frustum or experiment. That is the real trouble none of what has been shared about the many builds has shown two builders performing identical experiments.
...
Also you must have missed the part in Yang's second paper where she provided an explanation of an error source in the original that either would be the full cause of the result, or at least swamp any real signal making the data from the first experiment useless. While more detail on how she determined this would be helpful, there is no good reason to doubt the conclusion.
I agree with your general intent above.
As I said Yang has the right to change her opinion/conclusions, but she did not say that retested the earlier build. There is no real way to know that her conclusions based on a different experiment were valid interpretations of the earlier results... And yes this is based only on the absence of any information explaining exactly how the second dissimilar experiment invalidated the first. -
#762 by Mezzenile on 20 Sep, 2016 16:59
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Yes! This is why I mentioned the fact that the potential has been in the math for a very long time. The difficulty is demonstrating the solution experimentally or through some unambiguous or perhaps undebatable natural observation.
In General Relativity the curvature of space-time is defined by two factors :
With the exception of Dark Matter and even perhaps to some extent Dark Energy, both of which remain unproven theoretical solutions, where do we find any gravitational field that we can say with any certainty originates from anything other than the presence of mass?
While mass IS (in my opinion) a concentration of energy, not all concentrations of energy can currently be described as mass.
In a sense my point was and is, in that comment, that even though GR and for that matter even the Brans-Dicke theory are very successful descriptions of what we do observe of gravitational fields, as has been pointed out, not all solutions and/or predictions have been observed or confirmed.
None of this means that any non-trivial solution that has not been observed is not a real representation of reality. It just means that until it(they) has been observed in nature or recreated in the lab, they remain theoretical predictions.
1 - The distribution of energy and momentum (mass is included in these terms). In your post you don't talk about momentum which should not be forgotten.
2 - The boundary conditions imposed on the equations.
This explains why even if there no energy nor momentum, the boundary conditions are sufficient to impose curvature to a space-time metric solution to GR equations.
Now you are right : the potential solutions to GR equations are quasi infinite and we have only one space-time to check their validity.
It is the same for the equations of acoustic : they are able to provide solutions that we have not yet heard ! It is why we have the pleasure to discover with our ears day after day new musics, new songs, new sounds ! -
#763 by Bob012345 on 20 Sep, 2016 18:21
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Ah, Carl Sagan and his series "Cosmos"...
Yes, skepticism is healthy and a vital part of the scientific method !
http://www.skeptic.com/about_us/manifesto/
http://rationalwiki.org/wiki/Skepticism
In 1999, Skeptical Inquirer magazine named their top ten and other notable skeptics of the 20th Century.
....
Carl Sagan
.....
Brings back good memories : I recall, as an adolescent, being immensely fascinated by those tv-serie.
I still recall the scene where he walks through a (scale) model of the library of Alexandria.
It was really the first time that science was brought in an understandable way for a wider public.
Maybe I don't do him justice enough (for his other work), but personally, I'd consider the popularization of science as his most important achievement.
Now, many years later and with hindsight, i can say that, he, as no one else, understood the importance and the need to get a wider involvement of the public. To help people understand the importance of science and to find the right marketing strategy for science...
I don't have many hero's.. but... he comes close...
I always admired and liked Carl Sagan but I have to say his statement about extraordinary claims requires extraordinary evidence has been used like a hammer to basically discount good evidence on many fronts. In truth, it really takes the same quality of evidence to validate anything and it is only our perceptions of what is extraordinary or ordinary that mess things up. -
#764 by Bob012345 on 20 Sep, 2016 19:15
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Hello All,
.
My previous post regarding a complete cavity computer simulation using a sort of deterministic Heim/Broglie-Bohm theory interpretation of the drive was not very popular. This is understandable. Regardless, at this critical stage of the development we need to discuss the key practical factors which would move the drive from the region of skepticism into reality. For this we need a "high" thrust frustum which goes beyond simple modifications of material or EM source.
I have been hard at work brainstorming possible improvements to maximize the thrust of the cavity. My latest preferred idea on a high Q thruster is based on the wave-cancelling theory of propulsion shared by our Finnish friend Dr. Kolehmainen. I also appreciate the more prevalent spacetime warp theory as being an additional factor in thrust creation as this has been extensively discussed in previous papers and has solid theoretical support.
The idea: A lattice of quantumly entangled photons in an easily permissive pseudo-metallic structure, or maybe some sort of metallic electromagnetic conductors to channel photon cloud movements. This structure would also have a cooling consideration as entanglement and heat don't like to mix - there are potential Infra absorbents for the outsides which could be used including Aerogel. Introduction of microwave EM, or alternatively injection of high energy pulse lasers would be most efficient as fuel (note here theoretical discussion of high energy pulse lasers on creating negative energy densities). The entanglement and channeling of photons would amplify the tunneling effects per the QV theory and also ensure more destructive interference per the prevailing wave-cancelling theory.
It is also possible to combine this with an open cone cavity as shown before. The open cone cavity could provide equivalent propulsion, and perhaps bonus collimated photon propulsion, with resonance still occurring if the walls on the sides of the cone provide deflection back towards the narrow end, or if there is an unusual (Cannae style) geometry. The channeling of photons within the metallic lattice is simply an abstraction of the existing "loop" designs. The entanglement is arguably the most important aspect of this advanced experimental design as multiple groups could be "merged" continuously to provide the destructive cancellation (here we could also envision two opposing EM injection points?).
If this sounds too complex and fantastic for you then let me summarize and add this key takeaway: Q may represent resonance, but resonance does not necessarily imply thrust. For thrust to occur, most theories rely on the energy density (read: imbalance) of the electromagnetic fields. The best route to improve thrust then is focusing on internal geometries, especially focusing on photon channeling for the maximum density of the photon clouds. In other words the frustum should not be empty just for the sake of better resonance, as others have noted.
It seems to me that what the Finnish team proposed could be tested relatively straightforwardly. Not trying to measure photon pairs from an existing EmDrive test device but a direct measure of thrust from a setup which mixed co-propagating waves which also cancel. If that worked it might be greatly magnified over what happens randomly in their view in the EmDrive. Can that be done? Has anyone tried that?
If I were an experimentalist I would split a laser beam and recombine it as two parts exactly out of phase but co-propagating in the same direction and see what happens.
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#765 by Bob012345 on 20 Sep, 2016 19:35
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AFAIK,
Shawyer has:
- NO valid theory
- NO publicly verifiable & falsifiable experimental results
but only claims. SO, everything boils down NOT to Science, but to FAITH in the man who makes the claim.
No surprise he isn't on that panel.
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Besides, honestly, i think this behaviour is rather stupid.
IF EM drive works for real, but someone else develops the theory or shares the conclusive results first, hw won't get any merit for it: it will be someone else's name that goes through history (more precisely, the name of the person who does the first public & accepted demostrations, along with the names of those publishing the precise theoretical explanation of what's happening in the drive).
IF EM drive doesn't work, everybody will call him a scammer even if that wasn't his purpose to begin with.
From any point of view, it's a very suboptimal line of action. With his behaviour, Shawyer is locking himself out of the benefits its invention may produce either way.
If the emdrive appears to work, I hope that the name of the person that has discovered the phenomenon (I am not sure it was Shawyer, it seems there were other experiments before) will be remembered. No only the name of the scientist that made the right theory. Of course, the person who will provide a correct theory, maybe a general theory comparable with GR, maybe a theory that explain the cosmological data, will merit his name to be known, as Einstein, Plank, Feynman, etc.
But the person who made the physical invention still merit to be known. We still remember Ampere, Faraday, Volta, despite they have no explanation of the phenomenon. They did not knew the electron.
The problem with Shawyer is that, rather than giving no explanation, he gives a mathematically false explanation. As he is not a theoretical scientist, but an Engineer, since he found a formula that provides him the amount of thrust that he had mesured, he seems happy. I think many skeptics would feel more confortable if Shawyer was giving his results as an experimental result, with no false solution.
If no one really knows how the EmDrive really works then how can it be asserted that any solution is 'false'? -
#766 by RonM on 20 Sep, 2016 19:43
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The problem with Shawyer is that, rather than giving no explanation, he gives a mathematically false explanation. As he is not a theoretical scientist, but an Engineer, since he found a formula that provides him the amount of thrust that he had mesured, he seems happy. I think many skeptics would feel more confortable if Shawyer was giving his results as an experimental result, with no false solution.
If no one really knows how the EmDrive really works then how can it be asserted that any solution is 'false'?
If the math is incorrect.
Shawyer would have been better off just publishing the data. -
#767 by Mezzenile on 20 Sep, 2016 20:43
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“Extraordinary claims requires extraordinary evidence” applies to the Bayesian situation where you want to change a prior belief which is strongly in defavor to a new paradigm in a posterior belief more in line with it. If your mind follows a Bayesian inference process (may be Sagan's way of thinking) and if the prior and posterior belief are very different, you will have to apply many times the Bayes theorem with more evidence or information each time they become available to progressively update your believing. It can be a long and costly process which if not conducted at its end can let the new idea die.
Ah, Carl Sagan and his series "Cosmos"...
Yes, skepticism is healthy and a vital part of the scientific method !
http://www.skeptic.com/about_us/manifesto/
http://rationalwiki.org/wiki/Skepticism
In 1999, Skeptical Inquirer magazine named their top ten and other notable skeptics of the 20th Century.
....
Carl Sagan
.....
Brings back good memories : I recall, as an adolescent, being immensely fascinated by those tv-serie.
I still recall the scene where he walks through a (scale) model of the library of Alexandria.
It was really the first time that science was brought in an understandable way for a wider public.
Maybe I don't do him justice enough (for his other work), but personally, I'd consider the popularization of science as his most important achievement.
Now, many years later and with hindsight, i can say that, he, as no one else, understood the importance and the need to get a wider involvement of the public. To help people understand the importance of science and to find the right marketing strategy for science...
I don't have many hero's.. but... he comes close...
I always admired and liked Carl Sagan but I have to say his statement about extraordinary claims requires extraordinary evidence has been used like a hammer to basically discount good evidence on many fronts. In truth, it really takes the same quality of evidence to validate anything and it is only our perceptions of what is extraordinary or ordinary that mess things up.
Now on the contrary if you adopt from the beginning a more positive approach to something which is weak, delicate, largely unknown (like a new born which is full of potential and on which you don't imagine to put hard pressure), the process to become convinced will be far easier, even a small additional evidence will be of great value in your own edification and you will quicker converge to the correct assessment of the situation. This is may be the situation experienced by Shawyer and Woodward from the beginning with respect to a strange measurement for the first and for an intriguing idea for the second.
The rationnal Bayesian thinking can be the worst path to follow in some situation. It is why the Nature has may be invented the emotions as a better way to establish relation between humans and their ideas. -
#768 by giulioprisco on 21 Sep, 2016 03:07
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Yes, skepticism is healthy and a vital part of the scientific method !
I would reword as: healthy skepticism is a vital part of the scientific method.
The difference is that skepticism is not always healthy, sometime it can be unhealthy.
For example, doing nothing the all day because you are skeptical of the possibility to do something good is very unhealthy. Refusing to try something new and not yet fully established is unhealthy. -
#769 by TheTraveller on 21 Sep, 2016 06:21
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Interesting statement from the BBC:
http://www.bbc.com/news/magazine-35861334QuoteMeanwhile, Boeing has apparently licensed its own version of the EmDrive and the Pentagon has shown a keen interest.
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#770 by Flyby on 21 Sep, 2016 09:07
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True, but skepticism only becomes "dangerous" (sliding away to a form of nihilism, where nothing matters anymore) when you're unable to formulate answers to the questions you pose, to the doubts you formulate. You need anchor points that root you down before questioning everything.Yes, skepticism is healthy and a vital part of the scientific method !
I would reword as: healthy skepticism is a vital part of the scientific method.
The difference is that skepticism is not always healthy, sometime it can be unhealthy.
For example, doing nothing the all day because you are skeptical of the possibility to do something good is very unhealthy. Refusing to try something new and not yet fully established is unhealthy.
Let me give an EMdrive related example:
You start with the acceptance that conservation of momentum is true. It has been proven countless times, so that is your anchor point.
At the same time , skepticism should give you the ability to challenge and question that "dogma".
Not allowing such questioning (because it has been proven to be true!) is nothing more then scientific fundamentalism.
The trick with being a skeptic, is that when you're unable to provide an answer to your questioning, you HAVE to fall back on the known anchor point. If you don't, you start loosing all direction and sense of what matters in life, or science in this case.
So contrary to what some people trying to push, my personal opinion is that it is fine to challenge the notion of CoM, but if you fail to prove/validate your idea, you should -for the time being- stick with what is generally known and accepted, CoM in this case.
I've seen it up close with my younger brother, many years ago, how skepticism can slide into a "nothing matters anymore, what's the point?" type of nihilism. So , yeah, there is a danger to it...
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#771 by giulioprisco on 21 Sep, 2016 09:36
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You start with the acceptance that conservation of momentum is true. It has been proven countless times, so that is your anchor point...
Well, in many cases conservation of momentum is _apparently_ violated in the lab. Apparently, because the violation can be explained by new physics (that's how they theorized the neutrino) or existing physics that hadn't been correctly taken into account.
Since this has happened a lot of times, it seems naive to automatically dismiss experimental results that seem to violate conservation laws. Often, better theoretical models and better mathematics can explain the anomalous experimental results without violating conservation laws, which is what EmDrive theory is about.
But dismissing laboratory results automatically, in unthinking mode, is what the "professional skeptics" do all the time in this and similar cases. This attitude is unscientific and often emotionally (or politically) biased. -
#772 by francesco nicoli on 21 Sep, 2016 11:12
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Interesting statement from the BBC:
http://www.bbc.com/news/magazine-35861334QuoteMeanwhile, Boeing has apparently licensed its own version of the EmDrive and the Pentagon has shown a keen interest.
article of 6 months ago.
as far as I know, the "apparent" effect as remained so: there is no confirmation of either Boeing nor the Pentagon that such a device exists.
For what we know, could be a nice invention of the Journalist himself to spice up readership.
Waiting for references in the dream of being disproved. -
#773 by Mezzenile on 21 Sep, 2016 11:46
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You start with the acceptance that conservation of momentum is true. It has been proven countless times, so that is your anchor point.
It is certainly not proven at the level of the whole Universe for which the overall conservation of energy and momentum is not imposed by the equations of the General Relativity. It is even not possible within GR to give a meaning to the notion of energy of the Universe.
There are theorems in GR which identify the very specific conditions for which it is possible to talk of energy conservation within a limited region of the universe, but these conditions are easily bypassed as soon as exists an interaction with the whole remaining universe and if the geometry around the considered region is not asymptically flat.
So if Woodward device and EMDrive work thanks to Mach or Unrhu global interactions with the Universe it is not justified by General Relativity to impose on them a law of conservation of energy/momentum. -
#774 by Gilbertdrive on 21 Sep, 2016 12:07
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The problem with Shawyer is that, rather than giving no explanation, he gives a mathematically false explanation. As he is not a theoretical scientist, but an Engineer, since he found a formula that provides him the amount of thrust that he had mesured, he seems happy. I think many skeptics would feel more confortable if Shawyer was giving his results as an experimental result, with no false solution.
If no one really knows how the EmDrive really works then how can it be asserted that any solution is 'false'?
If the math is incorrect.
Shawyer would have been better off just publishing the data.
That is exactly what I meant. The math is incorrect, as it was explained earlier. So Shawyer's solution is incorrect, even if the effect his real, even if his formula was giving the right result.
In the Newtonian sense the vacuum is an empty space. There is no quantum structure or element to it. As such there is no possible interaction between a moving object and the empty vacuum.
Within the context of GR things are not quite as clear cut. While we have no conclusive evidence that the spacetime of GR has any independent substance, that we could describe as a QV, experiments like the Gravity Probe B experiment and its confirmation of the frame dragging effect, tend to support.., or at least open the door to this kind of interpretation. If, in any model of the QV a physical object interacts with the QV to any degree, we are no longer dealing with a vacuum we can think of as Empty Space.., and we can no longer discount the possibility that that interaction has consequences, on either the QV or the physical object.
The 20-30% c limit I used, just comes from the fact that in accelerators and in nature, detectable atoms exceeding this range seem to be fully ionized bare nuclei. Mostly protons and alpha particles in nature and up to gold and lead nuclei in accelerators.
While as I mentioned aspects of and even perhaps the existence of a/the QV remains controversial, Unruh Radiation is generally accepted. While at classical velocities the impact of Unruh Radiation is generally insignificant to atomic stability, it is not unreasonable to expect that at relativistic velocities, the situation may be different.
Both the potential existence of Unruh Radiation and any interaction between a physical object and Spacetime, as suggested by the frame dragging effect, open the door to the potential that, relativistic velocities may result in the ionization of atomic structures.
All of this leads to, at least the potential that the idea that all things in motion tend to stay in motion may not be entirely accurate beyond the classical environments and conditions, that it has been proven.
We are moving to 90% of C from billion light years distant galaxies. So, a speed higher than 30% of C is not a problem if it is relatively to a distant body. If it is a problem, it is locally.
Particles in accelerators on earth are also submitted to an important proper acceleration, so it may the important proper acceleration that causes the ionization.
We can not assert that an interplanetary ship in our galaxy would be limited to 30% of C. We have no evidence for that in standard physics. -
#775 by Flyby on 21 Sep, 2016 13:13
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Any news/updates somewhere from the SSI conference(s) ?
I thought it started yesterday, no? -
#776 by Star One on 21 Sep, 2016 13:24
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Any news/updates somewhere from the SSI conference(s) ?
I thought it started yesterday, no?
I believe Dr Rodal said the videos would go up afterwards but didn't know when. -
#777 by Flyby on 21 Sep, 2016 13:27
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Bah... patience is such an overrated virtue...Any news/updates somewhere from the SSI conference(s) ?
I thought it started yesterday, no?
I believe Dr Rodal said the videos would go up afterwards but didn't know when.
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#778 by JohnFornaro on 21 Sep, 2016 13:51
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'the ignorosphere'
Which both political candidates are utilizing to great effect to uhhhh.... "propel" their campaigns.
Sorry. Couldn't resist. -
#779 by HMXHMX on 21 Sep, 2016 13:52
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Bah... patience is such an overrated virtue...Any news/updates somewhere from the SSI conference(s) ?
I thought it started yesterday, no?
I believe Dr Rodal said the videos would go up afterwards but didn't know when.
Understood, but out volunteer videographers are being worked to exhaustion, will have several weeks of editing I expect, and at least one video has to be embargoed until after a paper appears in December. Going to SSI.org and signing up to be a Senior Associate will motivate our team to work faster.
