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#200 by Star One on 23 Jan, 2020 16:08
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Tajmar's paper is from 2013. I suspect he has moved on since then.
Ahhhh. So my analysis is spot on? There is still no such drive.
Isn’t that rather an assumption to make when we haven’t seen anything related to the more recent info posted above.
Shells posted this paper by Tajmar. Not sure what "more recent info" you're talking about.
https://www.researchgate.net/publication/288442595_Propellantless_propulsion_with_negative_matter_generated_by_electric_charges
I was referring to post #193. -
#201 by jstrout on 24 Jan, 2020 23:21
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Forgive me if this is out of line, but I just jumped into one of the threads from 2015, and then attempted to fast-forward to the present by skimming the last couple of pages (out of literally hundreds) of each of the threads since then, and then finally this one. Unfortunately that doesn't result in a very clear picture. But there's one development in particular I would like to follow up on:
Back in 2015, TheTraveller was building a test device, and saying that there would be a live stream, in addition to independent witnesses, when he turned it on (and expected it to spin up to 120 rpm). It sounded like that live demonstration was immanent. But here we are, five years later, and if that made big news, I somehow missed it...
Did that demo ever happen? Is the video still available anywhere?
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#202 by meberbs on 24 Jan, 2020 23:34
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Forgive me if this is out of line, but I just jumped into one of the threads from 2015, and then attempted to fast-forward to the present by skimming the last couple of pages (out of literally hundreds) of each of the threads since then, and then finally this one. Unfortunately that doesn't result in a very clear picture. But there's one development in particular I would like to follow up on:
Nope, TT has been making and breaking promises like that for years. I had missed and/or forgotten that particular one myself.
Back in 2015, TheTraveller was building a test device, and saying that there would be a live stream, in addition to independent witnesses, when he turned it on (and expected it to spin up to 120 rpm). It sounded like that live demonstration was immanent. But here we are, five years later, and if that made big news, I somehow missed it...
Did that demo ever happen? Is the video still available anywhere?
I am not sure the last few pages of threads are the best ones to get a feel for things, new threads sometimes happen when mods decide the thread needs a reboot due to too many "report to mods." First few pages might be a bit better, though not always. -
#203 by RotoSequence on 24 Jan, 2020 23:35
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It's been about four years of successive hype and then quietly slipping into silence after everyone's consistent failure to deliver a device that provides indisputable propellant-less thrust.
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#204 by JohnFornaro on 25 Jan, 2020 13:44
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It's been about four years of successive hype and then quietly slipping into silence after everyone's consistent failure to deliver a device that provides indisputable propellant-less thrust.
As I put it: Float the device across the conference room table. Make sure to have plenty of deposit slips at hand. -
#205 by cvbn on 30 Jan, 2020 21:28
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PROPOSAL OF A HANDY SETUP FOR DISCRIMINATING PARASITIC EFFECTS FOR THE MEASUREMENT OF IMPULSIVE THRUST FROM A MICROWAVE CAVITY:
http://www.jpier.org/PIERC/pier.php?paper=19090507 -
#206 by Alex_O on 06 Feb, 2020 15:59
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An interesting setting, note the low quality factor (3500). It is interesting to think about whether the authors can improve.
For example, they can deposit a silver layer galvanically on an aluminum resonator (if this is possible from the point of view of chemistry) and increase the quality factor of the resonator (and this will be a resonator weighing only 1 kg), and then study the issue of optimizing the movement of electromagnetic waves in the resonator, taking into account the design antennas. You can also change the stand setting so that the two resonators work in the same line at the same time (down, against interference from the cable). Use a ball with helium to compensate for the weight of moving parts and in general - see what happens in this case if they increase the length of the stroke of the balance lever. Then you can abandon the balancer at all, if you measure not force - but acceleration. -
#207 by flux_capacitor on 11 Feb, 2020 16:44
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Thanks to Mike McCulloch who pointed out a recent paper published a few days ago investigating the possibility of pair production from the quantum vacuum that would not require the tremendous electric fields or gigantic gravitational field gradients usually mandatory to reach the Schwinger limit:
• Smolyaninov, Igor I. (30 January 2020). "Optical analog of particle production in gravitational fields". EPL. 128 (5): 54002. doi:10.1209/0295-5075/128/54002. arXiv:1903.12263
Instead, Smolyaninov proposes an "optical analog" of such fields that, according to him, could enable the production of electron-positron pairs out of the vacuum, using some metamaterial within a waveguide of appropriate asymmetric geometry, involving electric and gravitational field strengths much lower than those required for the classical Schwinger limit. In other words, the EmDrive would enable pair production despite producing relatively small electric fields and being in weak ambient gravity.
The waveguide can either be of constant cross-section but filled with a metamaterial whose refractive index n gradually changes along the axis (refractive index gradient); a tapered waveguide with constant n; or a combination of both: a tapered waveguide filled with a metamaterial having a refractive index gradient. It is worth noting that this is similar to the three possibilities investigated initially for the EmDrive by… Roger Shawyer.
Then, as noted by McCulloch, in the EmDrive, "virtual photons are released moving towards the wide end, so the cavity moves towards the other way." An effect that is similarly predicted by his theory of quantized inertia.
Incidentally, Igor Smolyaninov is the physicist who may have experimentally confirmed the Unruh radiation predicted by quantum field theory: paper available at arXiv:cond-mat/0510743 for reference.
As a side note, this also reminds me Harold White's hypothesis, i.e. that virtual charged particles could pop out of the vacuum in the EmDrive and briefly come into existence at some extent, being able to be pushed on with electromagnetic forces like a plasma thruster.
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#208 by meberbs on 11 Feb, 2020 19:26
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Thanks to Mike McCulloch who pointed out a recent paper published a few days ago investigating the possibility of pair production from the quantum vacuum that would not require the tremendous electric fields or gigantic gravitational field gradients usually mandatory to reach the Schwinger limit:
The article is talking about an analogue system, it is showing how one system has math that produces similar results to another system. It is not the same, which is why it doesn't actually produce electron positron pairs. As the paper states, due to the properties of metamaterials, it is not even a complete analogue unless you dump in external energy, which is also required for the energy balance of creation of any kind of particle. (Note: I skimmed some of the stuff in the paper about axions, since that is all based on the assumption axions exist, and is simply not actually relevant to this thread anyway.)
• Smolyaninov, Igor I. (30 January 2020). "Optical analog of particle production in gravitational fields". EPL. 128 (5): 54002. doi:10.1209/0295-5075/128/54002. arXiv:1903.12263
Instead, Smolyaninov proposes an "optical analog" of such fields that, according to him, could enable the production of electron-positron pairs out of the vacuum, using some metamaterial within a waveguide of appropriate asymmetric geometry, involving electric and gravitational field strengths much lower than those required for the classical Schwinger limit. In other words, the EmDrive would enable pair production despite producing relatively small electric fields and being in weak ambient gravity.
The waveguide can either be of constant cross-section but filled with a metamaterial whose refractive index n gradually changes along the axis (refractive index gradient); a tapered waveguide with constant n; or a combination of both: a tapered waveguide filled with a metamaterial having a refractive index gradient. It is worth noting that this is similar to the three possibilities investigated initially for the EmDrive by… Roger Shawyer.
[snipped images P.S. it is preferred practice on the forum to attach images rather than embed them]
Then, as noted by McCulloch, in the EmDrive, "virtual photons are released moving towards the wide end, so the cavity moves towards the other way." An effect that is similarly predicted by his theory of quantized inertia.
Incidentally, Igor Smolyaninov is the physicist who may have experimentally confirmed the Unruh radiation predicted by quantum field theory: paper available at arXiv:cond-mat/0510743 for reference.
As a side note, this also reminds me Harold White's hypothesis, i.e. that virtual charged particles could pop out of the vacuum in the EmDrive and briefly come into existence at some extent, being able to be pushed on with electromagnetic forces like a plasma thruster.
The paper does not support McCulloch's claim in the tweet, as it does not talk about magically breaking conservation laws by generating particles with anything less than the energy that should be required to make them. Any reaction force described in the paper would be from the emission of photons taking the same ammount of energy as normally expected, and no different than pointing a laser out the back. Generating an electron positron pair and then sending them out the back is actually even less energy efficient even if this device was capable of such generation. (It is not because it is only an analogue.)
Since McCulloch's theory is inconsistent, and also experimentally disproven (see separate thread for details) and Shawyer's claims have trivial and blatant problems, the comparisons to them should raise major red flags. In this case, it appears that the issue lies with major misrepresentations of the paper rather than issues with the paper itself. -
#209 by JohnFornaro on 13 Feb, 2020 13:16
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Of course, I object to McCulloch's cutesy twitter spelling. But you all knew that. More importantly:
Instead, Smolyaninov proposes an "optical analog" of such fields that, according to him, could enable the production of electron-positron pairs out of the vacuum, using some metamaterial within a waveguide of appropriate asymmetric geometry, involving electric and gravitational field strengths much lower than those required for the classical Schwinger limit. In other words, the EmDrive would enable pair production despite producing relatively small electric fields and being in weak ambient gravity.
No. The EM drive would not "enable" anything based on this "optical analogue" thingie, which depends on "some metamaterial", some gind of specific geometry that is not revealed, and gravitational field strengths below the "classical Schwinger limit", with no suggestion on how to make and shape those gravitational fields. Here's the oracle:
Whoops! Wrong reference:
https://en.wikipedia.org/wiki/Schwinger_limit
"This is an enormous field strength, capable of accelerating a proton from rest to the maximum energy attained by protons at the Large Hadron Collider in only approximately 5 micrometers."
If anything, this poster is trying to say that somehow the work being done at the LHC on the Schwinger limit would "enable" EM drive, not the other way around. There are no starship propulsion designs being made possible by that work at the LHC. -
#210 by dustinthewind on 13 Feb, 2020 16:13
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If you create an electron and positron and you push against them then you're pushing against an electron and positron. That isn't photon propulsion. What happens after they annihilate is another question. Looks to me that in the paper he talked about a virtual photons. Virtual photons are not the same thing as a photon. If for some reason the momentum of an electron and positron are converted into some type of vacuum energy that escape the cavity, caring away that momentum it would not be photon propulsion but rather electron positron propulsion. If they annihilate and are converted into another form that can escape the cavity it's still e-p propulsion. There also must be some intermediate stages between full ep pair creation. One may question if it's possible to push against non fully created e-p pairs having some intermediate stage of mass. If in the Intermediate stage, does it remain virtual.
Feynman diagrams have a lot to do with virtual particles but I think that also has a lot to do with vacuum physics. The Connection between the vacuum and space-time is something many are pursuing. Probably having a lot to do with the reverse time operators predicted by wheeler that exists in the vacuum in annihilated form responsible for quantum mechanics ,tunneling, ect. probably a key ingredient in exotic propulsion, wormholes, gravity ect. -
#211 by meberbs on 13 Feb, 2020 19:18
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If you create an electron and positron and you push against them then you're pushing against an electron and positron. That isn't photon propulsion.
True it is not photon propulsion. As I said in my previous post, it is something even less efficient due to all of the energy that goes into create the pair of particles.
The math behind this is quite simple, the equation for relativistic energy including kinetic energy and particle creation is:
E = sqrt( (p*c)^2 + (m*c^2)^2 )
p is momentum, so the energy/ momentum ratio (E/p) is:
E/p = sqrt( c^2 + (m*c^2)^2 / p^2 )
This is clearly always greater than c and therefore less efficient than a photon rocket. You would be better off having them annihilate, taking the energy, and converting it into photons directed backwards. (Having them annihilate after leaving the ship is different, because the resulting photons would be moving in different directions, keeping momentum balanced, whereas on the ship you can intentionally direct the photons backwards so that your ship gets the extra momentum.)Looks to me that in the paper he talked about a virtual photons. Virtual photons are not the same thing as a photon.
Most notably they are different because virtual photons don't leave the system carrying momentum away, the paper does address the creation of real photons that carry momentum away. This requires the input of energy.If for some reason the momentum of an electron and positron are converted into some type of vacuum energy that escape the cavity,
You are again making a statement of the form "if magic happens." If you ignore the laws of physics, you get results inconsistent with physics, but that is not useful. The rest of your post from this point consists of you throwing around terminology that you have demonstrated no understanding of. It is not worth explaining to you what those terms mean until you demonstrate an understanding of the basics such as the math above.
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#212 by dustinthewind on 13 Feb, 2020 20:26
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That virtual photons can't carry momentum we don't really know. If the vacuum is related to space time we know the space-time can carry away momentum.
Remember the importance of a cavity in recycling and converting energy between systems. In a cavity photons can be recycled N number of times before being exhausted as heat. That energy then would be recycled maybe N number of times. Supposing it takes less energy than to create an ep pair, something of reduced Mass might be created with enough time to push on it and recreated N number of times and pushed on N number of times. This done at the frequency billions of times per second.
The energy used to create the effect of mass would go through a change of frame inducing respective Doppler shift. This should induce some kind of frequency spread. -
#213 by meberbs on 13 Feb, 2020 20:42
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That virtual photons can't carry momentum we don't really know.
Yes we know, because it is right in the definition of a virtual particle. Virtual particles can only exist in a temporary sense, that is what makes them virtual. They therefore can't be carrying away momentum because they literally stop existing.Remember the importance of a cavity in recycling and converting energy between systems. In a cavity photons can be recycled N number of times before being exhausted as heat. That energy then would be recycled maybe N number of times.
False. Cavities do not generate magic energy from nowhere, and their is nothing generated by photons bouncing back and forth in a closed system. Half of the bounces push the cavity in one direction, and half in the other. The net result is 0. This is basic physics 101 "internal forces cancel."Supposing it takes less energy than to create an ep pair,
Again, you are assuming a free energy machine. The paper being discussed explicitly says that you can't do that.The energy used to create the effect of mass would go through a change of frame inducing respective Doppler shift. This should induce some kind of frequency spread.
No it wouldn't. I provided math, you have replied with gibberish. If you are not interested inlearning what the words you use mean, then please stop wasting everyone's time. -
#214 by Alex_O on 14 Feb, 2020 12:01
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Just a question, what will happen if:If you create an electron and positron and you push against them then you're pushing against an electron and positron. That isn't photon propulsion.
True it is not photon propulsion. As I said in my previous post, it is something even less efficient due to all of the energy that goes into create the pair of particles.
The math behind this is quite simple, the equation for relativistic energy including kinetic energy and particle creation is:
E = sqrt( (p*c)^2 + (m*c^2)^2 )
p is momentum, so the energy/ momentum ratio (E/p) is:
E/p = sqrt( c^2 + (m*c^2)^2 / p^2 )
This is clearly always greater than c and therefore less efficient than a photon rocket.
1) a photon with high energy created a pair of particles with mass
2) the engine pushes a pair of particle
3) a pair of particles annihilates
4) annihilation energy is utilized, used to create a new photon
5) is repeated in a cycle, minus the efficiency
Has this trivial cycle been already discussed? -
#215 by meberbs on 14 Feb, 2020 16:24
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Just a question, what will happen if:
This step is impossible, you would need 2 photons colliding from different directions to obey conservation of energy and momentum. (One way to see this is that with just 1 photon, you could look from a different reference frame where the photon would not have enough energy to create the particles.)
1) a photon with high energy created a pair of particles with mass3) a pair of particles annihilates
Again, this step is impossible, annihilation can't conserve energy and momentum with just 1 photon, there needs to be 2, and these would not move in the same direction, they would move away from each other, so there would be no "cycle"
4) annihilation energy is utilized, used to create a new photonHas this trivial cycle been already discussed?
It isn't a cycle, it involves multiple physically impossible steps. Imagining some other more complicated variation where you don't break physical laws, the intermediate steps are irrelevant. At the end if the final thing the spacecraft pushes against is a electron positron pair, it obeys the equation I stated above. Any intermediate steps are irrelevant, as only the net result, the final momentum of the expelled particles matters. And as stated above, this is less efficient than letting the particles annihilate onboard and then reflecting the gamma rays to make sure that they go in the desired direction. (Or as a practical matter, probably easier to absorb the energy of the gamma rays and use it to power a laser at a frequency that is easier to control.) -
#216 by The_Optimist on 15 Feb, 2020 13:28
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Since McCulloch's theory is inconsistent, and also experimentally disproven (see separate thread for details) and Shawyer's claims have trivial and blatant problems, the comparisons to them should raise major red flags. In this case, it appears that the issue lies with major misrepresentations of the paper rather than issues with the paper itself.
Would you be so kind as to post a link to the thread which details the experimental rebuttal?
Thanks,
Stu -
#217 by meberbs on 15 Feb, 2020 15:32
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Would you be so kind as to post a link to the thread which details the experimental rebuttal?
https://forum.nasaspaceflight.com/index.php?topic=48497.0
Thanks,
Stu -
#218 by Alex_O on 16 Feb, 2020 07:24
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Just a question, what will happen if:
This step is impossible, you would need 2 photons colliding from different directions to obey conservation of energy and momentum. (One way to see this is that with just 1 photon, you could look from a different reference frame where the photon would not have enough energy to create the particles.)
1) a photon with high energy created a pair of particles with mass
I omitted the details - of course a couple of photons or gamma rays are fed to the target in a strong magnetic field. Pair production often refers specifically to a photon creating an electron – positron pair near a nucleus.3) a pair of particles annihilates
Again, this step is impossible, annihilation can't conserve energy and momentum with just 1 photon, there needs to be 2, and these would not move in the same direction, they would move away from each other, so there would be no "cycle"
4) annihilation energy is utilized, used to create a new photonHas this trivial cycle been already discussed?
It isn't a cycle, it involves multiple physically impossible steps. Imagining some other more complicated variation where you don't break physical laws, the intermediate steps are irrelevant. At the end if the final thing the spacecraft pushes against is a electron positron pair, it obeys the equation I stated above. Any intermediate steps are irrelevant, as only the net result, the final momentum of the expelled particles matters. And as stated above, this is less efficient than letting the particles annihilate onboard and then reflecting the gamma rays to make sure that they go in the desired direction. (Or as a practical matter, probably easier to absorb the energy of the gamma rays and use it to power a laser at a frequency that is easier to control.)
When discussing the idea of stellar engines, people should not violate the laws of conservation of energy and momentum. But people can think about increasing the coefficient of useful quality, about the recovery of energy and the use of resources of the environment (the universe). A simple example is a heat pump, where the coefficient of performance (COP) is greater than 100%.
1. I thought about the engine, where there is a long pipe (nozzle), where the energy of the reactor creates photons, photons create pairs of particles, and the energy of the reactor is spent on pushing pairs of particles through a long pipe into the jet nozzle.
2. When a pair of particles flies in a pipe, it can annihilate.
3. If the annihilation of particles creates a photon flux perpendicular to the axis of the pipe and these photons are absorbed on the side wall of the pipe and create radiation pressure on only the side walls of the pipe.
4.The annihilation energy will return back to the rocket reactor, but the rocket will continue its flight. -
#219 by meberbs on 16 Feb, 2020 08:17
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This isn't omitted details, but you describing something entirely different, and it doesn't change the conclusion I stated.
I omitted the details - of course a couple of photons or gamma rays are fed to the target in a strong magnetic field. Pair production often refers specifically to a photon creating an electron – positron pair near a nucleus.When discussing the idea of stellar engines, people should not violate the laws of conservation of energy and momentum. But people can think about increasing the coefficient of useful quality, about the recovery of energy and the use of resources of the environment (the universe). A simple example is a heat pump, where the coefficient of performance (COP) is greater than 100%.
If you actually spent any time thinking about what you just wrote, you would have realized that my previous post preemptively addressed any such scenario. Also the statements you just made about obeying conservation laws kills it. It obviously breaks conservation of momentum when you assume that the momentum just disappears when the particles annihilate. In reality, the photons contain the same net momentum and transfer it to the walls if they are absorbed, preventing any net motion.
1. I thought about the engine