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#1620 by SteveD on 11 Jan, 2016 20:14
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Rumors are flying (again) that we finally found gravitational waves.
http://gizmodo.com/rumors-are-flying-that-we-may-have-finally-found-gravit-1752259868
A word of caution, LIGO allows supervisors to introduce false positive, drill, results. http://www.nature.com/news/has-giant-ligo-experiment-seen-gravitational-waves-1.18449 I would take any leak out of that project with a grain of salt. -
#1621 by Rodal on 11 Jan, 2016 20:15
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..
The case is also interesting because we have the US Patent Office still awarding (just last week) a US patent for an invention claiming "zero power factor for purely resistive load" (and separately to the press claiming 7000% efficiency).
I did have one observation on the magnetron modification experiments with a few small neodymium magnets placed against the ring magnets...once heated over 100 degrees C, the small magnets lost much of their strength.
It returned once they cooled to room temp. How did I notice this? When I moved the magnets around the ring magnet, it was FAR easier to do when they were hot.
Back EMF is probably highly dependent on temperature. I did not see any thermal testing of this guys assembly.
Showing that getting a US patent awarded does not mean that the invention has to be consistent with the laws of Physics (nothing new to those familiar with US patent law, but whether US patents had to be consistent with laws of physics was a subject of discussion in previous EM Drive threads).
I also very much doubt that the US Patent Office has a working model of this device (I was told by US Patent Lawyers that the US Patent office run out of room a long time ago to store such models, even for devices claiming to go overunity).
Of course, the US Patent Office is free to later withdraw from issue patents granted, "due to contradictions with known physics laws." For example, a famous case is the one of BlackLight Power, a company founded by Randell L. Mills, who claims to have discovered a new energy source
https://en.wikipedia.org/wiki/BlackLight_Power
where the US Patent Office withdrew the patent on the basis that "the patent appeared to involve cold fusion and perpetual motion"
Google patents still shows it:
http://www.google.com/patents/US6024935
http://jiplp.oxfordjournals.org/content/early/2011/03/04/jiplp.jpr010.abstractQuoteA 2000 patent based on its hydrino-related technology[39][40] was later withdrawn by the United States Patent and Trademark Office (USPTO) due to contradictions with known physics laws and other concerns about the viability of the described processes, citing Park and others.[37]
A column by Robert L. Park[37][41] and an outside query by an unknown person[42] prompted Group Director Esther Kepplinger of the USPTO to review this new patent herself. Kepplinger said that her "main concern was the proposition that the applicant was claiming the electron going to a lower orbital in a fashion that I knew was contrary to the known laws of physics and chemistry", and that the patent appeared to involve cold fusion and perpetual motion.[41] Kepplinger contacted another Director, Robert Spar, who also expressed doubts on the patentability of the patent application. This caused the USPTO to withdraw from issue the patent application before it was granted and re-open it for review, and to withdraw four related applications, including one for a hydrino power plant.
BlackLight filed suit in the US District Court of Columbia, saying that withdrawal of the application after the company had paid the fee was contrary to law. In 2002, the District Court concluded that the USPTO was acting inside the limits of its authority in withdrawing a patent over whose validity it had doubts, and later that year, the United States Court of Appeals for the Federal Circuit ratified this decision.[41][42][43][44] Applications were rejected by the UK patent office for similar reasons.[41][45][46][47][48] The European Patent Office (EPO) rejected a similar BLP patent application due to lack of clarity on how the process worked. Reexamination of this European patent is pending -
#1622 by SteveD on 11 Jan, 2016 21:03
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Of course, the US Patent Office is free to later withdraw from issue patents granted, "due to contradictions with known physics laws." For example, a famous case is the one of BlackLight Power, a company founded by Randell L. Mills, who claims to have discovered a new energy source
https://en.wikipedia.org/wiki/BlackLight_Power
where the US Patent Office withdrew the patent on the basis that "the patent appeared to involve cold fusion and perpetual motion"
Google patents still shows it:
http://www.google.com/patents/US6024935
http://jiplp.oxfordjournals.org/content/early/2011/03/04/jiplp.jpr010.abstract
This is the same company that just announced some form of public demonstration on January 28th after showing off prototypes to members of Congress a couple of months ago? I can see why USPTO might have decided to start walking softly around energy patents. -
#1623 by zen-in on 11 Jan, 2016 21:06
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Thanks Zen...do you have a gut feel as to what the mil thickness should be?
A friend with a lathe spun some 10 GHz and 24 GHz feedhorns designed by Paul Wade, W1GHZ. He had no problem with the .020" Copper disks I gave him for the 10 GHz feedhorns but the .010" material just crumpled. For something as large as a fustrum my guess would be .030" - .040". I have raised metal with hammers (smithing) but have not done any metal spinning. I have heard from a good source it can be dangerous. The only downside of moving metal with hammers is your neighbors get very annoyed.
http://www.onlinemetals.com/merchant.cfm?id=966&step=2&top_cat=87&showunits=mm
Thanks - Dave -
#1624 by rfmwguy on 11 Jan, 2016 21:19
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History Alert - Much of what has been discussed in T1-T6 threads has also appeared in decade old papers, seeming focused around NASA Glenn. Marc Millis wrote several. I am not aware why Glenn stopped pursuing the work and can find no evidence of actual experiments beyond the paperwork. Regardless, for a history lesson in all things emdrive, here is a link to some of the 1990s work:
http://www.fcoiaa.it/tag/breakthrough-propulsion-physics-program/
This pre-dates Roger Shawyer's work by a few years, best I can tell.
Edit - Marc Millis has since left NASA and is the founder of: https://tauzero.aero/about/
More about this...doesn't appear emdrive is taken seriously by this group FWIW:
http://news.discovery.com/space/private-spaceflight/tau-zero-project-icarus.htm
Edit - according to the wiki page, the glenn research center was funded for bppp for about 6 years at about $200K a year...no hardware was produced best I can determine. Lots of papers...no hardware. Corrections welcomed. -
#1625 by rq3 on 11 Jan, 2016 21:21
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After much research, I've determined that this is the best way to construct a frustum...seamless at the small diameter:
...
This horizontal lathe was modified to include a spinning "form", or shape, that the copper sheet "folds" over. The left side of the lathe uses a compression disc that snugs the copper sheet onto the top of the form, which could be any shape. A frustum would be one of the more simpler forms to have constructed.
The brass-smith said he could make a bell/frustum but it would have a brazed seam that would have to be ground/polished away. More labor costs.
The cost is similar for both ways to do it. Looks like the spinning copper method is superior. Interior polishing would be needed.
I agree, metal-spinning would be best method as long 101 alloy (99.9% pure Cu) is used. A machinest may prefer using another alloy for safety or other reasons. Metal spinning is another way of moving metal. Part of the process involves keeping the periphery of the disk from getting too thick and cracking. The inside surface would be reasonably smooth and so would have very good surface conductivity. The outside would show the characteristic rings the turning tool leaves. Polishing the inside wouldn't be too difficult. Just clamp the fustrum to a workbench and have at it with a 6" Dia buffer wheel and some pumice compound for starters. The form is turned from laminated hardwood.
The problem with spinning copper and its alloys is that they work harden quite rapidly. You may have to anneal the copper several times during the process. I know. I've done it. Anyone with a decent wood lathe can spin sheet metal at home fairly easily (just watch your fingers and wrists!!!).
Many threads ago I suggested a machined wax substrate, electroformed with copper to whatever desired thickness. The wax provides the final surface finish, and can be microns RMS. Many, if not most, custom wavequides are made this way. Often the interior surface is silver plated for conductivity reasons after fabrication. Back when cameras actually used film that required developing, the spent developer made an excellent electroless immersion silver plating solution.
The beauty of the machinable wax is that you can "weld" strange wax structures like ports, studs, and rectangular wavequides onto the frustum substrate before electroforming, and end up with one contiguous structure. No joints, seams, soldering. Done that too, although something the size of the frustum at 2.4 GHz would be problematic in a home shop environment. -
#1626 by rfmwguy on 11 Jan, 2016 21:36
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This is very interesting, so the mold is wax (the interior of the frustum) and the external surface is electroplated to 20-30 mils copper? Am I getting the visual right?After much research, I've determined that this is the best way to construct a frustum...seamless at the small diameter:
...
This horizontal lathe was modified to include a spinning "form", or shape, that the copper sheet "folds" over. The left side of the lathe uses a compression disc that snugs the copper sheet onto the top of the form, which could be any shape. A frustum would be one of the more simpler forms to have constructed.
The brass-smith said he could make a bell/frustum but it would have a brazed seam that would have to be ground/polished away. More labor costs.
The cost is similar for both ways to do it. Looks like the spinning copper method is superior. Interior polishing would be needed.
I agree, metal-spinning would be best method as long 101 alloy (99.9% pure Cu) is used. A machinest may prefer using another alloy for safety or other reasons. Metal spinning is another way of moving metal. Part of the process involves keeping the periphery of the disk from getting too thick and cracking. The inside surface would be reasonably smooth and so would have very good surface conductivity. The outside would show the characteristic rings the turning tool leaves. Polishing the inside wouldn't be too difficult. Just clamp the fustrum to a workbench and have at it with a 6" Dia buffer wheel and some pumice compound for starters. The form is turned from laminated hardwood.
The problem with spinning copper and its alloys is that they work harden quite rapidly. You may have to anneal the copper several times during the process. I know. I've done it. Anyone with a decent wood lathe can spin sheet metal at home fairly easily (just watch your fingers and wrists!!!).
Many threads ago I suggested a machined wax substrate, electroformed with copper to whatever desired thickness. The wax provides the final surface finish, and can be microns RMS. Many, if not most, custom wavequides are made this way. Often the interior surface is silver plated for conductivity reasons after fabrication. Back when cameras actually used film that required developing, the spent developer made an excellent electroless immersion silver plating solution.
The beauty of the machinable wax is that you can "weld" strange wax structures like ports, studs, and rectangular wavequides onto the frustum substrate before electroforming, and end up with one contiguous structure. No joints, seams, soldering. Done that too, although something the size of the frustum at 2.4 GHz would be problematic in a home shop environment. -
#1627 by rq3 on 11 Jan, 2016 21:44
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History Alert - Much of what has been discussed in T1-T6 threads has also appeared in decade old papers, seeming focused around NASA Glenn. Marc Millis wrote several. I am not aware why Glenn stopped pursuing the work and can find no evidence of actual experiments beyond the paperwork. Regardless, for a history lesson in all things emdrive, here is a link to some of the 1990s work:
http://www.fcoiaa.it/tag/breakthrough-propulsion-physics-program/
This pre-dates Roger Shawyer's work by a few years, best I can tell.
Edit - Marc Millis has since left NASA and is the founder of: https://tauzero.aero/about/
More about this...doesn't appear emdrive is taken seriously by this group FWIW:
http://news.discovery.com/space/private-spaceflight/tau-zero-project-icarus.htm
To the best of my admittedly aging recollection, Shawyer's earliest work dates to 1988 or there-abouts? Which isn't a good thing, when you think about it. I mean, it's basically a copper can and a microwave oven component, right?
I'd think the folks working with free electron lasers could have helped out with a niobium frustum by now. They do that stuff all the time. And my local welding supply says they can get liquid helium on special order, next day delivery, 200 liter minimum (ouch, no I didn't even ask the price).
Which reminds me. Somewhere I still have a 3 liter tank of single isotope Xenon (or was it Krypton, I forget, I'll have to find it) gas that cost about $36000 back in 1984 if anyone needs such a thing. -
#1628 by rq3 on 11 Jan, 2016 21:50
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Thanks Zen...do you have a gut feel as to what the mil thickness should be?
A friend with a lathe spun some 10 GHz and 24 GHz feedhorns designed by Paul Wade, W1GHZ. He had no problem with the .020" Copper disks I gave him for the 10 GHz feedhorns but the .010" material just crumpled. For something as large as a fustrum my guess would be .030" - .040". I have raised metal with hammers (smithing) but have not done any metal spinning. I have heard from a good source it can be dangerous. The only downside of moving metal with hammers is your neighbors get very annoyed.
http://www.onlinemetals.com/merchant.cfm?id=966&step=2&top_cat=87&showunits=mm
Thanks - Dave
That's a reasonable range of thickness. Aircraft propeller spinners are generally about 0.050 inch thick aluminum alloy. Until recently they were fabricated by skilled people manually forming the aluminum disc over a wooden form on a large lathe. If the disc is sized properly, there is little if any loss of thickness during the process.
These days it is generally done by robots. Probably hardwired to the brains of skilled people
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#1629 by rq3 on 11 Jan, 2016 21:56
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This is very interesting, so the mold is wax (the interior of the frustum) and the external surface is electroplated to 20-30 mils copper? Am I getting the visual right?After much research, I've determined that this is the best way to construct a frustum...seamless at the small diameter:
...
This horizontal lathe was modified to include a spinning "form", or shape, that the copper sheet "folds" over. The left side of the lathe uses a compression disc that snugs the copper sheet onto the top of the form, which could be any shape. A frustum would be one of the more simpler forms to have constructed.
The brass-smith said he could make a bell/frustum but it would have a brazed seam that would have to be ground/polished away. More labor costs.
The cost is similar for both ways to do it. Looks like the spinning copper method is superior. Interior polishing would be needed.
I agree, metal-spinning would be best method as long 101 alloy (99.9% pure Cu) is used. A machinest may prefer using another alloy for safety or other reasons. Metal spinning is another way of moving metal. Part of the process involves keeping the periphery of the disk from getting too thick and cracking. The inside surface would be reasonably smooth and so would have very good surface conductivity. The outside would show the characteristic rings the turning tool leaves. Polishing the inside wouldn't be too difficult. Just clamp the fustrum to a workbench and have at it with a 6" Dia buffer wheel and some pumice compound for starters. The form is turned from laminated hardwood.
The problem with spinning copper and its alloys is that they work harden quite rapidly. You may have to anneal the copper several times during the process. I know. I've done it. Anyone with a decent wood lathe can spin sheet metal at home fairly easily (just watch your fingers and wrists!!!).
Many threads ago I suggested a machined wax substrate, electroformed with copper to whatever desired thickness. The wax provides the final surface finish, and can be microns RMS. Many, if not most, custom wavequides are made this way. Often the interior surface is silver plated for conductivity reasons after fabrication. Back when cameras actually used film that required developing, the spent developer made an excellent electroless immersion silver plating solution.
The beauty of the machinable wax is that you can "weld" strange wax structures like ports, studs, and rectangular wavequides onto the frustum substrate before electroforming, and end up with one contiguous structure. No joints, seams, soldering. Done that too, although something the size of the frustum at 2.4 GHz would be problematic in a home shop environment.
Exactly. And there is no practical limit as to the thickness of the plating. I have seen as much as an inch. The thickness can also be selectively varied during the plating process by masking different areas at different times during the plating process.
Vacuum or pressure tolerant frustum, anyone? This stuff is a pretty common industrial process. In fact, the master "press" discs for old LP vinyl records were made this way, so you can imagine the fidelity of the plating that followed the acoustic grooves cut into the wax master at the recording studio.
EDIT: spelling and additional technical bloviating (I don't trust spear chuckers, um, spiel chesters, um...SPELL CHECKERS). -
#1630 by frobnicat on 11 Jan, 2016 22:16
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...The exponential fitted by Rodal (net Poynting vector, not integrating the side walls) and that I somehow saw also on a longer run (by Aero) concerns a very short transient at initial power-on (that is not even realistic as no microwave source will switch on full power on a nanosec.). Edit : my plots were about energy content, not Poynting vector. ...
Correction: I think that you are referring to a nonlinear fit (with an R^2 exceeding 0.99) (with exponential,linear, and harmonic components) of the net force vs. time on both flat ends, based on the stress tensor components normal to the flat ends, instead of an exponential fit to a Poynting vector.
(Going from memory here)
The net force on the flat ends was variable with time, over the last two cycles of the Meep run (or a little longer), such that its time variation could be fit to that expression. This behavior was found, to a high degree of fit (R^2>0.99) over several runs. As I recall all those runs were at a very early transient stage (0.01 microseconds or so), nowhere near the point where one would expect steady state conditions (requiring tens of microseconds).
.../...
Ah yes, I mixed up again Poynting and stress. Thanks for the clarifications.
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#1631 by rfmwguy on 11 Jan, 2016 22:19
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rq3 - nice summary. So my visual brain sees a "frustum on a steek" er stick, on a wax mold. The stick would be round and centered on the large diameter (for my testing anyway). This wax would then be milled to frustum dimensions then plated externally....maybe 20-30 mils.
Once the wax was heated and removed through the base hole, the magnetron would be mounted there. Assembly complete! This gives a true seamless frustum, where a small radius bend could be made in the endplate seams rather than a sharp corner...but basically a seamless frustum.
Now...if only I knew the EXACT dimensions I wanted for 2.45 GHz resonance. Best to get that sorted out before this endeavor is undertaken...thanks! -
#1632 by rq3 on 11 Jan, 2016 22:49
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rq3 - nice summary. So my visual brain sees a "frustum on a steek" er stick, on a wax mold. The stick would be round and centered on the large diameter (for my testing anyway). This wax would then be milled to frustum dimensions then plated externally....maybe 20-30 mils.
Once the wax was heated and removed through the base hole, the magnetron would be mounted there. Assembly complete! This gives a true seamless frustum, where a small radius bend could be made in the endplate seams rather than a sharp corner...but basically a seamless frustum.
Now...if only I knew the EXACT dimensions I wanted for 2.45 GHz resonance. Best to get that sorted out before this endeavor is undertaken...thanks!
Well, that gets us into the realm of my other previous bloviations. I'm not sure how many times I've said this, but it's not generally, reasonably, possible to design a resonant cavity to a moving (magnetron) source. You need to design a resonant cavity to a TUNEABLE source.
As an example, when designing a Dielectric Resonant Oscillator (DRO), I would select the "puck" (the dielectric disc) for a particular resonant frequency. That selection would be quite broad-band. The cylindrical cavity into which it was placed was then designed to select a particular frequency and mode, out of the infinite number potentially available from the disc.
The cavity itself is the bandpass filter (like the quartz crystal in a quartz oscillator). The Q of the cavity in a DRO (like the Q of the crystal in a quartz oscillator), is what determines the spectral purity (phase noise) of the entire device.
And that, simply put, is why a conical cavity cannot be tuned to a frequency. It has no particular resonance point. What it CAN do is become a very high Q resonator for a SELECTED frequency and mode. But. To do that, you need to be able to select the frequency AT THE SOURCE. NOT the cavity.
None of this is "black magic", but experienced RF engineers soon learn tricks that appear to be so. I remember a colleague struggling for days with a high speed video modulator. It had all kinds of digital/analog crosstalk, and just plain wouldn't work. I casually licked a finger and placed it across the inputs to the Gilbert multiplier, and the cross talk disappeared.
"Solder a 10 pF cap here, with the shortest leads you can deal with". Problem solved. A wet finger (on a low voltage, low UHF circuit), is roughly 10 pF. A dry finger is roughly 2 pF. These are true "rules of thumb", but they can be valuable starting points in troubleshooting RF issues, and can be verified with experience and a network analyzer.
PLEASE don't try these tricks with a magnetron. In fact, DON'T EVEN THINK ABOUT IT!!! Or with any RF circuit running with more than 12 VDC. Even a 28 volt VHF RF amplifier can give you a nasty spot RF burn that can takes months to heal (remember, an oscillating circuit can reach roughly 4 times its supply voltage under matched load, and RF can burrow into flesh in very strange ways). Like the guy at Brookhaven that shorted himself across a 13.56 MHz RF sputtering supply. When he screamed, his partner tried to pull him off the vacuum chamber feed-through, and his arm came off the bone like a glove. No, I didn't see this, but I believe it from experience, and I believe the guy who claims he was there.
IF Mr. Shawyer got thrust from his initial rig, I would suspect that he was either delusional, or incredibly lucky. I'll assume the latter. Attempting to replicate luck is a chancy business at best.
EDITS: to include spelling corrections, ancient memories, and further tech bloviating. -
#1633 by rfmwguy on 11 Jan, 2016 23:56
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Tangential - emdrive does not fit a current interstellar template for propulsion
The following paper describes a decades-old collaboration between scientists exploring interstellar missions (including propulsion methodologies). It began as Project Daedalus in the 70's and morphed into Project Icarus after 2000. Emdrive experimentation is not on their radar, but knowing there is a confederation of scientists aligned with a project like this is interesting IMO. Note some of the names...they have appeared in print somewhat recently.
The paper is here: http://arxiv.org/abs/1005.3833 -
#1634 by Rodal on 12 Jan, 2016 00:22
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History Alert - Much of what has been discussed in T1-T6 threads has also appeared in decade old papers, seeming focused around NASA Glenn. Marc Millis wrote several. I am not aware why Glenn stopped pursuing the work and can find no evidence of actual experiments beyond the paperwork. Regardless, for a history lesson in all things emdrive, here is a link to some of the 1990s work:
http://www.fcoiaa.it/tag/breakthrough-propulsion-physics-program/
This pre-dates Roger Shawyer's work by a few years, best I can tell.
Edit - Marc Millis has since left NASA and is the founder of: https://tauzero.aero/about/
...
This is the same Marc Mills that is recently quoted as follows in Wired Magazine, referring to the EM Drive research:
http://www.wired.com/2015/05/nasa-warp-drive-yeah-still-poppycock/Quote“Even if it was done in a hard vacuum,” Millis says, “you have to take into account the distance between the drive and the chamber wall, whether those walls were conductive, and the geometry of the system.”
QuoteMillis, for his part, doesn’t even pay attention to White’s work out of Eagleworks: “If it’s not impartial, I don’t read it.”
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#1635 by birchoff on 12 Jan, 2016 00:25
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Of course, the US Patent Office is free to later withdraw from issue patents granted, "due to contradictions with known physics laws." For example, a famous case is the one of BlackLight Power, a company founded by Randell L. Mills, who claims to have discovered a new energy source
https://en.wikipedia.org/wiki/BlackLight_Power
where the US Patent Office withdrew the patent on the basis that "the patent appeared to involve cold fusion and perpetual motion"
Google patents still shows it:
http://www.google.com/patents/US6024935
http://jiplp.oxfordjournals.org/content/early/2011/03/04/jiplp.jpr010.abstract
This is the same company that just announced some form of public demonstration on January 28th after showing off prototypes to members of Congress a couple of months ago? I can see why USPTO might have decided to start walking softly around energy patents.
Sorry don't want to side track the conversation. but Please do not confuse Black light power, now Brilliant Light Power, with Brillouin Energy Corporation. While I would love nothing more than BLP to be more than snake oil it would take them actually delivering on their promise for me to change my mind. Brillouin Energy on the other hand has been completely above board so far. Not saying that either have the goods but neither should be painted with the same brush. -
#1636 by rfmwguy on 12 Jan, 2016 00:47
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Good catch, Doc. Millis cofounded icarus. In the negative wired article, eric davis was mentioned as well. Seems they've been collaborating in writing a few things.History Alert - Much of what has been discussed in T1-T6 threads has also appeared in decade old papers, seeming focused around NASA Glenn. Marc Millis wrote several. I am not aware why Glenn stopped pursuing the work and can find no evidence of actual experiments beyond the paperwork. Regardless, for a history lesson in all things emdrive, here is a link to some of the 1990s work:
http://www.fcoiaa.it/tag/breakthrough-propulsion-physics-program/
This pre-dates Roger Shawyer's work by a few years, best I can tell.
Edit - Marc Millis has since left NASA and is the founder of: https://tauzero.aero/about/
...
This is the same Marc Mills that is recently quoted as follows in Wired Magazine, referring to the EM Drive research:
http://www.wired.com/2015/05/nasa-warp-drive-yeah-still-poppycock/Quote“Even if it was done in a hard vacuum,” Millis says, “you have to take into account the distance between the drive and the chamber wall, whether those walls were conductive, and the geometry of the system.”
QuoteMillis, for his part, doesn’t even pay attention to White’s work out of Eagleworks: “If it’s not impartial, I don’t read it.”
https://en.m.wikipedia.org/wiki/Breakthrough_Propulsion_Physics_Program
This eric davis:
http://www.huffingtonpost.com/2013/07/20/physicist-eric-davis-mufon-symposium_n_3620126.html
Interstellar politics...gotta luv it
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#1637 by zen-in on 12 Jan, 2016 00:55
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...
Of course, the US Patent Office is free to later withdraw from issue patents granted, "due to contradictions with known physics laws." For example, a famous case is the one of BlackLight Power, a company founded by Randell L. Mills, who claims to have discovered a new energy source
https://en.wikipedia.org/wiki/BlackLight_Power
where the US Patent Office withdrew the patent on the basis that "the patent appeared to involve cold fusion and perpetual motion"
Google patents still shows it:
http://www.google.com/patents/US6024935
http://jiplp.oxfordjournals.org/content/early/2011/03/04/jiplp.jpr010.abstractQuoteA 2000 patent based on its hydrino-related technology[39][40] was later withdrawn by the United States Patent and Trademark Office (USPTO) due to contradictions with known physics laws and other concerns about the viability of the described processes, citing Park and others.[37]
A column by Robert L. Park[37][41] and an outside query by an unknown person[42] prompted Group Director Esther Kepplinger of the USPTO to review this new patent herself. Kepplinger said that her "main concern was the proposition that the applicant was claiming the electron going to a lower orbital in a fashion that I knew was contrary to the known laws of physics and chemistry", and that the patent appeared to involve cold fusion and perpetual motion.[41] Kepplinger contacted another Director, Robert Spar, who also expressed doubts on the patentability of the patent application. This caused the USPTO to withdraw from issue the patent application before it was granted and re-open it for review, and to withdraw four related applications, including one for a hydrino power plant.
BlackLight filed suit in the US District Court of Columbia, saying that withdrawal of the application after the company had paid the fee was contrary to law. In 2002, the District Court concluded that the USPTO was acting inside the limits of its authority in withdrawing a patent over whose validity it had doubts, and later that year, the United States Court of Appeals for the Federal Circuit ratified this decision.[41][42][43][44] Applications were rejected by the UK patent office for similar reasons.[41][45][46][47][48] The European Patent Office (EPO) rejected a similar BLP patent application due to lack of clarity on how the process worked. Reexamination of this European patent is pending
It looks like Mills eventually won his case. He has been paying his maintenance fees and changed the status of the invention to non-discounted. Below is a snapshot of the patent's transaction history from public pair.
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#1638 by frobnicat on 12 Jan, 2016 01:14
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@frobnicat:
Two questions, forgive me if I am reiterating previous content..
In your analysis of the "over unity" conditions of the theoretically operant emdrive, do you consider the power of the device as its loaded energy content or the input power?
Not clear what you mean by "loaded energy content". The argument goes with the effective power (Watts) that feeds the device as the electrical input. This is what the effect (thrust) is supposed to cost in terms of power consumption, as seen "from the outside", the device being a black box (could be a working EMdrive, could be a working Mach effect thruster, could be a working Dean drive, same argument goes). For this analysis, I'm not interested to know the details of what is going on inside the black box, only what apparently goes in (electric power) and what apparently goes out (force + radiated waste heat) + position of center of mass and mass of the box (if required), all that can be determined from the outside.QuoteI ask this because for any given optical cavity, if there were a constant em-kinetic conversion taking place, there is not a linearly varying power requirement. I touched on this in a post about the notion of elasticity, and how the power input will always inelastically (at an increasing rate of inelasticity) vary for any rising photon-in-resonance schema.
More simply, if the amount of energy to double photons in resonance is "A", to double the amount of photons again is not "2A". So my question is whether you have been interpreting the analysis in this way also, and if not, how does that change the over-unity power requirement (if thrust is considered variant to cavity resonating power rather than power input to cavity, with the given that one photon must be absorbed by the cavity [or quantum plasma, etc] in order to generate 1 unit of thrust)?
Again, not sure I get what you say. You mean a kind of saturation ? I don't think non linearities, whatever they are, change the analysis I did which is purely phenomenological (again : black box, input, output).
An experimenter gives me a box that thrusts at 300µN while consuming 1000W electric, φ=300µN/kW
An other experimenter gives me a box that thrusts at 30µN while consuming 100W electric, φ=300µN/kW
Same "figure of merit" φ, φ>3.33µN/kW (photon rocket) => possibility of apparent excess of power output when compared to electrical power input (if effect holds at any constant velocity).
Obviously the box shouldn't change mass (propellantless device) nor center of mass (no hidden translating actuated flyweight "one shot" trick).
So, even if for a given box 100W electric did thrust 30µN, 1000W electric did thrust only 40µN, 10000W electric did thrust only 50µN etc... that would be a very bad scaling for a single device, but the over-unity argument would still hold at any operating point for which φ>3.33µN/kW.
We tell you, this thing needs either an "aethereal" auxiliary source of power, or to not operate beyond a range of velocity spanning less than 1/φ (and the question of "relative to what ?" remains)
Side note :
I'm not saying any of the experiments so far have ever approached the conditions that the thrust would actually generate such amount of output power in a measurable manner. But an actually working EMdrive with φ>5000µN/kW (0.005N/kW) operated such as thrusting always (or only when) roughly in the forward orbit direction of the solar system around the Galaxy is already in a situation that increases the rotational energy content of the Galaxy more than its cost in fed electric energy... (contrary to relative translational kinetic energy, rotational energy does have a natural intrinsic absolute value). Even while sitting on the bench and pushing a little spring by a few µm, which indeed shows locally in the lab as a minuscule return power under 1µW (or 0 when static equilibrium reached) relative to a few 10W of fed electric power.QuoteQuestion two: if spacetime itself in the form of some Dirac sea formulation is given momentum by the drive, we cannot consider the drive to be frame-invariant any longer because the existence of a mutable quantum vacuum would essentially require a reformulation of special relativity as the Dirac sea, given that momentum can be imparted as per the theory of dr. White et. al is essentially proposing a shared privileged reference frame. Do you agree?
Not in my domain of serious knowledge anymore, any agreement or disagreement here would bear little weight :
I don't think that a mutable QV necessarily implies a privileged reference frame, depending on the model. Maybe it's possible to retain the essentially frame invariant characteristic (whatever the Lorentz boost) although not surprisingly that would pose problem with integrating total energy content (a problem that quantum field theory seems to have anyway : vacuum catastrophe).
Also, any mutable QV would have to appear frame invariant for a rather large range of relative velocities and conditions, to be consistent with observations. I don't think propellantless propulsion schemes proponents (Shawyer, White, Woodward... not talking of solar sailing) ever mentioned experimental consideration for orientation relative to the stars, hence from that my impression is that they are not (or not seriously) theorizing about a privileged reference frame. White theory seems to imply that the QV momentum is always "harvested" at rest relative to the device, that is by definition frame invariant. That would have the merit of explaining where the apparent excess energy (discussed above) comes from, making the device characteristics consistent with 1st principle of thermodynamics, but I have the feeling that would then become problematic with the 2nd principle.
Let's say by analogy we are navigating in a hot gas, molecules with all kind of velocities up to almost c on all directions, and we want to "harvest" only those that happen to have a velocity close to that of our gascraft while being ignorant of all the others. Those cheap harvested molecules are now ejected to get thrust with a good efficiency (in N/W). Depending on the conditions, this would allow extraction from the hot gas (at equilibrium initially) of more positive mechanical_power than spent electric_power. Basically it presupposes a cheap Maxwell's demon. That is, it now breaks second principle by extracting net mechanical energy from a single heat reservoir at single temperature.
Short of that, we can just take whatever incoming flow (like a propeller) but then the speed v(m/s) of the craft relative to the medium (now that we can't interact only with molecules of close velocity, the hot gas works as a privileged reference frame) will be limited, or the efficiency φ(N/W) limited, such that φ×v<1. For φ>0.1N/kW then v<10km/s. Depending of the privileged reference frame, unless it is solar bound and rotates with the planetary orbits, this is already quite a restrictive range of velocities to thrust for deep space missions. Still, aether sailing (aetherobraking ?) could enable interesting trajectories (depending on the privileged reference frame), and this would be ok with CoE and entropy.
Back to your question, the idea of "sharing the background" seems relevant : if the background is mutable then what do the "mutations" imply for 2 neighboring devices both coupling to this "medium" ? That's the only way that limits on scaling would make sense. If a single device does show non linear decrease in efficiency with increasing power, why not use N devices in parallel, each at its most efficient operational point : that would circumvent any scaling limitation. Unless there are background mediated interferences, in which case how far apart EMdrives should be operated ? 1m ? 1km ? 12742km ? 1AU ? 1LY ? How many optical nanocavities can thrust on the head of a pin ?
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#1639 by Prunesquallor on 12 Jan, 2016 01:19
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Tangential - emdrive does not fit a current interstellar template for propulsion
The following paper describes a decades-old collaboration between scientists exploring interstellar missions (including propulsion methodologies). It began as Project Daedalus in the 70's and morphed into Project Icarus after 2000. Emdrive experimentation is not on their radar, but knowing there is a confederation of scientists aligned with a project like this is interesting IMO. Note some of the names...they have appeared in print somewhat recently.
The paper is here: http://arxiv.org/abs/1005.3833
Hmm. The paper is sort of underwhelming IMHO. There is really no significant breakthrough identified that would fundamentally change the Daedalus findings that I can see. And there are a lot of pages describing how CURRENT space systems work (to be used as backup systems???) and potential onboard computer architectures (is this really a key challenge??). I can't see what the purpose of this study would be other than "we haven't done it for a while".
