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#2260
by
Star One
on 30 Sep, 2015 07:15
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Where is our friend Rodal? It seems he has been quiet for half a month.
I believe he is around just in lurking mode. Dr. Rodal follows EmDrive debate from the start, so in my opinion he also needs some time to focus on different things and some rest from this debate 
. I also believe we may see many folks returing once we see data from NASA EW by the end of this year.
Can we be so sure of hearing anything from NASA EW within that timeframe, I'm not after past events?
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#2261
by
rfmwguy
on 30 Sep, 2015 12:02
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Where is our friend Rodal? It seems he has been quiet for half a month.
I believe he is around just in lurking mode. Dr. Rodal follows EmDrive debate from the start, so in my opinion he also needs some time to focus on different things and some rest from this debate . I also believe we may see many folks returing once we see data from NASA EW by the end of this year.
Can we be so sure of hearing anything from NASA EW within that timeframe, I'm not after past events?
Only rumors from last year that new testing will be done by this past summers end. Lets cross our fingers.
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#2262
by
SeeShells
on 30 Sep, 2015 12:51
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When I started posting on the NSF blog months ago there was chat that EagleWorks was going to have results and a paper by the end of July. Ya, well it may happen, when Santa delivers his toys. I know the poo storm they started on the last release and all I would say is that had to be viewed as bad publicity for NASA and I heard hear they were told to shut up and then went dark.
A new report, new data? I don't know, maybe it's the same soup in a different can, but new and improved... with a fresher scent and longer lasting.
Honestly, I'm not going to keep my hopes up too high for anything from EW anytime soon or ever, if anything comes from them it's going to be under a microscope and heat right from the start and it better be rock solid and able to withstand the instant criticism from people who are waiting to pounce.
Other than that, I'm sorry I have been a little quiet but I'm right in the grove of building this drive and the devil is in the details. Unlike the superstars over at EW or some of the Universities, what data I (just me with some great help from other here) get had better be of a bullet proof nature.
I want to thank the group here for data mining rfmwguy's test (IMPRESSIVE!) and for him giving me hope that there just might be something there, just maybe and it's a big maybe I can get just a little cleaner data. My goal is to try to get this thing that's seen as thrust out of the noise and issues of thermal deviation of test data.
Shell
PS: Finally figured out a way to be able to fine tune the 2 plates in the test phase with VNA data and even during power tests (off times) to be able to sweep the distance between the end cavities. The .5" quartz rod I'm using between the plates and captured in the large bottom plate. It not only allows the distance to be adjusted between the plates but will also keep the tune distance allowing the sidewalls of the frustum to slide past the top plate has been solved.
Using scavenged parts from an old SEM controls I'm attaching the quartz rod to one of the micrometer bodies to run up through the center of the frustum. This sits in the center of the Large plate.
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#2263
by
rfmwguy
on 30 Sep, 2015 13:08
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You are my hero, even tho your Mercedes Turbo Coup design makes mine look like a VW beetle.
Godspeed in your build and tests. Thanks so much for the pics...you know, you have to take over for me for a while in pic & vid postings...
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#2264
by
SeeShells
on 30 Sep, 2015 13:41
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Dr. Rodel, the troops would like a "I'm here and fine". Believe it when I say, we all miss your posts. But I understand when other life issues (maybe by making a living) take front stage.
Our best to you.
Shell
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#2265
by
Flyby
on 30 Sep, 2015 13:56
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I've seen a few "like"s he made on some topics in the past 12 days, so Dr Rodal is still following the forum...
Consequently, I don't think there is a medical problem, like it was the case with TT going offline...
It just adds a bit more mystery...
... certainly when you realize he has been posting several times per day ever since this topic started...
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#2266
by
TheTraveller
on 30 Sep, 2015 14:16
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I've started my radiation treatment, which should complete end Nov 2015. If that works as expected, maybe 2-3 weeks later can get back to doing my build. If not clear, I'll start chemo.
I say again. Guys get your prostate checked. This cancer has almost no signals, except for increased PSA and reduced flow, but in 30% of cases, PSA is not that elevated. Mine was 3.7 and the left half of my prostate was full of Gleason 9 cancer that had grown outside the prostate.
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#2267
by
SteveD
on 30 Sep, 2015 14:42
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Hum I've got one of Bae's papers. Let me jump to the important bit
Under the auspice of NIAC/NASA, the author successfully demonstrated the proof-of-concept of a
PLT. [3,16] In this demonstration, a PLT was built from off-the-shelf optical components and a YAG
gain medium, and the maximum amplified photon thrust achieved was 35 μN for a laser output of 1.7 W
with the use of a HR mirror with a 0.99967 reflectance. This performance corresponds to an apparent
photon thrust amplification factor of ~3,000. More importantly, in the experimental demonstration, the
author accidentally discovered that the PLT cavity is highly stable against the mirror motion and
misalignment unlike passive optical cavities. In fact, in the demonstration experiment by the author, the
full resonance mode of the PLT was discovered to maintain even when one of the HR mirror was held,
moved, and tilted by a hand to the author’s surprise. In a more systematic experiment, the PLT cavity
was systematically demonstrated to be highly stable against tilting, vibration and motion of mirrors.
Subsequent theoretical analysis by the author showed that PLT can indeed be used for propulsion
applications, and proposed Photonic Laser Propulsion (PLP), the propulsion with PLT. [15] The reason
for the observed stability results from that in the active optical cavities for PLT and PLP the laser gain
medium dynamically adapts to the changes in the cavity parameters, such as mirror motion, vibration and
tilting, which does not exist in the passive optical cavities.
I've included a diagram of a conventional laser and of a proposed photonic laser thruster to make what the author of the paper is doing a bit more clear.
Um hum, if the author can maintain an optical
resonance by hand holding a mirror, then the gain medium must be capable of both redshifting and blueshifting the wavelength of the photon. Well I suppose the gain medium is receiving photons from both ends so it has some way of knowing what the resonant frequency is. I'd also note that, if the device only has to be in the ballpark of the right dimensions and the gain medium fixes the frequency for you, that would help to explain the functioning of every cheap $10 laser pointer ever made.
For an EMDrive, I wonder what would happen if you put a microwave gain media and a pump inside the cavity. The gain media could either be a gas or a solid state media. I wonder how big you could get a solid state media. While I've read the almost all solid state gain media for a Maser need cryogenic cooling to work, if you have a superconductor on one end of the cavity you already need that cooling.
Hum according to some reading: Ammonia works as a gain medium at a frequency around where the hackaday EMDrive resonates and hydrogen can be a gain medium around 1.4ghz.
Can I jump up and down a couple times and say that I think Bae's observation is important.
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#2268
by
sghill
on 30 Sep, 2015 14:58
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Dr. Rodel, the troops would like a "I'm here and fine". Believe it when I say, we all miss your posts. But I understand when other life issues (maybe by making a living) take front stage.
Our best to you.
Shell
I spoke with him yesterday. He's here. He's fine.
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#2269
by
Chrochne
on 30 Sep, 2015 15:46
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Dr. Rodel, the troops would like a "I'm here and fine". Believe it when I say, we all miss your posts. But I understand when other life issues (maybe by making a living) take front stage.
Our best to you.
Shell
I spoke with him yesterday. He's here. He's fine.
That "like" by Dr. Rodal now, was better shock than first beep of the Sputnik over the USA
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#2270
by
SteveD
on 30 Sep, 2015 16:13
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I've seen a few "like"s he made on some topics in the past 12 days, so Dr Rodal is still following the forum...
Consequently, I don't think there is a medical problem, like it was the case with TT going offline...
It just adds a bit more mystery... ... certainly when you realize he has been posting several times per day ever since this topic started...
This is also the point in the Fall semester where students have their first set of tests/things due.
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#2271
by
rfmwguy
on 30 Sep, 2015 16:29
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Dr. Rodel, the troops would like a "I'm here and fine". Believe it when I say, we all miss your posts. But I understand when other life issues (maybe by making a living) take front stage.
Our best to you.
Shell
I spoke with him yesterday. He's here. He's fine.
Doc, ya had me scared for a second, just when my experiment went into hibernation after successful testing. I was hoping it had not inadvertedly beam you off-planet throught some sort of spacetime collapse or something
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#2272
by
SteveD
on 30 Sep, 2015 16:45
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Hum, plugging along when I should be doing something else. Here is a visualization of a
https://en.wikipedia.org/wiki/Whispering-gallery_wave resonator. I can't help but notice that the wave pattern looks very much like the "nodules" that appeared on the MEEP output of the big base of CE-3.
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#2273
by
SeeShells
on 30 Sep, 2015 19:20
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Hum, plugging along when I should be doing something else. Here is a visualization of a https://en.wikipedia.org/wiki/Whispering-gallery_wave resonator. I can't help but notice that the wave pattern looks very much like the "nodules" that appeared on the MEEP output of the big base of CE-3.
This the one?
Added...
A thumbs up for who can tell me this mode....
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#2274
by
rfmwguy
on 30 Sep, 2015 20:50
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"Peer" review anyone?
I am ready to present my Paper on the NSF-1701 experiment. To keep with the spirit of scientific research, I would like to have it reviewed by fellow posters here. The only thing I ask is you take the time to read it and critique content, layout, spelling, anything you want.
I can credit you with a review on the paper if you want or not. That is up to you. PM me with the request to "peer review" think I'll need an email addess to send the file.
Dave
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#2275
by
Asteroza
on 30 Sep, 2015 23:45
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For an EMDrive, I wonder what would happen if you put a microwave gain media and a pump inside the cavity. The gain media could either be a gas or a solid state media. I wonder how big you could get a solid state media. While I've read the almost all solid state gain media for a Maser need cryogenic cooling to work, if you have a superconductor on one end of the cavity you already need that cooling.
Can I jump up and down a couple times and say that I think Bae's observation is important.
There was that recent discovery of solid state non-cryogenic masers using an organic crystal of sorts.
http://www.nature.com/nature/journal/v488/n7411/full/nature11339.html
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#2276
by
rfmwguy
on 01 Oct, 2015 00:12
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NSF-1701 paper review...Thanks, I've sent out several sets, and could probably use about 7 more reviewers...PM me.
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#2277
by
rfmwguy
on 01 Oct, 2015 21:52
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A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).
Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.
Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).
Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.
He shared this openly and if this helps future experimenters, he is please to do so.
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#2278
by
ort
on 01 Oct, 2015 22:01
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Since its been quiet in here today. I'd just like to offer congrats on the build and the experimental runs so far. Back to lurking and observing...
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#2279
by
R.W. Keyes
on 01 Oct, 2015 22:57
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Hi everyone, I've been away for a while, and I have tried to catch up but there's just so much to read.
What is that general opinion about a high Q being necessary for the emdrive to work efficiently? I haven't seen much about going to the extremes of high-Q, such as superconducting cavities at cryogenic temperatures. I understand that such a cool temperature makes test conditions more difficult, but if high Q will result in greater efficiency, isn't this worth trying? Also, magnesium diboride shouldn't be too hard to form (type II, cuprate superconductors might be quite a bit more of a chore). One thing, though, that concerns me: with such a high Q, the bandwidth would be very narrow, and that unless the microwave source is extremely well matched to the cavity's resonance, it will require tuning. From my experience with tuning high-Q antennas in amateur radio, I know that it is possible to just slide right past the point of resonance if tuning is too coarse. One solution to the problem might be to temporarily drop the Q, just so it's easier to find the proper range, and then gradually tighten it in fine tuning. Though I have a hunch that the highest-Q, available from superconducting cavities, might create such a shape bandwidth that none of our signal sources are going to be precise and stable enough to stay tuned to it, so we might have to always artificially drop the Q from what a superconducting cavity might be capable of. I haven't put this to the test, nor have I even done any numerical reasoning on the idea, but I think it's worth mentioning.
. I also believe we may see many folks returing once we see data from NASA EW by the end of this year.
... certainly when you realize he has been posting several times per day ever since this topic started...
