Quote from: ChrisWilson68 on 08/04/2014 07:14 pmQuote from: IslandPlaya on 08/04/2014 07:08 pmI think they did the test with an RF load also.They reported no force in this case. That must go someway to eliminating systemic errors in their setup.No, they reported there was some thrust detected from the RF load, also, but not as much, and they subtracted that from the measured thrust for the other two devices.They did? Going back over the abstract they mention the RF load, but nothing about testing of such.Did I just overlook it or do you have extra info?
Quote from: IslandPlaya on 08/04/2014 07:08 pmI think they did the test with an RF load also.They reported no force in this case. That must go someway to eliminating systemic errors in their setup.No, they reported there was some thrust detected from the RF load, also, but not as much, and they subtracted that from the measured thrust for the other two devices.
I think they did the test with an RF load also.They reported no force in this case. That must go someway to eliminating systemic errors in their setup.
Quote from: brokndodge on 08/04/2014 08:50 pmIANAS - But, I have read the report and it seems to me that they are only reporting on experimental results that they could not explain and honestly didn't expect to see. The first set of experiments and the "null" (they should have chosen a better word) device indicated results that were unexpected and invalidated 1 theory as to why results were seen. The so called "null" device was not really such a device. Rather, the engineer that made it had a theory that placing groves in one end of the device would create thrust and that not having the grooves would not create thrust. He was proven wrong in that the device appeared to create thrust irregardless of the groves. The second set of experiments conducted with a different device of a type more closely related to the EMDrive also yielded results. They were able to take lessons learned about their first experimental setup and apply them to the second set of tests. As such they were able to test at much higher frequencies. Among all of the tests, time available to test has been an issue. They stated in the opening brief about the setup of their vacuum chamber and pendulum that it takes "days" to pull an appropriate vacuum. Later in the paper they stated that one of the devices used had electrical components that were not vacuum friendly. I don't recall a specific mention of the second set of tests being performed in a vacuum. The paper did not make any conclusions as to what is causing the effect that they are seeing. It does state that the effect is worth investigating and that they are planning to test a more powerful 1GHz version at other facilities with better equipment. I believe that at this time such an advanced concept lab as this is doing the right thing in further researching the results that they measured. I also believe that they are confident to a high enough degree to warrant larger scale testing at facilities that are better equipped for such tests. I look forward to the results of such testing whether they be positive or negative.Great post.I may be slow today, but could you supply a link to the paper please?Cheers mate.
IANAS - But, I have read the report and it seems to me that they are only reporting on experimental results that they could not explain and honestly didn't expect to see. The first set of experiments and the "null" (they should have chosen a better word) device indicated results that were unexpected and invalidated 1 theory as to why results were seen. The so called "null" device was not really such a device. Rather, the engineer that made it had a theory that placing groves in one end of the device would create thrust and that not having the grooves would not create thrust. He was proven wrong in that the device appeared to create thrust irregardless of the groves. The second set of experiments conducted with a different device of a type more closely related to the EMDrive also yielded results. They were able to take lessons learned about their first experimental setup and apply them to the second set of tests. As such they were able to test at much higher frequencies. Among all of the tests, time available to test has been an issue. They stated in the opening brief about the setup of their vacuum chamber and pendulum that it takes "days" to pull an appropriate vacuum. Later in the paper they stated that one of the devices used had electrical components that were not vacuum friendly. I don't recall a specific mention of the second set of tests being performed in a vacuum. The paper did not make any conclusions as to what is causing the effect that they are seeing. It does state that the effect is worth investigating and that they are planning to test a more powerful 1GHz version at other facilities with better equipment. I believe that at this time such an advanced concept lab as this is doing the right thing in further researching the results that they measured. I also believe that they are confident to a high enough degree to warrant larger scale testing at facilities that are better equipped for such tests. I look forward to the results of such testing whether they be positive or negative.
Quote from: pagheca on 08/03/2014 07:01 amThe problem is that the article linked is not a scientific paper, but a clearly preliminary technical report, the typical "hat on the seat" (copyrighted by me ) paper required to ensure to be the first IF a sensational result is confirmed in order to get an high citation index in the future.A link to the actual paper may be found at https://plus.google.com/117663015413546257905/posts/C7vx2G85kr4 However this is a conference paper, which in many cases aren't peer reviewed in the same way a journal paper would be. I'm not sure about this particular case.In any case, if Baez summery is correct, there is really nothing worth talking about here... (which should be no surprise to anyone who read the original abstract)
The problem is that the article linked is not a scientific paper, but a clearly preliminary technical report, the typical "hat on the seat" (copyrighted by me ) paper required to ensure to be the first IF a sensational result is confirmed in order to get an high citation index in the future.
See below from about page 6 of this very thread. When you follow the link you will have to skip past about 2 or 3 paragraphs of the guy discounting the results to find two links to the actual paper:
QuoteWe're talking of net thrust because of course the setup was also tested with a null 50 ohm load connected, in order to cancel the effect from the drives and detect any detect any spurious force due to EM coupling with the whole apparatus (which exists, at 9.6 µN) and this "null" spurious force was evidently subtracted from any thrust signal due to the drives then tested on the pendulum.
We're talking of net thrust because of course the setup was also tested with a null 50 ohm load connected, in order to cancel the effect from the drives and detect any detect any spurious force due to EM coupling with the whole apparatus (which exists, at 9.6 µN) and this "null" spurious force was evidently subtracted from any thrust signal due to the drives then tested on the pendulum.
I think in these things we have to be very careful.There are two camps:- 1) People who would very much like it to be true.2) People who say it is (obviously) impossible.I would put myself in (1) but that doesn't mean I wouldn't except hard results disproving the effect.Anyway, whichever camp you are in, it pays to be objective and not succumb to confirmation bias.It can be difficult to do this, but we must try...
Quote from: FlyingMoose on 08/03/2014 04:43 amThis discovery came about because Shawyer was trying to explain the thrust generated by the microwave transmitters on satellites which exceeded what was expected and required additional fuel to correct.This would really make an interesting subject to read or a comparison point to read up on.who you be able to supply a link or a paper?
This discovery came about because Shawyer was trying to explain the thrust generated by the microwave transmitters on satellites which exceeded what was expected and required additional fuel to correct.
Quote from: Star One on 08/02/2014 09:21 pmYou might want to be rather careful in what you say here otherwise it might look like you're casting aspersions on the NASA scientists and their decision to investigate this.This is one little corner of NASA. NASA is a huge organization with lots and lots of people working on lots of things. Sonny White and friends are not equivalent to NASA as a whole.And there's nothing wrong with complaining that this one small part of NASA is wasting precious resources that could be better spent, and misleading the public by letting the NASA name get attached to wishful thinking in the guise of science.
You might want to be rather careful in what you say here otherwise it might look like you're casting aspersions on the NASA scientists and their decision to investigate this.
If you want to see bizarre, go here:http://www.physforum.com/index.phpBut this is a hot blogger topic world wide, I checked a French and Czech blog site (Google Translate) and they seem to be very hard over on this subject, too. Most bloggers seem to behave as though they fear that the EM drive will steal their women and destroy their sex life.
Guys I applaud trying to stay on topic, but you're giving so little detail I have no idea what you're talking about. Going to that site shows some terrible "scientific" thoughts, is that what you mean.Perhaps it needs a separate thread on "misunderstanding science" or whatever the concern is - otherwise an illustration of your concern would be great
In case it hasn't been posted, the full AIAA paper is available here:http://www.scribd.com/doc/235868930/Anomalous-Thrust-Production-from-an-RF-Test-Device-Measured-on-a-Low-Thrust-Torsion-PendulumA quick scan discovered the interesting item, that not two, but four devices were tested and reported. Three resulted in force being measured repeatably. Two devices were the disk shaped Cannae device, one of which was designed for null results but produced force anyway, one device was the Eagelworks in-house design, a conical shaped device similar the original Roger Shawyer and the chinese devices and the fourth device was a brick shaped RF load. It did not produce thrust. So what we have is at least 5 devices which have been reported as producing thrust, and at least 3 different test set-ups that have been blamed as being faulty by the blogger community, each with a different fault. To me, it seems time to apply Occam's razor. It is easy to show that the undetected flaw which the EagleWorks Lab is accused of, would not have gone undetected at the Chinese high power test. The suspected flaw is force resulting from heating and convective air flow. But in the Chinese high power test in order for this mechanism to give the measured force, the mass of air flow (mdot) times the change in air velocity (Ve) must equal the measured force. But that air flow would be easily detected by anyone who casually glanced at the operating device. So the flaw is different for different test set-ups. So in the end, there can be either a different flaw for each test set-up, or there can be one unknown but reproducible force generating mechanism. What does Occam's razor say?
Of course flaws can be imagined and theories can be laughed at, but doing so does not advance scientific knowledge