Quote from: WarpTech on 05/27/2015 01:48 pmQuote from: mwvp on 05/27/2015 06:19 am.... Shawyer's EM Drive proports to give you the cavity Q, many thousands of times more bang per photon.What the experimental data shows is that it doesn't. It gives you less than Q x momentum/photon, per bang. It stores them up and lets them go all at once. It cannot operate continuously at Q*Power in. That would violate CoE.ToddSorry, but this is flat wrong.For example, EW is running with approximately Q*P thrust for a continuous 20 seconds. And they are one of the examples of least thrust. Is 20 seconds long enough to disprove your conjecture? - I believe so. Numbers would be good though.
Quote from: mwvp on 05/27/2015 06:19 am.... Shawyer's EM Drive proports to give you the cavity Q, many thousands of times more bang per photon.What the experimental data shows is that it doesn't. It gives you less than Q x momentum/photon, per bang. It stores them up and lets them go all at once. It cannot operate continuously at Q*Power in. That would violate CoE.Todd
.... Shawyer's EM Drive proports to give you the cavity Q, many thousands of times more bang per photon.
Quote from: cometo on 05/27/2015 05:37 pmHi to everybody.Are somebody thinking in putting a cloud chamber under the base of fustrum in order to check if charged particles are emitted?If Emdrive were some kind of "vacuum particle extractor" this attachment should show that....Great idea to look at convection currents when doing experiments in air. Either natural convection currents produced by power dissipation at the EM Drive external surfaces or forced convection from heated moist air pressurized in its interior and leaving through gaps. Something that researchers doing experiments in air can use to validate or nullify experimental explanations. (Not so much for Quantum Vacuum as those are virtual particle pairs that have an ephemeral life governed by Heisenberg's uncertainty principle)
Hi to everybody.Are somebody thinking in putting a cloud chamber under the base of fustrum in order to check if charged particles are emitted?If Emdrive were some kind of "vacuum particle extractor" this attachment should show that....
Quote from: Rodal on 05/27/2015 05:48 pmQuote from: cometo on 05/27/2015 05:37 pmHi to everybody.Are somebody thinking in putting a cloud chamber under the base of fustrum in order to check if charged particles are emitted?If Emdrive were some kind of "vacuum particle extractor" this attachment should show that....Great idea to look at convection currents when doing experiments in air. Either natural convection currents produced by power dissipation at the EM Drive external surfaces or forced convection from heated moist air pressurized in its interior and leaving through gaps. Something that researchers doing experiments in air can use to validate or nullify experimental explanations. (Not so much for Quantum Vacuum as those are virtual particle pairs that have an ephemeral life governed by Heisenberg's uncertainty principle)Shawyer covered that. See the sealed Faraday Cage around the 1st Experimental device. I really don't know why this is still being brought up. It was designed out of his 1st test protocol.
The thrust is not being caused by heated air
I don't recall seeing any analysis proving that statement. What I recall is @frobnicat posting a good analysis showing that air exhaust was a plausible explanation for the measured thrust. Thus this possibility still remains open until proven otherwise. I am not saying it is an explanation, but the post indicating how to show air convection currents is indeed a positive post.
@Rodal Doc, thinking out loud here...might be tough to follow each new DIYEMer's latest updates buried in this thread. Is there a way to create new threads titled EM Drive Developments - Julian, Traveller, etc? Have a hunch we will be getting data at a pretty fast rate soon. This way, it consolidates specific replicator's efforts and gives them some kudos at the same time.
Group members try to minimize conflict and reach a consensus decision without critical evaluation of alternative viewpoints, by actively suppressing dissenting viewpoints, and by isolating themselves from outside influences.Loyalty to the group requires individuals to avoid raising controversial issues or alternative solutions, and there is loss of individual creativity, uniqueness and independent thinking. The dysfunctional group dynamics of the "ingroup" produces an "illusion of invulnerability" (an inflated certainty that the right decision has been made). Thus the "ingroup" significantly overrates its own abilities in decision-making, and significantly underrates the abilities of its opponents (the "outgroup"). Furthermore groupthink can produce dehumanizing actions against the "outgroup".
I am very surprised by those poll results. Based on those results, where individuals who feel their is propellantless thrust are slightly more numerous than those who claim no thrust, implies that the general consensus places the odds of their being a genuine, previously unknown//non-classical force at about 50% (ignoring all the people who don't have an opinion).I find that to be an extremely high estimate given everything we have seen so far. Yes, their have been replications, but this isn't a result that can easily be validated. Lots of hard to control for confounding factors, and it's a huge claim being made. I would have put the odds at somewhere in the 2-3% range. Maybe 5% if I was feeling optimistic. Interesting to learn that the forum overall is leaning to a much greater likelihood. Just my two cents.Edit: Here is the link to the poll: http://forum.nasaspaceflight.com/index.php?topic=37644.0
I finally figured out how to make my microwave fly! Give a good solid kick!But it doesn't fly very far, I think because the cord comes unplugged right away.If you replicate my experience, be very careful, you could get hurt - I recommend combat boots.
Quote from: deltaMass on 05/27/2015 06:28 pm@Rodal: The net stored momentum of all cavity photons is zero, almost. There is a contribution from the source.was using WarpTech's statement << It stores them up and lets them go all at once. It cannot operate continuously at Q*Power in. That would violate CoE.>> to frame the question in terms of the time intervals that he conjectures for these processes to require, in order to address your prior point (does the data show that or not ?)If the "net stored momentum of all cavity photons is zero, almost" that answers your question: as the time interval for storage is then practically zero, and not visible in the data charts.You are not going to find "small fractions of a second" time bursts in 20 sec data that does not have that level of time discretization detail.Quote from: deltaMass on 05/27/2015 05:49 pm...For example, EW is running with approximately Q*P thrust for a continuous 20 seconds. And they are one of the examples of least thrust. Is 20 seconds long enough to disprove your conjecture? - I believe so. Numbers would be good though.
@Rodal: The net stored momentum of all cavity photons is zero, almost. There is a contribution from the source.
...For example, EW is running with approximately Q*P thrust for a continuous 20 seconds. And they are one of the examples of least thrust. Is 20 seconds long enough to disprove your conjecture? - I believe so. Numbers would be good though.
...For the purposes of Todd's argument, we should be talking about stored energy and not stored momentum, since he explicitly mentions CoE. I recall calculating the stored energy a ways back to be substantially less than 1 Joule (if this forum had a half-decent search function, I'd quote the exact figure ). I think it was Q*P/omega, so for EW that's roughly 6,000*85/(2*Pi*1.9e9) = 5e-5 J. Looks about right. How long does the input power take to accumulate that energy? t = 5e-5/85 = 0.5 usec. I am pointing out that 20 seconds is substantially longer than 0.5 microseconds.
Would it be possible to use magnetic forces (e.g. electromagnets) to capture the microwaves in the cavity for a longer period of time? Maybe instead of extremely high Q cavities it would be easier to use electromagnets around the frustum to keep the microwaves inside and/or direct the microwaves in the required direction and/or slow them down as required?I mean instead of superconducting frustum, which requires heavy cooling, it may be easier to achieve the required thrust by putting the frustum in electromagnetic trap or even to replace the copper walls with electromagnets and injecting the microwaves in such magnetic box?
Quote from: X_RaY on 05/25/2015 08:30 pmHello i am new in this forum. Based on my own simple model(flat end plates) the frequency has to be approximately 2.52GHz.I hope this is helpfull Hi, can you share your model?
Hello i am new in this forum. Based on my own simple model(flat end plates) the frequency has to be approximately 2.52GHz.I hope this is helpfull
Quote from: deltaMass on 05/26/2015 08:22 pmI think my point is being missed for the case of a completely static gas.I've seen people arguing for a net nonzero force even in this case.The reason for pointing this out is to make you think.Point well taken.It would be very useful to get strong skeptical reviews of Prof.Yang's paper ((translated) page 4 ( http://www.emdrive.com/NWPU2010translation.pdf ) concerning her equations stating that having a gas/fluid with charged particles inside the EM Drive results in transfer of its momentum to the EM Drive metallic body. Just like the great job you did addressing energy conservation.It seems to me that she also needs to take into account directional attenuation in order to get a non-zero Poynting vector.If you have a chance to look at her equations, I'll for one, would appreciate knowing what you think about them
I think my point is being missed for the case of a completely static gas.I've seen people arguing for a net nonzero force even in this case.The reason for pointing this out is to make you think.