Quote from: aero on 09/19/2017 04:15 pmNot quite on the current topic, but I found this interesting link over on talkpolywell. There probably is or should be a similar link in advanced concepts.http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=5341&p=129833#p129833It relates because the PFRC engine is to provide one MW of power or 5 N of thrust, long-term in a space vehicle. How does the EM drive stack up to those numbers, which I translate to 5 micro-newtons per Watt?I don't understand why compare this to the EM Drive based on thrust per input energy.The direct fusion drive http://www.psatellite.com/fusion/ is a conventional rocket expelling propellant, it just uses fusion instead.Any comparison of thrust between a rocket expelling propellants and a propellantless concept like the EM Drive is not a fair comparison, because it misses the fact that propellant is a large ratio of the total mass of the vehicle and thus the payload (which is what matters) , duration of flight are not entering in the comparison as they should.The comparison depends on how far you are attempting to go:Quote Reaching Alpha Centauri in anything close to a human lifetime remains a significant challenge, but PFRC could be part of an architecture to reach the star in 300 to 500 years, and slow down enough to go into orbit around the potentially Earth-like planets there! http://www.psatellite.com/tag/dfd/
Not quite on the current topic, but I found this interesting link over on talkpolywell. There probably is or should be a similar link in advanced concepts.http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=5341&p=129833#p129833It relates because the PFRC engine is to provide one MW of power or 5 N of thrust, long-term in a space vehicle. How does the EM drive stack up to those numbers, which I translate to 5 micro-newtons per Watt?
Reaching Alpha Centauri in anything close to a human lifetime remains a significant challenge, but PFRC could be part of an architecture to reach the star in 300 to 500 years, and slow down enough to go into orbit around the potentially Earth-like planets there!
...Payload is really only a significant issue when launching from the earth's surface.., IOW initially overcoming the gravity well. Even from LEO not so much....
Quote from: OnlyMe on 09/19/2017 05:25 pm...Payload is really only a significant issue when launching from the earth's surface.., IOW initially overcoming the gravity well. Even from LEO not so much....Not so if one considers getting "there" in a reasonable amount of time, as you still have to overcome inertia in order to reach a given speed. Look at the tyranny of the rocket equation.https://www.nasa.gov/mission_pages/station/expeditions/expedition30/tryanny.htmlDestination Energy Cost (km/s)Surface of Earth to Earth orbit: 8Earth orbit to cis-lunar locations:Lagrange points: 3.5Low Lunar orbit: 4.1Earth orbit to near-Earth asteroids: > 4Earth orbit to surface Moon: 6Earth orbit to surface Mars: 8 [same as from surface to Earth orbit]If you want to go Jupiter, Pluto or even more, interstellar, and time is an issue, payload is a huge issue
The last few days have been spent calibrating the mirrored laser displacement sensors and the dampening system. I switched from antifreeze to light vegetable oil as it provided more dampening and is non-toxic. I was using the entire paddle with the antifreeze, while now I use a smaller portion. This means I can now adjust from over to under damped and here are two example calibration coil pulse tests. The pulse from today was 5.76uN as I added a 2.7ohm resistor to get the current down to 1A from 2.6A. But I think I still need a capacitor to keep the voltage steady.
Compared to No. 2 diesel fuel, all of the vegetable oils are much more viscous, are more reactive to oxygen, and have higher cloud point and pour temperatures
Quote from: Rodal on 09/19/2017 08:25 pmCompared to No. 2 diesel fuel, all of the vegetable oils are much more viscous, are more reactive to oxygen, and have higher cloud point and pour temperaturesI'm using soybean oil right now, but that is easy to change. I need something with a viscosity between antifreeze and vegetable oil. #2 diesel fuel looks promising as well as other fuel oils.
Mineral oil looks like it may work better than soybean. Depending on grade, its viscosity is about half at 20°C. It's cheap, widely available, and it won't evaporate at room temp.
...This means I can now adjust from over to under damped and here are two example calibration coil pulse tests. The pulse from today was 5.76uN as I added a 2.7ohm resistor to get the current down to 1A from 2.6A. But I think I still need a capacitor to keep the voltage steady.
Quote from: Propylox on 09/19/2017 10:30 amQuote from: Mulletron on 09/18/2017 04:57 pm......Utterly and completely wrong. Any information travelling faster than light would allow for sending messages to the past. See the FTL paradox thread for details.
Quote from: Mulletron on 09/18/2017 04:57 pm......
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Quote from: meberbs on 09/19/2017 02:21 pmQuote from: Propylox on 09/19/2017 10:30 amQuote from: Mulletron on 09/18/2017 04:57 pm......Utterly and completely wrong. Any information travelling faster than light would allow for sending messages to the past. See the FTL paradox thread for details.Whatever they said aside, I thought we've been through this, meberbs... You cannot sent messages "to the past" with Apparent FTL, it can only appear so to an observer. Traveling to actual location would reveal that whatever was seen, was ultimately a lie. Light/information that Observer can intercept can make him come to a conclusion that if he travels to a location X to tell this "message from the future", causality will be broken, but if you do the transformations correctly, it turns out upon arrival the time would be in the future of the said event. I only looks like messages can be sent to the past (and only from one frame of reference), but it wont work that way.
If you could provide a circuit diagram, some of us here on the forum may be able to provide some assistance with the calibration pulse circuit design. If a true constant current pulse is desired, I suspect the ideal circuit may be a little bit more involved than just adding a capacitor to a voltage divider circuit. (although I suspect the primary requirement is merely a reproducable current/voltage profile during the calibration pulse)
Someone finally translated Dr Chen Yue's recent interview on CCTV in English. Not perfect but much better than Google's automatic gibberish translation.You will not discover much, other than the fact CAST seems at the vey beginning of this research and they do not even know if it could work. To me, this is an attempt to make a propellantless RF resonant cavity thruster, but is has little to do with Shawyer's EmDrive, which is a very high-Q frustum resonant cavity with spherically shaped end plates, whereas this one is a flat cylinder with some slits and diaphragms at the bottom interior part.
Quote from: spupeng7 on 09/19/2017 08:59 am...You ask for an explanation of inertia differing from that which you accept...An explanation of inertia that I accept? On the contrary, I asked for experiments confirming the opinions expressed in the last few pages. For all the spilled ink in expressing subjective opinions (unsupported by experimental evidence) nobody has come up with a single experiment confirming any of those opinions. The fact is that there is no experiment showing any "Machian effect" not already present in Einstein's General Relativity. On the contrary, all the experiments (since the 1960's, trying to confirm Brans-Dicke's theory) looking for such Machian effects have failed to find any such evidence of Machian effects not present in Einstein's GR. Coalescence of black holes is calculated nowadays analytically and numerically using General Relativity and the results (gravitational waves including the kick of a binary black hole with accompanying star cluster out of its galaxy) are in excellent agreement with General Relativity. If anybody thinks that Mach's principle has anything to add to General Relativity that is lacking in General Relativity, please cite experiments supporting such opinion, and explain what is missing in General Relativity that is present in Mach's principle and cite experimental support for any such claim.
...You ask for an explanation of inertia differing from that which you accept...
Quote from: jmossman on 09/19/2017 11:30 pmIf you could provide a circuit diagram, some of us here on the forum may be able to provide some assistance with the calibration pulse circuit design. If a true constant current pulse is desired, I suspect the ideal circuit may be a little bit more involved than just adding a capacitor to a voltage divider circuit. (although I suspect the primary requirement is merely a reproducable current/voltage profile during the calibration pulse)Right now it is very simple so I haven't bothered to draw it up. The calibration coil and supply wires are 2.2ohm. I am using a 5V 2A power supply to energize the coil. The coil was getting hot and the pulse was too strong so I added a 2.6ohm 10W resistor in series with the coil to bring resistance up to ~5ohm and the current down to ~1A. On/off is controlled via a separately powered relay switch so it can be toggled from two different locations. The current/voltage profile is reproducible now, but if you look closely, there is still a small increase in voltage. It would be nice if both were regulated and constant throughout the 30 second pulse.
flux_capacitor,the advantages of this design are; simplicity of design and production, low mass and reduced overall volume and stackability and it may yet be found to have other advantages as a resonator, hopefully a high Q.Either way it clearly is an emdrive, which is Shawyer's invention.