-
#420
by
FattyLumpkin
on 07 Sep, 2016 16:07
-
Heads up again about Cannae and their designs: re the previous picture posted, Cannae does not have a "deep space freighter"....they have a design for a LEO to higher earth orbit "tug", and a design for a deep space probe. What was posted earlier was the propulsion module for the tug (which is enclosed with an apparent active Ne cooling system). The deep space probe is fully exposed to space. Please see attached. tug is 1st, DS probe is 2nd
-
#421
by
Star One
on 07 Sep, 2016 16:33
-
-
#422
by
Flyby
on 07 Sep, 2016 20:17
-
from the article :
....A team of engineers in China is also hoping to test their design of the EM Drive in space,....
euh? this is the first time i hear about that...
or is that the wacky rumor mill of half truths and make-believes, once more ?
-
#423
by
Star One
on 07 Sep, 2016 20:33
-
from the article :
....A team of engineers in China is also hoping to test their design of the EM Drive in space,....
euh? this is the first time i hear about that...
or is that the wacky rumor mill of half truths and make-believes, once more ?
Yes I did a double take at that as well.
-
#424
by
dustinthewind
on 07 Sep, 2016 20:53
-
dustinthewind, yes to your question, and could the hoop not also be suspended from the bottom? And while we're at it what about the from the side?
I was fairly sure that a while ago Dr Rodal suggested that for efficient energy transfer from the antenna it should be in the area of greatest electric field? Hopefully I didn't miss anything important in that. This is why I chose the top because that is where the electric field is the greatest. I also chose to drop the twisted wires through the center because the fields are weak there, but I think technically once the wires are twisted they could exit out the side or however you like. There would probably be some impact on interfering slightly with the fields to some small degree.
I know the part of the wire that induces the radiation in the cavity (the untwisted part) should match the shape of the electric field. This is because the time retarded acceleration of the electrons electric field is what induces the shape of the electric field and the counter currents in the cavity.
The half wavelength, perimeter of the circle is so all the electrons in the wire are moving in the same direction at some instant.
-
#425
by
tchernik
on 07 Sep, 2016 21:16
-
-
#426
by
RotoSequence
on 07 Sep, 2016 22:21
-
from the article :
....A team of engineers in China is also hoping to test their design of the EM Drive in space,....
euh? this is the first time i hear about that...
or is that the wacky rumor mill of half truths and make-believes, once more ?
I'd file that under interesting, but dubious; these guys are erroneously parroting the claim that Rodal deleted his post, which suggests that they're not doing much in the way of fact checking.
-
#427
by
Star One
on 07 Sep, 2016 22:26
-
from the article :
....A team of engineers in China is also hoping to test their design of the EM Drive in space,....
euh? this is the first time i hear about that...
or is that the wacky rumor mill of half truths and make-believes, once more ?
I'd file that under interesting, but dubious; these guys are erroneously parroting the claim that Rodal deleted his post, which suggests that they're not doing much in the way of fact checking.
That's been repeated not just by then about the deleting that is.
-
#428
by
simplex1
on 07 Sep, 2016 22:37
-
A microwave resonant cavity is a hot air balloonP = 101325 Pa
T_ambient = 300 K
T_envelope = T_amb + 1K
V = 1 dm^3
R = 287.05 J/kg*K
g = 9.80665 m/s^2
Lift = (V*P/R) x (1/T_amb - 1/T_env)*g =
38.33 micro N (the formula that gives the lift as a function of the balloon envelope temperature)
So, if the copper walls of a 1 litter truncated cone resonant cavity are heated with 1 degree Celsius, then a lift of 38.33 micro N appears. This is consistent with the force reported on this forum as obtained by NASA in a recent series of tests.
(Somebody made some experiments with a resonant cavity and he said that the temperature of the frustum had changed with 1 - 2 degrees, no more, see:
http://www.masinaelectrica.com/tag/emdrive-frustrum-size )
-
#429
by
RotoSequence
on 07 Sep, 2016 22:40
-
A microwave resonant cavity is a hot air balloon
P = 101325 Pa
T_ambient = 300 K
T_envelope = T_amb + 1K
V = 1 dm^3
R = 287.05 J/kg*K
g = 9.80665 m/s^2
Lift = (V*P/R) x (1/T_amb - 1/T_env)*g = 38.33 micro N (the formula that gives the lift as a function of the balloon envelope temperature)
So, if the copper walls of a 1 litter truncated cone resonant cavity are heated with 1 degree Celsius, then a lift of 38.33 micro N appears. This is consistent with the force reported on this forum as obtained by NASA in a recent series of tests.
(Somebody made some experiments with a resonant cavity and he said that the temperature of the frustum had changed with 1 - 2 degrees, no more, see: http://www.masinaelectrica.com/tag/emdrive-frustrum-size )
This is one of the oldest hypothesis to be put to the test, and Eagleworks' vacuum experiments have long since shown that the effect is not a thermal balloon.
-
#430
by
Star One
on 07 Sep, 2016 22:43
-
A microwave resonant cavity is a hot air balloon
P = 101325 Pa
T_ambient = 300 K
T_envelope = T_amb + 1K
V = 1 dm^3
R = 287.05 J/kg*K
g = 9.80665 m/s^2
Lift = (V*P/R) x (1/T_amb - 1/T_env)*g = 38.33 micro N (the formula that gives the lift as a function of the balloon envelope temperature)
So, if the copper walls of a 1 litter truncated cone resonant cavity are heated with 1 degree Celsius, then a lift of 38.33 micro N appears. This is consistent with the force reported on this forum as obtained by NASA in a recent series of tests.
(Somebody made some experiments with a resonant cavity and he said that the temperature of the frustum had changed with 1 - 2 degrees, no more, see: http://www.masinaelectrica.com/tag/emdrive-frustrum-size )
This is one of the oldest hypothesis to be put to the test, and Eagleworks' vacuum experiments have long since shown that the effect is not a thermal balloon.
It's a bit depressing to see people keep trotting out this long debunked theory and a perfect example of the misreporting around the EM drive.
-
#431
by
SeeShells
on 07 Sep, 2016 22:58
-
A microwave resonant cavity is a hot air balloon
P = 101325 Pa
T_ambient = 300 K
T_envelope = T_amb + 1K
V = 1 dm^3
R = 287.05 J/kg*K
g = 9.80665 m/s^2
Lift = (V*P/R) x (1/T_amb - 1/T_env)*g = 38.33 micro N (the formula that gives the lift as a function of the balloon envelope temperature)
So, if the copper walls of a 1 litter truncated cone resonant cavity are heated with 1 degree Celsius, then a lift of 38.33 micro N appears. This is consistent with the force reported on this forum as obtained by NASA in a recent series of tests.
(Somebody made some experiments with a resonant cavity and he said that the temperature of the frustum had changed with 1 - 2 degrees, no more, see: http://www.masinaelectrica.com/tag/emdrive-frustrum-size )
Very easy to test and factor thermal effects in drive orientation if thrust is a given direction.
-
#432
by
simplex1
on 07 Sep, 2016 23:00
-
NASA tests: "
For the EMdrive, the device that was tested here, thrust was consistently observed on the device to be between 30-and-50 microNewtons, giving us that 1.2 N/MW figure. But the limits of the measuring device’s threshold was just 10-to-15 microNewtons! In other words, these results may be consistent and interesting, but this isn’t as robust as anyone wants it to be." Source:
http://www.forbes.com/sites/startswithabang/2016/09/02/nasas-impossible-space-engine-the-emdrive-passes-peer-review/#1be7fbba692cThe thrust obtain by NASA is consistent with the thermal balloon lift I have calculated in my previous post (
38.33 micro N).
It is true, some people claim they debunked the hot air balloon theory but the thrust obtained by them is much higher than the one observed by NASA so likely they made some mistakes.
-
#433
by
FattyLumpkin
on 07 Sep, 2016 23:13
-
dustinthewind, also correct: I don't know where his post is, but Dr. Rodal did discuss the placement and size of the hoop antenna....if memory serves, I believe he indicated there was very little wiggle room re size and placement (my words). If he's on line perhaps he might confirm.
-
#434
by
dustinthewind
on 07 Sep, 2016 23:18
-
A question I would like some thought to. Please don't get mad if this seems stupid.
These devices seem critically dependent on high Q to enhance and multiply the force differential which is extremely difficult to achieve since destructive interference has infinite possibilities to happen. I wonder if there is fundamentally a different way to get to the same end yet without needing to sustain resonance. What I'm thinking of is an asymmetrically designed device that acts more as a waveguide to recirculate the radiation as opposed to bounce it back and forth interacting with the ends. This mode of operation would be similar to photon recycling schemes recently validated by experiment.
BTW, concerning resonance, in recent photon recycling experiments by Y. Bae, an effective resonance was set up between mirrors so stable, the author could move the mirror around with his hand and maintain the resonance. He used a so-called gain medium in the loop. Do you builders have an analogy with microwaves? Thanks.
Here is an experiment I was thinking of related to this. It is based on the high Q mirrors but there is a large voltage on the mirrors and the mirrors are not free to move with respect to each other.
The question is if the mass of the light will vary depending on which mirror it strikes (based on the charge density on the mirror). If so the mirror system may accelerate, similar to the Woodward effect but not by changing the mass of a capacitor, rather the light. It would possibly be related to the cavity because the difference in the photons impulse would be amplified by the Q of the cavity. The idea being the capacitor may some how polarize the vacuum modifying the mass of light. Some number figures would be needed for a prediction.
If DC voltage is too hard to ramp up it may be possible to use AC voltage (capacitance/inductance) to ramp up the voltage stored on the capacitors/mirrors and pulse the light such that when the light strikes the mirrors the system appears static in charge. I'm not sure if a dielectric may be required to pull such a stunt off or not to slow the light between the mirrors. Preferably not, because one would want the vacuum to be polarized more so than some dielectric, I think.
-
#435
by
RotoSequence
on 07 Sep, 2016 23:25
-
NASA tests: "For the EMdrive, the device that was tested here, thrust was consistently observed on the device to be between 30-and-50 microNewtons, giving us that 1.2 N/MW figure. But the limits of the measuring device’s threshold was just 10-to-15 microNewtons! In other words, these results may be consistent and interesting, but this isn’t as robust as anyone wants it to be." Source: http://www.forbes.com/sites/startswithabang/2016/09/02/nasas-impossible-space-engine-the-emdrive-passes-peer-review/#1be7fbba692c
The thrust obtain by NASA is consistent with the thermal balloon lift I have calculated in my previous post (38.33 micro N).
It is true, some people claim they debunked the hot air balloon theory but the thrust obtained by them is much higher than the one observed by NASA so likely they made some mistakes.
There was also Dave's first frustum, which used copper mesh and did not appear to be capable of thermal ballooning. We've looked pretty hard at the thermal effects for more than a year now, and this forum likewise determined that thermal effects
could produce the forces measured, but not all the frustums and experimental setups tested could produce those kinds of thermal effects.
-
#436
by
dustinthewind
on 07 Sep, 2016 23:30
-
dustinthewind, also correct: I don't know where his post is, but Dr. Rodal did discuss the placement and size of the hoop antenna....if memory serves, I believe he indicated there was very little wiggle room re size and placement (my words). If he's on line perhaps he might confirm.
I was speculating on the antenna experiencing propulsion inside the cavity but it turned out if the antenna experiences a force due to being in the magnetic field it develops an electric field in the magnetic field that is not in synch with the radiation in the cavity. I think the force on the antenna would be countered by the impulse from the light developed that then strikes the cavity itself.
This led me to a dead end for a form of propulsion by this method but I found it interesting that if you had a loose antenna in the cavity, I think it was that it should be pushed toward the region of high electric field. That region being where there isn't force on the antenna by F=q(v x B). If one measures the force on the antenna
and you already had radiation in the cavity it should tell you exactly where to place the antenna in the cavity.
It would probably be better to have a sensing antenna mounted separately for measuring radiation in the cavity. Preferably in a not so sensitive region.The other option to using an antenna is what Shell and others were using, and is the wave guide method. I'm not sure how to determine exactly your mode using waveguides, but it probably has to do with current stimulation and shape on the surface of the waveguide at the mouth/throat.
-
#437
by
simplex1
on 07 Sep, 2016 23:36
-
Cooper mesh or not, it does not matter too much because the pressure of the hot air inside the balloon (cavity) and that of the cold air outside are identical, just their densities are different, so the hot and cold air will not mix so easily.
-
#438
by
demofsky
on 07 Sep, 2016 23:37
-
NASA tests: "For the EMdrive, the device that was tested here, thrust was consistently observed on the device to be between 30-and-50 microNewtons, giving us that 1.2 N/MW figure. But the limits of the measuring device’s threshold was just 10-to-15 microNewtons! In other words, these results may be consistent and interesting, but this isn’t as robust as anyone wants it to be." Source: http://www.forbes.com/sites/startswithabang/2016/09/02/nasas-impossible-space-engine-the-emdrive-passes-peer-review/#1be7fbba692c
The thrust obtain by NASA is consistent with the thermal balloon lift I have calculated in my previous post (38.33 micro N).
It is true, some people claim they debunked the hot air balloon theory but the thrust obtained by them is much higher than the one observed by NASA so likely they made some mistakes.
No. NASA Eagle Works debunked this by running their tests in a vacuum chamber.
-
#439
by
dustinthewind
on 07 Sep, 2016 23:40
-
Cooper mesh or not, it does not matter too much because the pressure of the hot air inside the balloon (cavity) and that of the cold air outside are identical, just their densities are different, so the hot and cold air will not mix so easily.
Buoyancy only effects a drive in a direction parallel to the force of gravity. Most tests I have seen are perpendicular to the force of gravity. Even if the test was in the vertical direction you could just flip the drive over in the down direction and see if the force reverses. Correctly done, buoyancy is eliminated.