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Re: EM Drive

Posted: Sat Apr 16, 2016 1:20 am
by Diogenes
Image
Most EMDrives are powered by microwave magnetrons - which makes them easy to build but also defines the form factor: They are quite big. Bringing such an EMDrive into orbit would cost terribly much. I tried to build one that works with 24GHz instead of 2.4 GHz what makes it fit in your handpalm, and the latest results show that it´s working.
https://hackaday.io/project/10166-emdri ... ht-version

Re: EM Drive

Posted: Sat Apr 16, 2016 6:59 am
by ScottL
Diogenes wrote:
Most EMDrives are powered by microwave magnetrons - which makes them easy to build but also defines the form factor: They are quite big. Bringing such an EMDrive into orbit would cost terribly much. I tried to build one that works with 24GHz instead of 2.4 GHz what makes it fit in your handpalm, and the latest results show that it´s working.
https://hackaday.io/project/10166-emdri ... ht-version
The same guys that can't seem to label graphs properly. They update periodically, but nothing in their posts states they're capable of measuring such small amounts of thrust. At one point I believe they were complaining about the refrigerator in the guy's apartment causing issues. That's just a problem with DIYer level experimentation though, and I think they're giving it a hell of go as futile as it may be.

Re: EM Drive

Posted: Sun Apr 17, 2016 12:56 am
by kunkmiester
It's one of the exciting things about this and Mach effect thrusters though. Once the science settles out to the maker level, people will be able to build space ships in their garages.

The important thing for this stuff is designs that can generate thrusts above the noise levels, but that will take quite a bit of power. While it presents it's own challenges, in many ways bigger is easier for the diy experimenter, and does make power supplies easier as well.

Re: EM Drive

Posted: Sun Apr 17, 2016 3:32 am
by kurt9
This will likely land me in hot water, but I think I will say it anyways. These EM drive experiments have produced positive results under certain conditions. The experiments done at the Eagleworks involved the use of a plastic disk in the microwave chamber. Apparently plastic is weakly dielectric. If so, the effect is likely real and is based on Mach's Principle. Someone on Dr. Woodward's email list suggested that they do experiments with and without this plastic disk. For some reason the Eagleworks people have not done this.

Woodward and Fern have been doing experiments that have positive results. They are quite open about the technical details and the results of their experiments. If Eagleworks and others are getting positive results, its possible that they are also inadvertently producing Mach effects as well.

As far as replacing existing transportation (cars, airplanes, etc.), this drive technology would have to scale up to at least 1/3 g thrust (typical of airliner takeoffs) with reasonable input power source. Right now, Woodward's results suggest 1/100th of a g, comparable to an ion thruster, which would be useful for deep space transportation but not for replacing existing Earth-based transportation.

Re: EM Drive

Posted: Sun Apr 17, 2016 3:06 pm
by paperburn1
But if it presses against the rest of the universe then the faster it goes the less efficient it should become.
But everybody ignore the real reason this will never work , and that would be heat from the power plant.
You would have to radiate that heat out somewhere from the power plant and even with current tech that is no small feat.
For example Nuclear submarines get rid of heat by sucking in cold ocean water and spewing out hot heat sink water. This won't work in space, there isn't any ocean. To radiate this much heat into space the radiators would literally be square kilometers.
The EATCS is capable of rejecting up to 70 kW, that's what they use on the space station The PVR – the radiator Each flow path is independent and is connected to one of the two PFCSson the IEA. In total, the PVR can reject up to 14 kW of heat into deep space. The PVR weighs
1,633 pounds (740.7 kilograms) and when deployed measures 10.24 feet (3.12 meters) by 44.62
feet (13.6 meters). When the ISS assembly is complete, there will be a total of four PVRs or over100 square meters
Physics and law enforcement, ruining all my fun once again :(

Re: EM Drive

Posted: Sun Apr 17, 2016 7:19 pm
by Carl White
But everybody ignore the real reason this will never work , and that would be heat from the power plant.
Would there be any prospect for externally beaming power to the ship?

Re: EM Drive

Posted: Sun Apr 17, 2016 8:16 pm
by Giorgio
paperburn1 wrote:But everybody ignore the real reason this will never work , and that would be heat from the power plant.
You would have to radiate that heat out somewhere from the power plant and even with current tech that is no small feat.
That, I would say, is just an engineering issue, not something I would be concerned about.
"IF" this EM Drive work than engineers will find a way to work around the issue of dissipating (or collecting) the heat out of anything that will be needed to power this thing.
But so far there hasn't been any clear indication as if this drive actually work or not. I remember the first time i read about this on SPR Ltd website, I saw these videos of a EM Drive spinning. Now, an independent test of this would be enough to prove the machine as real.
Why (I wonder) we never heard anymore about this?
Sometimes the reply to an obvious question is just an obvious truth.......

Re: EM Drive

Posted: Sun Apr 17, 2016 9:03 pm
by ScottL
Giorgio wrote:
paperburn1 wrote:But everybody ignore the real reason this will never work , and that would be heat from the power plant.
You would have to radiate that heat out somewhere from the power plant and even with current tech that is no small feat.
That, I would say, is just an engineering issue, not something I would be concerned about.
"IF" this EM Drive work than engineers will find a way to work around the issue of dissipating (or collecting) the heat out of anything that will be needed to power this thing.
But so far there hasn't been any clear indication as if this drive actually work or not. I remember the first time i read about this on SPR Ltd website, I saw these videos of a EM Drive spinning. Now, an independent test of this would be enough to prove the machine as real.
Why (I wonder) we never heard anymore about this?
Sometimes the reply to an obvious question is just an obvious truth.......
One of the biggest problems is that everyone experimenting with this idea has a completely different setup that aren't fully described. This makes any form of replication near impossible. Furthermore, you have a few folks operating on faith instead of real evidence, similar to another "tech" we discuss around here. It's ridiculous. I'm not dismissing Woodward and his work which I feel is completely different, but Shawyer's ideas have already been dissected and refuted successfully in my opinion.

The biggest one that blows my mind is a guy claiming he built an emdrive that produces .4N of thrust, yet has not shown a single shred of evidence of said drive and deletes/deactivates his account on NSF and reddit when someone calls him on his bullshit. It's near identical to what happens with LENR when Rossi started claiming it was the mechanism in his vaporware reactor.

Re: EM Drive

Posted: Sun Apr 17, 2016 9:40 pm
by Skipjack
paperburn1 wrote:But if it presses against the rest of the universe then the faster it goes the less efficient it should become.
But everybody ignore the real reason this will never work , and that would be heat from the power plant.
I disagree. You can of course radiate the heat away from the power plant pretty easily with some cooling panels. How many of them you need depends on how hot the reactor runs. A hotter reactor needs LESS cooling panels (rather counter intuitive). Anyway, there are plenty of concepts for space based nuclear power plants out there.

Re: EM Drive

Posted: Wed Apr 20, 2016 6:45 pm
by TheRadicalModerate
The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster.

The assertion here is that it's quantized Unruh radiation.

Re: EM Drive

Posted: Wed Apr 20, 2016 6:57 pm
by ladajo
I swear this is in another thread. I recall commenting that it seems easy enough to test regarding thrust reversal and magnitude.

Re: EM Drive

Posted: Thu Apr 21, 2016 12:57 am
by AcesHigh
ScottL wrote:
Giorgio wrote:
paperburn1 wrote:But everybody ignore the real reason this will never work , and that would be heat from the power plant.
You would have to radiate that heat out somewhere from the power plant and even with current tech that is no small feat.
That, I would say, is just an engineering issue, not something I would be concerned about.
"IF" this EM Drive work than engineers will find a way to work around the issue of dissipating (or collecting) the heat out of anything that will be needed to power this thing.
But so far there hasn't been any clear indication as if this drive actually work or not. I remember the first time i read about this on SPR Ltd website, I saw these videos of a EM Drive spinning. Now, an independent test of this would be enough to prove the machine as real.
Why (I wonder) we never heard anymore about this?
Sometimes the reply to an obvious question is just an obvious truth.......
One of the biggest problems is that everyone experimenting with this idea has a completely different setup that aren't fully described. This makes any form of replication near impossible. Furthermore, you have a few folks operating on faith instead of real evidence, similar to another "tech" we discuss around here. It's ridiculous. I'm not dismissing Woodward and his work which I feel is completely different, but Shawyer's ideas have already been dissected and refuted successfully in my opinion.

The biggest one that blows my mind is a guy claiming he built an emdrive that produces .4N of thrust, yet has not shown a single shred of evidence of said drive and deletes/deactivates his account on NSF and reddit when someone calls him on his bullshit. It's near identical to what happens with LENR when Rossi started claiming it was the mechanism in his vaporware reactor.
are you following the experiments over at Nasa SpaceFlight Forums?

Re: EM Drive

Posted: Thu Apr 21, 2016 1:18 am
by ohiovr
kurt9 wrote:This will likely land me in hot water, but I think I will say it anyways. These EM drive experiments have produced positive results under certain conditions. The experiments done at the Eagleworks involved the use of a plastic disk in the microwave chamber. Apparently plastic is weakly dielectric. If so, the effect is likely real and is based on Mach's Principle. Someone on Dr. Woodward's email list suggested that they do experiments with and without this plastic disk. For some reason the Eagleworks people have not done this.

Woodward and Fern have been doing experiments that have positive results. They are quite open about the technical details and the results of their experiments. If Eagleworks and others are getting positive results, its possible that they are also inadvertently producing Mach effects as well.

As far as replacing existing transportation (cars, airplanes, etc.), this drive technology would have to scale up to at least 1/3 g thrust (typical of airliner takeoffs) with reasonable input power source. Right now, Woodward's results suggest 1/100th of a g, comparable to an ion thruster, which would be useful for deep space transportation but not for replacing existing Earth-based transportation.
You might find this story interesting:

MIT Technology Review

https://www.technologyreview.com/s/6012 ... -thruster/

The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster
Crucially, McCulloch’s theory makes two testable predictions. The first is that placing a dielectric inside the cavity should enhance the effectiveness of the thruster.
The second is that changing the dimensions of the cavity can reverse the direction of the thrust. That would happen when the Unruh radiation better matches the size of the narrow end than the large end. Changing the frequency of the photons inside the cavity could achieve a similar effect.

Re: EM Drive

Posted: Thu Apr 21, 2016 1:23 am
by ohiovr
TheRadicalModerate wrote:The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster.

The assertion here is that it's quantized Unruh radiation.
Ah I missed your post :mrgreen:

Re: EM Drive

Posted: Thu Apr 21, 2016 5:47 am
by ScottL
AcesHigh wrote: are you following the experiments over at Nasa SpaceFlight Forums?
Yeah and in my opinion they've gone off the rails significantly. The only one I'd entertain would be SeaShells experiment, but I feel like the experiment is always just days/weeks away since last October or so. Honestly though, it's hard to take them serious when the thread is moderated by a person who openly admits to trying to dox folks online. I'm not a fan of morally corrupt individuals.