Cap 23, 00 / Dec 24, 16 12:55 UTC

EMDrive: A pseudoscience in one community, a technology in use in another  

Chinese scientists announce that they had already been testing EMDrive in space while a part of Physics community is still partially skeptic about it. It also states that it will soon start using this technology for satellites:

http://www.sciencealert.com/china-is-claiming-it-s-already-started-testing-an-em-drive-in-space

  Last edited by:  M Moniruzzaman (NCM, Asgardian)  on Cap 23, 00 / Dec 24, 16 17:37 UTC, Total number of edits: 1 time
Reason: missed a word

Cap 25, 00 / Dec 26, 16 20:47 UTC

It's very difficult to check without the peer review, just as the article states, but think we have to reunite our best minds on that before this technology gets patented and become part of the enslavement of humanity through energy dependency.

Cap 26, 00 / Dec 27, 16 11:27 UTC

Maybe we could build a hybrid spaceship, like that you can use whatever engine you want. ;-)

Grtz, Dirk.

Cap 26, 00 / Dec 27, 16 12:47 UTC

"It's very difficult to check without the peer review"

Right. However, two separate papers regarding the core technology had previously passed peer review. They can be found here:

http://aip.scitation.org/doi/full/10.1063/1.4953807

http://arc.aiaa.org/doi/10.2514/1.B36120

"we have to reunite our best minds on that before this technology gets patented and become part of the enslavement of humanity through energy dependency."

Well :) , EMDrive was patented long ago, somewhere between 1999 to 2006, by original British inventor Roger Shawyer. That is why NASA had to use a slightly different design for this drive to test. Roger Shawyer recently even patented the second generation design of EMDrive, which you can find here:

http://www.ibtimes.co.uk/emdrive-roger-shawyer-patenting-new-design-next-gen-superconducting-thruster-1585982

"At present it produces too weak thrust, not practical."

EMDrive is not meant for high delta-V operations like throwing up a ship from ground, rather suitable for high T and low delta-V situations, like satellites, or time consuming interstellar flights where the slow but continuous propulsionless acceleration can eventually lead to extremely high velocity.

"Maybe we could build a hybrid spaceship, like that you can use whatever engine you want. ;-)"

That is the core idea and possible application so far it seems.

Aqu 02, 01 / Jan 2, 17 01:17 UTC

Even though it's pseudoscience, the concept behind this new technology is very interesting, and I find myself fascinated by it. If I have money to waste, I'd like to waste it on this kind of subject.

Aqu 02, 01 / Jan 2, 17 12:39 UTC

It's cheap enough to build, many people having done so for shed-based experiments.

It is low specific impulse, but that's not to say this is unusable, and this impulse is from commonly a small model. A larger one with a more powerful microwave transmitter may have increased effect - as may the shape of the cone etc. Concept proven, it's now about more efficient designs. It's worthy to note things like the eagleworks tests took place @ 17W»80W of input - really low, for propulsion.

And this could potentially lift from the floor, just slowly, as it does work inside atmos - IIRC it'd take a few hundred kilowatt and about twenty mins to lift about two tonnes out to LEO. Shawyer is more looking at satellite propulsion and assisting traditional launch methods more however.

Other "interesting" things of similar nature to be observing would be Fetta's "Cannae drive".

Aqu 12, 01 / Jan 12, 17 06:16 UTC

Would only work in near zero gravity. In Zero gravity it would be slow to start but could accelerate to near light speed given enough distance. Then you have to figure out how to slow down.

Aqu 13, 01 / Jan 13, 17 18:47 UTC

The low impulse is consequence of the low power model and early design being inefficient. Better waveguide designs and increased input will result in increased output. This is the dawn of a technology. Look at the average horsepower of a car in the late victorian times, and now - or the first ford and some common modern model... The first cars would struggle with a hill, or had more than one person - and mechanically fail every 30s - LeMans was impressive, just having a car that could run for 24hrs, let alone racing... over time, through development of the technologies itself, and supporting technologies, this technology became casually realiable... Better usage of the operating principles lead to more tangible output for a given input...

Currently, the tech is looking at least suited for microgravity application... specifically long operation or long distance projects. Not everything requires a lot of thrust, sometimes it's just about putting it in the right place, at the right time... and with EM-Drive, that also opens up for long enough... And you can can parallise - That's per unit. Add more units. If a single satellite can be made to be given viable vector control via such methods the three, maybe six, of these can begin to add together like ants and tow...

Eventually, it's suitable for gravity application, with sufficient development. It's do-able now, really, It's just generating that much energy - that's do-able too - safely is another question, and cheap is definitely another. 80W of microwave energy isn't a lot... most residential models topping 800W.. KW, hundreds of, is feasible. Megawatts if running multiple units for extra thrust is also possible, again not cheap - but it's not impossible to make it work in gravity as is... it would make more sense to make it more efficient before attempting to scale it, tho.

Aqu 17, 01 / Jan 17, 17 02:20 UTC

Actually, the EMDrive is not just about a good technology, it gets into the fundaments of physics, because the only way it could work is by violating the 3rd Newton's law and that is a very very very strong statement. There isn't a single experiment in the history of humanity in which that principle isn't right. That's why the majority of physicist aren't taking this too seriously. It requires investigation of course, but just like the news of super-luminal neutrinos were wrong this is probably an error in the experiment. If you look at the paper published by NASA they propose some explanations to why they measure a force.

Aqu 17, 01 / Jan 17, 17 11:47 UTC

It's definitely posing some interesting questions.

It doesn't have to be violating the third law.

The "body" the force is acting on doesn't actually have to be the waveguide, or the "engine" - it could be pushing against the waveform itself, transfering force through the waveguide, or it could be the waveform interacting with some hitherto unmeasured quanta to which the "sealed" nature poses insignificant resistance(or, not significant enough to remove detection of thrust).

But, there's loads of things it could be... securing .gov funding for devel of the mk2 EM-Drive I don't think it's likely to be an error in readings. I'm slightly unwilling to build a 80KW+ model in order to test it - maybe once I can generate that much power cheaply - I'd guess at it'd take about that, maybe a little more, to pick itself up off the floor - at which point there's pretty much no doubt as to if it does/doesn't, it's purely down to why.

Pis 18, 01 / Feb 15, 17 16:49 UTC

Except, the EM drive is complete rubbish and frankly pseudoscience. I am honestly saddened this conversation has gone on this long....

Pis 19, 01 / Feb 16, 17 05:32 UTC

So, you've built a model tested it thoroughly and concluded it produces no viable thrust?

Pis 22, 01 / Feb 19, 17 05:05 UTC

Yes, you keep saying this. And continually fail to offer any hard evidence for the feasibility of the product, or why we couldn't just take an existing design and scale it ourselves, but this time to the size of an 18650 instead and get even more impulse from the same amount of fuel.