New propulsion system

[Aghanim]

Well this is not VEEG BS drive, this BS drive has been tested by NASA, several times and it comes under the name of Woodward effect thruster or another version that KSP Interstellar uses, Quantum Vacuum Plasma Thruster

The good news is there are a lot of independent verifications of this:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492_2011024705.pdf

http://physics.fullerton.edu/~jimw/ASPW2012.pdf

http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=31119.0;attach=496011

http://www.otherhand.org/wp-content/uploads/2012/04/STAIF99-Paper-Mahood.pdf

The last paper is interesting because of this:

VALIDATION OF EXPERIMENTAL RESULTS

Naturally when faced with effects as sensational as these, one must be extremely cautious not to jump to

conclusions, tempting though it may be. Accordingly, a great deal of effort has been spent trying to make this effect

"go away." It doesn't, at least when it's not supposed to. While a complete discussion of validation efforts would fill

a paper many times the length of this, the topic deserves at least some mention. Some of the validations include:

· Running the devices with the capacitors shorted. In this case, the currents flowing within the device are the

same, the mechanical operation is the same, but there is no capacitance and no effect is present.

· To rule out non-linear responses of the weighing diaphragm (of which some are generated during testing), runs

were made energizing only the PZT or only the capacitors (the capacitors introduce negligible vibration into the

system). Thus the mechanical vibratory modes were duplicated (when running only the PZTs), but unless both

PZTs and capacitors were properly energized, the effect was absent. Also, holding the mechanical vibratory

modes constant, the effect was noted to scale proportionally to the power applied to the capacitor, while nonlinearities

should scale with the level of vibratory activity. Finally, it was found operation in a vacuum greatly

reduced the oscillatory response, while the stationary effect either remained constant or increased. Were the

effect generated by non-linearity of the spring diaphragm, it would scale with the oscillatory amplitude of the

diaphragm.

· Duplicating the EM environment within the test cell by running a device with unconnected capacitors, and

energizing capacitors immediately adjacent, but unconnected to the device, without effect.

· Running the device in both horizontal and vertical modes to rule out coupling with the local gravitational field.

The thrust produced was the same in both orientations.

· Observing the presence of the effect using several "garden variety" capacitors. While thrust produced was very

low and partially masked by the noise induced by the electromechanical activity of the capacitors, it was still

clearly identifiable.

· Verifying that the output scales proportionally to the power applied to the capacitors, as predicted.

· Noting that peak force outputs correspond with the measured peak, absolute accelerations of the capacitors.

· Shifting the phase relationship between the capacitors and PZTs over a sequence of runs. The results show a

shift from a maximum positive force, to a maximum negative force, and back to positive, over 2p radians, as

predicted.

· Running the device in a vacuum to rule out spurious effects from ultrasonic standing waves.

· "Inadvertent" validations wherein a capacitor unexpectedly cracks or becomes damaged during a testing

sequence and noting the simultaneous drop in the magnitude of the effect.

And in the PPT slide:

Thermal Effects:

Qualitatively, the spectacular thrusts of the previous slides

are hard to discriminate from thermal effects, for when

the rate at which heating takes place in the device changes

quickly, the rate of thermal expansion of the device also

changes, and this can produce a thrust on the balance

beam.

Steady heating and expansion do not produce a force on

the beam, for the expansion proceeds at constant velocity.

Dean drive effect:

Earlier work showed no appreciable change

in the thrust signals when all of the vibrations

damping was removed, indicating that the

thrust signals are not attributable to a Dean

drive effect.

That conclusion is further supported by the

response of the accelerometers fixed to the

central balance beam support column and

the collection of data for full vibration

isolation, and when part of the isolation

measures were removed.

TL;DR: They already tried hard to exclude another potential source of anomalous thrust, but it is still there

And the weird thing is most of those papers say that this effect could be used to make warp drives and transversable wormhole. Go figure.

[TheDarkStar]

I'll be interested to see what K^2 says about this. It seems fishy to me because of it's propellentlessness, and I doubt that it actually works as claimed - there will be a unsolvable practical problem somewhere.

[SargeRho]

It's propellantless in the same way a ship's propeller is. You still need to power the thing. It uses quantum fluctuations as propellant I think.

If the number I heard previously, of .1N thrust per kilowatt of power is correct, these things could make traveling to other stars withing a human lifetime a reality.

Edited January 21, 2014 by SargeRho

[Themohawkninja]

If this is the same thruster I stumble upon on Wikipedia, I was confused about one thing: How does a propellantless thruster have a finite ISP?

[Aghanim]

They shouldn't have any ISP at all?

[sojourner]

Same thing.

[Themohawkninja]

They shouldn't have any ISP at all?

Either 0 or infinity, but according to the Wikipedia article (with two sources on this quote):

Test results have suggested thrust levels of between 1000–4000 μN, specific force performance of 0.1N/kW, and an equivalent specific impulse of ~1x1012 seconds.

Now, it does use the term "equivalent", so that might have something to do with it.

[TheGatesofLogic]

It seems to check out from a cursory glance but i wouldn't bet money on it. It's just another quasi-reactionless propulsion mechanism of which there are a decent handful, many of which have survived similar if not more rigorous theoretical analysis and testing. The EmDrive, which i have been reviewing on the side for quite some time (mostly at the behest of a friend, but i have plenty of unused time) has equal value in this regard and is, from a theoretical standpoint, not entirely implausible. Though i hold my own doubts with regards to these, since any portion of the energy-momentum 4-vector must be maintained separately, and these seem to imply that this does not hold for these devices.

[Ravenchant]

If the number I heard previously, of .1N thrust per kilowatt of power is correct, these things could make traveling to other stars withing a human lifetime a reality.

It would be awesome if it is possible, but the power requirements seem absurdly low. Ion engines dream of such efficiencies!

[K^2]

All of the operational quantum thrusters are just a variation on photon drive. The nice thing about it is that they can be way more energy-efficient as photon drives than something like a laser. The downside is that they are still just photon drives. That means you need 300MW/Newton of thrust. Everything else is errors and misreporting.

[Aghanim]

Well photon drive should emit photons, right? So the theoretical drive emission could be detected somehow. Somehow...

[K^2]

Right, but there is a lot of EM noise coming out from the device itself, and the photon drive based on quantum plasma will have a broad radiation spectrum. So yes, it should be possible to detect, but it might be difficult to distinguish it from background. At least, until you get into high enough power ranges where it becomes unmistakable.

The current problem is that in this experiment they claim to measure 2 orders of magnitude more thrust then there should be at that power consumption. Now, they have a bunch of BS about universe as reaction mass to explain it, but that's just hand-waving. QFT predicts that any momentum transferred to quantum plasma will be emitted as radiation. Id est, a photon drive. And if on the output you have photons with certain amount of energy, you must have expended that much energy. They have absolutely no theory to go up against that. What they do have are measurements with a lot of noise, where their claim of measuring thrust precisely enough to say anything more than, yeah, there is some, is overstated.

So for now, assume that it should read 300kW per 1mN of thrust, and 3x10⁷s of I_SP, and the numbers they state are experimental errors.

Now, if they do manage to reduce noise and show that they really are getting more thrust, that will be very interesting, and we'll need new physics to explain it. But it's not going to happen. Just like there were no faster-than-light neutrinos or anti-gravity superconductors. Just experimentalists getting way too excited way too early and not checking their wiring properly.

That said, QT might still turn out the best damn photon drive we can come up with, and that's worth investing research money into.