Mach Effect progress

[vnbt4]

What is the purpose of the stepper motor and how does it relate to the optical displacement sensor?

[Carl White]

So what is holding Dr. Woodward up here? Lack of funding? Lack of successful reproductions of his work? A scientific community that won't even look at his work?

Why aren't we hearing about plans to launch a small test device into orbit, piggybacking on some other mission?

[GIThruster]

What is the purpose of the stepper motor and how does it relate to the optical displacement sensor?

Sorry but I don't recall the details of how the optical sensor works. This may be in Jim's book but mine is out on loan.

So what is holding Dr. Woodward up here? Lack of funding? Lack of successful reproductions of his work? A scientific community that won't even look at his work?

The answer to this question depends upon what you see as holding up Jim's work. Certainly, all scientific progress depends in large part on replication. The broader scientific community requires replication as part of the process, and Jim is not in the position to influence people here. Though he can make himself available to help anyone who wants to do a replication and I'm sure would/will, he can't fund a replication and still have that replication provide the adequate independence necessary for this to provide the veracity tests replication is after. So yes, so far as science is concerned, the work is being held up by lack of replication, but this is not something Woodward can change apart from being available to instruct anyone who wants to do such work.

I'd note too, the last decade of experience clearly shows that those who want to do a replication seldom look for instruction, and this is not limited to Jim's work. It is most common for those wanting to do a replication to put their own brand on it, by doing something new--in the case of Mach Effect physics, to work at higher frequency. When people do this sort of thing they are not strictly speaking doing a real "replication". One could argue that they're doing a parametric study, but that is different than a replication. For a real replication, one needs to use the same frequency, the same thruster design, etc. What one can do however is use a different kind of thrust balance, etc., but note that this is the part that takes most of a year to set up all by itself. Using a new experimental setup is therefore laborious unless one happens to have such a setup such as what Eagleworks has down in Houston.

The science community has indeed looked at Woodward's work. The official word from NASA's Chief Scientist on propulsion research is that they have no one on their team able to appropriately judge the physics, which is no surprise since NASA is composed primarily of engineers, not physicists, and the proper judge of such a thing would certainly be composed of not only a team of physicists, but physicists whom are primarily skilled in field theory rather than particle physics, and whom are previously familiar with Mach's Principle and are neutral toward it as opposed to owning a predisposition one way or another. Such a team is difficult to find, regardless of one's resources. This is however, the only way to judge theory. Prejudices in regard to theory essentially disqualify one as a judge for that theory, on purely scientific grounds.

So far as Jim's progress, I haven't heard from him recently about whether he's got the PMN on the balance. I see only three options here. First would be he has it on the balance but obtained a null result and is trying to figure out why. Second is he has obtained a positive result and is trying to figure out how to respond to it. Third is he has not obtained a result for lack of electrical engineering of the power system, which needs to be changed for a purely electrostrictive material, or some other technical difficulty. And I should note there are probably other possibilities I've yet to consider. And of course, he is fast approaching the end of his working season so it may be his progress will need to wait until the Fall. Last I heard, he has a student coming into the lab to rebuild his Data Acquisition System this summer; I think installing some Labview equipment. Could be he made an early start on this as well. There are several things that could explain the current standing of his work. In any case, I'd expect we'll know more by the Fall at the latest.

Note here again, that moving to PMN is a very large step in both proving out the physics, and producing more thrust. At its peak performance temperature, PMN has 20X the k value of the PZT he uses, and a higher electromechanical linking coefficient. All other things being equal (and they never are) one should expect at least a factor of 400 improvement in both thrust and thrust efficiency when the thruster is thermally stable. I don't know however, whether the current design includes active cooling nor whether it can even be run at the proper temperature which is significantly below room temperature. All I know is, replacing the ceramic could provide dramatic evidence for theory, as well as improved thruster performance. This is what we ought to hope for as Jim's work continues.

As to replication: Jim did express an interest in building two new thrust balances, but his decayed physical health has made it impossible to work in the university machine shop. He actually went in with his two canes (his legs are giving out on him as result of years of chemo) and was told he cannot use the equipment there in his condition. If there were someone available to do that work for him under his instruction, it's very possible he'd consent to fund three new improved balances instead of two, and that person would have access to their own world-class piece of lab equipment.

And of course there's the observation that given Jim's interest in building two new balances, odds are pretty good that he has already had a dramatic improvement with thrust using the PMN and has chosen not to make public statements about this. And there's the obvious, that lack of funding has always held up Jim's work. He can't afford to purchase the best ceramics, nor have an electrical engineer in the lab doing the power system work so he does it himself. That takes a lot of time, especially when you're in your seventies, on crutches, and can't see to solder effectively. Jim complains that both his hands and his eyes are going on him in addition to his legs. So yeah, the work is suffering for lack of investment, both financial and in human resources.

[tokamac]

I don't know however, whether the current design includes active cooling…

I am pretty sure Jim never used active cooling. It's doable but a bit tricky since experiments are done in vacuum (if you use liquid nitrogen for example, it already boils at standard atmospheric pressure so I would expect it to quickly evaporate in vacuum, though I'm not sure). But those experiments don't need to run for a long time.

… nor whether it can even be run at the proper temperature which is significantly below room temperature.

On a side note about room temperature: the device operates at room temperature, yes. But not a room pressure (atmospheric pressure). As I said above, it runs in a vacuum. And in vacuum, no air is present to dissipate heat through molecular collisions (i.e. thermal conduction). So heat dissipates only through a radiative process, which is very inefficient. That's why the temperature rises so fast in the device in a few milliseconds. Heat can't drain off in a vacuum. I hope too we can see some new setup running with active cooling soon.

[GIThruster]

One can put a couple Peltier coolers on the reaction mass for $5 and for another $30 get a temperature controller, all on EBay, but then new power leads need to be brought through the balance so modifications need to be made there. That may be the mods Jim was looking to do with the new balances. All those sorts of leads go through axially mounted galinstan pots so there's not even sub-nanonewton torques involved. Jim is dissipating about a watt, so at 2% efficient, Peltiers don't need much power to do the job.

Not all the experimentation requires vacuum. If you know you're looking at a garbage signal and need to remove it, then empty the chamber but I would think since there has never been any change in signal found with any pressure on the thruster that most times Jim doesn't spend the time to empty it. Probably just for taking formal readings.

[kunkmiester]

Would the new dielectric provide enough improvement to produce a signal above noise at normal pressure?

[GIThruster]

If Jim can run the PMN about 60 Khz at its peek 20,000 k value temperature--about 38*f--he could see a 3-4 orders magnitude increase in thrust with no increase in noise. The Carvin would clip the 2w portion though, so he'd need a better amp. I don't know what he plans to do, but he did say he plans to go to higher frequency. Thrust goes with the square of the frequency, so if he replaces the Carvin he could push up into the hundreds of Khz and get 5 orders increase. A lot depends upon the preload however. He already has a pretty crappy preload and that will get worse as the frequency climbs.

[AcesHigh]

Assuming all that Jim needs is materials and equipment, how much money would be need, in your opinion, to be able to create a definitive tech demonstrator w with magnitudes greater thrust without greater noise?

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[GIThruster]

From what I understand, he has what he needs to do this now. Even if he has to chill the PMN externally with an icepack before running it, if it is close to its peak k value when he does, he ought to be able to generate 2 full orders magnitude higher thrust at the same frequency he's been using. I'm anxious to hear how the work will go with the PMN but he has been silent on the issue.

If someone where to build their own lab to do similar work, by far the most expensive thing would be the pay for the people. Jim works unpaid. If you want to go out and buy a $100k high speed auto impedance matcher you can, but there are certainly ways around this. Duncan Cummins' switch mode generator was built into a coke can, along with the MLT he tested. It doesn't require impedance matching. If he can put in the magic doubler circuit Jim has for the 1w+2w signal, then he could use that to run a 1Mhz test item that should produce large mN of thrust. This is just one example of what is possible given the proper coordination of resources. There are others. For instance, one could just design a PZT based MET designed to work with Duncan's coke can. That's cheaper than almost anything else. The trouble is, you need to revisit the preload issue in a serious way and Jim has shown he is not willing to do this.

Personally I think the trouble is moving from pure research to R&D. There needs to be a new venue where building a TRL7 demonstrator is the immediate goal. Build something that can fly a nanosat from ISS to equatorial orbit and clearly demonstrate you can build commercial thrusters.

[hanelyp]

Putting the RF generator inside a can with the thruster device, with good bypass capacitors on the DC feed line, would tend to address one suspect source of false signal.

If possible, it would be nice to drive both piezo actuator and active mass element at resonance. This has an advantage of more power delivered for a given driver current, and a known phase relationship to voltage.

[GIThruster]

This is the common engineering concern with the feed, that it needs to be self contained. When you look at Jim's setup, it is perfectly obvious there is no spurious source coming from the feed. Not just that its AC and time averages to zero, but because one of the protocols is to twist the thruster 90* so that it consumes power identically but does not generate force in the direction the balance moves in. If the feed were creating a spurious signal, you would still see that with the thruster rotated and you do not. So there is no reason to go miniaturized so far as isolating spurious sources, but there are other, better reasons to go self-contained, including what is necessary for a TRL7 demonstration.

The piezo actuator is the active mass. It needs to be on both mechanical resonance so it develops proper extensions and accelerations, and on electrical resonance so it has the proper dE/dt to create Mach Effects.

[hanelyp]

From my radio background the influence from the transmission line having a time average of zero is anything but obvious. Put a conductor in the near field of the transmission line and induced currents could still produce a net force. The effect of quadrature phase shift control case isn't so clear to me without a more in depth look.

[GIThruster]

None of the concerns people have about the experimental setup are clear without an in-depth look. The process is however completely transparent and anyone who wants to write Jim and be put on his list for the next work season is free to do so. If you want his email shoot me a note.

Do keep in mind that the list is full of engineers, many of whom have PhD's and some of those from the best institutions around the world and whom are at the top of their field. Its not as if without a detailed look you'd find something they haven't. Especially after The Aerospace Corp did their analysis, I just don't think anyone is going to find a spurious source that's been overlooked. While this is always possible, it is extremely unlikely.

[AcesHigh]

Does anyone remembers the calculations for Dr. White's warp effect speed? There was the initial "boost" right, and some other factors, from which you could calculate the final speed in light years per hour or something?

I tried finding it but this thread is already 144 pages long...

[Betruger]

http://ntrs.nasa.gov/archive/nasa/casi. ... 015936.pdf ? I don't have time to read thru it