Mach Effect progress

[hanelyp]

2 rockets.
one "sitting still".
the other passing the observer at 1km/s.
Both expelling 1kg/s at 1km/s relative to the rocket in the direction opposite the second's motion.

How much thrust is each producing?
How much power is each expending?
How much power is absorbed by each rocket vs. the exhaust from each?

[93143]

It doesn't suggest anything like a preferred frame.

Actually, it does suggest a preferred frame, which is why I suggested that some obscure GR weirdness (or a basic principle of Galilean physics that I'm stupidly missing, or something in between) might be automatically matching the effective mean velocity of the "far off active mass" with that of the thruster - not by actually rearranging the distant mass, of course, but by selecting it and/or weighting the interaction.

It seems to me that the M-E math has nothing in it that suggests a preferred frame, and it unquestionably implies interaction with distant matter (since that's the foundation of the model of inertia that's being exploited here). If the theory is correct, therefore, an M-E thruster will produce thrust via interaction with distant matter without any preferred frame of reference becoming apparent. Exactly how it does this will be a question for the mathematicians.

...wait. Is the relevant parameter the size of the observable universe or of the Hubble volume? (I thought it was the observable universe, but you can't get an advanced wave back from 46 billion light years away.) And would the latter imply...

I need to read more. No. First I need to get this turbulence partitioning scheme worked out; then I need to read more about M-E and GR. I think in Newtonian, and it's not working at cosmic scales.

the faster the thruster accelerates, the more input power is required to generate the same thrust

What has acceleration got to do with it? The conservation argument only deals with relative velocity. Your statement is incorrect in either case - rockets, whether chemical or electric, have constant power-to-thrust ratios at constant operating conditions, because when the frame of reference changes, all the parts - including the propellant - receive the same velocity increment, so all the relative velocities stay the same.

If there's a variable velocity difference between the device and what it's pushing on, as with a car on a road, the power-to-thrust ratio will be linear with that velocity difference. But rockets are not like this. hanelyp is proposing that M-E thrusters are. I'm proposing that they're not - as are you, with your claim that there is no preferred reference frame.

Given that Woodward's results appear to be independent of the time of day/year and the orientation of the thruster, I would suggest that the experimental data (such as it is) is on our side here...

[GIThruster]

I do appreciate your interest here, but I have to bow out.

Just saying, unless you are well skilled in GR, you do not understand why input energy is variant.

And we've had this conversation several dozens of times here at T-P.

Engineers need to get a hold of the fact that energy, and thus power, are NOT INVARIANT. They change with various frames.

If you ignore this, you are doing what your high school physics teacher told you not to do--treating accelerating, non-inertial frames as if they were inertial frames.

Here's the simplest fact of the matter--when a frame accelerates, it is no longer "inertial" and unless you use a transform like the Lorentz transform, you will get a wrong answer.

Most engineers never see reasons to use transforms. I get that and I have nothing against any engineers. I am just noting, this trouble with folks saying they have identified a conservation violation, almost always is the result that they are doing what their high school physics teachers told them not to do--treating non-inertial frames as inertial.

And given that I am not an engineer nor a physicist, I can't much explain past that. Fact is, the first 15 times I ran into this issue, I had no idea how or why to say to the engineers "STOP DOING WHAT YOU'RE DOING. YOU ARE LOOKING AT A NON_INERTIAL FRAME."

http://en.wikipedia.org/wiki/Non-inerti ... ence_frame

[93143]

Nobody cares about the acceleration. You can attach the M-E thrusters to two different planets if you want, so the thrust is substantial but the acceleration is negligible - you still get the exact same issue with relative VELOCITY.

You're not addressing the correct issue here; you're just handwaving about something you don't understand.

...

Also, I suspect you should read my post again; I edited it. How substantially, I'm not even sure, because I forgot that I had already submitted and was fiddling with a visible message...

[GIThruster]

Nobody cares about the acceleration.

Please read the wiki link.

Just saying, we don't all, always remember what our high school physics teachers had to say.

Sorry folks don't like this but just reminding, in accelerating frames F =\ MA.

Please read the link at wiki.

[93143]

I'm a mechanical engineer. You don't think non-inertial coordinate systems were part of my training? I know how to handle them and what to watch for. I know what changes, and what doesn't.

(Also, I will remind you that an accelerating object does not necessarily imply an accelerating reference frame. You can still analyze it from an inertial frame.)

READ THE REST OF MY POST. The acceleration doesn't matter in this case because it's not where the issue comes from.

[GIThruster]

Seriously. . .

Pretending engineers understand General Relativity--something they as a group have NO training in--is ludicrous.

The reason we have so many engineers object to M-E physics is that they have no training in Minkowski space, no training in hyperbolic transformation and no training in General Relativity.

That's why so many engineers offer complaints about M-E physics--they don't understand what GR entails.

Most engineers pretend they understand this stuff, based upon the notion that GR corrections will be small.

But in fact, the GR corrections state explicitly, that in accelerating frames, F=\MA.

If you're an engineer and want to prove that this above is wrong--go ahead! You'll be wrong.

Ignore your high school teacher at your peril. You CANNOT do kinematics in accelerated frames without a transform.

And no shit. . .I went through this with a PhD physicist at NASA just 2 years ago, and he was hopelessly and stupidly wrong because he presumed, he can do his stuff without a transform.

I still count him a friend, but he was wrong, Wrong, WRONG.

You can't look at accelerating frames without a transform.

Read wiki on this. It's no surprise that we can't do this math without GR transforms.

[hanelyp]

I honestly don't understand ME thrusters in detail. Something about an object's mass having terms dependent on derivatives of energy with respect to time. When I asked how they differed in behavior from a basic reactionless thruster, the answer I got sounded like frame variance. And it made sense that if the rest of the universe is reaction mass, the power for a given thrust is minimum if the thruster is at rest relative to this reaction mass.

As far as I can make out, neither 93143 nor myself were implying accelerating reference frames.

As for Newtonian thinking, it remains a valid model as long as you keep the limits in mind. To my knowledge the ME experiments to date operate well within the speed, gravity, etc. limits where Newtonian mechanics is valid. But the theory is proposing an effect outside Newtonian mechanics.

[GIThruster]

Well if you are interested but don't get it , BUY THE BOOK.

Stop wasting time with those who have a clue.

http://www.amazon.com/Making-Starships- ... 1461456223

[93143]

This is surreal. GIThruster, you're abusing people for not knowing physics, when not only do you not know the relevant physics yourself, but you haven't even understood what we're arguing about.

I'm not sure how much more time I should spend on this. I can explain, but only if you're willing to listen.

[GIThruster]

With all due respect, you do not understand the issue. If you did you would have ceased to argue about it long ago.

I'm not abusing anyone. I'm simply telling you what I have posted about literally dozens of times in this thread. Your posts demonstrate the precise opposite--you do not understand the real issue.

Contrary to what you write above, one of the two primary conservation mistakes people make when looking at M-E thrusters, is they treat a dynamic thrust relationship as if it is stationary. Like all thrusters, M-E thrusters have a figure of merit describing stationary thrust efficiency in N/W. However, that figure changes once the thruster is permitted to accelerate, just as it will change for any/all thrusters. No, you cannot, as you state above; look at this issue and pretend that you're looking from the lab or launch frame and allowing the thruster to accelerate, because the FOM is for a stationary thruster only.

I have had this conversation here in this forum more than a dozen times, and at NSF, and at NBF and it's not as if I'm going to be cowed into pretending I don't know what I'm talking about. When you say, in the midst of this discussion, that I don't know what the conversation is about, you forget who started the current discussion by writing that this is one of two historic mistakes people make. It is. If you want to pretend this is not one of the two historic mistakes people make, that's up to you. I am just telling you that this is PRECISELY the mistake people most often make, from myself and Paul March when we wrote it into the Warpstar paper back in 2006, to Andrew Palfreyman who still clings to this mistake today, to the dozens of naysayers who claim they can look at the thruster in a launch frame, allow it to accelerate and then take the thrust efficiency to prove a conservation violation. I'm telling you, you CANNOT do this as you state above, because the figure of merit for the calculation stipulates it is STATIONARY.

Now if you want to talk about something else, that's fine. I'll listen. But you need to recognize it is you who is changing the subject.

I'm cool with that.

[GIThruster]

I have listened to everyone who disagrees, including you on several occasions, and you know this.

[93143]

You really need to seriously consider the possibility that you're wrong, that you've been wrong for years, and that you are only making yourself look bad by continuing to insist otherwise without even listening to anyone who disagrees with you.

The weird thing is, I can't even do a worked problem to show you that you're wrong, because you don't understand or accept the premises of modern physics.

[93143]

Sorry; delete/repost with edits...

You have read some of what I've posted, yes. But you haven't understood it. This becomes painfully clear when you start talking about Lorentz transforms instead of acknowledging the simple and obvious reality that getting energy conservation in an analysis of a thruster of any kind requires one to account for energy transferred to or from what the thruster is pushing on.

THAT is why an M-E thruster doesn't violate conservation. Not some general-relativistic transform you admit you have no idea how to do.

[GIThruster]

If you want to give an example of what you mean, I'll be happy to look at it and comment but just saying:

If you take any thrust efficiency figure of merit in force/input power (N/W) and allow the thruster to accelerate at any rate over an arbitrarily long period of time, you can show that all thrusters will appear to violate conservation at some time in the future. This is because thrust efficiencies are stationary. Energy and thus power are not invariant so GR requires anyone doing this calculation will seem to uncover a conservation violation. I think it was chris who stated the issue quite well, as well as one of the folks over at NBF (the physicist there, not GoatGuy), that power in is linear, but power out would be quadratic, so this MUST yield a conservation violation. The remedy is to note that the dynamical relationship for stationary thrust can only be used while the thruster is stationary.

If you don't believe me, take the case of an Ion thruster and do the calcs.

Now if you're talking about something else, that's up to you, but I'm telling you this is the number one mistake people have made over the years, starting with me and Paul. I'm shouldering the blame. It was my idea to take what seemed a reasonable thrust efficiency of 1 N/W and form an illustration with it, producing the "One Gee Solution", the travel times to the various planets in our system, and the criteria for "the Golden Age of Human Spaceflight" as defined by what is "safe, quick, convenient and economical". All of these concepts were derived from the notion that we can build a thruster with an invariant thrust efficiency, and this is not true.

These concepts don't fail because the basis was wrong. They're all still achievable. However, the notion of an invariant thrust efficiency is entirely wrong. That's why I'm not publishing on these concepts--the material basis for them is subject to severe misunderstanding and conservation criticisms. And just noting, Jim did warn us about this before we wrote the paper by telling us "you can't do the math that way". He was right. We put in a disclaimer that we had made no relativistic corrections thinking that since we were dealing with a smallish fraction of the speed of light we'd be fine, but we were wrong. The trouble with Newtonian kinematics is not reserved only for high fractions of the speed of light. It extends to the variable or invariant nature of specific entities used in these sorts of calculations.