Mach Effect progress

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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TallDave
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Postby TallDave » Mon Jul 18, 2011 4:35 pm

The energy goes into reducing the force of gravity, just like in a hovering rocket... even a perfectly efficient one.

A rocket would push particles the other way, which fly off with our lazy, no-work-doing kinetic energy. In the case of M-E, you're pushing against all the casually connected mass, which does the same thing but much less visibly.

The DC motor analogy is interesting though.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...

93143
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Postby 93143 » Mon Jul 18, 2011 5:36 pm

TallDave wrote:The energy goes into reducing the force of gravity


Wrong. You're comparing apples and triangles here. Arbitrarily large forces can be generated and/or resisted without expending any energy, as long as the components are stationary with respect to one another. This is what structural engineering is all about...

A rocket would push particles the other way, which fly off with our lazy, no-work-doing kinetic energy. In the case of M-E, you're pushing against all the casually connected mass, which does the same thing but much less visibly.


Bingo. This is what Stoney3K is missing.

@Stoney3K: you're treating the M-E thruster as a reactionless thruster, showing utter disregard for Newton's Second Law.

What is the thruster pushing on, and what is its velocity relative to the thruster?

Or, to approach it from a different angle, consider an M-E spacecraft with a power source on board. Can it generate any net thrust? If so, does the velocity of the spacecraft affect its power requirements?

...

I've explained all this before; you have no excuse for saying the things you're saying. I can only assume you haven't read my posts...

Stoney3K
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Postby Stoney3K » Mon Jul 18, 2011 5:36 pm

TallDave wrote:The energy goes into reducing the force of gravity, just like in a hovering rocket...


I don't know of any form of energy which corresponds to the 'force' of gravity.

Gravity itself is entirely passive, and something statically pushing against it (such as a pair of feet on a floor) is not a form of energy, let alone a flow of energy.

The rocket pushing particles out of the way is wasting energy because those particles have kinetic energy and bump into each other -- heat.

Think about this: What if you put your rocket into a sealed container, blocking the exit path of the particles on the other end, and fire it up?

Answer: It would build up pressure, and because of that, force pushing in against gravity. The gas particles will stay there, pressure will remain, and if you shut off the rocket's engines it will just stay where it is, 3 feet up the launch tube, standing on a pile of gas.

Of course, in real life, all of the gas would leak away and you'd be back where you started, but it does not necessarily take a sustained flow of energy to maintain a hover against gravity.

You are right, in the point that it takes an initial[i] infusion of energy (for example, the buildup of pressure) to gain altitude. This is perfectly explained because your rocket neets to increase its gravitational energy (mass * 9,81 * altitude) and it needs a source of energy to do so. In this case, its engines.

If it [i]stays
at the same altitude, its gravitational energy does not change (because neither its mass nor its altitude does) and if whatever static mechanism it has to maintain an upward force remains, it will just stay where it is.

Simpler example: We remove the rocket's engines and pull it 10 feet up with a hoist. Does the hoist need to keep running to suspend a rocket in the air? ;)
Because we can.

93143
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Postby 93143 » Mon Jul 18, 2011 5:43 pm

Stoney3K wrote:The rocket pushing particles out of the way is wasting energy because those particles have kinetic energy and bump into each other -- heat.

The rest of your explanation above is good, but this unfortunately is wrong.

It isn't just the random motion of the particles that causes a rocket plume to carry away energy. The bulk motion is actually even more important. A perfect, 100% efficient rocket engine (in vacuum) would exhaust a stream of mass at absolute zero, but with several km/s of relative velocity and thus a lot of kinetic energy. (Of course, once it hit anything it would stagnate and all that energy would turn back into heat/pressure, at least at the stagnation point...)

This is actually how the energy balance comes out okay for a rocket travelling faster than its exhaust velocity in the observer's reference frame - some kinetic energy is removed from the propellant by the engine...
Last edited by 93143 on Mon Jul 18, 2011 5:52 pm, edited 1 time in total.

TallDave
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Postby TallDave » Mon Jul 18, 2011 5:46 pm

93143 wrote:TallDave wrote:
The energy goes into reducing the force of gravity
---
Wrong. You're comparing apples and triangles here. Arbitrarily large forces can be generated and/or resisted without expending any energy, as long as the components are stationary with respect to one another. This is what structural engineering is all about...


Yes, very bad phrasing on my part. The force is not where the energy goes, it is just a result of where the energy goes.

I was re-reading your other posts, especially this:

For example, if you use an M-E thruster to push against a reinforced concrete wall, you will not get any energy out, because it is doing no local work. Distant matter is being shoved in the other direction, but that does us no good. (Well, technically it's probably doing more work on the Earth than on the distant mass, but it still does us no good.)

On the other hand, if you have the M-E thruster push on something that's moving faster than 1/E, you will get more energy out than you put in. This comes from the distant mass that is moving in the same direction as the thruster at about the same speed, and thus already has kinetic energy in the local reference frame. Some of that energy is being transferred to the object being pushed on, with the energy input to the thruster as a mere enabler.

Now do you understand why I posited that the mechanism of operation of the thruster would act preferentially on matter near the thruster's velocity? If something like that is not true, something really funky is going on (you know, assuming it works at all, and Woodward isn't simply barking up the wrong tree...)


Is your conclusion then that the M-E engine's efficiency doesn't determine whether an M-E flywheel generator is possible, but only its practicality (i.e. how hard it would be to build)? At least, according to the current theory that is supposed to explain the experiments.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...

93143
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Postby 93143 » Mon Jul 18, 2011 5:59 pm

TallDave wrote:Is your conclusion then that the M-E engine's efficiency doesn't determine whether an M-E flywheel generator is possible, but only its practicality (i.e. how hard it would be to build)?

Yes. Assuming Lorentz invariance applies to these thrusters and their thrust efficiency, at any thrust efficiency E there is a speed 1/E beyond which the thruster will do more local work in the laboratory reference frame than the power required to run it.

There are details of the principle of operation that I'm dubious about (notably how the effective average reference frame of the distant matter seems to stay stuck to the thruster, which seems to me that it may imply an entropy-condition violation), but the local mechanics are straightforward.

Stoney3K
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Postby Stoney3K » Mon Jul 18, 2011 6:05 pm

93143 wrote:
TallDave wrote:Is your conclusion then that the M-E engine's efficiency doesn't determine whether an M-E flywheel generator is possible, but only its practicality (i.e. how hard it would be to build)?

Yes. Assuming Lorentz invariance applies to these thrusters and their thrust efficiency, at any thrust efficiency E there is a speed 1/E beyond which the thruster will do more local work in the laboratory reference frame than the power required to run it.


So if I stick a 1N/W thruster on a shopping trolley and give it a push, rolling down the parking lot at 1m/s (3,6 km/h) I'm gonna need to run like hell if I want to catch it?

That doesn't really make sense. :wink:
Because we can.

93143
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Postby 93143 » Mon Jul 18, 2011 6:18 pm

Stoney3K wrote:So if I stick a 1N/W thruster on a shopping trolley and give it a push, rolling down the parking lot at 1m/s (3,6 km/h) I'm gonna need to run like hell if I want to catch it?

That doesn't really make sense. :wink:


No, it doesn't, because you haven't specified any way to harvest the work the thruster is doing in your reference frame and feed it back to the thruster. It's not doing any local work in the shopping cart's reference frame.

To do that you need a velocity difference in the apparatus - perhaps some kind of magnetic braking strip in the parking lot that's hooked to a power beaming device aimed at the thruster...

...or perhaps just alternators in the wheels; that would work too...

Of course, if there's a battery pack involved that's a different story, but that kinda sidesteps the whole question...

GIThruster
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Postby GIThruster » Mon Jul 18, 2011 6:56 pm

Stoney3K wrote:. . .Even an ideal thruster would comply with the law of conservation of energy: It may be able to supply a tremendous amount of static thrust, but once you start things moving and the thruster is under load, it will draw just as much energy as the work being effected on the target object.

Energy in means energy out, no strange physics here.


Technically this is true but I still think you're missing an important aspect of what makes M-E Thrusters so attractive. They don't draw just electrical power, they also draw power from the gravinertial flux in and out of the device, like a tide generator or a sail, so the power out can indeed be much more than the electrical power in. It just can't be more than the combination of electrical power in and gravinertial power in.

Once you have a thruster generating more than 100% mass fluctuation, where you have negative mass with its negative inertia, the vast bulk of the power into the device is going to be gravinertial, so you should be able to strap one to a flywheel and generate electricity with it.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

93143
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Postby 93143 » Mon Jul 18, 2011 7:13 pm

...I think you may be muddying the water here a bit. Given a thruster that works as described, it doesn't matter how well it works; it just has to work at all for energy harvesting to be possible in principle.

But I agree that it is good to point out that this isn't a device for converting supplied electrical power into local mechanical power. That idea isn't even consistent with what it does, and to maintain otherwise as Stoney3K is doing betrays a fundamental misunderstanding of mechanics.

GIThruster
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Postby GIThruster » Mon Jul 18, 2011 8:03 pm

93143 wrote:...I think you may be muddying the water here a bit. Given a thruster that works as described, it doesn't matter how well it works; it just has to work at all for energy harvesting to be possible in principle.


I'm still trying to understand how this is so. You think this is a result of locally decoupling the action and reaction masses, so that the reaction is always in the global frame?
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

93143
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Postby 93143 » Mon Jul 18, 2011 8:38 pm

GIThruster wrote:
93143 wrote:...I think you may be muddying the water here a bit. Given a thruster that works as described, it doesn't matter how well it works; it just has to work at all for energy harvesting to be possible in principle.

I'm still trying to understand how this is so.

So am I, but it has to do with the internal operating principle of the thruster, and if it works as described you don't need to know anything about that; you just do the analysis with the thruster as a black box, and this result pops out.

If you start to get to an appreciable fraction of lightspeed, other factors may come into play (redshift in an external power supply, for instance, or the mass of energy stored in batteries, corresponding to the limiting mechanisms in the rocket flywheel problem for liquid- and solid-fueled rockets respectively), but Newtonian mechanics imposes no absolute minimum thrust efficiency.

You think this is a result of locally decoupling the action and reaction masses, so that the reaction is always in the global frame?

What is the "global frame"? I thought the whole point of Lorentz invariance is that there is no such thing...

I'm thinking that it involves the effective average velocity of the distant matter with respect to the thruster, as seen by the thruster, being somehow always very small or zero. Otherwise (it seems to me) the M-E thruster would have a preferred reference frame corresponding to the mean velocity of the thruster's lightcone. I haven't really formulated a complete theory or anything here; I have yet to systematically read through the available M-E literature, and I'm weak in GR anyway...
Last edited by 93143 on Mon Jul 18, 2011 8:46 pm, edited 1 time in total.

Stoney3K
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Postby Stoney3K » Mon Jul 18, 2011 8:44 pm

93143 wrote:But I agree that it is good to point out that this isn't a device for converting supplied electrical power into local mechanical power.


Technically this is true but I still think you're missing an important aspect of what makes M-E Thrusters so attractive. They don't draw just electrical power, they also draw power from the gravinertial flux in and out of the device, like a tide generator or a sail, so the power out can indeed be much more than the electrical power in. It just can't be more than the combination of electrical power in and gravinertial power in.


Is there even any proof that there is gravinertial power going into the device? Have we even got any means to measure it at all, or is it just speculation following the theories in scientific papers?

When it sounds too good to be true, it probably is. I'm not saying I don't buy it, but right now I'm at least skeptical as you seem to make some claims that make no sense *yet* in lab experiments. If it does what it says on the tin when running on the bench, I'd gladly have a look.

Even though I'd like a set of inertial dampeners as much as the next guy, I have to see it before I believe it. And if the whole lot works as advertised, it could even be dangerous: What if your beautiful power-extracting device enters a positive feedback loop and spins wildly out of control because there s no mechanism to stop it from harvesting all of the energy that ever existed in the universe?

Hmmm... good movie material here. :mrgreen:
Because we can.

93143
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Postby 93143 » Mon Jul 18, 2011 8:53 pm

No, bad movie material. I can see it now...

It's not going to harvest all the energy ever; it's got a certain thrust rating and the mechanism it's attached to can only take so much stress. Most likely the thruster would burn out if you fed too much of the output back into the input, but even if it didn't, something else would fail long before the system got dangerous in a wider sense than "get out of the room and close the blast doors"...

Actually, that's an important point I'm not sure you got the first time. This thruster doesn't automatically power itself once it gets past a certain speed. It just consumes power and produces thrust, same as usual; after all, it doesn't know it's moving fast in whatever reference frame you happened to pick. You have to design a mechanism to extract the energy inherent in the velocity difference between the thruster (plus whatever it's pushing) and something else, and then actively feed that energy back in via the power supply. It's just that if the velocity difference exploited by this mechanism is greater than 1/E, it can produce more power than is necessary to run the thruster.

...

Feel free to be skeptical. The evidence that these things work at all, while it appears to be mounting, is still not what one might call ironclad...

GeeGee
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Postby GeeGee » Mon Jul 18, 2011 10:37 pm

Stoney3K wrote:
Is there even any proof that there is gravinertial power going into the device?


I think you mean evidence. There is really no such thing as scientific proof.


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