Gravity-based sensors

[Jedi Master Spock]

Actually, mass lightening is quite explicitly explained in "Deja Q." In order to move the moon, they reduce its inertial mass by reducing its local gravitational constant.

Okay, so the energy still has to come from somewhere, like being transferred to/from subspace via the warp field.

And reducing G locally won't reduce mass (thus making the object easier to push), just the gravity well.

And the gravitational pull outside the warp field could still be the same, the extra gravity well being generated by the warp field.

You aren't familiar with the episode in question, are you? They decide to reduce the inertial mass of the rock in question by reducing its local gravitational constant. The two are quite clearly unified in Trek's version of reality.

If you think for a moment about what the behavior of an object is in a gravitational field when you reduce its inertial, but not gravitational, mass, you may realize that we don't see this behavior in Trek.

(If you think about "Deja Q" in particular, the results of the rock in question suddenly sharply accelerating towards the planet would not be pretty.)

I could also bring up the issue of Romulans using artificial black holes as power generators with controlled outputs; gravitational blocking and/or local variation of G provide very elegant solutions to a number of problems that otherwise make things quite messy.

There's still no way to transfer this energy.

Is there any way to transfer gravitational energy? That's the basic idea behind invoking gravitons - an intermediary particle that transmits energy and momentum, i.e., communicates the gravitational force. The question of the mechanism of energy transfer is quite trivial.

There are two basic questions that need to be solved in order to figure out where the energy is being shifted around. First, the energy change resulting from the change in field when you block the graviton flux through the envelope. This in turn depends on the energy tied to the gravitational field, which is - to put it briefly - a question under research with many associated problems that aren't easy to solve and which may or may not have a good answer.

Second, the energy change involved in moving objects around near the field, which is what you are talking about. The basic requirement for the altered field itself to meet conservation of energy is actually a fairly simple one - g must be well behaved. If g is a nice well behaved function, then every closed loop path has a net zero energy change. Think about the mesh diagrams:

If g(x,y,z) is smooth and continous in all directions, you have no problems.

If you assume a continuous distribution of matter (part and parcel of the treatment, there are no true point sources), then as you go from one location to the next, the amount of mass being "blocked" from attracting you changes continuously, meaning in turn that g will be neatly smooth and continuous.

One thing you will notice then is that there's actually a bit of repulsion [outward] around the "edges" of what you seem to be thinking of as a column, and that even if you have a single source that you're shielding from, it's only locally "flat" in a relatively small region.

I can draw you a picture using the Earth and a graviton-blocking disc as an example to show where the "sideways" force comes from when you have a continuous distribution. Basically speaking, when you're on the left edge of your graviton-blocking disc, the whole right side of the Earth is shielded from you, while the whole left side is not, meaning you are pulled left as well as down. Shrink the gravitational source to something small, and the forces around the edges of the "shadow" start looking funnier and funnier, but as long as you're using continuous distributions, the field will be well behaved.

Make the blocking field(s) large enough with respect to your "source" object, and you get around to the case of the warp field that lightens mass to a fraction arbitrarily close to 0. Different sides to the same coin, really - blocking gravitons extrinsically or turning partially transparent to them, it amounts to the same level of complication in the end.

Exactly. But for the graviton shielding to work, that's exactly what would have to happen.

No, not really. Actually, it's pretty easy to express the change in the energy of a static situation pretty easily as the sum of the product of parallel fluxes of gravitons being blocked, but that's pretty limited.

If it's "quite possible" to explain it, then, by all means, do explain where the energy goes. From what I'm seeing, the system can either gain or lose energy depending on the direction objects are moving in the "shadow." How is it possible for the Graviton Eater 3000 to gain 100 MJ in one run (massive object moving closer to the planet through the "shadow") and to lose 100 MJ in another run (same object moving away from the planet)?

Your graviton blocking device needs to take up the energy from the change in gravitational field (and of course, since you turn it both on and off and move the device around, all those changes as well), i.e., the energy (and momentum, but gravity is symmetric, so that's taken care of by blocking gravitons in both directions), i.e., the positive or negative energy associated with the flux of gravitons being blocked.

Change the positions of the objects and the flux changes.

So, again, I have to ask: what mechanism is there that can allow the device to gain energy one time, and lose energy another time?

You yourself have suggested sending it in and out of subspace.

Why can there only be one trick question? (It could be testing his ability to logically think through imprecise terminology.)

If it was a trick question with incorrect premises, the proper logical Vulcan answer would have been to point it out as such (e.g., "Gravitons cannot be blocked.") If by "imprecise terminology," you mean "anti-graviton" vs "graviton," then the "trick" part of the problem wouldn't be relevant to our discussion in any case. (If you can block an anti-graviton you can block a graviton - no problem with that at all.)

Just because it's not noticeable to humans doesn't mean it isn't pulling 1e-8 g's on the gravimeter (which is enough for today's gravimeters to detect). Again, I don't see any evidence that require any absurd level of precision.

So? When they detect their gravimeters suddenly going from pointing whatever towards the CE, they know it's from the CE. Again, this doesn't require us to assume the Enterprise was equipped with absurdly sensitive gravimeters.

It wouldn't point suddenly towards the CE to take your claims in conjunction with a weak signal. After all, all the other sources are still present, "confounding" the vector. Aren't they?

The Enterprise was not at warp.

Are you sure?

Sure there is. So far, there hasn't been any evidence presented that would require the use of absurdly sensitive gravimeters.

Directional graviton flux detectors are much more strongly suggested than hypersensitive gravimeters.

Yeah, but it's not enough to tell you there's a starship hiding behind a moon when you're in orbit around a planet.

Actually, it is, provided you know the moon's field well enough. That's not the sort of light minute range you're talking about.

[SailorSaturn13]

That's assuming the warp field doesn't emit extra gravitons outside the field to keep everything in sync.

Reaching up to Andromeda Galaxy?

If it's "quite possible" to explain it, then, by all means, do explain where the energy goes. From what I'm seeing, the system can either gain or lose energy depending on the direction objects are moving in the "shadow." How is it possible for the Graviton Eater 3000 to gain 100 MJ in one run (massive object moving closer to the planet through the "shadow") and to lose 100 MJ in another run (same object moving away from the planet)?

Establishing field in bidirectional flux requires energy proportional to product of fluxes.

Releasing gives back energy proportional to product of fluxes AT RELEASE TIME.

The movement is automatically calculated by difference between what you give and what you get.

And again, soliton wave got energy from nowhere

How does CoE continue to be followed after the destruction of the device when the "shadow" is moving at lightspeed a million years later, still disrupting potential energy of objects?

The diffraction will nullify the effect over big distances.

A "photon detector" encompasses more wavelengths than the visual range we call "light."

No a photon detector can measure properties of photons which a light (or EM) detector can not.

[Jedi Master Spock]

If you assume a continuous distribution of matter (part and parcel of the treatment, there are no true point sources), then as you go from one location to the next, the amount of mass being "blocked" from attracting you changes continuously, meaning in turn that g will be neatly smooth and continuous.

... provided, mind you, that I have my sketch straight on the well-behaved nature of the function. If not, stick in the proper outwards repulsive effect (invoking whatever appropriate Treknobabbled explanation you feel like) and you can meet up with COE.

Something that can't be overemphasized is just how problematic it is to speak of the energy of a gravitational field and the number of problems that "antigravity" produces...

...along with how essential the "antigravity" technologies are to the fictional franchises we're talking about. As I've said, Romulan power plants, the warp field, the directional gravitational sensor, Spock's magnetic envelope question, the landspeeder with its "magnetic" levitation, and the antigravity drive that only works near planets... all rely on the same basic idea.

[Keiran]

You aren't familiar with the episode in question, are you? They decide to reduce the inertial mass of the rock in question by reducing its local gravitational constant. The two are quite clearly unified in Trek's version of reality.

If you think for a moment about what the behavior of an object is in a gravitational field when you reduce its inertial, but not gravitational, mass, you may realize that we don't see this behavior in Trek.

(If you think about "Deja Q" in particular, the results of the rock in question suddenly sharply accelerating towards the planet would not be pretty.)

Encompassing the moon in a warp field would then obviously require pulling KE from the moon as the mass decreased, so that the velocity could stay the same.

I could also bring up the issue of Romulans using artificial black holes as power generators with controlled outputs; gravitational blocking and/or local variation of G provide very elegant solutions to a number of problems that otherwise make things quite messy.

That would depend on the mass of the artificial black hole, now, wouldn't it?

And violation of CoE is messier than anything you've brought up. Period.

Is there any way to transfer gravitational energy? That's the basic idea behind invoking gravitons - an intermediary particle that transmits energy and momentum, i.e., communicates the gravitational force. The question of the mechanism of energy transfer is quite trivial.

There are two basic questions that need to be solved in order to figure out . First, the energy change resulting from the change in field when you block the graviton flux through the envelope. This in turn depends on the energy tied to the gravitational field, which is - to put it briefly - a question under research with many associated problems that aren't easy to solve and which may or may not have a good answer.

The lack of a gravity well in the "shadow" makes giving the object potential energy rather difficult, wouldn't you say?

Second, the energy change involved in moving objects around near the field, which is what you are talking about. The basic requirement for the altered field itself to meet conservation of energy is actually a fairly simple one - g must be well behaved. If g is a nice well behaved function, then every closed loop path has a net zero energy change.

[...]

If g(x,y,z) is smooth and continous in all directions, you have no problems.

If you assume a continuous distribution of matter (part and parcel of the treatment, there are no true point sources), then as you go from one location to the next, the amount of mass being "blocked" from attracting you changes continuously, meaning in turn that g will be neatly smooth and continuous.

Great, now prove your assertion that the altered field's curl is 0.

Then all you have to do is show how energy travels to or from the object to the Graviton Eater 3000. Y'know, the question I've been asking you to answer. Remember: the energy can flow both ways, so there has to be a provision for bidirectional transfer. Gravitons move one way, and since one of those directions is blocked, only half of the problem is explained (at best).

One thing you will notice then is that there's actually a bit of repulsion [outward] around the "edges" of what you seem to be thinking of as a column, and that even if you have a single source that you're shielding from, it's only locally "flat" in a relatively small region.

I can draw you a picture using the Earth and a graviton-blocking disc as an example to show where the "sideways" force comes from when you have a continuous distribution. Basically speaking, when you're on the left edge of your graviton-blocking disc, the whole right side of the Earth is shielded from you, while the whole left side is not, meaning you are pulled left as well as down. Shrink the gravitational source to something small, and the forces around the edges of the "shadow" start looking funnier and funnier, but as long as you're using continuous distributions, the field will be well behaved.

Making the problem more complicated (and, yes, more realistic) doesn't so that less energy is lost doesn't magically make the CoE violation go away: energy is still gained/lost with no apparent source.

And by combining a number of Gravity Eater 3000's in various ways, we can create any shape we want, including a "bucket" shape, as needed.

Your graviton blocking device needs to take up the energy from the change in gravitational field (and of course, since you turn it both on and off and move the device around, all those changes as well), i.e., the energy (and momentum, but gravity is symmetric, so that's taken care of by blocking gravitons in both directions), i.e., the positive or negative energy associated with the flux of gravitons being blocked.

Change the positions of the objects and the flux changes.

If we talk about it handling the energy of all the gravitons that would move through it, then we still don't explain how the potential energy is given to objects in the "shadow."

You yourself have suggested sending it in and out of subspace.

That's for a problem where subspace is obviously involved. How could subspace link any arbitrary object that enters the "shadow" to the graviton blocker?

If it was a trick question with incorrect premises, the proper logical Vulcan answer would have been to point it out as such (e.g., "Gravitons cannot be blocked.") If by "imprecise terminology," you mean "anti-graviton" vs "graviton," then the "trick" part of the problem wouldn't be relevant to our discussion in any case. (If you can block an anti-graviton you can block a graviton - no problem with that at all.)

Or perhaps you altered the graviton's path around the outside of the envelope. (Anything inside the field is shielded from gravity. Movement inside the field would require the field or its generator to compensate.)

It wouldn't point suddenly towards the CE to take your claims in conjunction with a weak signal. After all, all the other sources are still present, "confounding" the vector. Aren't they?

You're assuming the signal is too weak for a modern detector to notice. What evidence is there of this?

Are you sure?

Yes. The Enterprise was in orbit around a moon at the time they detected an incoming Borg vessel.

Directional graviton flux detectors are much more strongly suggested than hypersensitive gravimeters.

They aren't required. Parsimony suggests that we need not invoke new properties on gravitons when we have an explanation that works without inventing new physics.

Actually, it is, provided you know the moon's field well enough. That's not the sort of light minute range you're talking about.

A light-second would still require absurd sensitivity.

[Keiran]

Reaching up to Andromeda Galaxy?

Yes, gravity has infinite range.

Establishing field in bidirectional flux requires energy proportional to product of fluxes.

Releasing gives back energy proportional to product of fluxes AT RELEASE TIME.

The movement is automatically calculated by difference between what you give and what you get.

Where does the energy go in the meantime?

And again, soliton wave got energy from nowhere

Subspace (since it was a subspace disturbance, otherwise it wouldn't allow FTL travel) isn't "nowhere."

The diffraction will nullify the effect over big distances.

You mean "reduce." The effect won't be completely nullified, because there's still a tiny bit of gravity that should be reaching the target but isn't. A tiny CoE violation is just as impossible as a big one.

No a photon detector can measure properties of photons which a light (or EM) detector can not.

A camera is just a primitive photon detector.

Unless you're telling me that a camera doesn't detect the presence of photons...

[Jedi Master Spock]

Encompassing the moon in a warp field would then obviously require pulling KE from the moon as the mass decreased, so that the velocity could stay the same.

And? Even if the initial velocity remains the same, the acceleration vector increases severely. Face it - dialogue, visual effects, the sequence of events - however you look at the episode, it loudly and rudely demands a unified reduction of both inertial and gravitational mass.

That would depend on the mass of the artificial black hole, now, wouldn't it?

Actually, it doesn't. No matter what mass you have, it gets messy in the extreme. You end up having to invent ... oh, I'd call it roughly 2-3 unmentioned new sub-departments of Trek physics if you don't want to address it gravitationally through the two really simple pieces of Treknology we have canon support for the existence of.

And violation of CoE is messier than anything you've brought up. Period.

Except it doesn't have to be violated at all - meaning no mess at all. Just plain and simple elegance, which I really like in my explanations of Treknology. It's so rare to find a conceptually elegant solution to Treknology.

The lack of a gravity well in the "shadow" makes giving the object potential energy rather difficult, wouldn't you say?

You're still looking at question two - moving objects in and out of the field - so far as I can tell. As I said, there's no part of the problem that requires transmitting energy directly from the generator to the object, excepting through the change in flux of gravitons.

Great, now prove your assertion that the altered field's curl is 0.

But the line integral is so much easier to do directly rather than through computing the curl! Why bother to integrate the curl over a region?

The proof is in the picture. If you can draw a continuous function z=f(x,y) (or, analogously, w=f(x,y,z) if you're drawing in an extra dimension to graph g(x,y,z)) as a surface whose gradient is, at any point, g, then the change in energy is (by definition) the sum of the changes in altitude (df=g dot dl), which is for any closed loop zero, just as it is for any surface that is continuous and may be regarded as a function of the Cartesian x and y.

The gravitational potential energy of an object on a traditional mesh diagram is simply the altitude times the mass. It really simplifies matters That's why we like the pretty pictures - it's a translation that simplifies the problem enormously. Now...

... if we work with a point mass and sharp edges to the envelope, we of course do not have a continuous surface, but even then we can always piecewise in a lovely little gravitational eddy "outwards" to patch the edges off.

Since in models of continuous masses we do see something of an outwards eddy effect anyway, I can't be bothered to actually crunch the figures to see if it's the right size eddy. The simple fact is that the problem of conserving energy with objects moving in the altered field is trivially easy to fix, even within a model that isn't compatible with a quantized model of gravity.

The tricky part comes in changing the field in the first place - and a good and experimentally verifiable treatment of the energy density intrinsic to a gravitational field has yet to come, and may never come in spite of it being a lively field of research.

Then all you have to do is show how energy travels to or from the object to the Graviton Eater 3000. Y'know, the question I've been asking you to answer. Remember: the energy can flow both ways, so there has to be a provision for bidirectional transfer. Gravitons move one way, and since one of those directions is blocked, only half of the problem is explained (at best).

Not at all. Any magnetic envelope blocking gravitons is going to block them in both directions, as I mentioned. To do otherwise invokes apparent COM problems.

And by combining a number of Gravity Eater 3000's in various ways, we can create any shape we want, including a "bucket" shape, as needed.

Eventually arriving at the completely enclosed object, which then behaves much like an object in a warp field lightening its mass to a small fraction.

If we talk about it handling the energy of all the gravitons that would move through it, then we still don't explain how the potential energy is given to objects in the "shadow."

It's ordinarily (to use the sign conventions of our classic treatment of gravity) subtracted from them by the graviton flux. Blocking the gravitons then gives them that energy - and the envelope has to account for all the energy involved in the blocked gravitons. As I said, trivial.

That's for a problem where subspace is obviously involved. How could subspace link any arbitrary object that enters the "shadow" to the graviton blocker?

... how many times do I have to tell you? It doesn't.

Or perhaps you altered the graviton's path around the outside of the envelope. (Anything inside the field is shielded from gravity. Movement inside the field would require the field or its generator to compensate.)

Why, deflecting the graviton around the envelope would work quite well too, and we could refer to that as blocking as well with relatively little stretch of literalist Vulcan semantic habits. Point taken.

Of course, you don't quite have it right there - movement within the envelope is free (relative to the outside) since there is no gravitational force on the inside. Moving the envelope itself is not - and in the end, we're back to the non-trivial part of the whole problem, which is ascribing a spatial energy density to gravity fields.

The only change is that now the magnetic envelope is simply a perfect gravitational cloak rather than having detectable eddies ("shadow" with all its assorted curiousities) and you only have to deal with the added complication of objects moving in and out of the envelope.

Remember, an anti-neutron can pass through this envelope as modulated by Spock - and if you assume that it moves freely based on the fact that chargeless matter is unaffected by magnetic fields, you're going to run into an unresolvable COE problem based on the fact that your field does necessarily have discontinuities, so you're definitely going to have to add gravitic or gravity-like eddies within the envelope edges themselves in order to maintain COE. (Distribute it through the inside and you have no way to tell that you've blocked any gravitons - unless again you have a distinct method of detecting individual gravitons, which brings us back to the really simple case.)

You're assuming the signal is too weak for a modern detector to notice. What evidence is there of this?

Not at all. The magnitude-direction vector confusion problem you invoke has problems with the relative strength of vectors period.

Yes. The Enterprise was in orbit around a moon at the time they detected an incoming Borg vessel.

An incoming warp speed Borg vessel, correct? Hypothesis: The gravitons detected, much like a detached saucer, continued ahead of the Borg vessel for some distance before dropping out of warp.

They aren't required. Parsimony suggests that we need not invoke new properties on gravitons when we have an explanation that works without inventing new physics.

Actually, it is, provided you know the moon's field well enough. That's not the sort of light minute range you're talking about.

A light-second would still require absurd sensitivity.

Not really. Sensitivity on the order of angstroms per second squared isn't very bad, all things considered.

[SailorSaturn13]

And violation of CoE is messier than anything you've brought up. Period.

Not as messy as time travel.

A tiny CoE violation is just as impossible as a big one.

Well, Given that in ST:IV they take two wales in the future (thus reducing mass of Universe for hundreds of years), CoE is NOT followed in ST.

Subspace (since it was a subspace disturbance, otherwise it wouldn't allow FTL travel) isn't "nowhere."

An EMPTY subspace can give no more energy then empty space. The wave is tapping some field.



Note, btw: POTENTIAL ENERGY IS NOT STORED IN THE BODY, IT IS STORED IN THE FIELD (in the case of gravitons, the gravity field.) Thus changing this field (so an area is gravity-free) will require energy - exactly the difference between the stored energies.

Oh and there are similar designs with EM, too. Having 2 magnets pulled from each other creates an electric field between them. This field circular and particles gain energy by circling in it. So energy can be transferred in this situation just fine.

Where does the energy go in the meantime?

In the blocking field.

If we talk about it handling the energy of all the gravitons that would move through it, then we still don't explain how the potential energy is given to objects in the "shadow."

Potential energy is NOT given to objects - it is the energy of the field. A falling object doesn't get energy from the other object - it taps the gravoty field. It's shape changes, that's it.

And this assumes gravitons interact with matter directly. If they "eat space", which is even more preferable as explanation, then the space curvature itself will translate the energy.

There's still no way to transfer this energy. The whole lack of a gravitational field to transfer energy and all... (Remember: any arbitrary amount of mass could be moving in any direction, but there's no mechanism there for the Graviton Eater 3000 to supply/absorb/reflect the varying possibilities.)

The Gravity field itself provides this.

[Keiran]

And? Even if the initial velocity remains the same, the acceleration vector increases severely. Face it - dialogue, visual effects, the sequence of events - however you look at the episode, it loudly and rudely demands a unified reduction of both inertial and gravitational mass.

How is that a problem? The "acceleration" would be two vectors canceling out, so the velocity remains the same.

Actually, it doesn't. No matter what mass you have, it gets messy in the extreme. You end up having to invent ... oh, I'd call it roughly 2-3 unmentioned new sub-departments of Trek physics if you don't want to address it gravitationally through the two really simple pieces of Treknology we have canon support for the existence of.

If the artificially-maintained black hole is small enough so that its gravity well is enough for the ship's inertial compensator to handle inside the ship and is insignificant outside the ship, then what specificproblems do we have to address?

Except it doesn't have to be violated at all - meaning no mess at all. Just plain and simple elegance, which I really like in my explanations of Treknology. It's so rare to find a conceptually elegant solution to Treknology.

...

You never explained how energy is conserved. Energy has to have a way of getting from one point to another, and the situations you describe lack a viable means of energy transfer.

You're still looking at question two - moving objects in and out of the field - so far as I can tell. As I said, there's no part of the problem that requires transmitting energy directly from the generator to the object, excepting through the change in flux of gravitons.

I'm still looking at question two because it hasn't been answered.

Why would the flux of gravitons leaving the planet change when an object in the graviton "shadow" is moved? (Is the planet or are the gravitons precognitive?)

Further, the energy gained or lost by the Graviton Eater 3000 depends on the direction the object is moving within the "shadow." If a 10 kg ball moves towards the gravity well 100 m, then there will be a transfer of 9800 J. If the ball moves 100 m back to its original location, then there will be a transfer of 9800 J in the opposite direction.

However, the number of gravitons absorbed from the planet will be different than the number of gravitons absorbed from the ball. (As should be obvious due to the disparity in the gravity wells generated by each.)

Further, you have not explained how absorbing the same gravitons with the same properties from the planet can sometimes gain energy and other times lose energy.

These problems arise because of the assertion that gravitons have to be blocked. If the gravitons continue but are canceled out by another force, then we simply have a second field that can do the work. None of these CoE problems come into play then. (See The Museum of Unworkable Devices for more information.)

But the line integral is so much easier to do directly rather than through computing the curl! Why bother to integrate the curl over a region?

The proof is in the picture. If you can draw a continuous function z=f(x,y) (or, analogously, w=f(x,y,z) if you're drawing in an extra dimension to graph g(x,y,z)) as a surface whose gradient is, at any point, g, then the change in energy is (by definition) the sum of the changes in altitude (df=g dot dl), which is for any closed loop zero, just as it is for any surface that is continuous and may be regarded as a function of the Cartesian x and y.

The gravitational potential energy of an object on a traditional mesh diagram is simply the altitude times the mass. It really simplifies matters That's why we like the pretty pictures - it's a translation that simplifies the problem enormously. Now...

... if we work with a point mass and sharp edges to the envelope, we of course do not have a continuous surface, but even then we can always piecewise in a lovely little gravitational eddy "outwards" to patch the edges off.

Since in models of continuous masses we do see something of an outwards eddy effect anyway, I can't be bothered to actually crunch the figures to see if it's the right size eddy. The simple fact is that the problem of conserving energy with objects moving in the altered field is trivially easy to fix, even within a model that isn't compatible with a quantized model of gravity.

The tricky part comes in changing the field in the first place - and a good and experimentally verifiable treatment of the energy density intrinsic to a gravitational field has yet to come, and may never come in spite of it being a lively field of research.

Enough talk: do it. Let's see some numbers. And let's design an array of fields in a spherical shape where fields are permeable by matter (antineutrons, maybe?), and then let's path the matter through that ball (changing altitude within the sphere) and back to its original point.

Now, this is a completely valid setup, but work will not be 0. (The altitude change within the sphere is unaccounted for.)

By the way, your "outwards eddy effect" won't be enough to compensate, because the gravitational pull there is much less than the pull elsewhere.

Not at all. Any magnetic envelope blocking gravitons is going to block them in both directions, as I mentioned. To do otherwise invokes apparent COM problems.

The planet emits more gravitons than a 10 kg ball moving around in the "shadow," so, no, that does not explain why a 100 m altitude change will transfer 9800 J whether the movement is towards or away from the planet.

Eventually arriving at the completely enclosed object, which then behaves much like an object in a warp field lightening its mass to a small fraction.

You're completely and utterly wrong. The mass is unaffected and inertia behaves the same. The object doesn't magically become easier to push.

It's ordinarily (to use the sign conventions of our classic treatment of gravity) subtracted from them by the graviton flux. Blocking the gravitons then gives them that energy - and the envelope has to account for all the energy involved in the blocked gravitons. As I said, trivial.

Then move the 10 kg ball 100 m in the opposite direction, and suddenly the 9800 J is taken away. How did that happen? There was no change in graviton flux coming from the planet. And the ball certainly didn't pump out enough gravitons to account for all of that.

... how many times do I have to tell you? It doesn't.

It was your suggestion here, not mine. Is a little consistency too much to ask?

Me: So, again, I have to ask: what mechanism is there that can allow the device to gain energy one time, and lose energy another time?

You: You yourself have suggested sending it in and out of subspace.

Me: That's for a problem where subspace is obviously involved. How could subspace link any arbitrary object that enters the "shadow" to the graviton blocker?

You: ... how many times do I have to tell you? It doesn't.

So, if it's not subspace and the graviton flux isn't changing, then what causes the transfer of energy?

Or perhaps you altered the graviton's path around the outside of the envelope. (Anything inside the field is shielded from gravity. Movement inside the field would require the field or its generator to compensate.)

Why, deflecting the graviton around the envelope would work quite well too, and we could refer to that as blocking as well with relatively little stretch of literalist Vulcan semantic habits. Point taken.

Of course, you don't quite have it right there - movement within the envelope is free (relative to the outside) since there is no gravitational force on the inside. Moving the envelope itself is not - and in the end, we're back to the non-trivial part of the whole problem, which is ascribing a spatial energy density to gravity fields.

The only change is that now the magnetic envelope is simply a perfect gravitational cloak rather than having detectable eddies ("shadow" with all its assorted curiousities) and you only have to deal with the added complication of objects moving in and out of the envelope.

Remember, an anti-neutron can pass through this envelope as modulated by Spock - and if you assume that it moves freely based on the fact that chargeless matter is unaffected by magnetic fields, you're going to run into an unresolvable COE problem based on the fact that your field does necessarily have discontinuities, so you're definitely going to have to add gravitic or gravity-like eddies within the envelope edges themselves in order to maintain COE. (Distribute it through the inside and you have no way to tell that you've blocked any gravitons - unless again you have a distinct method of detecting individual gravitons, which brings us back to the really simple case.)

Read what I said more carefully: "Movement inside the field would require the field or its generator to compensate." If the field can prevent gravitons and neutrons from entering inside it, then it obviously isn't a normal magnetic field. And because the object is inside a field, then there is a mechanism that can allow energy transfer. So we don't have the conundrum that appears when something is moving in the absence of a field.

Not at all. The magnitude-direction vector confusion problem you invoke has problems with the relative strength of vectors period.

You're kidding, right? Please tell me you're kidding. You have the "before" value of the ambient gravity, and it's pretty stable (not much going on in the system). Suddenly, you have a new "after" value that's much different. Subtract the "before" value from the "after" value and you have have the vector of the new gravity source (within tolerances of the known fluctuations). There is no problem here, and I can't imagine what could be going through your head in trying to invent one.

An incoming warp speed Borg vessel, correct? Hypothesis: The gravitons detected, much like a detached saucer, continued ahead of the Borg vessel for some distance before dropping out of warp.

Luxons don't experience time. Also, you're postulating gravity detection of a starship from lightyears away. Perhaps you have some evidence that this is possible?

They aren't required. Parsimony suggests that we need not invoke new properties on gravitons when we have an explanation that works without inventing new physics.

This was quoted but not addressed. I'll leave it in to be addressed, because it is a very good point.

Not really. Sensitivity on the order of angstroms per second squared isn't very bad, all things considered.

Heheh, you're not quite there. You're calculating the amount of gravity the starship is feeling. However, that's roughly what the entire starship is feeling. What the gravimeter has to calculate (and I mentioned this before, in my first post in this thread) is the difference between what it feels and what the ship feels.

If we have a ship that evenly accelerates due to gravity (perfectly rigid), with a gravimeter 500 m closer to the source (say a 1 km starship facing the target), and the source is 300,000,000 m away, and this source happens to be the Borg ship discussed earlier (measured at 2.5 million tons; for reference, the Doctor hinted that Voyager massed 700,000 tons) then our gravimeter would have to detect an acceleration on the order of 10^-24 m/s^2. That's 14 orders of magnitude weaker than your estimation.

I believe I used the word "absurd" to describe this level of sensitivity.

And please be more careful in making calculations. There really was no reason for you to be so careless considering that I mentioned the acceleration differential the gravimeter would have to measure in my first post in this thread.

[Keiran]

Not as messy as time travel.

It's a good thing we haven't talked about time travel, then! I mean, what a red herring that would be...

Well, Given that in ST:IV they take two wales in the future (thus reducing mass of Universe for hundreds of years), CoE is NOT followed in ST.

... and, like I said, that's a red herring. Besides, the simple explanation is that an equal amount of energy must be left behind during time travel.

An EMPTY subspace can give no more energy then empty space. The wave is tapping some field.

Since when was subspace empty?

Note, btw: POTENTIAL ENERGY IS NOT STORED IN THE BODY, IT IS STORED IN THE FIELD (in the case of gravitons, the gravity field.) Thus changing this field (so an area is gravity-free) will require energy - exactly the difference between the stored energies.

Oh and there are similar designs with EM, too. Having 2 magnets pulled from each other creates an electric field between them. This field circular and particles gain energy by circling in it. So energy can be transferred in this situation just fine.

Fine, remove the field and have the energy required to remove the field come from the GE3k. Now take a million-ton starship, move it into the gravity "shadow," and move it towards the GE3k, just before it reaches the GE3k, move it out of the shadow.

The starship should have gained a huge amount of kinetic energy, but didn't. Where did that energy go? What absorbed the energy?

And how?

In the blocking field.

How does the blocking field "know" how to gain or lose energy depending on the direction that million-ton starship moves? Is it possible to suck the blocking field of energy by moving too much mass around in the gravity shadow above it?

Potential energy is NOT given to objects - it is the energy of the field. A falling object doesn't get energy from the other object - it taps the gravoty field. It's shape changes, that's it.

And this assumes gravitons interact with matter directly. If they "eat space", which is even more preferable as explanation, then the space curvature itself will translate the energy.

Let's take a proposed perpetual motion machine based on using a gravity shield.

As the eccentric weight moves up in the gravity shadow, energy must leave the gravity shield. Or, if the weight moves towards the shield, then the shield must gain energy.

But the eccentric weight isn't moving in a field (the shadow is the lack of a field), so what relationship exists between the weight and the gravity shield that would allow the shield to gain or lose energy depending on the weight's motion?

The fundamental problem that you are attempting to sidestep is that the amount of energy gained or lost by the gravity shield is directly related to the movement of mass within the gravity shadow. However, said mass is not moving in a field, so there is no means for the gravity shield to "know" that it needs to gain or lose energy.

The Gravity field itself provides this.

How? There's no longer a connection between the gravity field and the mass.

[Jedi Master Spock]

How is that a problem? The "acceleration" would be two vectors canceling out, so the velocity remains the same.

What two vectors cancelling out?

There is no magically appearing vector that will simply cancel out the g vector. It's simple: F=m'g, F=m''a, g=a*m'/m''. Decrease m'' by a factor of 100 without changing m', and acceleration due to gravity increases by a factor of 100. In the case of a normal stable circular orbit, this means that the orbit sharply decays, as the equilibrium condition of a=v^2/r no longer applies.

In the case of an already decaying orbit which you are unable to reverse conventionally (“Deja Q”), this means the orbit decays more sharply. The force required to restore the equilibrium condition is unchanged by applying a field of the sort you describe.

It is simply an indefensible claim explicitly (i.e., dialogue states otherwise) and implicitly (all onscreen action disagrees with your interpretation by implication.)

If the artificially-maintained black hole is small enough so that its gravity well is enough for the ship's inertial compensator to handle inside the ship and is insignificant outside the ship, then what specificproblems do we have to address?

For starters, try on the fact that the black hole evaporates at a fixed rate which is either insufficient to provide warp power or leaves you with no black hole.

I'm still looking at question two because it hasn't been answered.

Why would the flux of gravitons leaving the planet change when an object in the graviton "shadow" is moved? (Is the planet or are the gravitons precognitive?)

It doesn't. See the mesh curve I described. Were you not paying any attention? The shadow must be surrounded by a repulsive “eddy” in a continuous model.

By the way, your "outwards eddy effect" won't be enough to compensate, because the gravitational pull there is much less than the pull elsewhere.

The outward eddy – as I pointed out – can as I already pointed out be magnified if necessary (it probably does indeed as exemplified by the discontinuities in point source models - I do make careless mistakes posting from the hip sometimes - but I can't be bothered to care, as any magnified eddy effect can be easily explained in terms intrinsic to the blocked flux), and will actually be experienced over a fairly large region angularly. Force along distance, remember? The only problem with your objection is constructing the conservative vector field... which is, as I pointed out, trivially easy. The weight on the "perpetual motion machine" you linked to slows as it pushes in against the eddy, and is spit back out laterally at what winds up being the same total (kinetic+potential) energy by the time it has fully left the "shadow." No energy gained, none lost except through friction.

The planet emits more gravitons than a 10 kg ball moving around in the "shadow," so, no, that does not explain why a 100 m altitude change will transfer 9800 J whether the movement is towards or away from the planet.

How many times have I had to explain this to you? Within a zero-g region, the object experiences no change in energy.

It was your suggestion here, not mine. Is a little consistency too much to ask?

Me: So, again, I have to ask: what mechanism is there that can allow the device to gain energy one time, and lose energy another time?

You: You yourself have suggested sending it in and out of subspace.

Here we're talking about the device itself – the blocking field. This necessarily has to be doing something with energy.

Me: That's for a problem where subspace is obviously involved. How could subspace link any arbitrary object that enters the "shadow" to the graviton blocker?

Here you're talking about an object within the “shadow,” which is not what I talked about. And the object does not gain or lose energy except as normally mediated through the vector field it passes through, which can – and should – be constructed as a conservative field.

If you can't understand why the first question, the energy contained in the field/gravitons itself/themselves, is the only important question in any plausible model, then I really don't have anything more to say to you about COE.

Read what I said more carefully: "Movement inside the field would require the field or its generator to compensate." If the field can prevent gravitons and neutrons from entering inside it, then it obviously isn't a normal magnetic field. And because the object is inside a field, then there is a mechanism that can allow energy transfer. So we don't have the conundrum that appears when something is moving in the absence of a field.

Actually, we do. There's a distinct absence of field internal to the envelope if the graviton can be measured to have been blocked from entering it. You're having to invoke what is at best a very similar "eddy effect" with slightly more complications (e.g., explaining how a magnetic envelope is not only going to affect gravitons and neutrons, but also cause an object to gain/lose energy when magnetic fields as we understand them do no work on matter, etc.)

You're kidding, right? Please tell me you're kidding. You have the "before" value of the ambient gravity, and it's pretty stable (not much going on in the system). Suddenly, you have a new "after" value that's much different. Subtract the "before" value from the "after" value and you have have the vector of the new gravity source (within tolerances of the known fluctuations). There is no problem here, and I can't imagine what could be going through your head in trying to invent one.

I'm not inventing one, I'm pointing out the problem is exactly the same as one you were trying to invoke earlier. The new vector could be the result of multiple coinciding sources that simply happen to add up to the same new vector. See?

Luxons don't experience time. Also, you're postulating gravity detection of a starship from lightyears away. Perhaps you have some evidence that this is possible?

Remember, anything that leaves a starship at warp remains at warp... but not indefinitely. Why should light and gravity be any difference? Two objects paralleling each other at warp speed can be seen through the medium of photons.

Shall we assume that unlike everything else, lightspeed particles never lose their associated warp field? At a minimum, the field should be decaying through interaction with static non-warp particles (see “The Battle.”)

This was quoted but not addressed. I'll leave it in to be addressed, because it is a very good point.

It has no foundation as an objection in anything I've said.

Heheh, you're not quite there. You're calculating the amount of gravity the starship is feeling. However, that's roughly what the entire starship is feeling. What the gravimeter has to calculate (and I mentioned this before, in my first post in this thread) is the difference between what it feels and what the ship feels.

If we have a ship that evenly accelerates due to gravity (perfectly rigid), with a gravimeter 500 m closer to the source (say a 1 km starship facing the target), and the source is 300,000,000 m away, and this source happens to be the Borg ship discussed earlier (measured at 2.5 million tons; for reference, the Doctor hinted that Voyager massed 700,000 tons) then our gravimeter would have to detect an acceleration on the order of 10^-24 m/s^2. That's 14 orders of magnitude weaker than your estimation.

Well, I made the mistake of assuming that when you were talking about “the diameter of an electron” - 1e-14 m/s^2 - and light minutes at the same time that you were using appropriate figures for what you were talking about. My apologies.

The assumption that the starship is free-falling is not precisely justified. The course of the ship itself through space is very precisely kwown. When you measure the weight of an object on an airplane that has no net acceleration relative to Earth, you measure not the differential between that object and the rest of the plane, but the force itself. If you know the plane's acceleration as a body, you can then use that to compute g regardless of your acceleration vector.

This is not to say that the differential isn't important. Measuring the differential between different gravimeters is the only thing that would let you precisely locate an object using a set of simple gravimeters, and ranging is not easy.

Neither, incidentally, is your starship stationary. It moves through space, providing you not with a single set of datapoints separated by 500m or so from one another, but a stream of data along a path on the order of 500m across.

[SailorSaturn13]

It's a good thing we haven't talked about time travel, then! I mean, what a red herring that would be...

Point: our laws are broken in ST; why should CoE stand?

Besides, the simple explanation is that an equal amount of energy must be left behind during time travel.

So when ship appears, it sucks out his mass' worth?! How that's not mentioned???

Since when was subspace empty?

Space is empty. Subspace should too.

Fine, remove the field and have the energy required to remove the field come from the GE3k. Now take a million-ton starship, move it into the gravity "shadow," and move it towards the GE3k, just before it reaches the GE3k, move it out of the shadow.

The starship should have gained a huge amount of kinetic energy, but didn't. Where did that energy go? What absorbed the energy?

It gained energy while moving out of the shadow, going from place with potential zero to one with negative potential.

How does the blocking field "know" how to gain or lose energy depending on the direction that million-ton starship moves? Is it possible to suck the blocking field of energy by moving too much mass around in the gravity shadow above it?

The gravity field does know

Let's take a proposed perpetual motion machine based on using a gravity shield.

I can build same thing without shielding - just immerse left half into water right half weights more now and is pulled down, so the wheel rolls - or is it?

JMS answers why not:

The outward eddy – as I pointed out – can as I already pointed out be magnified if necessary (it probably does indeed as exemplified by the discontinuities in point source models - I do make careless mistakes posting from the hip sometimes - but I can't be bothered to care, as any magnified eddy effect can be easily explained in terms intrinsic to the blocked flux), and will actually be experienced over a fairly large region angularly. Force along distance, remember? The only problem with your objection is constructing the conservative vector field... which is, as I pointed out, trivially easy. The weight on the "perpetual motion machine" you linked to slows as it pushes in against the eddy, and is spit back out laterally at what winds up being the same total (kinetic+potential) energy by the time it has fully left the "shadow." No energy gained, none lost except through friction.

MO.

How? There's no longer a connection between the gravity field and the mass.

There is because gravity well is provided by VIRTUAL gravitons, and they only exist between two masses.

Btw, stopping gravitons DOES NOT negate pull for distant objects - a lightsecond big graviton is virtually unimpeded by meter-long stopper.

[Keiran]

What two vectors cancelling out?

There is no magically appearing vector that will simply cancel out the g vector. It's simple: F=m'g, F=m''a, g=a*m'/m''. Decrease m'' by a factor of 100 without changing m', and acceleration due to gravity increases by a factor of 100. In the case of a normal stable circular orbit, this means that the orbit sharply decays, as the equilibrium condition of a=v^2/r no longer applies.

In the case of an already decaying orbit which you are unable to reverse conventionally (“Deja Q”), this means the orbit decays more sharply. The force required to restore the equilibrium condition is unchanged by applying a field of the sort you describe.

1) What does acceleration due to gravity have to do with this situation? The equation you're looking for is KE = .5m*v^2. (Decrease the mass but keep the same kinetic energy and velocity must increase. An inertial damping field could counter this acceleration.)

2) Where are your equations coming from? They're not even consistent with each other.

3) g is given by G * M / d^2.

4) You clearly have a severe misunderstanding somewhere.

It is simply an indefensible claim explicitly (i.e., dialogue states otherwise) and implicitly (all onscreen action disagrees with your interpretation by implication.)

Not at all. A warp field surrounds the moon and somehow decreases its inertial mass. As the mass is reduced, velocity increases (therefore, acceleration) to keep the kinetic energy the same. Meanwhile an inertial damping field provides counter-acceleration to reduce the KE and keep the velocity the same.

CoE can thus be held. And since CoE can be held without invoking new laws of physics for realspace, can we move on?

For starters, try on the fact that the black hole evaporates at a fixed rate which is either insufficient to provide warp power or leaves you with no black hole.

Hawking radiation would be my best guess as to how a starship can obtain energy from a black hole. The energy obtained via Hawking radiation would be substantial. What makes you think otherwise?

Obviously, mass would need to be continually pumped into the black hole in order to serve as fuel.

It doesn't. See the mesh curve I described. Were you not paying any attention? The shadow must be surrounded by a repulsive “eddy” in a continuous model.

That still isn't enough. Remember, it would be entirely possible to set the shadow up such that there are sections with zero graviton flux. Objects starting at any point in the full shadow could all be moved to the same point (one at a time) and then thrown out. Each would receive the same gravitational pull while exiting, yet the math doesn't work out because of the different starting positions. (Or even different entrance points.)

The outward eddy – as I pointed out – can as I already pointed out be magnified if necessary (it probably does indeed as exemplified by the discontinuities in point source models - I do make careless mistakes posting from the hip sometimes - but I can't be bothered to care, as any magnified eddy effect can be easily explained in terms intrinsic to the blocked flux), and will actually be experienced over a fairly large region angularly. Force along distance, remember?

Gravity increases suddenly? How?

The only problem with your objection is constructing the conservative vector field... which is, as I pointed out, trivially easy.

Then why haven't you done it? Give me that function and I can perform tests on it and verify that it is actually conservative. (Of course, it must fit the specification where there's an area where no gravitons pass through, because it's possible to construct such a scenario by placing multiple gravity shields strategically.)

The weight on the "perpetual motion machine" you linked to slows as it pushes in against the eddy, and is spit back out laterally at what winds up being the same total (kinetic+potential) energy by the time it has fully left the "shadow." No energy gained, none lost except through friction.

Nope, that doesn't work.

Let's assume that your "outwards eddy" is enough to completely counter the potential energy gained inside the shadow for the wheel.

Now let's make a bigger wheel with the same mass weight such that the weight enters at the same altitude as the original weight but exits the field at a higher altitude.

Since the force of gravity is effectively the same on each weight at the bottom and top (the variance in g is insignificant at this range), then that means the same acceleration would be felt at entry and exit on the bigger wheel. However, since the wheel should have gained more potential energy (higher max altitude), the acceleration is no longer enough.

No matter how you look at it, your explanations are full of holes and are not consistent when actual math is brought to the table.

Oh, another fun thing we could do is push the wheel in a bit such that the eccentric weight is inside the shadow for most of the cycle and only touches the "outwards eddy" for portion of the trip down. The "outwards eddy" thus speeds the descent of the weight while doing nothing to counter trip up. In other words, your explanation is fundamentally flawed and ill-thought out.

How many times have I had to explain this to you? Within a zero-g region, the object experiences no change in energy.

That's precisely the problem...

Here you're talking about an object within the “shadow,” which is not what I talked about. And the object does not gain or lose energy except as normally mediated through the vector field it passes through, which can – and should – be constructed as a conservative field.

Then construct just such a field... you said it's trivial, so it can't possibly be too much to ask.

Can it?

Don't worry, I can do all the nasty calculations on it to prove or disprove that the field is plausible.

If you can't understand why the first question, the energy contained in the field/gravitons itself/themselves, is the only important question in any plausible model, then I really don't have anything more to say to you about COE.

The Gravity Shield PMM (modified such that the weight only enters the "outward eddy" while moving down, as described above) cycles clockwise and gains speed. Does the gravity shield gain or lose energy?

The same Gravity Shield PMM cycles counter-clockwise and loses speed. Does the gravity shield gain or lose energy?

If the answers are different, explain the mechanism for the bidirectional transfer of energy.

If the answers are the same, explain where the unaccounted energy goes to (or is taken from) in the system, and what mechanism allows this.

Actually, we do. There's a distinct absence of field internal to the envelope if the graviton can be measured to have been blocked from entering it. You're having to invoke what is at best a very similar "eddy effect" with slightly more complications (e.g., explaining how a magnetic envelope is not only going to affect gravitons and neutrons, but also cause an object to gain/lose energy when magnetic fields as we understand them do no work on matter, etc.)

A neutron inside a field that could have the potential to block neutrons is in an area with "a distinct absence of a field"!? ROFL.

I thought we had to accept the movie at its word that this "magnetic field" could possibly block both gravitons and neutrons from entering. That being the case, the only question I should need to concern myself is how CoE applies to the problem, right? So why bother bringing that stuff up now?

I'm not inventing one, I'm pointing out the problem is exactly the same as one you were trying to invoke earlier. The new vector could be the result of multiple coinciding sources that simply happen to add up to the same new vector. See?

The Crystalline Entity was in visual range. The new vector was pointing directly at it. Your objections are silly and a waste of time, if not on the verge of being offensive.

Remember, anything that leaves a starship at warp remains at warp... but not indefinitely. Why should light and gravity be any difference? Two objects paralleling each other at warp speed can be seen through the medium of photons.

Shall we assume that unlike everything else, lightspeed particles never lose their associated warp field? At a minimum, the field should be decaying through interaction with static non-warp particles (see “The Battle.”)

And just how long does it take before something drops out of warp? (I don't recall anything staying in warp for hours before dropping out.)

Can it be predicted? If it can, then the massless particles would drop out at a set distance, and thus couldn't reliably be used to measure mass FTL because the area of effect is fixed. If it can't, then how do they get a measurement when they don't know what percentage of the actual gravitons they are receiving is?

It has no foundation as an objection in anything I've said.

Directional graviton detectors require new properties for gravitons to be invented. We do not need to resort to directional graviton detectors in order to explain events in Star Trek canon. Therefore, we do not need to invent new properties for gravitons.

Well, I made the mistake of assuming that when you were talking about “the diameter of an electron” - 1e-14 m/s^2 - and light minutes at the same time that you were using appropriate figures for what you were talking about. My apologies.

So basically you didn't do the math. Heh. I was using the diameter as a reference point, nothing more.

The assumption that the starship is free-falling is not precisely justified. The course of the ship itself through space is very precisely kwown. When you measure the weight of an object on an airplane that has no net acceleration relative to Earth, you measure not the differential between that object and the rest of the plane, but the force itself. If you know the plane's acceleration as a body, you can then use that to compute g regardless of your acceleration vector.

*snicker*

If the plane has no acceleration relative to earth, then it is at a constant altitude and thus any object in it will be subjected to a normal (for that altitude) level of acceleration relative to the plane. That's a red herring, completely irrelevant.

And how does one measure force without measuring acceleration, anyway?

And how is a spaceship going to measure its current acceleration due to gravity, anyway?

Neither, incidentally, is your starship stationary. It moves through space, providing you not with a single set of datapoints separated by 500m or so from one another, but a stream of data along a path on the order of 500m across.

If your instruments aren't precise enough, then you don't receive any meaningful data. Unless you can divine meaning from a stream of zeros.

[Keiran]

Point: our laws are broken in ST; why should CoE stand?

Without CoE, analysis of onscreen events is impossible. Anything even remotely realistic has to obey CoE somehow, otherwise we might as well be using cartoon physics.

So when ship appears, it sucks out his mass' worth?! How that's not mentioned???

The energy could be in the form of neutrinos.

Space is empty. Subspace should too.

The subspace tear in Insurrection would beg to differ.

It gained energy while moving out of the shadow, going from place with potential zero to one with negative potential.

How did it gain the energy? It didn't move through the field enough to get it from the field.

How does the blocking field "know" how to gain or lose energy depending on the direction that million-ton starship moves? Is it possible to suck the blocking field of energy by moving too much mass around in the gravity shadow above it?

The gravity field does know

That doesn't answer the question "How?"

Nor did you answer the second question: Is it possible to suck the blocking field of energy by moving too much mass around in the gravity shadow above it?

I can build same thing without shielding - just immerse left half into water right half weights more now and is pulled down, so the wheel rolls - or is it?

LOL! No, that wouldn't work at all. Water is denser and would slow the movement of the weight down. (And water would pour out at the entrance, the pressure would accelerate the weight away from the entrance.)

JMS answers why not:

I responded to him. His explanation is bunk. He didn't bother to think the situation through or to see what would happen if multiple, different experiments were run on the same "outward eddy."

There is because gravity well is provided by VIRTUAL gravitons, and they only exist between two masses.

Virtual particles can't be detected by definition (otherwise they wouldn't be virtual). Therefore, direct graviton detection is impossible.

Btw, stopping gravitons DOES NOT negate pull for distant objects - a lightsecond big graviton is virtually unimpeded by meter-long stopper.

I'm not sure whether I should laugh or cry. Or maybe laugh until I cry. Since when did gravitons have length?

[Jedi Master Spock]

1) What does acceleration due to gravity have to do with this situation?

Everything, Keiran. Have you seen the episode in question at all?

The equation you're looking for is KE = .5m*v^2.

No, it isn't.

Where are your equations coming from?

Basic kinematics. Everything follows from f=ma.

They're not even consistent with each other.

Yes, they are. If you don't understand them, you're not on very good ground here.

3) g is given by G * M / d^2.

And?

Not at all. A warp field surrounds the moon and somehow decreases its inertial mass. As the mass is reduced, velocity increases (therefore, acceleration) to keep the kinetic energy the same. Meanwhile an inertial damping field provides counter-acceleration to reduce the KE and keep the velocity the same.

I see I'm going to have to explain precisely what's going on in the episode and also go over a quick refresher of Newtonian kinematics before I can make any progress in getting through to you.

After that, we can return to talking about how it is possible to create a conservative field while blocking gravitons, why Hawking radiation is a most peculiar power source for a warp engine, containment problems for black holes, etc, but there's no point in my trying to teach you how to deal with modern physics if you can't grasp Newtonian mechanics.

Let's go back. What happens when an object is in a gravitational field? It experiences a force F=mg, its mass multiplied by the local gravitational vector g. Here, the mass is the "gravitational mass" of the object.

Understand that?

Now, let's say you have any force F applied to an object. Force equals mass times acceleration (F=ma). Here, the mass is the inertial mass of the object. To put it another way, the acceleration (m/s^2) is the force (kg m/s^2) divided by the inertia (kg).

Consider the acceleration of an object due to gravity. It is the force (mg) divided by the inertia (m) which happens to be precisely equal to g.

Directly, a=F/m=mg/m=g. Got that?

But what happens if we change the inertia without altering the gravitational mass? We can't take that last step of cancelling out the "mass" terms. Instead, we are left with the gravitational mass divided by the inertia, which is then multiplied by g - so if the inertial mass is reduced to 1% of the gravitational mass, m(gravity)/m(inertia) would be 100g - in the case of an object near earth, it would fall at 980 m/s^2 instead of 9.8 m/s^2.

Now, do you understand that yet?

With respect to equilibria of forces, I needed 9.8 N/kg upwards to hold the object still before reducing the inertial mass, and I need exactly the same non-gravitational force after reducing the inertial mass.

With respect to equilibrium for a perfectly circular orbit, a=v^2/r inwards (this is the condition for uniform circular motion; if you still can't figure out where it comes from, say so and I'll walk you through the derivation.) If v doesn't change, and r doesn't change, but we increase a by a factor of 100, the orbit turns from stable.

So how does this relate to "Deja Q" and other examples? Well, in "Deja Q" the problem was a moon that suddenly started to decay in its orbit. In order to stabilize the orbit, the starship needed to apply a net delta-v of 4 km/s over 29 hours - i.e., an average acceleration of 3.8 cm/s^2. Keep this acceleration in mind.

The moon is also decaying fairly slowly, all things considered - it's going to take it the better part of a day after it hits 500 km altitude to actually impact the planet, and that's with atmospheric friction contributing to the decay rate. So it's very close to being in a stable orbit, and spiraling in at a very slow rate.

The Enterprise was unable to apply this amount of force to the asteroid for very long - the engines shut down after applying a total delta-v of only 92 m/s, not enough to stabilize the orbit. (That would take about 40 minutes according to the rate given above, which is not inconceivable given the cuts; however, we can be sure that the acceleration from the ship is substantially less than a g by the amount of time involved.)

Now, Q throws out the suggestion of meddling with gravitational constants. Geordi thinks about it and then says this:

GEORDI
We can't change the gravitational
constant of the universe but if
we wrap a low level warp field
around that moon, we could reduce
its gravitational constant...
make it lighter so we can push
it.

Now, the dialogue itself is clear enough. Both inertial mass (easier to push) and gravitational mass (its gravitational constant) are being reduced in tandem. They're linked inextricably in Trek by this simple line of dialogue.

So what happens? They wait until they're being attacked by the Calamairan and the moon is making its closest pass to the planet. An atmosphere-skimming pass. The warp field mostly envelopes the moon, reducing its mass to the paltry quantity of 2.5 million tons.

Now, let's say this is 1% of the moon's mass (this would be a very high percentage given the fact that the moon had tidal effects on the planet below). The starship can tug it at 3.8 m/s^2 or so, but the planet will pull it downward at around 800-900 m/s^2 - meaning that the starship's contribution to the moon's acceleration is negligible (Ouch!) Meanwhile, the orbit is only fast enough to be almost in equilibrium with 8-9 m/s^2 net acceleration inward...

... meaning that if your misinterpretation of what's actually going on is correct, we should see the moon swerve sharply towards the planet.

However, if the inertial and gravitational mass are both reduced, the starship need only provide the original amount of delta-v necessary to stabilize the orbit - which would take about 17 minutes if we're talking about a reduction to 1%, 1.7 minutes for a reduction to 0.1%, etc - plus whatever velocity has been lost to atmospheric friction.

Now, the warp field has to provide a large amount of energy, but energy wasn't the limiting factor - just the impulse engines and tractor beams.

[Keiran]

1) What does acceleration due to gravity have to do with this situation?

Everything, Keiran. Have you seen the episode in question at all?

It's been a while since I've seen it. When you mentioned it accelerating into the planet, I thought you were taking into account what would happen if kinetic energy stayed the same while mass was reduced.

The equation you're looking for is KE = .5m*v^2.

No, it isn't.

Oh, so you just forgot it (and I thought you were using it earlier). Too bad, it's interesting and you really should have accounted for it.

They're not even consistent with each other.

Yes, they are. If you don't understand them, you're not on very good ground here.

You used: F=m'g, F=m''a, g=a*m'/m''.

That last equation should be g=a*m''/m'. Of course, everyone makes mistakes, right? I guess we shouldn't just take what people say directly at face value, because they might be wrong. Even when trying to be teachers.

Of course, since inertial mass and gravitational mass are equivalent, you'd just get g=a, and that's not really a surprise, now, is it?

3) g is given by G * M / d^2.

And?

An object's own mass will not affect its acceleration due to gravity. And the gravitational constant is applied to the mass that creates the gravity well, not the object's own mass.

Of course, you're essentially claiming than an object's rest mass in Star Trek has an additional that incorporates some kind of oxymoron variable local gravitational constant.

I see I'm going to have to explain precisely what's going on in the episode and also go over a quick refresher of Newtonian kinematics before I can make any progress in getting through to you.

Oh, you don't care to deal with the inherent velocity increase that occurs when mass suddenly drops and kinetic energy stays the same? Interesting.

After that, we can return to talking about how it is possible to create a conservative field while blocking gravitons, why Hawking radiation is a most peculiar power source for a warp engine, containment problems for black holes, etc, but there's no point in my trying to teach you how to deal with modern physics if you can't grasp Newtonian mechanics.

Yes, I still expect you to try and give me a conservative vector field that has gravitons blocked (and where there are areas with 0 graviton flux). I've already requested this "trivial" task from you several times, so I'm kind of puzzled as to why it's taking you so long.

The others are nice, too, so make a rebuttal attempt if you wish, but they are sidetracks to my main point.

Let's go back. What happens when an object is in a gravitational field? It experiences a force F=mg, its mass multiplied by the local gravitational vector g. Here, the mass is the "gravitational mass" of the object.

Understand that?

Now, let's say you have any force F applied to an object. Force equals mass times acceleration (F=ma). Here, the mass is the inertial mass of the object. To put it another way, the acceleration (m/s^2) is the force (kg m/s^2) divided by the inertia (kg).

And inertial and gravitational mass are equivalent. That means they're the same. Y'know, not different things, hence, the principle of equivalence.

So changing one will change the other.

'Cause they're equivalent.

Consider the acceleration of an object due to gravity. It is the force (mg) divided by the inertia (m) which happens to be precisely equal to g.

Directly, a=F/m=mg/m=g. Got that?

But what happens if we change the inertia without altering the gravitational mass? We can't take that last step of cancelling out the "mass" terms. Instead, we are left with the gravitational mass divided by the inertia, which is then multiplied by g - so if the inertial mass is reduced to 1% of the gravitational mass, m(gravity)/m(inertia) would be 100g - in the case of an object near earth, it would fall at 980 m/s^2 instead of 9.8 m/s^2.

Now, do you understand that yet?

Reducing one reduces the other, so there's no dilemma.

GEORDI
We can't change the gravitational
constant of the universe but if
we wrap a low level warp field
around that moon, we could reduce
its gravitational constant...
make it lighter so we can push
it.

Now, the dialogue itself is clear enough. Both inertial mass (easier to push) and gravitational mass (its gravitational constant) are being reduced in tandem. They're linked inextricably in Trek by this simple line of dialogue.

Reducing G locally won't reduce the gravitational mass. You seem to be confused as to what gravitational mass is, and what its relationship to G is.

Take: ma = GMm/d^2 -> a = GM/d^2. Now, changing G as the local gravitational constant affects the gravity well generated by the object (a at as set distance d). G outside of the warp field is still the universal gravitational constant, so the object continues to feel the same acceleration from other gravity wells that it did before.

Now, I suppose you could rewrite that as M = a * d^2 / G. However, in this case, reducing the local gravitational constant will increase the object's gravitational mass (and therefore also its inertial mass). Geordi clearly had things backwards. Maybe he misspoke and meant to say he was increasing G?

However, fortunately for us, changing the inertial mass will automatically change the gravitational mass. The fact that the moon becomes "lighter" allows us to infer that both inertial and gravitational mass have decreased. Therefore, no matter what Geordi actually did (let's just say he got things mixed up when he said it out loud and meant to increase G; after all, people make mistakes), the end result was that the inertial and gravitational mass was reduced.

Incidentally, if Geordi did increase G locally and if the object's gravity well stayed the same (a wouldn't change), then both inertial and gravitational mass would decrease instead, and the object would be easier to push. Neat, eh? Everything gets wrapped up nicely.

(I'm actually disappointed you didn't bother to investigate what would happen as G changes, since Geordi gave you a link between G and mass.)

It would be even easier, actually, if we paid attention to KE = .5mv^2. Since m just dropped, then either the moon's kinetic energy has to drop, or the moon's velocity will increase rapidly. However, since the moon didn't accelerate on its own, it appears that the warp field has some kind of inherent inertial damping effect that reduced the KE of the moon.

Anyway, yeah, inertial and gravitational mass would both decrease. What's your objection, again? That they'll both decrease? Okay, cool.

Now can we please get into that conservative vector field?