Gravity-based sensors

[Jedi Master Spock]

As promised:

There's more to it than just that, given that each gravimeter is going to lump everything within detection range into one vector. You'll have a bunch of possible gravity well combinations that could match your readings, and the problem becomes trying to figure out which range of possibilities is close enough and which ranges to ignore.

Herein lies the difference (theoretically) between graviton detector (detecting individual gravitons) and a gravimeter. If you can actually measure the flux of gravitons through a surface, you can get the base vectors instead of the sum, and if there's a doppler signature that can be resolved for gravitons*, that would wrap up all your problems neatly. Given some of the odd bits of miscellanea that pop up, it's actually reasonable to assume that Trek sensors will actually be detecting (in some sense) individual gravitons with their strength and vector of approach.

But even with simple gravimeters measuring local g, it's actually possible to sort out quite a bit, especially over time and especially with multiple detectors.

If you have multiple detectors off-set from each other, they give you a total of two variables each in measurement - g(x1), g'(x1), g(x2), g'(x2), etc. Each is a vector quantity, so we're not concerned about the dimensionality problem.

For our problem of n bodies in detection in the general case, we have three variables each - mass, velocity, and distance. Leaving aside the effects of warp fields (presumably warp fields have a distinctive subspace field and you can sort them out), once you've resolved these three variables, you can hold mass constant and fix position in relation to velocity over the time in which you track the object.

Assuming fine resolution, therefore, you have three variables to solve for when an object initially enters a range at which you can resolve it, but you can reduce this to what amounts to one independent variable once you have successfully resolved the object if your measurements are exact enough, and at worst two variables if your tracking is fuzzy and the error for integrating velocity into position would be too high.

If you know the velocity's pattern, e.g., as with an orbiting planet, you can eliminate this to zero variables and simply correct for the known vector.

While it is true that there is a limit to the number of independently moving objects you can resolve at once, which is in general linearly related to the number of gravity measuring devices on board, it's not the case that any plurality of bodies is impossible to resolve; if the number of independent and determining variables measured exceeds the number that need to be calculated, you can find a unique solution to the problem.

(In turn, of course, the number of distinct measurements possible is limited by the sensitivity of the devices and the volume you have to place them in.)

*"Yes and no" is the reasonable assumption for that. You should, if there's anything resolvable as individual gravitons by sensors, be able to get relative speed but not relative velocity.

[Keiran]

Herein lies the difference (theoretically) between graviton detector (detecting individual gravitons) and a gravimeter. If you can actually measure the flux of gravitons through a surface, you can get the base vectors instead of the sum, and if there's a doppler signature that can be resolved for gravitons*, that would wrap up all your problems neatly. Given some of the odd bits of miscellanea that pop up, it's actually reasonable to assume that Trek sensors will actually be detecting (in some sense) individual gravitons with their strength and vector of approach.

What evidence is there of Federation (or other Trek groups) sensors directly detecting gravitons?

It seems more likely that they detect the effects of gravity and then--obviously--that means they have found gravitons.

But even with simple gravimeters measuring local g, it's actually possible to sort out quite a bit, especially over time and especially with multiple detectors.

You'd have to have multiple detectors for a spaceship. The gravimeters would actually detect the difference between their acceleration and the overall ship's acceleration.

The ship as a whole will accelerate at one rate, and the gravimeters will each accelerate at a slightly different rate. Because the starship won't be perfectly rigid, however, there will be some loss of information.

Another big problem is that 1 person within 100 meters exerts more gravitational influence than a 100 million ton starship 100,000 kilometers away. Your crew's movements will cause significant interference with the gravity sensors.

For our problem of n bodies in detection in the general case, we have three variables each - mass, velocity, and distance. Leaving aside the effects of warp fields (presumably warp fields have a distinctive subspace field and you can sort them out), once you've resolved these three variables, you can hold mass constant and fix position in relation to velocity over the time in which you track the object.

Assuming fine resolution, therefore, you have three variables to solve for when an object initially enters a range at which you can resolve it, but you can reduce this to what amounts to one independent variable once you have successfully resolved the object if your measurements are exact enough, and at worst two variables if your tracking is fuzzy and the error for integrating velocity into position would be too high.

Given the limitations I have mentioned, the interference will lower the resolution to the point that you will have multiple valid solutions for the given data. How do you discover which solution is the correct one?

If you know the velocity's pattern, e.g., as with an orbiting planet, you can eliminate this to zero variables and simply correct for the known vector.

Of course, planets are massive enough such that the inherent measurement errors due to other gravity sources won't significantly alter the results.

While it is true that there is a limit to the number of independently moving objects you can resolve at once, which is in general linearly related to the number of gravity measuring devices on board, it's not the case that any plurality of bodies is impossible to resolve; if the number of independent and determining variables measured exceeds the number that need to be calculated, you can find a unique solution to the problem.

(In turn, of course, the number of distinct measurements possible is limited by the sensitivity of the devices and the volume you have to place them in.)

When the movements of someone eating is more than enough to mimic the gravity well of a spaceship flying in circles a light-minute away (or something like that), the number of solutions you can find will be greater than what you expect.

*"Yes and no" is the reasonable assumption for that. You should, if there's anything resolvable as individual gravitons by sensors, be able to get relative speed but not relative velocity.

Tracking individual gravitons would be like tracking individual photons. It's not a capability that I've seen mentioned.

[Who is like God arbour]

What evidence is there of Federation (or other Trek groups) sensors directly detecting gravitons?

It seems more likely that they detect the effects of gravity and then--obviously--that means they have found gravitons.
[...]
Tracking individual gravitons would be like tracking individual photons. It's not a capability that I've seen mentioned.

google results = graviton + Star Trek Minutiae



Examples:

From STAR TREK: DEEP SPACE NINE "Q-Less":

• DAX (to O'Brien) Chief, are you reading any graviton flux around the transfer systems.

From STAR TREK: THE NEXT GENERATION "Relics":

• I'm reading intense graviton emissions on the surface of --

From STAR TREK: THE NEXT GENERATION "Silicon Avatar":

• Captain, I'm reading a transmission from the Entity... a series of graviton pulses...

These quotations and more were provided already in the original debate on SDN, as you should know very well.

[Jedi Master Spock]

What evidence is there of Federation (or other Trek groups) sensors directly detecting gravitons?

It seems more likely that they detect the effects of gravity and then--obviously--that means they have found gravitons.

There are the examples WILGA mentioned, but there's something a little more definitive in Star Trek IV - something that's very easy to miss if you blink. In Spock's review session, this pops up:

Adjust the sine wave of this magnetic envelope so that anti-neutrons can pass through it but anti-gravitons cannot.

To me, this strongly suggests the model of individual graviton detection. This also implies (more directly) gravitational shielding (if you can block anti-gravitons, you can block gravitons), which in turn would allow any formerly simple gravimeter to be turned into a directional receptor.

You'd have to have multiple detectors for a spaceship.

Of course you would.

The gravimeters would actually detect the difference between their acceleration and the overall ship's acceleration.

The ship as a whole will accelerate at one rate, and the gravimeters will each accelerate at a slightly different rate. Because the starship won't be perfectly rigid, however, there will be some loss of information.

I don't get what you're trying to get at here. A starship is essentially a rigid body whose motion relative to itself (e.g., turning) is well known.

Another big problem is that 1 person within 100 meters exerts more gravitational influence than a 100 million ton starship 100,000 kilometers away. Your crew's movements will cause significant interference with the gravity sensors.

The crew's movements are very well known indeed, however. Internal sensors can track that. There's also the issue of gravitic control/shielding to consider, and compensating for whatever effects the artificial gravity on board the ship may have. As I said, it is a computationally complex problem - but it is not in principle unsolvable, simply very ugly.

Given the limitations I have mentioned, the interference will lower the resolution to the point that you will have multiple valid solutions for the given data.

Not really. You'll have a certain range of solutions - and below a certain signal strength, you won't be able to be sure of an object - but the family of solutions of signals of resolvable strength isn't going to include many bogus objects - not that last for any length of time, in any case.

When the movements of someone eating is more than enough to mimic the gravity well of a spaceship flying in circles a light-minute away (or something like that), the number of solutions you can find will be greater than what you expect.

Actually, it isn't enough. If I have a ring of detectors, someone eating inside the middle is going to look completely unlike any coherent motion from the outside. The behavior of the signal across different receptors is distinct even if whatever is going on inside the ship isn't going straight into the computer and compensated for, or shielded directly from the sensor. Internal sensors give you sufficient resolution to give a very good guess as to the strength and dynamics of the signals from the interior, which may in turn be corrected for with surprisingly good precision if you're smart about it.

Theoretically speaking, there's not a problem with regard to the location of objects being tracked - only the number of sources whose motion cannot be otherwise predicted.

Tracking individual gravitons would be like tracking individual photons. It's not a capability that I've seen mentioned.

Note that while the line above from STIV doesn't require individual graviton detection, it implies the ability to filter them directionally at a minimum. So, while measuring a Doppler effect of gravitons is not insured (only suggested to be possible), the problem of sorting out direction vectors is vastly simplified by the presence of such filtering.

It is, of course, quite obscure, and I can understand you having overlooked it, but it is part of the canon, and does help explain why it is that Trek ships appear to be using gravity based sensors in a few cases (as in the post above).

[Keiran]

These quotations and more were provided already in the original debate on SDN, as you should know very well.

How do we know that they are detecting gravitons directly instead of detecting the effects of the gravitons (gravity)? We detect particles by how they interact with other particles. The only way gravitons would interact with other matter (as far as we can tell), is by causing gravitation. Ergo, by detecting the acceleration caused by gravity, they can infer that gravitons are being measured. (At least, as long as gravitons are accepted as actual particles, as is the case in Trek.)

The only way another way of detecting gravitons could exist is if gravitons have another interaction that could give more information than existing methods of detecting gravitation.

[Keiran]

There are the examples WILGA mentioned, but there's something a little more definitive in Star Trek IV - something that's very easy to miss if you blink. In Spock's review session, this pops up:

Adjust the sine wave of this magnetic envelope so that anti-neutrons can pass through it but anti-gravitons cannot.

To me, this strongly suggests the model of individual graviton detection. This also implies (more directly) gravitational shielding (if you can block anti-gravitons, you can block gravitons), which in turn would allow any formerly simple gravimeter to be turned into a directional receptor.

An inertial compensator (and/or artificial gravity) can counter the effects of gravity. When the forces cancel out, it's as if they aren't there. (a + b = <0, 0, 0> m/s^2)

Of course, the effect wouldn't apply outside of the field. (A cloaked ship wouldn't be able to mask it's gravity well by using such a field.)

A magnetic field won't affect gravitons, and so very likely wouldn't affect anti-gravitons. (Even assuming that a graviton isn't its own antiparticle. Photons are their own antiparticle, yet Voyager had anti-photons. In other words: photons.)

I don't get what you're trying to get at here. A starship is essentially a rigid body whose motion relative to itself (e.g., turning) is well known

How can starships shake if they are perfectly rigid? (If it were perfectly rigid, then the ship wouldn't shake--it would shatter.) When we're talking about measuring an acceleration on the order of 1e-15 m/s^2 or less, then the body can no longer be considered perfectly rigid.

The crew's movements are very well known indeed, however. Internal sensors can track that. There's also the issue of gravitic control/shielding to consider, and compensating for whatever effects the artificial gravity on board the ship may have. As I said, it is a computationally complex problem - but it is not in principle unsolvable, simply very ugly.

Internal sensors can't always track everyone, though. There have been times when a crew member couldn't be found even though the person was still on the ship because the comm badge was removed. Someone taking a shower would throw off the sensors.

Not really. You'll have a certain range of solutions - and below a certain signal strength, you won't be able to be sure of an object - but the family of solutions of signals of resolvable strength isn't going to include many bogus objects - not that last for any length of time, in any case.

The range could be fairly large. Is that a shuttle nearby, a small frigate a few thousand klicks away, or a larger battleship even further out?

Actually, it isn't enough. If I have a ring of detectors, someone eating inside the middle is going to look completely unlike any coherent motion from the outside. The behavior of the signal across different receptors is distinct even if whatever is going on inside the ship isn't going straight into the computer and compensated for, or shielded directly from the sensor. Internal sensors give you sufficient resolution to give a very good guess as to the strength and dynamics of the signals from the interior, which may in turn be corrected for with surprisingly good precision if you're smart about it.

Theoretically speaking, there's not a problem with regard to the location of objects being tracked - only the number of sources whose motion cannot be otherwise predicted.

Even after for compensating for estimates of most of the known masses on the ship, you're still going to have a huge range of static-filled solutions.

Note that while the line above from STIV doesn't require individual graviton detection, it implies the ability to filter them directionally at a minimum. So, while measuring a Doppler effect of gravitons is not insured (only suggested to be possible), the problem of sorting out direction vectors is vastly simplified by the presence of such filtering.

It is, of course, quite obscure, and I can understand you having overlooked it, but it is part of the canon, and does help explain why it is that Trek ships appear to be using gravity based sensors in a few cases (as in the post above).

Of course, we know that gravity can be detected in other ways in Star Trek. For example, the Crystalline Entity detected graviton pulses from light-years away. The Entity would have had to use subspace in detecting the gravity pulses.

There's a good chance that subspace is affected by gravity:

PICARD: Ensign, full about -- go to warp two.

ENSIGN FELTON: The gravitational distortion is too high -- we can't maintain a warp field.

So gravitational influence on subspace could be a more convenient way of detecting gravity.

Gravity sensors could also be useful for detecting gravitational abnormalities once known gravity sources are factored out. Of course, you'd also need to have their mass in order to factor them out reliably.

But detecting the gravity via subspace would probably be easier. (After all, it allows much further ranges, where the actual gravitational pull would be very weak.)

[Jedi Master Spock]

The only way another way of detecting gravitons could exist is if gravitons have another interaction that could give more information than existing methods of detecting gravitation.

Which is exactly what that little bit in STIV asserts - another interaction.

An inertial compensator (and/or artificial gravity) can counter the effects of gravity. When the forces cancel out, it's as if they aren't there. (a + b = <0, 0, 0> m/s^2)

Of course, the effect wouldn't apply outside of the field. (A cloaked ship wouldn't be able to mask it's gravity well by using such a field.)

That has nothing to do with the above, which speaks not of cancelling one gravitational force with another, but blocking an antigraviton from passing through altogether.

A magnetic field won't affect gravitons, and so very likely wouldn't affect anti-gravitons.

Canonically, a "magnetic envelope" does in the Treknology of the 23rd century. (We do not IRL predict this behavior. The energy density of a magnetic field is generally quite low, and therefore interacts quite weakly with gravity - not to mention we know of no way of blocking gravity at all, or for that matter even generating artificial gravity fields.) We have to bend the rules of modern physics a bit when it comes to things like gravitic manipulation, warp fields, and transporter beams.

(Even assuming that a graviton isn't its own antiparticle. Photons are their own antiparticle, yet Voyager had anti-photons. In other words: photons.)

The "antigraviton" is, for all intents and purposes, a graviton so far as those of us in the real world are concerned.

How can starships shake if they are perfectly rigid? (If it were perfectly rigid, then the ship wouldn't shake--it would shatter.) When we're talking about measuring an acceleration on the order of 1e-15 m/s^2 or less, then the body can no longer be considered perfectly rigid.

No, but the minor deviations from rigidity are in general predictable, involving vibrations that you can zero out by frequency range or run through a smart filter.

Internal sensors can't always track everyone, though. There have been times when a crew member couldn't be found even though the person was still on the ship because the comm badge was removed. Someone taking a shower would throw off the sensors.

And? It's generally quite good enough, and even if the expected directional filtering was not present (a poor assumption when they are capable of directional filtering), the characteristic inversion patterns from signals interior to the array can be used in filtering out internal noises. Again, this requires an awful lot of work, but if you really want to do it, you can.

The range could be fairly large. Is that a shuttle nearby, a small frigate a few thousand klicks away, or a larger battleship even further out?

That's the example you brought up for a single-sensor system, and I explained why you're not going to have that sort of dramatic error if your resolution is decent with a multi-sensor system. You will inevitably have a margin of error, but if the object is in range for your system, it will not be a question of orders of magnitude of dependent scaling errors.

Even after for compensating for estimates of most of the known masses on the ship, you're still going to have a huge range of static-filled solutions.

Not really. The primary problem is - as with any low energy resolution system - losing signals in the noise - not some strange "static-filled solution" appearing out of the blue to produce a consistent illusion of a persistant object behaving in a manner that would be misrecognized as shiplike.

Of course, we know that gravity can be detected in other ways in Star Trek. For example, the Crystalline Entity detected graviton pulses from light-years away. The Entity would have had to use subspace in detecting the gravity pulses.

There's a good chance that subspace is affected by gravity:

PICARD: Ensign, full about -- go to warp two.

ENSIGN FELTON: The gravitational distortion is too high -- we can't maintain a warp field.

So gravitational influence on subspace could be a more convenient way of detecting gravity.

Who's to say subspace technology isn't involved in Trek's gravitic sensors? And does it matter exactly what sort of Treknobabble is involved in those sensors?

However, I'll note that we already knew that warp fields - even at STL speeds when simply used for mass lightening - involve a local redefinition of G. It may not be simply not possible in a high distortion environment for reasons that have nothing to do with subspace.

There is a lot of poor treatment of gravity in general in soft SF. IMO, one of the most realistic descriptions of gravimetric sensors is that of the CGTs in the Thrawn trilogy. Large, bulky, finicky, and highly limited systems, but useful for a few particular purposes.

[Who is like God arbour]

These quotations and more were provided already in the original debate on SDN, as you should know very well.

How do we know that they are detecting gravitons directly instead of detecting the effects of the gravitons (gravity)? [...]

Why would they say again and again gravitons, if they would only mean gravitation?
If they wouldn't be able to detect gravitons directly, it wouldn't be necessary to refer to gravitons instead of gravitation. Quite the contrary, it would be misleading.
To know theoretical, that gravitation is caused by gravitons, is useless knowledge, as long as the gravitons are not detectable.
We don't call a lamp a photon emitter or light a photon beam. We speak of photons only if we really mean photons.
They wouldn't have a reason to call something a gravtion-(field)-generator or graviton-emitter, if all they know is, that this generator or emitter creates gravitation, which is theoretical caused by gravitons.
That's why in my opinion, we can assume beyond a reasonable doubt [1 / 2], that they mean gravitions and not only gravitation, which is caused by gravitons, when they refer to gravitons and not only to gravitation.

[Who is like God arbour]

Not really. You'll have a certain range of solutions - and below a certain signal strength, you won't be able to be sure of an object - but the family of solutions of signals of resolvable strength isn't going to include many bogus objects - not that last for any length of time, in any case.

The range could be fairly large. Is that a shuttle nearby, a small frigate a few thousand klicks away, or a larger battleship even further out?

That's what I don't understand. If there would be a ship, you would, as you have partially admitted, at least get a vector only with the gravimeters, on which along the ship have to be.

You would know, that there would have to be something, what your other sensor-systems can't detect (maybe a cloacked ship?).

If you would change your own position in relation to this vector, you would get a new vector to the ship (assuming, that it hasn't changed its course).

Both vectors would cross with each other. The ship would have to be at this point. Now, you have its position at this moment.

In German, we call this method "Triangulieren". I couldn't find a matching Englisch term. But I assume, that you know this method. It could be done with two or more ships at the same time or if two gravimeters on one ship are far enough away from each other, with one ship at the same time.

I don't understand, why this should be impossible.

[Who is like God arbour]

Of course, we know that gravity can be detected in other ways in Star Trek. For example, the Crystalline Entity detected graviton pulses from light-years away. The Entity would have had to use subspace in detecting the gravity pulses.

That was a major dispute in the original debate on SDN.

• • • [quote="STAR TREK: THE NEXT GENERATION
      "Silicon Avatar""]
      
      • 36 INT. DATA'S QUARTERS - LATER
        
        [...]
      DOCTOR MARR: Captain Picard has told me that you have done work in trying to establish communication with the Entity.
      
      DATA: That is true. I have experimented with producing vibrations in crystal by means of graviton pulses.
      • [...]
        
        48 EXT. SPACE - THE ENTERPRISE (OPTICAL)
        
        at warp.
      PICARD (V.O.): Captain's Log, stardate 45125.7.
      We are still in pursuit of the Crystalline Entity. Data and Doctor Marr are prepared to attempt communication with the being when we intercept it. I will admit to some uncertainty about the prospect... it could prove to be a scientific triumph... or a catastrophe.
      
      • 49 INT. BRIDGE
      • Picard, Riker, Troi, Worf; Data and Doctor Marr at an aft science station; Geordi at the other; supernumeraries.
      WORF: Sir, the Brechtian Cluster is now five light years away.
      
      RIKER: Are we still picking up the Entity's pattern?
      
      DATA: Yes, Commander. But sensors do not yet have a lock on its exact whereabouts.
      
      DOCTOR MARR: Captain, we are reasonably certain it's between here and the Brechtian Cluster. If I start emitting the graviton beam now, it may act as a lure... a kind of beacon.
      
      PICARD: Make it so.
      • Marr and Data begin keying controls.
      • STAR TREK: "Silicon Avatar" - 7/31/91 - ACT FIVE 51.
        
        49 CONTINUED:
      DOCTOR MARR: We'll start with a pulse width of five nanoseconds, frequency one pulse per second.
      
      DATA: Commencing graviton emission now...
      • There is a brief silence, as all on the bridge wait tensely for results.
      
      GEORDI: No change in the sensor readings.
      
      DOCTOR MARR: Let's ramp the frequency.
      
      DATA: Emissions now at ten pulses per second.
      • Again, the charged silence. Then, Worf reacts to something on his controls.
      WORF: Sir...
      
      DOCTOR MARR: What is it? Do you have something?
      
      WORF: A large mass... approaching at warp speed...
      
      PICARD: Full stop. Doctor Marr, continue emitting your signal. On screen, Mister Worf.
      
      
      • 50 ANGLE - VIEWSCREEN (OPTICAL)
      • Nothing yet but the starfield. The crew on the bridge stare at it, rapt, waiting for the first indication that they have again encountered the mysterious Crystalline being. A beat. Still nothing... and then, a tiny white spot... approaching rapidly...
      • STAR TREK: "Silicon Avatar" - 7/31/91 - ACT FIVE 52.
        
        51 ON DOCTOR MARR
      • looking at the screen. This is what she has been waiting to see for so many long, agonizing years.
      • 52 ANGLE - VIEWSCREEN (OPTICAL)
      RIKER: Shields up.
      
      • The Crystalline Entity is approaching... looming larger and larger... Doctor Marr is staring, transfixed...
      DOCTOR MARR: It's beautiful...
      
      DATA: Doctor... shall we change the frequency?
      
      • She looks at him, as though coming out of a trance.
      DOCTOR MARR: Yes... yes, Commander. Proceed.
      
      DATA: Changing to twenty pulses per second...
      
      • And as he makes the changes... the Entity glides to a stop. It hangs there, in space, a magnificent and ominous being, overwhelming in its pristine, faceted beauty.
      RIKER: What's it doing? Checking us out?
      
      PICARD: Possibly... just as we are checking it out.
      
      • Then, the Entity does something quite remarkable. It turns, slowly, in space... a kind of enigmatic pirouette, fascinating in its lumbering grace.
      TROI: Is it... responding to us?
      
      DOCTOR MARR: Let's test that. Ramp the frequency again, Commander...
      
      
      • STAR TREK: "Silicon Avatar" - 7/31/91 - ACT FIVE 53.
        
        52 CONTINUED:
      DATA: Emissions at thirty pulses per second...
      
      GEORDI: Captain, I'm reading a transmission from the Entity... a series of graviton pulses...
      
      DOCTOR MARR: It's working... that's a response to our signal...
      
      • Now the Entity begins to slide, from side to side... then turning in a circle... almost like a kitten that is being teased and tickled...
      PICARD: Remarkable...
      
      DATA: Captain, there is a pattern emerging from its signals.
      
      PICARD: It's trying to communicate with us?
      
      DATA: I believe so... although it will take some time to decipher the patterns...
      
      • A sense of anticipation begins to rise in Picard.
      PICARD: Then it's possible... communication... understanding...
      
      DOCTOR MARR: Let me try something else... a continuous graviton beam.
      
      • She bends to the controls, keys in instructions.
      • Now, the Crystalline Entity exhibits different behavior. It comes to a rigid stop. Then it draws close to the ship.
      [/quote]

As it is to read, the Enterprise and the Crystalline Entity were at warp speed and up to five lightyears away from each other. Nevertheless the Silicon Entity was able to detect the graviton beam from the Enterprise.

It was a graviton beam and not only a gravitation-wave or a wave in subspace, caused by a gravitation wave in real space. I think - and have argued at SDN - that we have to assume, that the gravitons, fired in subspace, propagate with high warp-speed because they don't leave subspace unless they collide with an object - in this case, the Crystalline Entity or maybe after some time, in which they could have become slower. Otherwise the gravitons would have never reached the Crystalline Entity.

To corroborate my these, I have refered to the TNG episodes "Chain of Command", in which was seriously dicussed the possibility to launch dormant metagenic material on a subspace carrier wave and the TNG episode "New Ground", in which a whole ship was transported through subspace by a carrier subspace wave, the soliton wave.

Metagenic material would consist of complex biological molecules and a whole ship a fortiori too (OK, no biological molecules for the ship unless it is a biological ship.). But gravitons are only elementar particles. Therefore I think, it would be far easier to send such elementar particles, which have no mass and can't be ruptured through subspace, than heavy complex biological molecules, which are held together only by molecular bonding forces.

I have argued, that the first could be therefore already in common use while the latter, which would be far more difficult, was only in a test phase.

[GStone]

I think 'Triangulieren' is german for triangulation, but my german sucks.

[Who is like God arbour]

I think 'Triangulieren' is german for triangulation, but my german sucks.

It sounds at least similar.
My dictionary and google aren't able to provide me with the translation.
But I think triangulation is correct.
What is the verb and what is the noun?

[GStone]

In english, the verb is 'triangulating' (present tense), 'triangulated' (past tense) and 'triangulate' (future tense), though the future tense can be used as the noun form in certain contexts, like 'I need you to triangulate...', meaning 'I need you to perform the act of triangulation because...'. The 'main form' of the noun is 'triangulation'.

Edit: The german version of wikipedia does have this search page I tried. You'd probably do better at finding what's what.

http://de.wikipedia.org/wiki/Spezial:Su ... angulieren

[SailorSaturn13]

slightly off top, but the best way for warp would be sending gravitons via subspace to create a pulling channel - which pulls the ship forward supraluminal.

he only way gravitons would interact with other matter (as far as we can tell), is by causing gravitation. Ergo, by detecting the acceleration caused by gravity, they can infer that gravitons are being measured. (At least, as long as gravitons are accepted as actual particles, as is the case in Trek.)

If gravitons exist, then they have wave properties, too. They not only pull, they also bend space and create forward-backward movement.

The important formulas are: the closer to object, the more energy each graviton has (slower vibrations).
And the direction of gravitons gives us a vector to target.
Detecting vector is easy: jst build long , small tube which blocks gravitons in walls and the only gravitons coming through (to detector) are in correct direcition

The only way another way of detecting gravitons could exist is if gravitons have another interaction that could give more information than existing methods of detecting gravitation.

And given they can emit gravitons by random (shields) it is likely they do know more intractions.

[Keiran]

I don't have time to reply to all the posts since last night, so I'm going to address what I can.

Which is exactly what that little bit in STIV asserts - another interaction.

That has nothing to do with the above, which speaks not of cancelling one gravitational force with another, but blocking an antigraviton from passing through altogether.

Canonically, a "magnetic envelope" does in the Treknology of the 23rd century. (We do not IRL predict this behavior. The energy density of a magnetic field is generally quite low, and therefore interacts quite weakly with gravity - not to mention we know of no way of blocking gravity at all, or for that matter even generating artificial gravity fields.) We have to bend the rules of modern physics a bit when it comes to things like gravitic manipulation, warp fields, and transporter beams.

Given that terms such as "anti-photons" and "gigawatts of particle energy" are used, relying on dialog being technically accurate may not be wise. (The question Spock was answering may have been somewhat of a trick question, given that it was referring to "anti-gravitons" in the first place.)

No, but the minor deviations from rigidity are in general predictable, involving vibrations that you can zero out by frequency range or run through a smart filter.

Including vibrations due to people walking around? If the internal sensors had this level of detail, nobody could ever hide while on a starship.

There's a strong implication that gravimeters aren't used for [a primary method of] detecting masses in TNG's "The Survivors," however. A ship that appeared out of nowhere was assumed to have been hiding in a Lagrange point.

If the Enterprise were equipped with with gravimeters as sensitive and precise as you would require to get around the interference I have mentioned, then a ship could not hide in a Lagrange point, because its own gravity well would not be affected by the Lagrange point. The suggestion that a ship could hide in one would be outright silly with sensors that capable.

Direct graviton detection would have the same problem: the gravitons being emitted by the starship would not be affected by simply originating from an L-point, so again the suggestion would be very silly.

And? It's generally quite good enough, and even if the expected directional filtering was not present (a poor assumption when they are capable of directional filtering), the characteristic inversion patterns from signals interior to the array can be used in filtering out internal noises. Again, this requires an awful lot of work, but if you really want to do it, you can.

And the amount of work is completely unnecessary if gravimeters are being used, because the effects of gravitation can be detected FTL.

That's the example you brought up for a single-sensor system, and I explained why you're not going to have that sort of dramatic error if your resolution is decent with a multi-sensor system. You will inevitably have a margin of error, but if the object is in range for your system, it will not be a question of orders of magnitude of dependent scaling errors.

Then what is the range of the system?

And how do you handle two starships near each other? Your sensors will, at best, only see a single blip because the gravity is pulling to the center of mass of the system.

Not really. The primary problem is - as with any low energy resolution system - losing signals in the noise - not some strange "static-filled solution" appearing out of the blue to produce a consistent illusion of a persistant object behaving in a manner that would be misrecognized as shiplike.

The alternative to phantom blips appearing and disappearing to fit the data would be a margin of error listed for each detected object.

Who's to say subspace technology isn't involved in Trek's gravitic sensors? And does it matter exactly what sort of Treknobabble is involved in those sensors?

It'd matter for determining capabilities and limitations.