(originally posted here)
Very often I see people confidently think or claim that the Star Trek warp drive works like the warp “drive” first proposed by physicist Miguel Alcubierre in 1994. Unfortunately, this is in error (I put “drive” in quotes because Alcubierre apparently dislikes calling it a drive, preferring to call it a “warp bubble”). As Alcubierre himself says, it was Star Trek that gave him the inspiration for his metric, not the other away around.
Why there is this conflation may be because people desperately want to think that Star Trek is based on hard scientific principles, or that the same principles in Star Trek are actively being worked on in real life. I don’t propose to speculate further. There are also several fan ideas and beta canon ideas in licensed fiction about warp drive (notably in the excellent novel Federation by Judith and Garfield Reeves-Stevens) but for the sake of brevity, I’m limiting my discussion to what we see on-screen and related behind-the-scenes documents.
Background
The basic obstacle to superluminal or faster-than-light travel is Einstein’s Theory of Special Relativity. Special Relativity says that as the velocity of an object with mass accelerates towards the speed of light (c), the mass of that object increases, requiring more and more energy to accelerate it, until at c, that object has infinite mass, requiring infinite energy to push it past c. In fact, Special Relativity says that nothing with mass can reach c - photons are massless and can only travel at c. From there, it follows that theoretical objects with negative mass can only travel above c, hence given the name tachyons, from the Greek tachys, or “fast”.
Alcubierre wondered: if you can’t move the object/ship without running into relativistic issues, why not move space instead? Alcubierre’s idea was to warp space in two ways - contract space in front of the ship and expand space behind it, an effect he compares to a person on a travelator. So while the ship itself remains stationary in a flat area of spacetime between the two areas of warped space (the whole thing being the “warp bubble”), that flat area gets moved along like a surfboard on the wave of warped space. Of course, warping spacetime in this manner involves incredible amounts of negative energy, but that’s another discussion.
So this is how the Alcubierre metric circumvents relativistic issues. Because the ship itself remains essentially motionless, there is no acceleration or velocity and thus no increase in inertial mass.
But that’s not how Star Trek’s warp drive works, and has never been.
Warp Drive pre-TNG
There is no description on how Star Trek warp drive works on screen in TOS except perhaps for a vague pronouncement that the “time barrier’s been broken” in TOS: “The Cage” (in the episode Spock also calls it a “hyperdrive” and refers to “time warp factors”).
During the production of Star Trek: The Motion Picture (1979), science consultant Jesco von Puttkamer, at the time an aerospace engineer working at a senior position in NASA, wrote in a memo to Gene Roddenberry dated 10 April 1978 (The Making of Star Trek: The Motion Picture by Susan Sackett and Gene Roddenberry, 1980, pp153-154) his proposal for how warp drive was supposed to work, in a way eeriely similar to Alcubierre’s metric:
When going “into Warp Drive,” the warp engines in the two propulsion pods create an intense field which surrounds the entire vessel, forming a “subspace”, i.e. a space curvature closed upon itself through a Warp, a new but small universe within the normal Universe (or “outside” it). The field is nonsymmetrical with respect to fore-and-aft, in accordance with the outside geometry of the Enterprise, but it can be strengthened and weakened at localized areas to control the ship’s direction and apparent speed.
Because of the its non-symmetry about the lateral axis, the subspace becomes directional. The curvature of its hypersurface varies at different points about the starship. This causes a “sliding” effect, almost as a surf-board or a porpoise riding before the crest of a wave. The subspace “belly-surfs” in front of a directionally propagating “fold” in the spacetime structure, the Warp - a progressive, partial collapse of spacetime caused by the creation of the subspace volume (similar to but not the same as a Black Hole).
But there’s no evidence that Roddenberry actually used this concept. In fact, Puttkamer said further in the memo that at warp, Enterprise would have “little or no momentum”, which we will see is not how it’s portrayed. Puttkamer was even against the now famous rainbow effect of going into warp:
The effect should not be firework-type lights but a more dimensional, geometric warping and twisting, an almost stomach-turning wrenching of the entire camera field-of-view.
So while an interesting document, there’s no evidence that Puttkamer’s ideas made it into any on screen incarnation of Star Trek.
Warp Drive in TNG and beyond
In TNG, the first publicly available description of how warp drive is supposed to work came from the licensed Star Trek: The Next Generation Technical Manual (1991). At page 65:
WARP PROPULSION
The propulsive effect is achieved by a number of factors working in concert. First, the field formation is controllable in a fore-to-aft direction. As the plasma injectors fire sequentially, the warp field layers build according to the pulse frequency in the plasma, and press upon each other as previously discussed. The cumulative field layer forces reduce the apparent mass of the vehicle and impart the required velocities. The critical transition point occurs when the spacecraft appears to an outside observer to be travelling faster than c. As the warp field energy reaches 1000 millicochranes, the ship appears driven across the c boundary in less than Planck time, 1.3 x 10^-43 sec, warp physics insuring that the ship will never be precisely at c. The three forward coils of each nacelle operate with a slight frequency offset to reinforce the field ahead of the Bussard ramscoop and envelop the Saucer Module. This helps create the field asymmetry required to drive the ship forward.
As described here, Star Trek warp drive gets around Special Relativity by using the warp field to distort space around and lower the inertial mass of the ship so that the shaping of the warp fields and layers around the ship can push and accelerate the ship itself towards c with reasonable energy requirements. The stronger the field (measured in units of millicochranes), the lower the inertial mass gets and it becomes easier to accelerate. When the field hits a strength of 1000 millicochranes, the ship pushes past the c barrier. Presumably at this stage it’s in subspace, where Relativity no longer applies, and can accelerate even faster to each level of warp until the next limit at Warp 10 (TNG scale), or infinite speed. I’m not getting into how warp factors are defined (but see here for a discussion on the change between TOS and TNG warp scales, which also goes into the definition of warp factors, if interested).
The Technical Manual was written by Rick Sternbach and Michael Okuda, who were both technical consultants behind the scenes, and evolved from a document prepared by them in 1989 (3rd Season) to aid writers on the show in writing the technobabble in their script. (See also the history here.)
Here’s what the first, 3rd Season edition says about the way warp works, which is simply that the drive “warps space, enabling the ship to travel faster than light,” and that the ship is “‘suspended in a bubble’ of ‘subspace’, which allows the ship to travel faster than light”. This description also shows up in the 4th Season edition, and the Star Trek: Voyager Technical Guide (1st Season edition) in identical form.
While the actual text of the manual never made it on screen, there are several pieces of on-screen evidence that tell us Sternbach and Okuda’s description of warp drive is followed: warp fields lower inertial mass, and the ship experiences acceleration and inertial forces during warp.
Evidence of warp fields lowering inertial mass
In TNG: “Deja Q” (1990), Enterprise-D uses a warp field to change the inertial mass of a moon:
LAFORGE: You know, this might work. 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.
Later in that episode, we see the effect the warp field has on the moon:
DATA: Inertial mass of the moon is decreasing to approximately 2.5 million metric tonnes.
At the time “Deja Q” was broadcast, all that was said about warp drive in the technical guide was that warp drive “warps space” and the ship is in a subspace bubble with no mention of lowering inertial mass. Yet “Deja Q” shows warp fields doing exactly that, which tells us that either the writer gave Sternbach and Okuda that idea or they already had their ideas in place behind the scenes. The latter is more likely, given that the Technical Manual was published the following year.
In DS9: “Emissary” (1993), O’Brien and Dax use a warp field to lower the mass of the station so they can use thrusters to “fly” the station to where the wormhole is.
DAX: Couldn’t you modify the subspace field output of the deflector generators just enough to create a low-level field around the station?
O’BRIEN: So we could lower the inertial mass?
DAX: If you can make the station lighter, those six thrusters will be all the power we’d need.
Evidence of inertia during warp
We’ve known from TOS on that during warp speed, inertia still exists. If it didn’t, then there wouldn’t be the bridge crew being subjected to inertial forces when maneuvering at warp speeds and being tossed around the bridge (TOS: “Tomorrow is Yesterday”, when Enterprise slingshots around the sun at warp - with the last reported speed being Warp 8 on the TOS scale).
In TMP (1979), we see Enterprise accelerating to warp speed before the engine imbalance creates a wormhole.
KIRK: Warp drive, Mr Scott. Ahead, Warp 1, Mr Sulu.
SULU: Accelerating to Warp 1, sir. Warp point 7… point 8… Warp 1, sir.
As noted, a ship using the Alcubierre metric doesn’t need to accelerate, because it’s space that’s moving, not the ship. Additionally there’d be no need for an inertial dampening field (as we see in TNG and beyond) that is supposed to protect the crew when accelerating to superluminal speeds. From VOY: “Tattoo” (1995):
KIM: Could we go to warp under these conditions?
PARIS: The ship might make it without inertial dampers, but we’d all just be stains on the back wall.
In the 2009 Star Trek movie, Enterprise was unable to go to warp unless the external inertial dampeners were disengaged.
SULU: Uh, very much so, sir. I’m, uh, not sure what’s wrong.
PIKE: Is the parking brake on?
SULU: Uh, no. I’ll figure it out, I’m just, uh…
SPOCK: Have you disengaged the external inertial dampener?
(Sulu presses a couple buttons)
SULU: Ready for warp, sir.
PIKE: Let’s punch it.
If there’s no acceleration or inertia, there’s no reason why them being on would impede warp drive operation.
Closing Remarks
Taking all these pieces into account, I hope I’ve shown convincingly that the way the show treats Star Trek warp drive is consistent with a drive system that involves acceleration and inertial forces, and with warp fields that lower inertial mass - just like Sternbach and Okuda describe in the Technical Manual, and definitely not consistent with way the Alcubierre metric is supposed to work.
For those who want a deep dive into Star Trek warp physics, some canon and some speculative, I heartily recommend Ex Astris Scientia’s series of articles on warp propulsion. I also recommend Jason W. Hinson’s series on “Relativity and FTL Travel”. Hinson was a regular participant in rec.arts.startrek.tech in the 90s and educated us on how Relativity worked and how it applied to Star Trek.
well, this is certainly a c/daystrominstitute post if I’ve ver read one!
too bad there’s no M-1 bot, or I’d nominate it for post of the week!
Thanks - I basically wrote this because I was tired of explaining again and again why the two drives are different and wanted to have a single link I could just cut and paste in future. 😂
been there, lol
too bad there’s no M-1 bot, or I’d nominate it for post of the week!
The moderators have the code, and could probably tweak it for Lemmy if/when they got around to it. Most things probably work close enough that it isn’t that big of a change.
It seems to me that your proof that Star Trek warp is not the same as Alcubierre’s warp seem to rely excessively on the specific results of the corner solution that Alcubierre used in his own proof.
For example, the lack of velocity going into warp and inertia within the warp bubble are specific to that corner solution, as is the lack mechanism to change direction.
But Albucierre’s corner solution would require unrealistic amounts of exotic matter even as compared to the antimatter engines in Star Trek.
So, we should expect that the advances to any kind of usable Albucierre drive will go beyond that specific closed-form solution. The last reported works to advance his finding did start to get beyond the limited case of one direction and inertia.
It’s pretty much a given that when someone is trying to find a solution around a theory as robust as general relativity, the starting point is going to be some kind of corner solution.
Others may extend the work, but it would go to far to say that the practical solutions with the additional variables allowed to have nonzero values are not Albucierre’s warp.
When people say that warp drive is like Alcubierre, they’re specifically talking about the idea that the ship doesn’t move and space moves around the ship. That in essence is an idea that doesn’t involve inertia or acceleration.
Once you start moving away from the idea it’s space that’s moving, not the ship, then it’s not Alcubierre - at least not in its popular conception.
I readily admit I don’t know what kind of additional ideas they’ve come up with and await further edification on that score, but I have my doubts that it will square with the idea of warp fields lowering inertial mass, accelerating to warp or the use of inertial dampers already depicted in the show.
You may be able to have both.
The key point is that the fundamental concept of space warping around the ship doesn’t necessarily mean that the ship cannot have velocity (and therefore inertia) going into warp.
That is, the idea that a ship would have to be at a full stop prior to engaging warp, rather than taking the speed from the impulse (or whatever sublight) engines, isn’t inconsistent with the basic concept of Albucierre’s drive, just the specific extreme solution he worked out the proof for.
As for thing like light stretching around the ship, it not obvious what the light outside the warp bubble or field would appear like to those inside the field. I haven’t seen a worked example to show why the light of stars in space exterior to the field would appear normally. One would rather think the opposite even if it’s the space and not the ship that’s pulled superluminally.
I remain skeptical - you can’t have warp drive be the Alcubierre drive without having to retcon a lot of how warp fields are shown to behave, least of all their inertial mass lowering properties.
Everyone saying that it acts like the Alcubierre drive has to ignore the evidence before them. I can’t think of anything that indicates that warp drive behaves like the Alcubierre drive is supposed to be, but I’m open to be corrected on this.
So until shown otherwise by the series, I’m quite content with sticking with my claim and the explanation in the TNG Tech Manual, which was the technical advisors’ intent at the time.
I dearly love the TNG Tech Manual.
I’m not sure why we would give it primacy over science advisor Dr Erin MacDonald’s current explanation of how warp works, especially as she frequently takes examples from Voyager to demonstrate it.
I also have the original edition of the TNG Technical Manual and it’s very well worn. I saw Rick Sternbach present at cons in the 90s and have seen more sketches and schematics beyond the Tech Manual which he put on screen (TNG, DS9, space stations etc.)
I can’t consider these supporting publications and insights into the minds of the designers to be canon though, at least not alpha canon, any more than I would give that status can tonthr the ‘official’ posters and books with schematics with the insides of the ships - from the TOS era through to the Shipyards books.
As you note in your own critique in the OP, what the designers and EPs had in mind doesn’t necessarily get validated or consistently brought on screen. Not to mention Okuda had and has his own firm ideas about ships that he put into graphics that don’t necessarily align.
One of the biggest examples of this is interior schematics.
Many fans love and cling to their charts of interior schematics of the hero’s ships. This includes some of the EPs and writers. (Michal Chabon talks about the one of the 1701 he had on his bedroom wall as a child.)
The TNG Tech Manual however validates the modular concept of the interior of ships where modules for different labs, sickbay, quarters etc are hung within the volume of the slacked frame. These line up as decks but aren’t a stacked structure like an office tower or a cruise ship. The turbolifts wind around these modules. I’ve heard this called the ‘habittrail’ ship interior model after the old environments for small pets. The concept dates back to the plans and scematics for TMP.
Anyway modular ship interiors are described in the Tech Manual and were confirmed in presentations by Sternbach at the time. In fact, when asked why he didn’t provide deck charts for the D, Sternbach would reply that the ship interior was modular and adaptable to the different needs of crews and missions. Turbolifts and Jeffries Tubes would wind between these suspended modules and deck sections.
I would argue however that, despite Sternbach’s statements and the manual, the modular interior structure has only recently been confirmed in the 23rd century was only onscreen (Discovery and Short Treks) in the wills vfx scenes of the turbolifts travelling within the ship, and the fight in the turbolift in a Discovery episode. Whether or not one believes that the interior volumes shown in those vfx shots were too large, it’s indisputable that a modular interior with interior spaces hanging in a space frame has been established for that era (or at least as it’s been overwritten).
For the 24th and early 25th century, we have have conflicting onscreen evidence from Okuda’s graphics. On LCARS panels, we are shown distinct vertical cutaway elevations with an office-tower or cruise ship rigid/fixed deck structure. Lower Decks doubled down on this in the episode where Boimler crawled through Jeffries tubes to reach the bridge to meet Tom Paris.
Anyway, I’ve dove down another rabbit hole with this, and I expect that the issue of the interiors has been previously well-canvassed at the Daystrom Institute’s old location, but it’s another key example of some very different ideas having floated around in the background of production having influenced what gets established onscreen as canon.
As I noted in my response to another post, I view all of this as a kind of creative dialogue that ranges from the writers and technical and production staff to the licensed tie-in publications through to fan thinking and back.
Albucierre is a fan who is also a physicist. He’s feeding back and inputting into the dialogue. Just because the production had played around with something like but unlike warp, doesn’t mean he doesn’t have what’s canonical warp.
His fandom led to his finding a very significant workaround the limits of General Relativity. His doctoral thesis proof used, necessarily, the most extreme corner solution to make the math tractable because that’s how one establishes that there is a way around a theory that has hasn’t been previously recognized.
I do find your claim that people understand Alcubierre’s warp to be just the specific extreme case a bit puzzling, as I see the concept being picked up and extended in a wide swath of recent sci-fi literature outside the Trek franchise.
More useful and practical applications of his warp concept can only come from adding in those other variables, likely by massive computational estimates where the neat closed form math solutions aren’t possible. It seems other writers appreciate this and are looking to speculations about the theory can be expect to advance, rather than freezing it in the PhD thesis version.
In the end, I can only agree that we’ll need to seen onscreen confirmations, even if what we have from behind the scenes thinking is strongly suggestive one way or another.
In that vein, I would caution that it would be more fair to say that it remains to be confirmed as Alcubierre’s warp concept rather than that it is not.
When did she explain how warp works?
If you’re talking about her Trektech video, that’s her talking about how a warp drive could work in real life, not how it works in-universe in Trek.
My position is that it’s been established how warp works in-universe, and if the powers that be now say it acts like an Alcubierre drive, well, that’s their prerogative - and my response is that that’s a major retcon.
And I’m not saying they can’t do that. I’m saying that if it happens it’ll be an inconsistency and they need to own it as such and figure out some explanation like messing with the timeline.
So I don’t think it’s fair to say it hasn’t been confirmed that it’s an Alcubierre drive. The fairest thing to say is that they haven’t said that it is one at all.
But there’s no evidence that Roddenberry actually used this concept. In fact, Puttkamer said further in the memo that at warp, Enterprise would have “little or no momentum”, which we will see is not how it’s portrayed
In fact, we all but know that it does not appear to be how it’s used, since subspace is treated as a fundamental part of reality as of TNG, rather than a function of a starship’s warp field.
If subspace was a creation of the warp field, Omega particle detonation would not be a significant issue.
That said, though, the idea seems to have still been kept, since we also see things like subspace/warp fields being used to generate entire separate universes, which would not be possible otherwise.
At the time “Deja Q” was broadcast, all that was said about warp drive in the technical guide was that warp drive “warps space” and the ship is in a subspace bubble with no mention of lowering inertial mass. Yet “Deja Q” shows warp fields doing exactly that, which tells us that either the writer gave Sternbach and Okuda that idea or they already had their ideas in place behind the scenes. The latter is more likely, given that the Technical Manual was published the following year.
At the same time, we know that the warp field was creating alternate universe with alternate rules, with both the Traveller experiment, and when Dr Crusher was marooned in an alternate universe. It’s not that much of a stretch to think that a lesser alteration could just give the law of physics enough of a slight nudge that it might be theoretically possible to tow a moon using the warp field.
As noted, a ship using the Alcubierre metric doesn’t need to accelerate, because it’s space that’s moving, not the ship. Additionally there’d be no need for an inertial dampening field (as we see in TNG and beyond) that is supposed to protect the crew when accelerating to superluminal speeds. From VOY: “Tattoo” (1995):
The Alcubierre drive just compresses space, but it doesn’t move the ship. The ship would still need a secondary engine within to use that kind of drive, which they would still need inertial dampeners for. An impulse engine, for example, which could exert inertial forces upon the ship.
If there’s no acceleration or inertia, there’s no reason why them being on would impede warp drive operation.
Although it could also be that the external dampener doesn’t actually have much of a bearing on it. The engines don’t seem to engage or do anything, so it’s equally possible that having the dampener on engages an interlock that prevents the ship from firing its warp engines, to minimise the risk of damage if the engines are accidentally activated due to error, malfunction, or theft attempts.
Similar to the door interlock on modern public transport, which prevents the train/bus/tram moving until the doors are closed.
At the same time, we know that the warp field was creating alternate universe with alternate rules, with both the Traveller experiment, and when Dr Crusher was marooned in an alternate universe. It’s not that much of a stretch to think that a lesser alteration could just give the law of physics enough of a slight nudge that it might be theoretically possible to tow a moon using the warp field.
What occurred in TNG: “Where No One Has Gone Before” directly inspired Wesley’s experiment in TNG: “Remember Me”, so the two are one and the same. And that wasn’t actually a standard warp field, but a “static warp bubble” - a deformation in space that is sometimes unintentionally created, but not a usual effect of a warp field. What we see in “Deja Q” is perfectly in line with what a warp field as described in the TNG Tech Manual is supposed to do - lower inertial mass, and similarly in DS9: “Emissary”. Dialogue in “Deja Q” makes it extremely clear that it wasn’t the warp field doing the movement of the moon - it was the tractor beam engaging the moon with the warp field helping to lower the mass so it wouldn’t burn out while doing it.
The Alcubierre drive just compresses space, but it doesn’t move the ship. The ship would still need a secondary engine within to use that kind of drive, which they would still need inertial dampeners for. An impulse engine, for example, which could exert inertial forces upon the ship.
Correct - the Alcubierre drive doesn’t move the ship - it moves space around the ship, and the ship within the Alcubierre “warp bubble” is moved along like on a travelator without actual velocity or acceleration. But in this way, it doesn’t need any other secondary engines. Besides, in VOY: “Tattoo” the conversation about needing inertial dampers is specifically about engaging warp - not impulse.
The engines don’t seem to engage or do anything, so it’s equally possible that having the dampener on engages an interlock that prevents the ship from firing its warp engines, to minimise the risk of damage if the engines are accidentally activated due to error, malfunction, or theft attempts.
But why an inertial dampener for this purpose? Why not an actual “gear lock” or parking brake? The fact that they refer to an inertial dampener must mean something - and if the warp engines can’t engage when their inertia is arrested externally, then it means that inertia must be present when warp engines are engaged, which mean acceleration at warp.
And that wasn’t actually a standard warp field, but a “static warp bubble” - a deformation in space that is sometimes unintentionally created, but not a usual effect of a warp field.
However, it is still a “warp bubble”. An unusual one, but not a subspace field, or anything particularly funky that would require specific modification of the ship’s engines, or some other device.
Dialogue in “Deja Q” makes it extremely clear that it wasn’t the warp field doing the movement of the moon - it was the tractor beam engaging the moon with the warp field helping to lower the mass so it wouldn’t burn out while doing it.
As far as I recall, it was a bit of both. The tractor beam was to keep the moon in the warp field, or the Enterprise in lock around the moon without having to use their engines, with the warp field being used to provide more motive force to move the moon compared to the impulse engines, and then to change the mass of the moon.
If it was just lowering the mass, it would be possible for them to just project out a mass alteration field similar to DS9, instead of using the warp field for that task.
But why an inertial dampener for this purpose? Why not an actual “gear lock” or parking brake? The fact that they refer to an inertial dampener must mean something - and if the warp engines can’t engage when their inertia is arrested externally, then it means that inertia must be present when warp engines are engaged, which mean acceleration at warp.
Mechanism of operation, and function? If it relies on inertial dampeners to work, compared to the force-based options of modern braking systems. It’s not a brake, since there are no brakes in space, and not a gear lock, since there are no gears to lock.
The fact that they refer to an inertial dampener must mean something - and if the warp engines can’t engage when their inertia is arrested externally, then it means that inertia must be present when warp engines are engaged, which mean acceleration at warp.
Not if the engine function is separate from the dampener, and it is simply a safety interlock that prevents the engines from engaging under those conditions. The ship wasn’t trying to drag itself through the dampener, instead, the warp engines simply refused to engage in the first place, to prevent the engines shearing off the ship, or exploding from the strain of fighting the dampeners.
I’d be surprised if warp engines didn’t have a bunch of safety interlocks just to prevent the warp engines from being accidentally activated under a bunch of conditions, such as when the ship is docked, with overrides for alert conditions, or manual override if necessary.
Think of it like a microwave. A microwave will not start if the door is open, thanks to that safety interlock.
However, it is still a “warp bubble”. An unusual one, but not a subspace field, or anything particularly funky that would require specific modification of the ship’s engines, or some other device.
No, it’s not. In “Where No One Has Gone Before” it allegedly needed modifications of the warp equations to modify the engines, but in the end it was actually created by the Traveler’s own powers. In “Remember Me”, Wesley was experimenting with creating a static warp bubble in the warp core using Kominsky’s equations, but he couldn’t keep it stable. The “static warp bubble” is different from the standard warp field and in fact the terminology was distinct. The first time anybody used the term “warp bubble” to talk about a warp field in-universe was in PRO: “Mindwalk”. But it’s very clear from the context that the pocket universe created by the static warp bubble in “Remember Me” is not a standard effect but a result of experiment, and not stable at all.
As far as I recall, it was a bit of both. The tractor beam was to keep the moon in the warp field, or the Enterprise in lock around the moon without having to use their engines, with the warp field being used to provide more motive force to move the moon compared to the impulse engines, and then to change the mass of the moon.
From the episode itself:
LAFORGE: The moon will hit its perigee in 10 hours. Now, we match its trajectory, increase emitter coolant rate so we can apply continuous warp-equivalent power nine to the tractor beam. We can push it for nearly 7 hours and I think that just might do it. But, there’s a problem.
DATA: The Enterprise will be dangerously close to the atmosphere.
LAFORGE: That’s the problem.
So the plan is initially to use the tractor beam alone - to push it. Geordi doesn’t come up with the warp field notion until Q suggests changing the gravitational constant of the universe.
LAFORGE: You know, this might work. 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.
So the operative text is “Make it lighter so we can push it”, not “use the low level warp field to push it”. And in fact, the two act in tandem.
DATA: Inertial mass of the moon is decreasing to approximately 2.5 million metric tonnes.
LAFORGE: It’s working. We can move it. Firing impulse engines.
[Bridge]
DATA: Captain, the moon’s trajectory has moved .3 percent. .4 percent.
WORF: Emergency! Shields up.
RIKER: Disengage tractor beam.
This is entirely consistent with and an extension of the original plan to use the tractor beam to push the moon, but with the added warp field effect of lowering inertial mass. This also consistent with what O’Brien does in DS9: “Emissary”:
DAX: Couldn’t you modify the subspace field output of the deflector generators just enough to create a low-level field around the station?
O’BRIEN: So we could lower the inertial mass?
DAX: If you can make the station lighter, those six thrusters will be all the power we’d need.
If wrapping a warp field around the station alone could provide propulsive effect like you suggest, there’s no need for thrusters.
The reason why warp engines can move the ship as stated in the Tech Manual is because the nacelles are capable of shaping the warp field around the ship.
In the case of the moon in “Deja Q”, they are extending the Enterprise’s warp field so it’s not being shaped by nacelles in the same way - any propulsive effect is limited to the ship alone, so the warp field extension is merely to lower inertial mass. In “Emissary” the warp field is being generated by the deflectors, not nacelles whose coils can be adjusted to fire in sequence to shape a warp field, so they still need Newtonian thrusters.
In an Alcubierre situation, if you manage to encompass the moon within the Alcubierre bubble, then there’s no need for a tractor beam at all - you can just carry it along with you. Similarly, in relation to “Emissary”, you don’t need your thrusters. That fact that you still see acceleration effects at warp in countless episodes already puts paid to the idea that it’s an Alcubierre drive.
Not if the engine function is separate from the dampener, and it is simply a safety interlock that prevents the engines from engaging under those conditions. The ship wasn’t trying to drag itself through the dampener, instead, the warp engines simply refused to engage in the first place, to prevent the engines shearing off the ship, or exploding from the strain of fighting the dampeners.
But why would engines be shearing off or exploding from the strain? Strain of what? What are the inertial dampers stopping the ship from doing, and how? Inertial dampeners are to reduce momentum and acceleration. If warp drive is Alcubierre, there is none of that, hence no strain or shearing off - there are no forces acting on the ship itself with an Alcubierre drive, that’s the entire point. So inertial dampers being on would do absolutely nothing to stop a ship equipped with an Alcubierre drive from warping because the ship never actually moves within its Alcubierre warp bubble.
Anyway, we’re kind of going around in circles and I’m repeating myself, so I think I’d stop here.
