Impulse use within warp travel

[Johnny]

Just looking for peeps thoughts on this.

Been thinking about warp drive and what it actually does to space. Compresses at the front and expands at the back, etc. What would be the propulsion that actually drives it through that space? Since it still is space, albeit compressed.

...assuming the space is compressed before it hits the ship, and then expanded once its reached the aft most point...

The only two things i can think of are that the warp engines are able to move space as well as compress it, but im not sure ive come across anything that would explain that. Or that impulse engines are used to drive the ship through the compressed space.

If the latter is true then does time dialation still apply, to varying degrees, depending on how compressed space is?

Its a heavy thinking day... :s

Ta, J.

 

[C.E. Evans]

Or warp propulsion is achieved by the nacelles generating multiple layers of subspace, pushing a ship forward.

 

[Timo]

FWIW, in "Obsession", Scotty was conducting impulse repairs and this in no way impaired a warp chase. In fact, it turns out that the repairs were such a non-factor in warp drive that Scotty forgot all about them, and a vent left open for said repairs became a plot point.

It might be that only part of the impulse system was shut down and the rest was moving the ship at warp. But the fact that Scotty forgot about the repairs suggests that he didn't think impulse systems would in any way be featured in warp travel - after all, when Kirk did order that warp chase, everybody felt he was crazy and was ready to talk back at him, and Scotty usually doesn't hesitate to speak his piece when operational or safety concerns arise.

In contrast, in ST:TMP, Kirk specifically orders impulse power and then warp 0.5 (rather than, say, 0.5 lightspeed), and later it is commented that full warp power may not be available. The terminology mismatch is unique, though, and relates to untested warp engines. Perhaps Kirk both orders Sulu to proceed at best possible impulse and tells him to warm up the new warp engines at half a factor?

Timo Saloniemi

 

[JES]

I was under the impression that warp 0.5 is comparable to saying mach 0.5. That it is halfway to warp speed. Maybe the warp drives are somehow used to prevent time dilation at high impulse speeds (either that, or they have something akin to a dilation dampener, that keeps the ship from moving forward in time, unless that is a side effect of having warp drive in the first place, even at sublight).

 

[Timo]

I was under the impression that warp 0.5 is comparable to saying mach 0.5. That it is halfway to warp speed.

Might be - it's never used outside ST:TMP so it's hard to tell. (Probably warp 0.5 isn't the same as 0.5 c, even if warp 1 might equal 1.0 c - if the warp scale is exponential, then this probably holds for factors lower than 1, too!)

Generally, we aren't told that it would be necessary to achieve a certain speed before jumping to warp, nor which engines achieve the acceleration from zero to warp one. Cochrane's old experiment takes forever to accelerate to warp one, while Archer's own ship jumps to that speed in a split second. In theory, some sort of a "threshold speed" at sublight might need to be reached first (possibly by using impulse engines or the like) before warp can engage, and this just is reached faster in Archer's time than in Cochrane's.

Timo Saloniemi

 

[SicOne]

The JJPrise's impulse engines go dark as the warp nacelles spool up, suggesting that impulse drive isn't a factor in propelling ships at warp speeds.

I don't really know how warp drive is purported to allow the ship to travel at warp speeds, but I tend to think that some function of the warp drive, rather than the impulse engines or RCS thrusters, is also responsible for forward/backward motion.

 

[Nexarc]

I always thought that through various tech manuals that impulse engines were high-efficiency fusion-based rockets while warp drive was retroactively considered an in-universe equivalent of the Alcubierre drive.

Impulse, at least nowadays, refers to the driver coils lowering the ship's relative mass by "hiding" some mass in subspace, so the propellant exhaust accelerates the ship faster i.e. the "Impulse-Momentum" Theorum of Force = Mass * Acceleration. (DS9 in "Emissary" is not equipped with the coils since it is meant as a stationary object, so the shields had to create the intended field). Time-dilation and fuel efficiency limits the drive to sublight speeds. It also conviently explains why those glowing ports tend to look so tiny.

Warp Coils actually bend space itself via subspace, compressing space in front and expanding space behind. The region between the distortions can accelerate faster than light. Since objects within do not move faster than light relative to anything else inside the warp field, they experience little to no time dilation. I believe the only difference from the Alcubierre drive is that ST warp drives use subspace as the intended distortion medium rather than "normal" space. (In this sense, the Soliton Wave from TNG's "New Ground" is an externally produced effect rather than resulting from the component system of a starship).

Other apparent faults aside, the Abramsverse at least is accurate in the sense that the impulse coils are not necessary when going to warp so are shut off. Either that or in earlier shows the exhaust ports glow but aren't creating enough force to actually move the ship in the bubble.

This is a fictional universe, so our opinions can always be taken with a grain of salt.

 

[T'Girl]

I always thought that through various tech manuals that impulse engines were high-efficiency fusion-based rockets ...

Or, the impulse engines include small warp coils that use the plasma from the impulse engines fusion reaction to generate a warp field around the ship, smaller than the large field generated by the nacelles, but still a warp "bubble."

The impulse engines therefor are a baby warp drive, if necessary capable of moving the ship at low warp speeds.

This would explain events in the second pilot WNMHGB, the main warp drive was inoperable, yet Kirk still had the expectation of being able to reach a Earth base in "years."

Also in a TNG episode, when Riker order maximum warp, LaForge engaged full impulse. So (IMHO) the impulse engines supplemented the main warp drive to increase speed.

 

[Timo]

Regarding impulse engine glow, I'd argue it is associated with the engine system being powered up, but unrelated to any propulsive exhaust. Essentially, it's just the "glowing radiator that keeps the engine from overheating", or its more complex subspace-iso-duonetic counterpart or whatever. It is turned on about 100% of the time in TNG era ships, even at stationkeeping, and its glow in TOS-R and the TOS movies isn't all that closely related to the propulsive state of the ship, either.

in general, the glowing bits of impulse engines aren't optimally placed for being rocket nozzles. in specific, they sometimes are placed so as to make such a thing flat out impossible - being blocked by other ship structures and the like. It might be that some starships make incidental use of whatever is leaking out of those glowing bits for propulsion, just like some propeller aircraft make incidental use of the hot exhaust gases coming out of the piston engines for extra thrust. But that's an exception rather than a rule; the "fusion rocket" thing might be something specific to the Galaxy class and other ships of that configuration, but a Sovereign let alone a Steamrunner would have just the "fusion" bit without the "rocket" bit.

Chiefly, I'd agree the impulse drive is a baby warp drive - but the ability to ramp it up to FTL isn't necessary in plot terms. Kirk could reach Earth bases in "years" at STL, assuming they were dozens rather than hundreds of lightyears away, or assuming Einstein came to help.

Also in a TNG episode, when Riker order maximum warp, LaForge engaged full impulse.

More exactly, Riker in "Conspiracy" wants warp speed to be increased by one factor, and LaForge says "Aye, full impulse". Which may be a joke, because the heroes were headed for a vacation on Pacificia, LaForge as usual was making jokes that made everybody cringe, and Riker's order to increase speed was solely because he didn't want to spend any extra time listening to his annoying helmsman. For all we know, the ship did not increase speed (because LaForge understood that Riker's command was pure needling aimed at him) nor slow down to full impulse (even though LaForge quipped about doing this exact opposite of Riker's command, indicating he got Riker's meaning).

Timo Saloniemi

 

[trekshark]

I always chalked the full impulse response to an order of warp 6 to be a "it's season one and the writers haven't settled on technology consistency yet" mistake and wouldn't try to fit the tech to the dialog

 

[drt]

It is turned on about 100% of the time in TNG era ships, even at stationkeeping, and its glow in TOS-R and the TOS movies isn't all that closely related to the propulsive state of the ship, either.

They're good about correlating it in TMP, when they're more careful about consistency in the way Enterprise works - other than a single flyby which is supposed to be sublight, where the inboard nacelles are lit blue, indicating the warp drive is engaged (just after Spock's arrival). The "always glowing, all the time" started more with the later movies.

 

[T'Girl]

I always chalked the full impulse response to an order of warp 6 to be a "it's season one and the writers haven't settled on technology consistency yet" mistake and wouldn't try to fit the tech to the dialog

In The Corbomite Maneuver, when the Enterprise is trying to breaking free of Balok's tractor beam, it was obvious (to me) that they're using the Enterprise's warp engines, just before they actually shear away we get this piece of dialog;

Kirk: "Now, Mister Sulu, impulse power too."

That was the straw that broke the tractor beam's back. The impulse engines act in conjunction with the warp engines.

 

[Timo]

...Except clearly they normally don't, as this is a nonstandard trick Kirk specifically has to call for.

Is the ship at warp or impulse (that is, FTL or STL) during the tow? In TOS, it's often difficult to tell. But they do say "down to .64 of light", suggesting that impulse engines in this case are doing a STL job, while warp engines are operating a sublight - nothing out of the ordinary there, then, compared with the model where impulse somehow contributed to FTL.

Timo Saloniemi

 

[T'Girl]

...Except clearly they normally don't, as this is a nonstandard trick Kirk specifically has to call for.

There are many things in the world of Trek that we see only once, but one appearence does establish it as part of the universe. Yeoman Rand likely went on more than one landing party.

 

[Timo]

But this is the equivalent of Kirk saying "Rand, since you so cleverly identified the planet as second Earth, I reward you with a landing party assignment!" at the start of Miri, establishing if not uniqueness, then at least extreme rarity. (Or then levity, which often is a good explanation for oddity.)

Clearly, the ship doesn't normally engage impulse when at warp or else it would already have done so before Kirk's command...

Also, engaging impulse at 0.64 c to struggle free of a tractor beam is very different from engaging it at warp five to increase speed to warp six, so establishing one wouldn't really support the other.

Timo Saloniemi

 

[Lord Manitou]

Re: Impulse use within warp travel and me

Engaging engines suppose to be putting the ship into subspace(what is subspace?). This is a sphere of symmetrical subspace and the warp drive suppose to move the sphere at astronomical speeds. Apparently the ship with it's drives are partially outside of the space-time continuum so outer-space has little contact with the sphere itself. Warp speed or .65 warp speed indicates the velocity is speculative and a multiple of what impulse engines are for. I've heard Voyager crew mention anti-gravity force when landing the ship on a planet as well as impulse but warp is powered down. I can easily immagine impulse is the use of gravity. There is no mention of impulse engine theory in the series. If they want to get closer to home in the future they should expand impulse theory.

 

[Timo]

This is a sphere of symmetrical subspace

...Or so say some backstage sources. But the onscreen warp diagrams depict highly complex shapes for the warp field, and sometimes those also have complex states of motion (see TNG "Where No One Has Gone Before", even before Wesley implements his wilder modifications). I don't mean to say these odd shapes couldn't be "symmetric spheres" in subspace - but it would be rather natural to assume that the ship "swims" through subspace like an amoeba when doing that amoeba-like dance with her fancily shaped warp field...

I can easily immagine impulse is the use of gravity. There is no mention of impulse engine theory in the series. If they want to get closer to home in the future they should expand impulse theory.

It would make dramatic and perhaps engineering sense to bundle up several of these magical future technologies and claim that they all are based on the same breakthrough. We know that gravity manipulation was learned back in the 1990s at the very latest (it's seen aboard the Botany Bay), and the fantastic feats of propulsion might indeed be derived from the same technology that allows normal walking, dancing and minigolf playing in zero gee.

"Space Seed" suggests there were sublight propulsion breakthroughs well after DY-100 went out of the fashion. So perhaps floors that pull at one gee come first, then engineers fiddle with the tech and use it to make engines that push at a thousand gees, and then somebody tries out a zillion gees and finds out that further laws of nature break down and FTL drive suddenly becomes possible?

Then again, impulse and warp might come from a second, unrelated magical breakthrough; there are these "subspace" and "phasing" phenomena available for that at the very least. Other magical techs such as phasers and transporters and tractor beams and shields could then be bundled up with those, rather than with gravity manipulation.

I'm sort of thankful personally that we don't get any more detail on these things, as it allows us to believe in something that makes sense...

Timo Saloniemi

 

[publiusr]

I once thought the Klingon Bird Of prey had some type of FTL impulse...now we are told the warp drive is in the wings--not even the hinges that look like coils.

 

[Timo]

So many alien species have warp without having nacelles or coils in evidence that it's actually pretty amazing Starfleet doesn't try out such alternatives more often! I could buy warp wings for the Klingon design. But it's also still possible there are more conventional coils somewhere inside...

Timo Saloniemi

 

[Lord Manitou]

This is the CD with the USA.
That is the Centrifics Dampener with the
Universal Synchronization and Adaptability.

Suppose we should refer to Von Savant with this stuff.