Impulse speed and physics

[Mytran]

If the Enterprise were flying under standard Newtonian physics, flying at 0.25c would indeed require fuel with more mass than the entire ship to achieve that speed! This is why many postulate that something else is going on as well. The TNG technical manual talks about a "sub-space driver coil" as being part of the impulse engine. Simply put, this coil lowers the overall mass of the ship, thus requiring less fuel to push it to ever greater speeds.

A cheat? Well, maybe. But one that is vital for telling Star Trek stories.

 

[Jefferies]

If the Enterprise were flying under standard Newtonian physics, flying at 0.25c would indeed require fuel with more mass than the entire ship to achieve that speed! This is why many postulate that something else is going on as well. The TNG technical manual talks about a "sub-space driver coil" as being part of the impulse engine. Simply put, this coil lowers the overall mass of the ship, thus requiring less fuel to push it to ever greater speeds.

A cheat? Well, maybe. But one that is vital for telling Star Trek stories.

Okay so they have a thingy ma jig to deal with the energy cost but what about time dilation? Do they have one for that too?

 

[Timo]

Warp does away with time effects, essentially resulting in "universal time" or "Newtonian time" existing throughout the Trek universe. I don't see why impulse drive couldn't feature elements of this technology, too.

At 0.25c, time dilation is in the range of three percent... At half lightspeed, it's about fifteen percent, which is already going to hurt if you're used to universal time, but won't solve your problems if you want to rely on Einstein to make an unbearably long cruise shorter. FWIW, it's only at 0.9999995c that you get a thousandfold time dilation effect out of impulse travel.

http://www.1728.org/reltivty.htm

My hunch is that the amount of energy required for that would be colossal.

And, interestingly, Spock worries about fuel consumption when the Enterprise is forced into an impulse battle in "Doomsday Machine", declaring that fuel will be exhausted in mere hours this way. Yet the ship can spend days or weeks at high warp.

This sort of suggests that warp uses a significant "cheat" while impulse is subject to at least some Newtonian-Einsteinian energy considerations (although necessarily cheating a bit, or else even tiny fractions of c would be impossible to achieve with the propellant quantities evident, never mind the actual energies).

Timo Saloniemi

 

[Mytran]

Or that the "cheaty" aspects of the warp engines are used to suplement and/or refuel the impulse engines. In the case of Doomsday Machine, warp drive had been knocked out.

Compare that to Paradise Syndrome where only the "stardrive" had been burned out (whatever that might be) and the Enterprise spends 2 months at impulse.

 

[Timo]

Or that the "cheaty" aspects of the warp engines are used to suplement and/or refuel the impulse engines. In the case of Doomsday Machine, warp drive had been knocked out.

Indeed.

Compare that to Paradise Syndrome where only the "stardrive" had been burned out (whatever that might be) and the Enterprise spends 2 months at impulse.

Not at impulse, but coasting - there apparently was no attempt to create a velocity difference between the ship and the asteroid. In most visuals, the ship isn't even facing away from the rock!

Evidently, Spock saw no benefit in flying back and forth inside this star system at sublight speeds when there was nothing at the planet for them to do (Kirk was gone, beyond their means to track down) and nowhere else to go. Which was a pretty cold decision for him to make: he chose to be at the planet four hours before the asteroid, and not a minute earlier, where a human commander would probably have spent the entire two months at the planet doing nothing useful.

(Of course, Spock was dead wrong there - Kirk had resurfaced as Kirok and could have been located easily enough. But the idea that Spock was unable to reach the planet any faster than that is pretty silly, unless we assume the asteroid had a warp engine and for that reason was faster than the ship in most situations and only equally fast if Spock stayed within the asteroid's warp field. And even then, the four-hour lead would make no sense.)

Timo Saloniemi

 

[Start Wreck]

"The unique thing about the speed of light is that it is fixed for all observers"

However, your statement that the light would move from the torch at 1 c to the person holding the torch, but move at 0.1c to the stationary observer, contradicts this statement. If it is fixed for all observers than it moves at 1 c for all observers.

No, it "seems" to contradict, because most people assume that time is a constant, but it isn't.

To clarify (somewhat!) the above example. The stationary man is seeing light move at 1c compared to his stationary self, and at .01c compared to the flying man. The flying man also sees the light move at 1c compared to himself, not - as you might expect - the 0.01c that the stationary man is seeing.

In both instances, they're seeing light move at 1c from themself. Everyone sees light move at 1c from themself, no matter how fast they're personally travelling. "Velocity + velocity" is in fact an incorrect formula, just one that happens to suit slow everyday life (and simpler thinking) well enough!

Okay, enough about flying men...

Outside of your argument, and going with known physics, light's ability to go from points A and B at a finite speed, but the hue will Doppler shift, this is a proven fact (and one of the few proven facts with light physics). Light transmitting from a source moving away from you becomes red, but from a source moving towards you it shifts to blue.

The part about light having both a fixed speed and susceptible to the Doppler shift is the seeming contradiction that has always confused me. I believe it has something to do with the waves slowing and speeding, but the movement of the particle is finite. Well, that's the only guess I have.

Blue is a higher frequency, red is a lower frequency. It just means that the photons are more "bunched up" when the object emitting them is moving towards you, and more "spaced out" when it's moving away from you. The photons are still travelling at the same speed in either case.

I don't think it's relevant to the effects of time dilation.

Arguments that attempt to explain the twin paradox and so on, I completely disregard all of these arguments because they operate on the premise that light speed is time speed (that which has never been proven) and confuse signal delay for time delay.

On the contrary, the effects of time dilation have been thoroughly and rigorously proven, and form the basis for - amongst other things - working satellite navigation systems. You should read up about it, it's quite fascinating!

You state that if Enterprise moved at light speed they’d be getting around the universe, from their perspective, really really fast. However, that's not true, and it's why warp speed (faster than light) was invented to explain how they could actually get around. After all, Proxima Centauri, the closest star to our own, is 4.2 light years from our sun.
So if kirk moved at sub light speed, his 5 your mission would basically be to go take a look at the alpha centari star system. Actually, it would have taken 8.4 years for a round trip.

From an outside observer's perspective, yes, it would take the ship 8.4 years to complete the trip.

But, if you were on that ship, travelling at close to the speed of light, the passage of time would slow down. Years will have passed outside, but for you and everyone aboard the ship, perhaps only hours, minutes or seconds will have passed.

This is all because of the effect of time dilation. Time is not fixed, it is relative, and passes more slowly for objects that are moving more quickly.

Theoretically, then, if you could actually achieve lightspeed itself (c), you would arrive anywhere and everywhere in the Universe simultaneously, because time will have completely stopped! Naturally, this means you would need infinite energy to achieve this, which is why it's impossible.

Wikipedia article:
http://en.wikipedia.org/wiki/Time_dilation

 

[RB_Kandy]

Start Wreck, I am going to forfeit my argument. You know more about this than I do. I've always had a hard time understanding the relativity part of physics... and the math part too LMAO

 

[Start Wreck]

Read up about it anyway, it's utterly, confusingly, brilliant.

 

[Mytran]

Hear hear, the universe is a weird place!

 

[blssdwlf]

Or that the "cheaty" aspects of the warp engines are used to suplement and/or refuel the impulse engines. In the case of Doomsday Machine, warp drive had been knocked out.

Indeed.

Compare that to Paradise Syndrome where only the "stardrive" had been burned out (whatever that might be) and the Enterprise spends 2 months at impulse.

Not at impulse, but coasting - there apparently was no attempt to create a velocity difference between the ship and the asteroid. In most visuals, the ship isn't even facing away from the rock!

Under normal circumstances, we know from "The Mark of Gideon" and to some extent "Where No Man Has Gone Before" and "The Naked Time" that the ship's main power system regenerates her power which effectively gives her unlimited range.

But when her warp drive is knocked out she loses that advantage and on impulse only, she can easily burn through her impulse power stores if under duress.

• "The Immunity Syndrome" - at 100% impulse power she would exhaust it in 7 minutes against the shield and propulsion strain of the space amoeba.
• "Elaan of Troyius" - with only 93% impulse power, in the space of a few disruptor hits and lots of hard impulse maneuvering (about <10 minutes? ) she was down to 31% power.
• "The Doomsday Machine" - continuously evading the DM would exhaust their impulse power in well under a day (the time to repair warp drive).
• "Mudd's Women" - less than two day's worth of power available on impulse although I'm assuming it is because the crew is pushing the ship to get to the miners as fast as possible. When she arrives, she does not have any impulse power left to leave orbit.
• "Where No Man Has Gone Before" - similar problem as "Mudd's Women" where their arrival would not leave enough power to blast out of orbit.

Which leaves "The Paradise Syndrome" where Spock has the Enterprise travel at Warp 9 for "several hours" to get to the asteroid but on the return trip on impulse only stretches it out to 59.223 days with only a 4 hour head start. I'd argue that if the ship was able to regenerate power or supply additional fuel for the impulse engines she'd get back to the planet a whole lot faster. Instead, it appears that the Enterprise's slow return was to conserve as much impulse power as possible, perhaps more than enough to leave orbit in a hurry when the asteroid strikes the planet and/or make it to a nearby starbase. If Spock decided to get back on impulse a whole lot faster, it would likely doom the ship to being stuck in orbit when the asteroid strikes the planet.


As to the speeds involved, Warp 9 while in system you could place the "actual" average speed at 177c @~4 hours and the impulse return trip at 0.5c. It would be consistent with TOS for Warp "actual speed" slowing down as the ship travels deeper into a star system and speeding up while further away from a star system.

Of course, this doesn't apply to TNG where they operated under different rules.

 

[Crazy Eddie]

"The unique thing about the speed of light is that it is fixed for all observers"

However, your statement that the light would move from the torch at 1 c to the person holding the torch, but move at 0.1c to the stationary observer, contradicts this statement. If it is fixed for all observers than it moves at 1 c for all observers.

No, it "seems" to contradict, because most people assume that time is a constant, but it isn't.

Time IS constant. Key word in that sentence is "seems." Time SEEMS not be constant, which is why the speed of light is observed to be the same in all reference points.

Since there is no such thing as a universal reference frame, you cannot have one frame experience time dilation while the other does not; that would imply that there is a universal truth for which observer is in motion and which is stationary, and relativistically, this is not possible. Time dilation occurs only relative to the two observers (while a third observer at a different speed will have a completely different perception about what's really going on).

On the contrary, the effects of time dilation have been thoroughly and rigorously proven, and form the basis for - amongst other things - working satellite navigation systems.

I heard this claim often enough to investigate the details only to discover that it is, in fact, bullshit. The GPS system does NOT take relativistic time dilation into account, it's actually a fairly nuanced (and little known) gravitational effect that is only peripherally related to time dilation.

From an outside observer's perspective, yes, it would take the ship 8.4 years to complete the trip.

But, if you were on that ship, travelling at close to the speed of light, the passage of time would slow down. Years will have passed outside, but for you and everyone aboard the ship, perhaps only hours, minutes or seconds will have passed.

On the other hand, from the traveler's point of view, the people back at his point of origin are the ones experiencing time dilation since they are moving away from him at the same velocity. The equation works in both directions, and BOTH observers will see the other experiencing severely compressed time relative to their own clock.

This is so, because apparent time dilation is a consequence of those relativistic velocities; a photon from the ship sent back to Earth is "seen" leaving at C and arriving at C, and the opposite is also true, which means that both the ship and its mission control look at each other and see the exact same distortion of time in the exact same magnitude.

Theoretically, then, if you could actually achieve lightspeed itself (c), you would arrive anywhere and everywhere in the Universe simultaneously, because time will have completely stopped!

No, time merely SEEMS to stop; at those speeds you effectively loose the ability to draw meaningful information from the outside universe and you can no longer see what's happening outside your own reference frame (all events seem to happen simultaneously; it's all just a big incomprehensible blaze of compressed light). Then you slow down again to a stop relative to your point of origin and find your clock and your mission control clock are still, strangely, in perfect sync.

 

[Start Wreck]

I heard this claim often enough to investigate the details only to discover that it is, in fact, bullshit. The GPS system does NOT take relativistic time dilation into account, it's actually a fairly nuanced (and little known) gravitational effect that is only peripherally related to time dilation.

Can you elaborate on this further and cite some sources? Thanks.

EDIT: Never mind, found this:
http://www.alternativephysics.org/book/GPSmythology.htm

 

[yenny]

If impulse speed is sub-light, with half impulse being half the speed of light and full impulse being as near to the speed of light as possible, how do starships compensate for relativistic effects?

Ie; if the Enterprise travels from Wolf 359 to the Sol system at full impulse, why isn't the Earth they arrive at 80(?) years into their future?

It will take a starship 7.81 years to reach Wolf 359 from Earth at full impulse power.

 

[Timo]

Or then not.

You seem to be assuming that full impulse power means the Newtonian speed of one lightspeed, so that the 7.8 lightyear distance between Earth and Wolf 359 would be covered in that time. But you make no allowance for acceleration or deceleration, which certainly aren't infinite for the starships we see. And if the ship travels at nearly lightspeed, she will actually be at Wolf 359 in a matter of minutes or seconds, from the ship's point of view.

FWIW, we've never heard of a ship maintaining impulse power, full or otherwise, for more than a few days at most; the record, for fairly low impulse, would seem to be from "Elaan of Troyius". Seven hours at impulse combat was said to drain the hero ship's fuel in "The Doomsday Machine"...

As regards verifying of the theory of general relativity, and specifically the time dilation aspect of it, through the use of spacecraft, this is a valid approach as long as the distances involved are fairly long. The effect of high speed of a spacecraft can be replaced by the effect of significant gravity (that of the Sun or planets) on electromagnetic radiation sent by the spacecraft; an experiment of this specific sort was conducted using the Cassini spacecraft as it neared Saturn.

Timo Saloniemi

 

[blssdwlf]

Not only that, in TOS at least, impulse was implied to be able to drive a starship up to FTL speeds so it might only be a "couple of days away" at impulse...

 

[Timo]

...I'm still far from convinced that TOS features any FTL impulse evidence.

Say, in "Where No Man", the distance the Enterprise has to cover at impulse is explicitly stated to be short; the use of impulse by the Valiant in turn is related specifically to the barrier phenomenon rather than interstellar distances.

Timo Saloniemi

 

[Mytran]

Then what got the Valiant out to the edge of the galaxy in the first place? Yes it was swept out by a "magnetic space storm", as the "old Impulse Engines" weren't strong enough to resist. If the Impulse Engines are not superluminal, they're never going to be able to compete against a FTL energy wave, ever!!! No mention is made of "the old Warp Engines" at all, implying that impulse was most significant source of propulsion available.

Plus, there's the distance the Valiant covers under her own steam:

SPOCK: ...swept past this point, about a half light year out of the galaxy, they were thrown clear, turned, and headed back into the galaxy here...

Half a light year without FTL capability is a long time in space, and that's just to get back into the galaxy!

 

[Timo]

Then what got the Valiant out to the edge of the galaxy in the first place?

Kirk thinks it impossible that this could have happened at all, meaning we get no data on the propulsive capabilities of the Valiant from this act. So it doesn't count as evidence of "old impulse engines" getting them there - according to Kirk, that's impossible. The rest is open to speculation, and there's no reason the Valiant couldn't have had perfectly ordinary warp engines for all FTL travel and perfectly ordinary impulse engines (okay, a bit older than what "Relics" considers the benchmark) for STL travel.

Yes it was swept out by a "magnetic space storm", as the "old Impulse Engines" weren't strong enough to resist. If the Impulse Engines are not superluminal, they're never going to be able to compete against a FTL energy wave, ever!!!

Why not? You can hop out of a train going 80 mph even if you can barely run at 3 mph. You could jump out of a plane doing 2,000 mph if you could get the door open, too.

All we need to assume is that warp engines won't help you when you're caught in a magnetic storm. We know from "Court Martial" that they do work when you are caught in an ion storm, but since the names are different, the phenomena may be, too. Clearly Kirk knows what a magnetic storm is, and apparently the crew of the Valiant did, too, unless Spock is correcting/perverting what he is reading from the log tapes.

Half a light year without FTL capability is a long time in space, and that's just to get back into the galaxy!

The ship had two centuries to do it. And at high impulse, this would have taken them no time at all, even if for everybody else it took those two centuries.

"Just to get back into the galaxy" is all they needed, anyway, since that's where Kirk found the recorder marker.

Timo Saloniemi

 

[MikeS]

Interesting points, I've thoroughly enjoyed reading your responses. I've learnt a few things;

* "Full impulse" doesn't necessesarily mean "full impulse speed", it may mean "full impulse power" and nowhere is it suggested that half impulse is half light speed etc.
* Getting back to Earth from the Wolf 359 system at light speed would take 7.81 years not my guessed 80! (still it would be hard seeing my son age 7.81 years in what would seem from my perspective to be an instant)
* That this tech forum is a really interesting place and I should never bother to post anything remotely worthy of thought in "General Trek Discussion" again.

 

[swaaye]

It seems that TNG Warp 10 has some physical similarities to real world relativistic effects.