Newtonian Physics and Artificial Gravity/Inertial Dampers

[GeorgeKirk]

Imagine a two starships accelerate to a high sublight speed, say 0.8c, then cut their engines. Since Newtonian physics is a real thing (even if most Star Trek writers ignore it) they'll continue to travel at that same speed and appear motionless relative to each other. But what if a shuttlecraft takes off from one ship and attempts to fly over to the other? On a real-world spaceship without artificial gravity and inertial dampening fields, the stuff inside the ship is moving at the same speed in as the ship itself, so if an auxiliary spacecraft exits the main ship on thrusters it should continue moving along at pretty much the same speed and direction as the parent vessel, and therefore such a maneuver should be possible even if it is a bit tricky.

But on a Star Trek vessel, don't the artificial gravity and inertial dampening fields effectively prevent the stuff inside the ship from "inheriting" its velocity? So if a shuttlecraft exits the ship on thrusters, wouldn't it immediately get left behind as soon as it exits its parent vessel's artificial gravity/inertial dampening fields, since it's only moving at a few meters per second?

 

[Tenacity]

on a Star Trek vessel, don't the artificial gravity and inertial dampening fields effectively prevent the stuff inside the ship from "inheriting" its velocity?

then cut their engines

Starship apparently are usually running their impulse engines while sublight, even if just maintaining a steady rate of speed, glowing engine "exhaust." So when the ship cut their engines and if they have no inertia, they would lose sped. If all that's true, then a shuttle moving between them, also with no inertia, would be losing speed at the same rate.

No problem traveling between the two ships.

On the other hand, if the ship's equipment maintains their speed without constant use of the engines, then similar equipment on the shuttle could maintain the current speed of the mother ship.

 

[David cgc]

But on a Star Trek vessel, don't the artificial gravity and inertial dampening fields effectively prevent the stuff inside the ship from "inheriting" its velocity? So if a shuttlecraft exits the ship on thrusters, wouldn't it immediately get left behind as soon as it exits its parent vessel's artificial gravity/inertial dampening fields, since it's only moving at a few meters per second?

If anything, the inertial dampers do the opposite, and constantly ensure objects within the ship "inherit" its momentum. Without the dampers, the stuff inside the ship doesn't move with the structure except by being pushed by it, which is bad when the structure is accelerating with lethal force. The dampers accelerate all matter within the ship evenly, rather than the engines pushing the structure pushing the interior compartments pushing the walls pushing the crew.

Let's flip the experiment around a bit. We've got a shuttle inside a shuttlebay of a ship traveling at a constant velocity. It lifts off, the bay doors open, and the mothership begins accelerating. On a real-world ship, the shuttle is left behind as the ship flies away from it. On a Star Trek ship, the shuttle would still be hovering inside the bay, as the dampers are "pinning" it to the ship.

Now, if we did the same thing, but first we have the shuttle fly outside the bay and then come to a relative stop a little bit away from the mothership (outside its various magic gravity fields), and then the mothership accelerates, the shuttle would be left behind in both cases.

What you're describing sounds more like how a warp drive would work, the ship carrying a little bubble of normal, unaccelerated space around it through subspace, and then the shuttle coming to a stop when it crosses from the ship's private, walled-off frame of reference to the larger universe's.

 

[GeorgeKirk]

If anything, the inertial dampers do the opposite, and constantly ensure objects within the ship "inherit" its momentum. Without the dampers, the stuff inside the ship doesn't move with the structure except by being pushed by it, which is bad when the structure is accelerating with lethal force. The dampers accelerate all matter within the ship evenly, rather than the engines pushing the structure pushing the interior compartments pushing the walls pushing the crew.

Let's flip the experiment around a bit. We've got a shuttle inside a shuttlebay of a ship traveling at a constant velocity. It lifts off, the bay doors open, and the mothership begins accelerating. On a real-world ship, the shuttle is left behind as the ship flies away from it. On a Star Trek ship, the shuttle would still be hovering inside the bay, as the dampers are "pinning" it to the ship.

Now, if we did the same thing, but first we have the shuttle fly outside the bay and then come to a relative stop a little bit away from the mothership (outside its various magic gravity fields), and then the mothership accelerates, the shuttle would be left behind in both cases.

What you're describing sounds more like how a warp drive would work, the ship carrying a little bubble of normal, unaccelerated space around it through subspace, and then the shuttle coming to a stop when it crosses from the ship's private, walled-off frame of reference to the larger universe's.

Thanks. I figured my thinking was backward somehow, but I couldn't figure out exactly how.

 

[Timo]

In terms of in-universe references, Picard in "The Battle" chooses to lecture his first officer on the subject of "conservation of tractor beam power", that is, an object accelerated to a speed by a tractor beam will retain that speed even when the beam is turned off.

Apparently, since Starfleet Academy feels it must give lectures on the subject, it actually is far from said that momentum gained by "cheats" such as gravity manipulation devices, tractor beams or whatever would be conserved in a Newtonian fashion. Tractor beams do obey Newton, like the possessed Picard claims and then demonstrates, but other such technologies by this token might not.

As for impulse engines, we don't know for certain what sort of a "cheat" they employ, but we have every reason to believe they do cheat, for achieving so much with so little. But it's difficult to tell whether momentum gained by impulse drive would be conserved or not.

Impulse nozzles glow red (or some other color) completely regardless of whether the ship is moving or not. That is, in TNG/DS9/VOY and ENT, they always glow; in TOS, they basically never do. But Uhura in ST6:TUC equates impulse engine exhausts with "tailpipes", suggesting a closer analogy with the tailpipe of a car than with the nozzle of a jet fighter. Indeed, a car idled at a curb and a starship idled on orbit both would seem to constantly emit an exhaust, since a constant exhaust is what Spock's seeker torpedo vitally depends on, and Chang's invisible ship isn't actually moving all that much.

We might dismiss any connection between impulse engine glow/exhaust and motion, then. But it would seem sensible for a starship to constantly accelerate while under impulse - even at the demonstrated multi-hundred-gee accelerations it still takes time for the ship to reach a practical percentage of lightspeed. Then again, impulse drive supposedly rapidly consumes fuel (as per "Doomsday Machine" where the issue alarms our heroes who are limited to impulse and must keep on moving) while warp drive does not (as per every other episode of Trek where nobody worries about fuel when going to warp).

Perhaps a ship coasting (with or without the impulse engines glowing) would be "truly Newtonian" and any auxiliaries launched from her would retain the momentum, while a ship accelerating would be un-Newtonian to a degree, and a shuttlecraft would experience weird things when detaching from the mothership's "impulse field". We simply don't know much about this because we usually can't tell whether motherships are accelerating or not.

Timo Saloniemi

 

[Ronald Held]

Seemed that impulse drive used some inertial lowering field to move the ship close to fractions of lightspeed.
Impulse engines use fusion power,so the waste products are likely to be vented.