"A Fistful of Datas"

[Lord Poe]

If we assume the chair is fairly heavy, we may be forced to rationalize it as a device which can levitate things by putting an antigrav "cushion" underneath them, in effect pushing against the floor rather than the device itself (analogous to putting an air balloon under an object and inflating it from a pump which you're holding in your hand). Either that, or it simply cancels the effect of the ship's artificial-grav field in its locality. The preferred Edam solution (decide that Conservation of Momentum is ignored) is just silly; by that token, ships should not even shake when objects hit their shields, and we know for a fact that this is not the case.

Can't we assume that this Wesley thing projects an antigrav field, like the handheld antigrav devices introduced in TOS?

[Lord Edam]

Oh wait, you're trying to prove the conservation of momentum doesn't apply because you want to eliminate the possibility of rational analysis in this case, aren't you?

The preferred Edam solution (decide that Conservation of Momentum is ignored) is just silly

If you bothered reading what I wrote, rather than going for these ridiculous lies, you'd see that what I actually proposed - or rather what TedC proposed that I suggested could be applied to Worf as well - was that the forces are somehow directed at something that canhandle them, rather than simply ignored. Nowhere have I (or TedC, since I simply suggested alternative anchors from his solution of a similar problem) suggested or implied the forces just vanish so that CoM can be ignored.

[Lord Edam]

Can't we assume that this Wesley thing projects an antigrav field, like the handheld antigrav devices introduced in TOS?

Antigrav would make someone float, rather than bounce off it as the engineers did later in the episode.

TedC's anchor idea isn't that far fetched (and contrary to Wong's opinion, doesn't need to ignore CoM) - if Worf's device or wesley's device can project a forcefield in one direction, why can it not project a balancing force elsewhere through the same forcefield?

[Lord Edam]

If we assume the chair is fairly heavy, we may be forced to rationalize it as a device which can levitate things by putting an antigrav "cushion" underneath them, in effect pushing against the floor rather than the device itself (analogous to putting an air balloon under an object and inflating it from a pump which you're holding in your hand).

So, basically, what you're saying is, it is possible for the forcefield generators to create a force without experiencing the force themselves - as long as there is something for them to brace the force against. Wesley's device can create a force between the floor and the chair. Similarly, Worf's and other personal forcefields can create forces between the bullet/whatever and "something else".

This seems to be the exact same idea Ted originally gave - they work by bracing against something that can handle the forces. Naturally, you've hidden "force" behind "antigrav", so you can limited it to the up/down effects of gravity, though this need not be the case. Your air balloon will work just as well to push two vertical plates apart, as long as it has the pressure to do so.

Given this, "if it's carried on the man, it will be anchored to him, so he will catch the reaction forces on his body" (your words) need not be true, any more than you feel the forces from the air balloon in your example.

However...

ships should not even shake when objects hit their shields, and we know for a fact that this is not the case.

Unless there's a planet conveniently close, ships have to deal with the forces themselves. They don't have a convenient object to generate a force between it and whatever's about to hit them so they must shake - as, infact, we see them do.

[Darth Wong]

If we assume the chair is fairly heavy, we may be forced to rationalize it as a device which can levitate things by putting an antigrav "cushion" underneath them, in effect pushing against the floor rather than the device itself (analogous to putting an air balloon under an object and inflating it from a pump which you're holding in your hand).

So, basically, what you're saying is, it is possible for the forcefield generators to create a force without experiencing the force themselves - as long as there is something for them to brace the force against. Wesley's device can create a force between the floor and the chair. Similarly, Worf's and other personal forcefields can create forces between the bullet/whatever and "something else".

Either that, or it simply cancels the artificial-G field around the chair.

This seems to be the exact same idea Ted originally gave - they work by bracing against something that can handle the forces. Naturally, you've hidden "force" behind "antigrav", so you can limited it to the up/down effects of gravity, though this need not be the case.

Of course. How silly of me to restrict to what we saw in the scene.

Your air balloon will work just as well to push two vertical plates apart, as long as it has the pressure to do so.

Yes, because they're already close together. It wouldn't do much good if the plates are a hundred metres apart, or at the very least, it would require considerably more effort.

Given this, "if it's carried on the man, it will be anchored to him, so he will catch the reaction forces on his body" (your words) need not be true, any more than you feel the forces from the air balloon in your example.

Bullshit. What is the anchor, then? The ground? The ground is not perpendicular to the direction of force, and you will end up with a bending moment applied around the fulcrum of the user's feet, which should knock him over. Some faraway building? If it can apply force at such range, why wait for the bullet to get within a few inches of your body before acting on it?

Unless there's a planet conveniently close, ships have to deal with the forces themselves. They don't have a convenient object to generate a force between it and whatever's about to hit them so they must shake - as, infact, we see them do.

Unless they're a few hundred metres from the ground, they have nothing which is in range of the force range demonstrated by their shields even if they're in orbit.

PS. I see my earlier point about the safeties was ignored, of course.

[Lord Edam]

This seems to be the exact same idea Ted originally gave - they work by bracing against something that can handle the forces. Naturally, you've hidden "force" behind "antigrav", so you can limited it to the up/down effects of gravity, though this need not be the case.

Of course. How silly of me to restrict to what we saw in the scene.

We saw the same device work both as an anti-grav device and as a repulsor, so clearly the basic idea applies to more than just up/down. Don't concentrate on just one scene - take the whole episode.

(which remind me, I never dealt with Poe's comment about the device being plugged into the ship's systems - Wesley would have to do this is he wanted a longer lasting or higher power than was possible with just the device. There is no reason to assume this changes the mechanism of the device itself)

Your air balloon will work just as well to push two vertical plates apart, as long as it has the pressure to do so.

Yes, because they're already close together. It wouldn't do much good if the plates are a hundred metres apart, or at the very least, it would require considerably more effort.

Sorry, I assumed your air-cushion idea was just a basic illustration. Obviously, you need a mechanism that would actually apply a force to both objects.

Given this, "if it's carried on the man, it will be anchored to him, so he will catch the reaction forces on his body" (your words) need not be true, any more than you feel the forces from the air balloon in your example.

Bullshit. What is the anchor, then? The ground? The ground is not perpendicular to the direction of force, and you will end up with a bending moment applied around the fulcrum of the user's feet, which should knock him over. Some faraway building? If it can apply force at such range, why wait for the bullet to get within a few inches of your body before acting on it?

The force could be at any arbitrary angle, so long as it was enough to deflect the bullet. And since we've already established the force could be directly between the bullet and the ground, the user wouldn't experience a thing.

Lets extend your air balloon analogy, so you end up with a rigid tube sticking out of the ground at 30 degrees. Apply a force at the end of the tube it might bend, it might slip slightly, but you, standing at the end of the hose with your pipe, you won't move as a result (assuming, of course, your pipe is long enough). The force on the end of the tube has been transmitted into the ground.

Unless they're a few hundred metres from the ground, they have nothing which is in range of the force range demonstrated by their shields even if they're in orbit.

exactly

PS. I see my earlier point about the safeties was ignored, of course.

We know the holodecks can create bullets that act real (as well as other objects with momentum or at least exert a force when they hit something). This won't change any of the possibilities were were discussing regarding personal forcefields. The mere fact that Worf gotshot would seem to indicate your comment regarding the safeties is irrelevant.

edit: I thought the edit button was disabled in this forum? If I'd known it worked I'd have put everything into one post earlier. Ho hum. I'll fix my quoting in this one then

[Ted C]

If I'm reading it right, Mike's comment regarding the holodeck safeties implies a variation of option 2, from my original post: the bullet is not a replicated object, so it has no mass. This would explain why it could be deflected without having any noticeable effect on Worf, as well as why the hit didn't hurt Worf as badly as you would expect from a .45 caliber bullet.

[Darth Wong]

We saw the same device work both as an anti-grav device and as a repulsor, so clearly the basic idea applies to more than just up/down. Don't concentrate on just one scene - take the whole episode.

You are mixing two things together. If it can cancel out an artificial-G effect, that doesn't necessarily mean it can apply third-party force between object A and arbitrary anchor B regardless of nature or location, even if it's capable of applying force to object A. Indeed, even if it is capable of applying third-party force between object A and anchor B, we cannot assume arbitrary type/range is OK. Forcefields in Trek are geometry and range-sensitive.

(which remind me, I never dealt with Poe's comment about the device being plugged into the ship's systems - Wesley would have to do this is he wanted a longer lasting or higher power than was possible with just the device. There is no reason to assume this changes the mechanism of the device itself)

It does for the chunk of rock heading toward the ship, since the device had no clear line of sight to it.

Sorry, I assumed your air-cushion idea was just a basic illustration. Obviously, you need a mechanism that would actually apply a force to both objects.

Given the range limitations, I don't see how it can work in most cases, unless the anchor is conveniently close (like the body of the user).

The force could be at any arbitrary angle, so long as it was enough to deflect the bullet. And since we've already established the force could be directly between the bullet and the ground, the user wouldn't experience a thing.

Lets extend your air balloon analogy, so you end up with a rigid tube sticking out of the ground at 30 degrees. Apply a force at the end of the tube it might bend, it might slip slightly, but you, standing at the end of the hose with your pipe, you won't move as a result (assuming, of course, your pipe is long enough). The force on the end of the tube has been transmitted into the ground.

Fair enough, except that this anchor point should be affected, and we have seen the forcefield's range limitations (otherwise it could have easily started deflecting the bullets from 10 feet away instead of waiting until they're within inches of the target). Why isn't the ground being disturbed by these impacts?

It seems easier to simply conclude that the bullets carried very little momentum, if any, due to the fact that the situation involved malfunctioning safeties rather than safeties explicitly turned OFF. Either that, or the forcefield could actually reach out much farther than it appeared, and deflect the bullets from considerable range so they would not affect the wearer (but this does not appear to match my recollection of the visuals).

We know the holodecks can create bullets that act real (as well as other objects with momentum or at least exert a force when they hit something). This won't change any of the possibilities were were discussing regarding personal forcefields. The mere fact that Worf gotshot would seem to indicate your comment regarding the safeties is irrelevant.

The holodecks CAN create bullets which have solidity when the safeties are completely turned off. That doesn't mean it does so when the safeties are turned on, where immaterial bullets would be much safer and more logical. The fact that the bullets injured Worf (very lightly) could simply mean that the safeties were miscalibrated as a result of the malfunction.

[Lord Edam]

Mike, I think we've pretty much come to agree that personal forcefields might theoretically work against bullets over a very limited range - a few feet at best.

The rest seems to be a disagreement on whether or not holodecks create solid object

Personally, I believe that there are plenty of examples showing the objects in the holodeck are apparently solid object, including the bullets in FC, the snowballs in an early (ist season?) episode, Data's rock bouncing off the wall in the very first episode of TNG and pretty much any of Worf's various martial simulations. The way bullets act normally will be no different to how they acted in FC against the borg - the only change will be that, with the safeties on, they stop being real when they would kill (or, depending on the safety level of the hologram, injure). However, this seems more suited to a more general discussion of holodeck technology, and since I'm going away this weekend is something I can't pursue so I'll drop it.

[hvb]

It could be that the device does not affect the bullets in a conentional sense, but that it "reprograms" the characteristics of holo-projected objects that enter a set speed/range regime of the device or Worfs location?
(this is of course a dodge to avoid the physics , but we are dealing with simulated objects here, the device could be a "holodeck-tuner/reprogrammer" kind of thing.)

If we try physics:
what about a double-layered grav field, not projected from the device itself? The device could use the same criteria as above to activate the ships grav field in two <10cm seperation vertical sheets, one repulsive further from Warf, and one attractive (like normal gravity) closer to Worf, thus decelerating the bullets? We know they have a "negative-gravity" ability from the existence of tractor beams, and the reactive force from the momentum could be applied to the walls of the holodeck if any is present, akin the one of the better suggestions of the nature of shields in Wongs shield pages.

Was this device/similar devices used outside the holodeck, if so was there no solid anchors nearby? Some posts seem to deal with such an event, and I do not recall the episode. If so you should just ignore this as it cannot explain events outside a holodeck respectively without reaction bodies.

[DocMoriartty]

Here is an idea.

Worf modified his communicator. Maybe all he did was reprogram it to communicate with the holodeck and cause the holodeck to generate a forcefield around him.

There would be no problem with transfer of momentum since the forcefield generators in question would be the ones built into the walls of the holodeck and thus easily able to handle the transfer of momentum from the deflected bullets.

[Ted C]

Here is an idea.

Worf modified his communicator. Maybe all he did was reprogram it to communicate with the holodeck and cause the holodeck to generate a forcefield around him.

There would be no problem with transfer of momentum since the forcefield generators in question would be the ones built into the walls of the holodeck and thus easily able to handle the transfer of momentum from the deflected bullets.

Option 1 from my opening post.

[Lord Poe]

(which remind me, I never dealt with Poe's comment about the device being plugged into the ship's systems - Wesley would have to do this is he wanted a longer lasting or higher power than was possible with just the device. There is no reason to assume this changes the mechanism of the device itself)

Why not? Its doing something OTHER than lifting an object. Also, this was in answer to your "bracing" questions about the device, if you recall.

It would be as good as whatever was acting as the brace when Wesley was flying chairs around with the exact same device as later became a repulsor in a doorway.