Artificial gravity - can it be "negative"?

[Tobias]

I don't know if there is any canonical or even apocryphal answer to this.
Grav plates can generate simulated gravity in a zero-G or micro-G environment. Can they also be used to generate a reduction in felt gravity in a high-G environment? For example, could you build a hotel room with reduced gravity to cater to guests from lower-G worlds?
My gut feeling is yes, but has such an application ever been mentioned in any sources?

 

[AnotherDilbert]

Yes, just as well.

MT RM, p56:
The second major breakthrough is artificial gravlty. Created by manipulating subatoma forces, artificial gravity is not anti- gravity but is instead a unique force that acts upon the natural gravity field created by all matter. Artificial gravity can be made to either push or pull.

That is exactly what "Inertial Compensators" are. Just make an artificial gravity field in another direction ("up" instead of "down").

TNE FF&S, p77:
Artificial gravity G compensators create an artificial gravity field in direct opposition to the axis of acceleration, thus negating the acceleration (up to the limit of the artificial gravity field). Compensated Gs is the number of acceleration or evasion Gs negated by the compensator. The amount of Gs which can be compensated vary by tech level as shown on the table below.

 

[whartung]

That is exactly what "Inertial Compensators" are. Just make an artificial gravity field in another direction ("up" instead of "down").

Indeed, the question is whether they can "go beyond" compensating the existing field to the point of "negativity".

Can inertial compensator cope with centrifugal force? Like on a rotating space station? That's arguably "artificial" gravity, because, I dunno, it's not "gravity" as in it's not the attraction of masses -- its an artificial force kinda sorta like gravity.

Same with acceleration. Obviously the compensators work for that, that's the entire point. But, through squinty eyes, that's not "gravity" either. It's not "the attraction of masses", its more related to centrifugal force. We express it as gravity because we measure the force through things like our weight and such.

Maybe inertial compensators don't work on high-G worlds, or its a different tech, because it's a different force.

All sorts of room to handwave here and make stuff up.

 

[Condottiere]

Anything with external movement, and currently it's a field effect generated by the manoeuvre drive countering their thrust.

Maybe tractor/repulsor beams.

 

[Marcatlas]

In order to counteract ship thrust (a ship with an M drive rated 6 accelerates at 6 G's so unless you are squashing the crew to death while underway) you'd have to be able reduce the experienced G's in the ship.

 

[kilemall]

In order to counteract ship thrust (a ship with an M drive rated 6 accelerates at 6 G's so unless you are squashing the crew to death while underway) you'd have to be able reduce the experienced G's in the ship.

Pretty clear you have to have at least 6G for the sleeve shirt flight most fast movers play like.

IMTU I have a different tech level to CT/HG with adding 3% per G above 6, mostly for faster missiles although high end units can do it, but the inertial compensators lag.

1G negative effect can be knocked off by being a tail sitter, but otherwise the Gs hurt when pushing beyond compensator levels. So on a practical basis the very high Gs are not designed or only fully used in emergencies. Combat vessels using high G will have their crew under 3G+ stress with negatives to their rolls, and eventually take crew damage over sustained accel- faster if using it for agility and not a pilot with a g-suit.

Example from Expanse without juice-

 

[Grav_Moped]

Inertial compensation has to be omnidirectional if it works in canon ships.

Look at the Type T Patrol Cruiser (link to my revised version, though the original FASA and the MgT versions are similar). The bridge is about 35m forward of where I'd figure the ship's center of mass would be, somewhere in the cargo hold.

Rapid pitch and yaw rotations will impart significant forward and lateral G forces on the bridge crew.

 

[mike wightman]

The following is repeated in some form in many ship write ups in CT:

Acceleration compensators are also installed to negate the effects of high acceleration and lateral G forces while maneuvering. The passengers on the ship would be unable to tell whether they were moving through space or grounded on a planet without looking outside.

Grav plates which provide the artificial gravity are a different, though likely linked, system.

grav plates built into its flooring. These plates produce standard gravity within the ship's interior.

 

[Condottiere]

Gravity pulls you in one direction.

The opposite would be weightlessness, or neutralization of weight.

What artificially actually causes that, I don't know, except in our terms, neutralization of all or part of that gravity pull.

So, in theory, we could install gravity tiles in the ceiling, though that creates a force that would, if strong enough, just make you fall upwards.

In raw form, would that mean to countervailing forces acting on the body?

If you had two Earths close enough that at equidistance, a human could feel the effect of both one gee gravity fields, would he float in microgravity, or have two one gee gravity fields pull him apart?

 

[AnotherDilbert]

The following is repeated in some form in many ship write ups in CT:


Grav plates which provide the artificial gravity are a different, though likely linked, system.

Sure, if we ignore LBB5 and FF&S e.g.:

LBB5'79, p17:
Tech level requirements for maneuver drives are imposed to cover the grav-plates integral to most ship decks which allow high-G maneuvers while the interior G-fields remain normal.

This is the original "inertial compensator": grav-plates in most ship decks.

 

[mike wightman]

They are separate systems in every CT Adventure and supplement source and in the.MT construction rules.

 

[AnotherDilbert]

They are separate systems in every CT Adventure and supplement source and in the.MT construction rules.

Same tech, just more of the same, budgeted separately.

TTA, p132:
_ _ Gravity: Deck flooring includes integral grav plates which provide a constant 1 G artificial gravity field. Acceleration compensators are also installed and negate the effects of high acceleration and lateral G forces while maneuvering, A ship's passengers can not normally tell whether they are moving through space or grounded on a planet surface unless they look at a viewscreen.
_ _ Notwithstanding the use of grav plates, personnel are normally confined to their staterooms or to acceleration couches in the lounge when the ship is taking off or landing.

Compensators are in the "Gravity" section.
The next paragraph refers to both as "use of grav plates".

There is no hint that acceleration compensation is some special magic, just the plain regular agrav magic. As per the Equivalence Principle.

 

[whulorigan]

Gravity pulls you in one direction.

The opposite would be weightlessness, or neutralization of weight.

What artificially actually causes that, I don't know, except in our terms, neutralization of all or part of that gravity pull.

So, in theory, we could install gravity tiles in the ceiling, though that creates a force that would, if strong enough, just make you fall upwards.

In raw form, would that mean to countervailing forces acting on the body?

If you had two Earths close enough that at equidistance, a human could feel the effect of both one gee gravity fields, would he float in microgravity, or have two one gee gravity fields pull him apart?

You would float in microgravity, unless there was a tidal gradient due to differential gravity across your body length.

 

[mike wightman]

You posted this

Deck flooring includes integral grav plates which provide a constant 1 G artificial gravity field. Acceleration compensators are also installed

are also installed, as in, they are installed as well as, in addition to. Different systems, same tech base.

 

[Condottiere]

Alternatively, install giant ventilators on the floor.

 

[whulorigan]

Can inertial compensator cope with centrifugal force? Like on a rotating space station? That's arguably "artificial" gravity, because, I dunno, it's not "gravity" as in it's not the attraction of masses -- its an artificial force kinda sorta like gravity.

According to the Equivalence Principle under General Relativity, however, they are the same and indistinguishable, as both situations are a function of mass, motion and curved spacetime. Gravity, properly speaking, is not a force in the sense that electromagnetism is. It is just convenient to treat it as such in everyday experience and for common interactions because the Classical Newtonian approximation is mathematically the same.

 

[whulorigan]

Same with acceleration. Obviously the compensators work for that, that's the entire point. But, through squinty eyes, that's not "gravity" either. It's not "the attraction of masses", its more related to centrifugal force. We express it as gravity because we measure the force through things like our weight and such.

Maybe inertial compensators don't work on high-G worlds, or its a different tech, because it's a different force.

All sorts of room to handwave here and make stuff up.

This is the key thing to remember: In Traveller, "Artificial Gravity" is "Pseudogravity". It is NOT gravity. It is a polarizable short-range force (i.e. not inverse-square with distance) that acts on mass, either some force that we currently do not know about or a spin-off or secondary-effect force arising from some "Hyper-Grand Unified Field Theory" of Nature that we currently do not have. Perhaps it is secondary field effect related to or arising from the Unification of the Strong and/or Weak Force and Gravity (or "Hypergravity" if we are including Jump-space physics in our gravity calculus).

 

[whulorigan]

are also installed, as in, they are installed as well as, in addition to. Different systems, same tech base.

But this could simply mean that the "internal gravity" grav-plate system for floor gravity is a separate system of plates installed within the outer "cage" environment of grav-plating used for the acceleration compensation system which is tuned to vary its vector with engine output. That it is not the only interpretation of course, but a possible one.

 

[Condottiere]

Some kind of interference with the local gravity field, that decreases pressure or the force compelling attraction.

Likely some form of quantum effect.

 

[mike wightman]

There is no force.
Gravity is treated as a force because it make the equations easier.
Gravity is the curvature of spacetime, or more precisely it is the path followed by an object along a geodesic in no-euclidean spacetime.
Spacetime curvature is due to energy mass, pressure. momentum, however you want to measure it.

Gravitics don't have the energy to be bending spacetime, so there must be some other mechanism for the artificial gravity of Traveller.