Author Topic: Gravity Nullification? (Read 4595 times)

markc · « **on:** July 29, 2009, 12:49:09 PM »

What do people think of a device that can nullify a % of gravity a craft experiences? [They are not drives as they have no propulsion they only nullify a % of gravity.]

MDC

Marc R · « **Reply #1 on:** July 29, 2009, 12:56:39 PM »

Do you mean external gravity, like a shielding effect against being pulled toward a star/planet. . .or to allow a ship sitting on a 2g world to experience 1g inside?

Or

Do you mean reduction of inertia, so you can make high g maneuvers without ripping to peices or turning the crew to paste?

(One would mostly affect the ship, while the other would mostly affect the contents and structure of the ship.)

markc · « **Reply #2 on:** July 29, 2009, 02:02:45 PM »

I was thinking about a piece of equipment that would reduce the effect of gravity on a ship. So on a 2G world it would be some % of the real gravity.
MDC

Marc R · « **Reply #3 on:** July 30, 2009, 12:10:20 PM »

Inertial dampening systems, that allow for high G maneuvering, would seem to be suited to being tuned to have that sort of effect.

"Artificial Gravity" systems, ones capable of adding G without motion (so down is down, without having to spin the ship to make out = down) would be able to ADD gravity to a ship that has none.

"Inertial Dampeners" or "Gravity Shielding" could reduce Gs, either from motion or mass gravity, but not create it.

At a certain tech level, I'd assume that ships would have both, some ships could even vary G deck by deck, or even compartment by compartment, if the tech itself is built into the decking or bulkheads.

Neither exist in the real world, so it crosses the line into magic-future tech so really it can do as you want.

On the limits side, I have been in games wherre the AG system worked off the drive, which could not be turned on while on the surface of a planet, as the interaction of the drive field and the planetary gravity field, at that proximity, would blow the drive in a spectacular manner. . .since it's magic tech, it can work as you choose, or not work as you choose, as GM.

markc · « **Reply #4 on:** July 30, 2009, 12:50:41 PM »

Yes SM:P does have artificial gravity for starships but I think it just requires energy and not directly tied into any system. But I do like the idea that the AG system can require more energy [and maybe a bigger AG system] to compensate for higher gravity levels. ie 3G world might require the AG system to require x2 the energy points to drop the ships decks gravity to 1G.
I was thinking about the contra-gravity and high efficiency contra-gravity systems of another game system that reduce the mass of the ship by 99%. So the starship can take off from a planet with a much smaller drive than would be required if they did not have the CG-device.
BTW I was watching Gundum-00 the other day and noticed that they hooked up their Gundums to provide their main ship with some type of CG-Device that allowed them to escape a trap with a few complications.

MDC

Marc R · « **Reply #5 on:** July 30, 2009, 02:34:26 PM »

Consider the inertial damping systems though. . . .ships can execute pretty crazy maneuvers. . . .how many Gs of accelleration or turning effect?

You could assume those are surge systems, not meant for constant use, but if your ID system allows 15gs of accelleration or turning, then it should be able to damp 2g to 1g casually.

providence13 · « **Reply #6 on:** July 30, 2009, 11:13:49 PM »

IIRC, whenever TOS Enterprise was in a bind/low on power, gravity would be turned down to .8 to save energy.

markc · « **Reply #7 on:** July 31, 2009, 02:42:58 PM »

Just doing some math in my head a 10,000T ship that normally has a acc of .5G would have a new acc of 5G if they had AntiG-Equi of 90%. That is a big difference and can mean very slow craft can still make it out of atmo.

MDC

Marc R · « **Reply #8 on:** July 31, 2009, 03:07:31 PM »

Depends, if that .5 G limit is due to thrust, or planetary resistance. Your mass stays the same. . . .if it's gravity nullification 90% you'd be on earth:

1g of G
vs
0.5g of thrust
net of -0.5g

can't get off the ground.

90% nullification would

1-90%=0.1g
vs
0.5g of thrust
net of 0.4g

can get off the ground.

But it wouldn't give you 5g unless it was a gravity repulsion field shoving against the planetary field for 6gs of thrust vs 1g of gravity. It would allow you to reach escape velocity on any planet with less than 5gs. (Since 5gs -90% = 0.5gs, your half g engine would only let you hover, not escape on a 5g world.)

If, on the other hand, the field reduced the ship's mass by 90%, then it would act as a x10 thrust multiplier, and give you 5gs accelleration.

markc · « **Reply #9 on:** July 31, 2009, 05:41:01 PM »

I think the device in the other game nullifies the weight of the ship trying to escape the gravity of the planet or other object. But I will check when I have some time tonight or tomorrow.
MDC

Marc R · « **Reply #10 on:** July 31, 2009, 10:07:24 PM »

If it's reduces the pull of an object, it's effect will be to reduce drag and will only help near large objects.

If it reduces the mass of the ship, it will effectively multiply the effect of thrust regardless of where you are. (it would work just as well in deep space as it would in a gravity well).

markc · « **Reply #11 on:** July 31, 2009, 11:22:18 PM »

The equipment is described as reducing the mass of the ship in a gravity environment. So in deep space it has no affect.

Any thoughts? Good? Bad? Too magicy?

MDC

providence13 · « **Reply #12 on:** August 01, 2009, 08:38:30 AM »

I always had an issue with "mass reduction"...

But I really like the gravity repulsion... Weren't they called.... Contra-grav lifters?
Maybe Mega Traveler? IIRC, the idea was like repelling magnets, but with gravity..?

Didn't a Swedish scientist make some "gravity shield" that reduced weight by 2%? I'm not saying it's credible, but it might be what you're looking for.

markc · « **Reply #13 on:** August 01, 2009, 01:14:56 PM »

I thought CG lifters reduced the weight of the craft but I will go back and check FF&S.
MDC

Defendi · « **Reply #14 on:** August 01, 2009, 06:02:30 PM »

Quote from: markc on July 31, 2009, 02:42:58 PM

Just doing some math in my head a 10,000T ship that normally has a acc of .5G would have a new acc of 5G if they had AntiG-Equi of 90%. That is a big difference and can mean very slow craft can still make it out of atmo.

MDC

If you have .5 g of ACCELERATION you can certainly make it out of atmosphere regardless, unless your drive cuts out at a certain altitude. Actually if your drive doesn't give out at altitude or after a certain burn time, any ship can leave the atmosphere. Escape velocity is the point where you can cut your engines, not a minimum speed.

Defendi · « **Reply #15 on:** August 01, 2009, 06:04:03 PM »

Quote from: LordMiller on July 31, 2009, 03:07:31 PM

Depends, if that .5 G limit is due to thrust, or planetary resistance. Your mass stays the same. . . .if it's gravity nullification 90% you'd be on earth:

1g of G
vs
0.5g of thrust
net of -0.5g

can't get off the ground.

90% nullification would

1-90%=0.1g
vs
0.5g of thrust
net of 0.4g

can get off the ground.

But it wouldn't give you 5g unless it was a gravity repulsion field shoving against the planetary field for 6gs of thrust vs 1g of gravity. It would allow you to reach escape velocity on any planet with less than 5gs. (Since 5gs -90% = 0.5gs, your half g engine would only let you hover, not escape on a 5g world.)

If, on the other hand, the field reduced the ship's mass by 90%, then it would act as a x10 thrust multiplier, and give you 5gs accelleration.

What he said. I assumed you meant .5 G vertical when under the pull of gravity (so really 1.5 G).

markc · « **Reply #16 on:** August 01, 2009, 11:16:37 PM »

I am thinking very simple like back in Physics 1A, you have 1G of force down and .5G of force up. So the ship which does not have enough thrust cannot get off the planet. Now put the device that nullifies 90% of the crafts weight in a gravity field and that ship can now take off.

MDC

Marc R · « **Reply #17 on:** August 02, 2009, 01:33:06 PM »

If the device acts upon the mass of the ship, it would act as a x10 thrust multiplier.

If it affects the pull of outside G forces only, then it would reduce those fields by 90% without affecting thrust directly. (i.e. on earth 1g becomes 0.1g)

You're going to need to make a call as to which one it is. . .as:

A) MASS REDUCER
0.5x10=5G which allows a 5g - 1g = 4g liftoff from earth, and 5g of thrust any time the field is active.

is a very different result from:

B) EXTERNAL GRAVITY SHIELD
1g - 90% = 0.1G which allows a 0.5g-0.1g=0.4g liftoff from earth, and 0.5g of thrust any time, with reduced external pull on the ship due to any gravity wells you travel into.

Your description seems to be closer to B than A. . .as a GM I'd definitely call B a high tech level, while A would be a really really high tech level. . .based on the fact that current real world experiments are beginning to touch on making effects like B possible, while current physics dictates that A is just flatly impossible. (i.e. A is far closer to supertech akin to magic than B is.)

Oldgrue · « **Reply #18 on:** January 16, 2010, 10:28:26 PM »

If you're using artificial gravity I'd suggest being careful about how granular the control you let the players have. Last thing you need to do is have rapid switching systems and overpowered (anti)grav so they can frappe boarding parties on a whim. Although turning the tables ("You mean I'm taking a C crush crit every round from shear forces? Eep!") could be exciting.

There's no real reason that artificial gravity can't be treated as a positive and negative value. If its a hardware delimited feature of 'deck' plating then players get a feel for how bad a power outage is. Bind it directly into life support subsystems and they're less likely to risk playing with it. It then gives them a feel for common tools that might be able to apply the artificial gravity.

I like the image of large landing plates exerting an artificial -(local)g and relying on weaker thrusters to propel a ship - especially cargo type ships. It gives the feel for everyday high tech (because microwaves and bluetooth are pretty cool when you think about them) in a frame of reference that seems less magical. This might also make more sense in your deep space environment where exerting +/-1g doesn't really do any good without something to act against.

David Johansen · « **Reply #19 on:** January 18, 2010, 08:23:35 PM »

Frapping boarding parties with the artificial gravity is a standard tactic in Traveller. It's why you don't board ships with functional powerplants and it's also why most pirates try to have an infiltrator or two on board.

They have a colourful name for it and everything.

It's called Grav Pong and in the AI virus outbreak that ended the final war better than 90% of the remaining naval crews died that way.

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Author Topic: Gravity Nullification? (Read 4595 times)