[ericthered]

Originally Posted by Anthony

The simple version is that you need to have two plates (one attractive, one repulsive) and it applies in the region between the plates.

I considered that model of artificial gravity, and ultimately I decided against it. It probably does make things simpler.

Originally Posted by Daigoro

Wouldn't you also get 2G above and below them? And you'd get the disks pulling toward each other at 2G, which would be nasty for anything in the middle if their screws came loose. And... wouldn't they just cancel each other out, and still leave whatever stray gravity field lines you have lying about active? i.e. There'd be no useful effect on the target object, it'd still be subject to whatever forces are acting on it from the environment.

Yes, you've read that correctly. You get a null zone between them that's still effected by external forces, they are pulling on each other, and if you get your overlaps wrong you're got 2G on the far sides of the plates. I would not plan on securing these things with mere screws, regardless of if they're facing each other or not. I think the one thing you might be missing is that the height or the field is not related to the height of the disk.

Originally Posted by Daigoro

This result falls out naturally from the geometry, although that height depends on the diameter of the disk.

The inverse-square law holds when you consider a test mass at a distance from an object that you can treat as a point, as the field lines diverge spherically.

When your test mass is near a field-emitting plane, there is no field strength drop off w.r.t. distance as the field lines are all parallel, until you move far enough away from the plate for it to "look" like a point source.

Simple engineering tricks could be making the plate concave or convex (not sure which would get the desired result...) Otherwise, you can just handwave the attenuation distance.

Oh wow, I'd forgotten about that particular geometric quirk of gravity. That's intriguing. I wonder what the natural height of the effect from a disk is? I'm a touch worried the effect will be small compared to the radius of the disk. I don't have to use this, but its a nice piece of math to think about and play with.

Originally Posted by Fred Brackin

It's not the orientation of the floor that's in question. It's the net direction of gravity+acceleration and the way that affects liquids. Not the way it effects how the spacehands stand. The artifical gravity is only going in for human comfort (and possibly health). Making everyone apply a 5% "Kentucky windage" on all the hot coffee they pourfor soem reason I don't really understand is bizarre.

Gravity and Constant acceleration are indistinguishable from each other in a closed system. I usually see that statement made right before people talk about general relativity and gravity. I will grant that if the acceleration is from spinning you can get some fun effects, and if the acceleration is changing that can really cramp your style.

At this point, I think I'm either lining up gravity with the main acceleration, minimizing how often those main engines fire, or using a disk to apply a neutralizing effect.

As for Spaceships and attitude thrusters, Spaceships is a simple, limited detail system for designing spaceships quickly. Attitude thrusters are one of those things that gets tossed into the mandatory "Control Room" which actually includes many things that aren't in the physical control room.

I know where attitude thrusters come from. I'm just saying the spaceships requires you to be burning fuel with your main engine to be allowed to dodge in spaceships combat. Attitude thrusters presumably don't match your main engine. But as we both said, its a simple system to get the game going, so its not hugely important.

You'd have to go out of your way in Ve2 to include special extra engines for sideways thrust for dodging. At the ultra-realism level spitting out a hot reaction plume to your side while trying to change your motion would probably do more to tell your enemy where you actually are than the effect of changing your motion would disrupt his aim. Maybe you want to shut down your drives and use extra EW when you go into combat.

That's not a bad point. The reaction plume is likely to be among the most visible parts of your ship. I suppose it depends on how tight the loop between their telescopes, computers, and gunnery corrections are. If they've got telescopes that can quickly determine how much plume you just shot out, and in precisely what direction, and the organizational and computing power to feed the guns updated estimates of where you're going, it reduces the utility of dodging a lot. But if any one of those fails, its effective if expensive dodging.

Originally Posted by Anaraxes

As long as you're exactly equidistant between the disks? If you're slightly closer to one than the other, presumably you accelerate toward the close one. The zero-G spot isn't stable -- unless the force doesn't depend on distance from the disk. (Is that the case?)

Yes, the disks have a set distance at which they apply uniform gravity. Though Diagro has me thinking about that.