Little aside, but matching rotation to a hab is going to a cakewalk compared to matching orbit with it to dock in the first place. There's no loss of momentum in a vacuum, so its just a matter of small thrusts to spin you until the docking bay is stationary to your perspective. That said...its probably rather nauseating, though, since everything else would be spinning damn fast, and you will have centrifugal force of your own to deal with in the ship. Admittedly, this is based off limited knowlege and a lot of Kerbal.

jKaiser wrote:

Given the typical cross section of a torus, with a fair bit of open air over the living area midsection...I have a feeling some idiots have turned jumping from the ceiling-window and taking advantage of that deflection into a sport. "Aim for the lake!"

Hah that's awesome :) remember to ask your muse to calculate the trajectory - I doubt factoring in coriolis and wind is humanly possible.

Forget the skateboard, think about the people who consider flying wing suits to be the best form of entertainment. Mind you, if I had a backup, I'd be all over that. Looks fun as hell!

Smokeskin wrote:

jKaiser wrote:

Neither is the specific angle of a skateboard at any time during its existence, but that doesn't stop people. And we don't have backups, either.

Jumping at 3 m/s in a 250m radius hab gives you 83 seconds of flight time. The lake will do full rotations beneath you in that time. You have to factor in coriolis and wind. If the lake is 50 meters wide, you have 0.65 seconds of margin to either side, or a 0.73% margin. Estimate the needed angle or speed wrong, or get either of them wrong when you're jumping, or your drag profile in flight - if those errors add up to more than 0.73% in either direction and you hit the ground instead of water. I'd want some guidance for the jump and for in flight drag profile adjustments. Maybe you could learn to do it, but unlike the body eye coordination needed for skateboarding, humans are very bad at things like estimating distance and speed. It's going to be very hard to learn.

Ah, I see where I wasn't clear. I didn't mean jumping from the hub, I meant from the hubward window of a large enough torus hab's ring. Like so: http://4.bp.blogspot.com/_VoFM4aW7x9A/THRQUZnAyXI/AAAAAAAADIE/77r3ZSbFgA... If it's big enough, there'd be enough velocity differential to give some deflection, but not the spiral of splat we're talking. Though I'm sure there are some entertainment-purposed habitats that have figured out how to make that sort of gravity drop in a disk hab practical. Jamming a sphereoid or something and being launched into an obstacle course...oh, God, that's basically transhuman pinball and I want to play it so badly.

Chernoborg wrote:

Make it a swarmanoid and play pachinko

I am laughing so goddamn hard right now at that mental image. Japanese Game Shows a century and a half in the future are gonna be amazing if even half of EP comes true.

If an evil demon spun the Earth around an axis through the equator instead, then it makes perfect sense ;)

Going back to the OP, is there a good replacement text/rule of thumb to start with? Maybe this: The artificial "gravity" used in rotating habitats is a product of centripetal acceleration - the rotation of the habitat accelerates everything inside its reference frame outward, just as gravity accelerates everything downward on a planet. The further you are from the axis of rotation, the stronger the acceleration. In most rotating habitats, incoming ships dock at the axis, where microgravity makes movement easier and fewer hard thruster burns are necessary to match rotation. Elevators make the transition to the outer surface simple and safe. In larger habs, aircars are sometimes used to reach the axis, but a skilled hand or AI is needed to match the speed of the "ground" which may be moving at 100 km/h relative to the axial "sky." Still, a leisurely trajectory can make this transition gradual and safe. Transhumans left adrift in the microgravity of the axis are not so lucky. While a body left at the axis isn't "falling," without a thruster pack or another way to keep station it will eventually drift towards the "ground." As a rule of thumb, after about thirty seconds the hapless character will begin to experience high velocity Coriolis winds (SOMx3 test or suffer 1d10 SV per Combat Turn). The "fall" may take as much as ten minutes depending on the radius of the habitat, at which point the faller hits the ground or a building. The "falling" damage is equal to falling from the same height on a planet. During this time a flying vehicle or morph can try to intercept the drifter, but perceiving a transhuman against the noisy background of the opposite side of the hab (a long-range Perception test) and matching velocities in time without hitting the ground (a hard piloting or flight test) make for a hair-raising rescue) Of course, like all hazards, hard gravity transition has been made into a sport. "Habdiving" is popular in some Cole bubble and cylinder habitats, in which specially designed parachutes, smartfabric wing suits, and variable-geometry synthmorphs are used to build enough drag to match velocities to something safe - or at least survivable - during the long drift to the surface. Needless to say, most heavily populated habitats outlaw such activity for safety reasons, which doesn't stop the enterprising divers, but some embrace the pastime. Colorful "landing strips" with targets and well-wishes drawn across the inner surface are favorite venues for habdivers. I may have gone overboard with that last part, but I think the falling rule is a bit more realistic (and maybe more dramatic) than the original. I'm not by books at the moment to assign appropriate difficulties to the tests. Thoughts?

Those are some very detailed and useful tables for when specific speeds become relevant; you're getting well past the level of simulation that I'm comfortable with, anymore. (Not a criticism, a matter of taste). I appreciate the perspective on skydiving velocities; once again my desire for drama appears to be dashed. Is there good information on how fast and predictable high altitude winds in a rotating habitat might be? If falling from a hab axis is barely a problem, my hopes of reenacting the train explosion from Babylon 5 are for naught. Maybe EP technology is just too good for such things.

I definitely get the physics involved; I'm just trying to put it into the context of things like midair laser fights, agonizing death spirals, and tense last-minute rescues. Also extreme sports.

Alan Wiggs wrote:

Those are some very detailed and useful tables for when specific speeds become relevant; you're getting well past the level of simulation that I'm comfortable with, anymore. (Not a criticism, a matter of taste).

I sort of agree - I don't like the simulationist approach much, especially when it slows down gameplay. However, in my geekier moments I've made some tables like this. They're very easy and quick to read, you only really need to do it once per hab, and I think it is easier and faster that rules actually. If I don't know the surface velocity of a hab I may need to look up a whole host of rules to cover different situations, or I have to dream up modifiers and effects with nothing to judge them by. If I know the surface velocity (say 100 km/h) I can make good calls on lethality of getting smacked by a building, what sort of vehicle can dock with the hab on the outside, etc., just by knowing a single number. Anyways, it works for me.