Science question.

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AEmer
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Re: Science question.

Post by AEmer »

@DDL

The gravity in Mass Effect is restricted to the ship interior somehow. It's like a gravity flux field or something. I mean, think about it: If it wasn't a shaped field, it would affect the ship as well, which means you would still be functionally in zero gravity. After all, in mass effect, mass effect fields don't obey newtons law of action and reaction: You just run power accross and element Z core, and zippety zop, there's a force being acted out somewhere.

Since it's an aritificial field, I presume it emulates gravity as if from a distant source, like is the case with earths gravity.

@ Phas

well, you can easily have gravity emulation if you don't mind the ship using thrust to emulate gravity. That would be the way to do it: If you have thrusters that you can run continuously, you can enter into a gravity spin to perfectly emulate gravity. It won't cause any changes to the direction the ship is moving in, either...or you can just use thrust towards the direction you're going to get there faster.

The other possibility is to have tethers, wires hooking up seperate parts of the ship which can seperate so as to emulate a spinning space station design. I wonder where I've heard that idea before... ^^
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Phasmatis
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Re: Science question.

Post by Phasmatis »

The problem with thrust is I need the ship to be still so thrust might be a bit complicated. The ship has decks, from the bottom up; there's engineering, the main deck (this has a mess hall/restaurant, medical bay, security, reception and the staff dorms), then there's the passenger habitation deck and finally storage. Kind of a like space hotel, actually more like a ferry and I need the player to be able to move around the ship via engineering tunnels or by going through the main door of each room.

It seems trying make everything adhere to science doesn't quite create a nice game friendly design or at least doesn't let me do what I need to. Even with the deck system I'm beginning to think it's a bit too boring. I'm limited by the engine too, I'm not sure I can change the direction of gravity... I should really look into that. I've spent weeks on this layout, oh well, it's all experience at the end of the day.

You guys are being extremely helpful, discussing this is helping me progress much faster than I think I would on my own.
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DDL
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Re: Science question.

Post by DDL »

Aemer: you might have to explain that ship point: why would having a ship being affected by its own gravity make everything zero gravity? The earth is very much affected by its own gravity (or have all those collapsed rockfaces been lying to me??), and it doesn't result in zero G for all earth's inhabitants.

Plus of course, once you handwavily accept that you can generate linear fields of arbitrary gravity, you open the door to all manner of things (why don't they have gravity mines? etc). Mind you, that's a failing of the mass effect universe in general: I seem to recall they came up with some bullshit regarding unalterable safety systems to explain why everyone didn't just stick eezo drives on rocks and fire them at the reapers, which would otherwise be genius. You don't need fucking railguns when you have rock-mountable FTL engines. DODGE THIS, HARBINGER

(also, it doesn't really make any sense when they used the EXACT SAME METHOD in ME:Arrival)

Phas: a common method for having a deck layout in a ship is to have it built perpendicular to thrust direction, so when you're under thrust, the acceleration provides your 'down'. Accelerate at a smooth 1G, and you'd never know you weren't on earth. When you reach the halfway point to your destination, engines off, brief weightlessness as they flip the ship around, engines back on to slow down, and now DEceleration is providing your 1G of fake gravity.

This would probably work quite well in a game: you could allow the player to move around freely, then every once in a while have an announcement like "everyone secure themselves for turnaround!", make the player stow themselves in a cubicle, turn the lights red, make a few choice decos float briefly, lights back to normal, continue.
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Jaedar
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Re: Science question.

Post by Jaedar »

If humans have mastered artificial gravity to the point where every dingy little ship has one, I think we'd also have figured out how to weaponize it. Gravity well grenades anyone?(its the future of non-lethal weaponry!)
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Phasmatis
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Re: Science question.

Post by Phasmatis »

In my game the ship needs to come to a complete stop because another ship has a medical emergency and the crew of the other ship only know basic first aid. This all happens before the player starts the game, I don't want to give too much away but once the other crew are aboard (this is when the game starts), something goes wrong and the ship will stay completely still for the rest of the game so gravity generated by thrusters creates a problem.

I've just had a quick google. I was always under the impression that gravity on Earth is created by it spinning as well as it mass, am I dumb or is that true?
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Re: Science question.

Post by DDL »

The spin of the earth would oppose the force of gravity, making us marginally lighter than mass would otherwise suggest.

http://en.wikipedia.org/wiki/Gravity_of_Earth

Apparently you're 0.3% heavier at the equator than at the poles coz of centrifugal force. Accounting for the slightly non-spherical nature of earth (further from centre at the equator coz earth bulges) that adds up to 0.5%.
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Re: Science question.

Post by Phasmatis »

Ah, I am dumb then haha. I thought perhaps if the mass of the floor was high enough it could create the gravity but that's pretty much the same as a gravity manipulating device, only manipulating mass instead.

Screw it, I'm going with a the "Rampkin Field Generator" named after the inventor by the inventor, everyone else thought it should be called the Newton Field Generator but Donald Rampkin was very arrogant.
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AEmer
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Re: Science question.

Post by AEmer »

You should call him rumpkin because that would be hillarious.

Will respond more in a bit when I've drawn some sketches.
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Re: Science question.

Post by AEmer »

http://imgur.com/2JTjnru,wyVDyZU#0

Ok, so. Imagine we have the capacity to generate a force field. Let's imagine it is an electromagnetic forcefield, for now, just to humor ourselves.

We draw a square around a part of the field, and we put something within the field. That's the left drawing in the first image.

Well, guess what. If we exert a force onto an object, according to newtons third law, that object exerts and equal and opposite force onto us. So if we put a magnet into an electromagnetic field, and that magnet was pushed downwards, then the coil (or whatever) generating the field would be pushed upwards. Simple stuff, really.

In mass effect, not so much. When bioware decided to go with mass effect field drives, they also decided to fuck over newtons third law. In numerous locations in the game, you will find that mass effect fields are like gravity. When used for spaceship propulsion, the fields make the ship 'fall' forward. That's also why passengers don't need to concern themselves with inertia: they fall together with the ship! For that reason, Joker can do all sorts of crazy maneuvers, and nobody aboard will feel a think.

Obviously, there is no equal and opposite force acting on the eezo core in a ship, because if there were, the ship either wouldn't be able to use the core for propulsion, or the core would fly out of the ship.

Ok, so the second illustration asks, can we make any kind of field? Signals point to yes: The pull ability appears to be able to lock a biological or mechanical being in a mass effect field precisely the size and shape of its own body and suit and belongings. How or why, we don't really know, and we know that (somehow), if the being is shielded, has a mass effect barrier (whatever that is), or is specially armored, it seemingly cannot be targeted with such a field. OK.

It's a bit weird how stuff can't even get caught in a singularity field while shielded, armored or barrier'ed, but one conundrum at a time (I guess their suit comes with, eh...inertial mass effect dampeners or something).

So in the second picture, I outline how I think it works: What you see is a very crude picture of the normandy with layout. Within the corridors of the ship, there are limited, parallel-force flux mass effect fields. There's an equal and opposite field being _generated_ onto the ship hull (so the pressure of the stuff under gravity doesn't push the ship as it touches it at the hull), and then there's a larger, external field which is used for propulsion.

See, with any other setup, it just doesn't work and creates massive inconsistencies, but if you allow for arbitrary shaped fields and break newtons 3rd law and all the laws that follow, it all works.

Now here's what I don't get: How is it that we've apparently learned to break newtons 3rd law for mass effect fields but not for EM fields? And why do guns have recoil?
AEmer
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Re: Science question.

Post by AEmer »

oh, and phas:

http://i.imgur.com/drK05x6.jpg

This is a gravity spin. Any capsule with significant thrust can enter into a gravity spin. It's a bit like a pendulum - think of it like having a weight in a piece of string and swinging it around - but the capsule can commit to a spin of arbitrary size.

The cool thing is, the object will still be on the same course - nothing about it's movement changes so far as the outside world is concerned, beyond the circle.

If a ship generally moves under the presumption of thruster-gravity, then an autopilot could have the ship enter gravity spin instead of simply floating as dead-weight. For some purposes, being in gravity spin is the same as turning the engines off - for instance, if something detached from the ship and is now floating around in space, you will remain close to it whether you're deadweight or you're in gravity spin. It would probably also be the way to go if you want to maintain orbit around something, but you also want simulated gravity.
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Re: Science question.

Post by Made in China »

If you're talking about artificial gravity, you're essentially talking about applying a constant force on an area. But since itself ARTIFICIAL, you don't need to actually use gravity.

Instead, use electromagnetism. Build a ship that's shaped like a tube, and through its center run strong electric current. That'll create a magnetic field adhering to the right hand rule, making it spin constantly as long as there's power - which you can justify as the power to run the ship's devices. That way, the floor will always be pushed against you.
Also, because there is no real "down" (if you're always going down will eventually do a full circle), the best transportation is to indeed drop between decks, using ceiling/floor hatches. Or, by using corridors that run outside the ship for almost zero gravity (the closer the corridors are to the core, the less artificial gravity there will be, due to angular momentum not changing).

BE AWARE that this could only be possible only in very specific conditions. As the ship's size varies, its power consumption also needs to vary - but since you're building a luxury ship, it can be assumed to have regular gravity practically everywhere due to its size - while other ship in that same universe may have far higher or little to no gravity.

Cutaway of the ship using 1337 paint skillz:
http://i.imgur.com/byZha1M.jpg
P = propulsion system, may also works as a generator.
Blue = electric current flow through the ship.
Purple = magnetic field.
Brown = hatches.
Green = maintenance corridors through zero gravity.
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Re: Science question.

Post by DDL »

I'm not sure "make your ship a giant dynamo" is the safest or wisest way to ensure rotation. Just use a motor, or at worst: external jets.

Also, it's worth noting that giant rotating cylinders generate an awful lot of torque if you want to maneuver (they're basically gyroscopes), so it's a common trope to use two, contrarotating cylinders instead. And/or to lock the rotation down and go to zeroG conditions prior to actual battles.
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Re: Science question.

Post by Made in China »

DDL wrote:I'm not sure "make your ship a giant dynamo" is the safest or wisest way to ensure rotation. Just use a motor, or at worst: external jets.
Well, it will be quite lethal if you have a pacemaker\metal prosthetic, and I can anticipate a lot of problems with electronic devices (which could be fixed with custom technology). Non the less, it's the most energy efficient solution out there since it uses an unused property of the already prevalent electricity.
DDL wrote:Also, it's worth noting that giant rotating cylinders generate an awful lot of torque if you want to maneuver (they're basically gyroscopes), so it's a common trope to use two, contrarotating cylinders instead. And/or to lock the rotation down and go to zeroG conditions prior to actual battles.
You know better than me on that - but I think battle cruisers and battle pods would not have the luxury of earth gravity, even under normal conditions - they'll be designed more for damage output, crew survival and damage mitigation rather than comfort. I guess military training would need to take it up a notch in the future.
Also, since we're talking about heavy machinery, it'll be far more useful for it to function under zero gravity at all times, similar to the maintenance tunnels I've got in my design.


BTW, on takeoffs\landings you'd need to be secured to one of the walls, in case of a system failure and in order to have a smooth transition from the real gravity field to the artificial one. Just another thing that needs to be added to the interior design.
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Re: Science question.

Post by AEmer »

@DDL
I want to know more about gyros.

I know that they work very counter-intuitively, and that the angular rotation means that when you try to twist them one way or another, the force you apply to the gyro ends up acting in another direction.

So when you have two gyros rotating in opposite direction, how does their allignment play into it? How do you make them cancel eachother out? can you just put them next to eachother and rotate them in opposite directions? Do they need the same amount of edge mass?, do they need the same mass distribution? Do they need to be disc shaped or do they just need the same amount of angular kinetic energy?

Do you know the answers to any of these questions?
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Jaedar
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Re: Science question.

Post by Jaedar »

Iirc, their torque needs to cancel, so the speed of rotation*distance*mass (or something like that) should be the same.

Rigid body mechanics was so long ago :(
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