Fabrial Machinery

[CosmereScholar]

What technologies could be created using fabrials we know to exist/be possible (besides flying ships, which we all know will happen)? Here are my ideas:

Reverse-Conjoined Fabrials: First, a little examination of the physics of these fabrials.

Zero momentum principle:

Imagine you have two reverse-conjoined gemstones of the same mass, at rest when they are linked. Once the link is established, the two gemstone system cannot gain momentum. The velocity of one will always be the opposite of the other, so the sum of their momentum is 0. This means these fabrials do not obey conservation of momentum. Imagine floating in space and shooting one gemstone out of a gun (assuming the fabrial can be made small enough). Its partner would shoot in the opposite direction with the opposite velocity, and you would be flung back. The gemstones have not changed their momentum, but you have. This offers the potential for interesting applications.

Force cancelation principle:

Imagine reverse-conjoining two gemstones on a table, then lowering the table. What would happen? Both experience the force of gravity, so each would also experience an upward force from its partner equaling their weight. So, the gemstones would hover in midair. Indeed, any force that acts equally on both gemstones will automatically cancel in this fashion (unless it overwhelms them and causes them to crack.)

Locking:

Now, imagine that two reverse conjoined gemstones are set in the same object. What would happen? Any force applied to the object would also be applied to both stones equally, so it would automatically cancel (that is, unless it overwhelms the fabrials/breaks the object). This means that the object would be locked into its current velocity, and would ignore forces that attempt to change its trajectory.

Perfect shock absorber: Using the locking phenomenon, we can design a perfect shock absorber, of great practical use in engineering. Just inset two reverse conjoined gems into the same object. When the link is established, the object will automatically reject any vibrations/impacts applied to it. One useful application would be to create recoil free weapons. Imagine a gun with two gemstones inset, which automatically reverse-conjoin when the trigger is pressed. The gemstones will automatically compensate for the recoil. 

Flying machines: Using the same technique, one can create floating platforms, with the same forces involved as the hovering platforms in WoR. Just inset pairs of reverse conjoined gemstones into a platform, hoist it up, then activate. The platform will hover in place. With the same method, one can create flying machines which automatically maintain their velocity. This way, one could construct a fabrial lift using different technology, or set a rocket flying upwards then lock it into place, the gemstones providing propulsion. These would be useful to incorporate into Navani's flying ships.

Motors: Now, imagine setting a pair of gemstones onto opposite sides wheel, setting it spinning, then reverse-conjoining. What would happen? The wheel would be locked into its current rate of rotation (and position). Nothing, other than overwhelming the gemstones/ breaking the wheel, will cause the rate of rotation to change. This creates a fabrial motor. One could attach it to a machine, like a loom. The amount of work the wheel could generate would be the sum of the maximum work limits of each gemstone pair in the motor (the more pairs, the more work it can do). The only drawback is that, because of the locking that makes it work, the motor cannot be placed on an object accelerating with respect to Roshar. But, one could attach it to a generator if one wishes, or use it to wind springs. So, one can create a fabrial car, using spring power to get it started, and activating the motor one it gets going, simultaneously locking the car into its current velocity and winding springs to provide power for acceleration/turning. The gemstones on the car's motor would be disconjoined when the car needs to accelerate/turn.

Null propulsion: Of theoretical interest is the ability to construct a propulsion system with no propellant. This could be used to propel buoyant air vehicles or in space. Here is one such model. Imagine a pair of parallel pistons, each with a gemstone inside. The first starts retracted, the other extended (the extended one is closer to the back of the vehicle). The gemstones are reverse-conjoined, then the first piston is pressed forward by an engine. The force transmits through the bond, pushing back the second piston. This, the total impulse of the engine is transmitted into your vehicle. Just before the pistons strike the gemstones at the end of their tubes, the gemstones are disconjoined (this is necessary, if the bond were active, the effect would be reversed, transferring momentum in the reverse direction). Then, when the pistons halt, the gemstone are relinked, and the process starts again, this time pushing against the second piston, which is now the retracted one. Each cycle generates forward momentum, while the "propellant" of the gemstones gains none (as they always have 0 momentum, see above.)

 

What ideas do you all have?

Edited March 21, 2019 by CosmereScholar

[Karger he/him]

What about spacecraft?  Using your constant velocity you could move upward at a constant speed for as long as you have stormlight.

[CosmereScholar]

Indeed, you are correct. This would be another application of rocketry with these devices. It would also probably be less Stormlight-intensive that a Lashing based ship, though not nearly as fast.

[Karger he/him]

Also a good battlefield application.  Levitate and then release a massive stone wall that flies at the enemy army.

[Scion of the Mists]

15 hours ago, CosmereScholar said:

Force cancelation principle:

Imagine conjoining two gemstones on a table, then lowering the table. What would happen? Both experience the force of gravity, so each would also experience an upward force from its partner equaling their weight. So, the gemstones would hover in midair. Indeed, any force that acts equally on both gemstones will automatically cancel in this fashion (unless it overwhelms them and causes them to crack.) Of course, this would also cancel the gravity of the sun and galaxy, which are enormous forces constantly acting on both, instantly overwhelming the stones and flinging them in a random direction with catastrophic velocity. But, we also have a WoB that spanreeds compensate for the orientation of the planet (which also does not conserve momentum) so perhaps these reverse conjoined stones automatically neglect extra-Rosharian forces.

1. I'm assuming you're still talking about reverse-conjoining.  
2. The force applied by the sun to objects on a planet is much, much less than the gravitational force applied by the planet itself.  Yes, the sun is much larger than the planet, but it's much, much farther away.  

[CosmereScholar]

48 minutes ago, Scion of the Mists said:

1. I'm assuming you're still talking about reverse-conjoining.  

Indeed I was.

48 minutes ago, Scion of the Mists said:

The force applied by the sun to objects on a planet is much, much less than the gravitational force applied by the planet itself.  Yes, the sun is much larger than the planet, but it's much, much farther away.  

I did the math, and you’re right, the forces involved would be very small, all causing acceleration orders of magnitude less than 1m/s^2. I’ll edit these two.

 

 

I realized that I also assumed that the stones can have an initial velocity greater than 0. This should be possible, as the Earth is rotating beneath them (and indeed there would be a slow upward drift of any locked object because of the earth’s surface acceleration). However, it may be there’s some crazy rule that ensures they must start at rest with respect to Roshar. In this case, it would not be possible to lock an appearently moving object, and there could be no fabrial motor in a car (unless it’s very massive, like with speed bubbles?) But, the motor itself, the shock absorber, and the flying platforms would work, and the massless propulsion would work only if this strange restriction went away in space, on a sufficiently massive spaceship, because you would need the gemstones to start at the velocity of the ship with each cycle.

Edited March 21, 2019 by CosmereScholar

[Karger he/him]

What about making a gate that no one can break down this way?  The gate stays in place as long as infused gemstones are on it and opens by sliding to the right or left.  No one would have to worry about battering rams.

[CosmereScholar]

This would certainly help, and it would relieve the strain of the hinges a great deal, though the strength of the gate itself would not be increased, you could still break it. Unless you made the whole thing a half shard.

 

But, the gate couldn’t slide left or right without unconjoining the gemstones. The sideways force would be resisted just like the force of a ram.

[CosmereScholar]

Just realized the motor I proposed would not work. The forces acting on the wheel would act on the stones in opposite directions so there would be no effect! Also, it requires the stones to start with different velocities, but that was not out the question since spanreeds can do it.

 

Any ideas for a motor?

 

Edit: Assuming one can have an initial velocity, we could construct a motor by putting two gemstones in a vertical piston head with a spring on each side of the chamber. The piston would bounce off the bottom spring, lock its velocity to head to the top, then unlock and fall. It would oscillate up and down pretty rapidly. But, because of locking, it couldn’t be put on an accelerating vehicle, and would have to be managed carefully.

If one assumes we cannot have initial velocity, it is more challenging.

 

Additional application: in machines, we could connect wheels by attaching conjoined fabrial at their rims to transmit the rotation. Reverse-conjoined ones would reverse the direction of rotation.

Rotational Stablizers  We could use conjoined fabrials to rotationally lock an object. Imagine two conjoined rubies set in a flying ship. It is starts to rotate, it would force the rubies to move in oppose directions, and they would resist.

Edited March 21, 2019 by CosmereScholar

[Turin Turambar]

Shields - they won't break. Barring that, a wall.