Force Neutralisation System (FNS)[1] is a technology which utilises Zero-Mass blocks to eliminate inertia between two bodies.
Background[]
Newton's second law of motion states . For example, an object weighing 1kg under the effect of gravity (9.81m/s²) will require a force of 9.81 newtons to stop it from falling.
Using NoBounds, it is possible to set the mass of a Ballast or Scaling Block to zero. As force is proportional to mass as described above, it follows that any force exerted by the zero-mass block would also be equal to zero.
Effectively, if one part of the machine moves, and another part of the machine is only connected through zero-mass blocks, the other part will be moved as if it were weightless. Any force from thrusters or Overflow will also be ignored.
Applications[]
The most common application of FNS is as part of a high-power Recoil Suppression system; using it makes it practical to use ballast of (almost) arbitrary mass[2] as part of the cannon assembly. This enables recoilless cannons of utterly absurd power, unmatched by any other method.
It is possible to use FNS for lifting disproportionately heavy payloads - in the gif above, a rotor powered only by a 2x power wheel is lifting a tank weighing 300 units.
Black Armour can also be formed using FNS; under the right conditions, zero-mass blocks will stop high-speed projectiles dead.
In theory, it is also possible to suspend extremely heavy blocks with FNS, which would also no-sell cannons and other kinetic weaponry.
Usage[]
To assemble an FNS connector, first place the block which will hold the zero-mass block, and then place the zero-mass block so that the first block connects to its center. There are a few methods for connecting the separated mass:
- Chamber FNS - Use super-high-strength springs to connect the separated mass; this requires the mass to be held in tension, so a box (or chamber) of connectors needs to be formed around the mass.
- Inline FNS - In theory, only two connectors are required to hold the mass, but in practice the extreme response of the high-power springs required to do that makes this difficult and requires stabilisation using Overflow or high-drag Build Surfaces.
- Sword FNS - Use Spring Tethers and Overflow blocks to suspend the mass; since tethers are rigid-ish they don't need an enclosing chamber, but they're limited to much 'smaller' masses (as they're not rigid enough to suspend thousands of tons on their own, or to drag around that mass suspended with Overflow without problems).
Use of FNS is not straightforward, as it exploits a quirk of the physics system:
- As the rigidity of a connection is proportional to the block's mass, a zero-mass block cannot connect to anything itself if there's any mass hanging off of it.
- The same applies for all blocks connecting to the zero-mass block, except for the first placed block and non-rigid dragged blocks (Contractible Springs and Winches). Other connected blocks will act as if not connected (but have some effect on rotation).
- If the zero-mass block sustains any serious impact (while suspending heavy loads), physics glitches will destroy the rest of the machine. This can be avoided by using Build Surfaces, which can have their colliders disabled.
Advantages and Disadvantages[]
The main advantage FNS has over Overflow for recoil suppression and armour is that it does not limit the speed of the machine. This means that a 'siege mode' is unnecessary for firing high-power weaponry and activating high-power armour.
The main disadvantage of FNS is that it is finicky and annoying to get working properly, especially compared to Overflow. Holding zero-mass blocks in place is difficult, holding the separated mass in place is difficult, and holding heavy objects in place with springs is also difficult. It also destroys the machine if any zero-mass block is hit.