The Miller-Chadwick (or MC) drive is a quantum jump drive that relies on the specific para-aetheric characteristics of certain inner-transition elements, most notably lanthanum. These characteristics are in many ways similar to paramagnetic effects. Put simply, in the same way that a coil rotated within a magnetic field will generate current, a lanthanum armature rotated within a para-aetheric field will produce a quantum jump orthogonal to the axis of rotation. Each quantum jump is relatively small, however the rate of subsequent jumps is exactly equally to the rate of rotation of the armature. This effect is relatively simple to demonstrate, but was not discovered until spaceflight was achieved because the effect only exists in microgravity. The presence of any significant gravity field rapidly attenuates the MC effect, such that the efficiency of a MC drive drops to effectively zero within approximately 100 planetary diameters.
To further complicate matters, the field generated by a MC drive has a deleterious effect on semiconductors. As such, devices that rely on semiconductors will not function in the presence of a MC field. Alternative technologies such as microtubes and mechanical computers are required to operate a starship while under MC drive. As a consequence, electronic equipment including computers which are rated for use with MC drive are necessarily much larger.
The shape and size of the MC field is a product of the mass of the drive armature and the construction of the vessel. While the MC field will normally propagate in a spherical shape, it tends to follow conductive materials, and so will normally be generally shaped to match the metal hull of a starship. This effect can be maximized by applying a thin layer of para-aetheric material to the exterior of the hull. Not only will this maximize the useful area of the field, it will also prevent the field from capturing objects near to the ship’s hull. By using para-aetheric plating, the size of the armature becomes directly proportional to the mass of the spacecraft. The general rule of thumb is that the armature must be about 10% of the mass of the ship. This may be in the form of a single armature, or several smaller ones however a single is more efficient, resulting in a loss of about 3% efficiency per additional armature. There is a cutoff point, known as the armature mass limit (AML) below which the drive will not function. The ratio of armature mass to ship mass must never drop below this point (approximately 9.86% or π2) or the drive will simply stop working. It is perfectly acceptable to have additional armatures, or increased armature mass for redundancy, however there is no gain in pseudovelocity – that is strictly a function of armature rotation rate.
Some of the effects of this drive, which may be of interest to Referees:
- Because the MC drive does not operate in the presence of gravity, some other means of propulsion is required while in a gravity well. This can be anything from simple reaction drive to more advanced propulsion systems.
- The drives themselves are relatively uncomplicated – no more so than any large electric motor. And the armatures can be driven by anything so long as they spin. Steam, gas turbine, diesel, electric or even manual power could be used to operate the MC drive armature. Yes, you could have galley slaves if you wanted to.
- Higher tech will allow for better armature design, better lanthanum allows and higher rpms, meaning that higher tech ships will be faster. But starships could actually be build at relatively low tech, provided there is some means to get them into microgravity where the MC drive will function.
- Due to the AML, should the armature lose mass (or one of several be damaged) it will be possible to restore FTL by jettisoning cargo or otherwise reducing the the total ship mass.