Clarke is an extremely interesting substance, commonly found in the cores of large gas giants, dying stars or the remnants of dead stars. After the lengthy extraction and refinement process, clarke can be seen as an extremely low density, gel-like solid of faint blue glow which also exhibits some strange refractive properties, however, this is definitely not the main interest in clarke. What is the main interest, is that when charged, clarke is the only substance that produces a field that can warps space-time in such a way as to cause a continuum distortion that reduces, or ‘pushes back’ the effects of relativity within the field, thus allowing speeds exceeding that of light. The space-time within the field is therefore termed ‘clarkespace’, and the field termed a ‘clarke field’. It follows then, that the stronger the continuum distortion/clarke field, the easier it is to accelerate to the speed of light and beyond and therefore the greater the speed that can be achieved. However, the increase in the strength of the field is not directly proportional to the increase in maximum speed, in fact the relationship between maximum velocity and clarke field strength is exactly the same as that of velocity and energy in normal space-time, in that the field strength required approaches infinity, and becomes infinity at a maximum-maximum speed, a new universal speed limit, of approximately 805 times the speed of light, known as the ‘clarke barrier’. However, even speeds approaching this are unfeasible due to the amount of energy required to create a strong enough field, and even at ‘slow’ speeds a very large amount of energy is required to have a useful effect meaning it is highly unlikely that this barrier will be approached any time soon.
Besides causing the continuum distortion effect, clarke fields have another extremely useful effect, much to the delight of engineers everywhere because, although one could use normal space traveling engines, thanks to clarke fields you don’t have to. This is because anything generating a clarke field behaves as if it were a ‘clarke magnet’ and attracts other ‘clarke magnets’. Therefore if you place a weak clarke field generator, A, within the field of strong clarke field generator, B, then A will experience a strong force of attraction and thus a movement toward B, B will also experience a force of attraction towards A of course, but this will be minute in comparison. To take advantage of this, ships that utilise Clarke Drive will contain a primary clarke field generator, and a much smaller, secondary clarke field generator placed behind it. Since both generators are built into the rigid structure of the ship, they cannot move towards each other and thus the force of attraction pushes the entire ship forward in the direction of the field. This would of course mean that different parts of the ship experience varying amounts time dilation, but this can be minimised to the point where it makes no real difference by having the primary, or better, both generators shaped like rings and placed on the outside of the hull. This is because in the centre of the ring, the field is uniform, but outside the ring, the field drops off rapidly.
The Clarke Drive is the preferred method of travel in the Arctannian Commonwealth because of it’s very high efficiency, in fact it is practically the only method in use in Commonwealth because the navy, as the sole manufacturer of ships uses it, and foreign-bought vessels are subject to extremely rigorous licensing. Clarke Drive is also increasing in popularity in the Tri-National Republic, but is unlikely to replace Hyperspace as the preferred and most popular drive method there in the near future.