The Science Of A Jump Drive

The Science of A Jump Drive - A Primer on Astrophysical Concepts in the Fourth Dimension

The Jump drive is a magnificent technological advancement that has, for thousands of years, allowed the various sentients of the galaxy to travel beyond their earthly confines, expanding into the greater Galactic territory. It has made conquest and trade on a stellar scale not only possible, but simple facts of life for the untold many citizens who, today, count themselves as citizens of the Third Imperium. Bringing wealth, civilization and knowledge to the farthest reaches of known and unknown space, the Jump Drive is the single most significant technological advancement in the history of the Major Races, perhaps even in the history of the Galaxy at large. And yet, for its significance, the specific workings of a Jump Drive are absolutely alien to most who do not create or service them, including many galactic travellers. In an effort to enlighten those individuals, and indeed anyone who might be curious, this primer has been written. While it shall not go into true detail - the depth of such information is sufficiently advanced and numerous as to fill several University-level Astrophysics courses - it should provide a working knowledge of the functions and processes by which a Jump Drive operates.

Introduction: What Is a Jump Drive?

A Jump Drive is one of two propulsion systems present in any ship intended for interstellar, as well as in-system travel. Whereas the M-drive is a traditional thrust-based propulsion engine, the J-drive is utilised for faster-than-light (FTL) travel, allowing ships to bridge the massive gaps in space between systems in a relatively negligible timeframe. The most common unit for measuring the distance a given J-drive can travel is the parsec, as this is the distance a Jump-1 drive will cover. More powerful drives (Jump-2, Jump-3, etc., up to Jump-6) are capable of covering multiple parsecs in a single Jump, making travel between systems separated by minor rifts possible. As of present, the highest rating a J-drive has accomplished is Jump-6. No known experimental engine has ever been able to manage Jump-7. It is important to remember, however, that Jump ratings are assigned for the capability of a drive to reliably, and stably transport a given hull volume a given distance - misjumps can cover vastly greater distances, but are not controllable and often either strand or destroy the misjumping ship.

Jump travel is also related to a specific quantity of time - 168 hours, or a single week. This is the amount of time any ship making a Jump will spend in Jump Space (J-space, as opposed to Normal Space, or N-space). It is otherwise known as the Jump Time Constant. Every race that discovers or otherwise gains Jump technology will inevitably experiment with the J-drive in an attempt to decrease the time taken to Jump, but it is generally accepted within the scientific community that no act of man or God will ever produce a Jump of a time other than one week. Reports of misjumps occurring instantaneously, or taking several months, or other such things nonetheless propagate within the various bars and taverns of Charted Space, but no record of any such incidents has ever been taken, even when crews have survived or been recovered from misjumps.

The actual Jump drive consists is, in fact, two components on the ship, separate but connected. The first is the J-drive itself, a massive fusion reactor with several specialised parts that diffrentiate it from standard hydrogen fusion reactors. The other is a lanthanum grid laid into the hull itself, through which energy is channeled to created the N-space bubble necessary for safe passage in J-space.

The J-Drive Reactor

The drive itself is a hydrogen fusion reactor designed to produce immense amounts of energy very quickly. For this reason, the engine consumes incredible amounts of fuel while functioning, rendering M-drive fuel needs paltry by comparison. Most commonly, interstellar ships judge their fuelling by how many Jumps they expect to make back-to-back, which is rarely more than 1, and stock extra fuel for the M-drive to make it to a Starport to refuel. (As an aside, an occasional Major Race is encountered who managed to create a J-drive which utilized something other than hydrogen as fuel, but these are usually produced due to conditions in the home system and almost invariably perform poorly alongside the traditional hydrogen-fusion J-drive. The difficulty of fueling alternate drives is also a major strike against them.)

Energy from the initial cold fusion reaction (the pre-Jump charging of the drive, if you will) is stored in Zuchai crystals within the drive, compounds capable of storing energy to an incredible near-100% efficiency. Unfortunately, Zuchai crystals will also store and replicate any variation or instability in the energy flow from the cold fusion reactor, meaning using impure or poor-grade fuel is a bad idea unless you have literally no other option. From there, the power will be shunted into the lanthanum jump grid, forming a bubble of N-space around the ship which is necessary for travel in J-space. When this process is finished, the remaining majority of the power will be used to bombard the radioactive at the core of the J-drive, creating a "hole" into J-space which the ship falls into. From there, the ship will spend a week in jump, before emerging at the target destination.

It is important to note that close proximity to local gravity wells is capable of skewing calculations and causing catastrophic misjumps. As a result, a Jump cannot be made within 100 diameters of any significant gravity well, and it is advised that no Jump is made within 100 diameters of any physical object at all - though frequent naval fleet jumps prove that the danger of this is negligible at worst.

The Longinus Compound

The Longinus Compound, or the J-space "spear" is a naturally-occurring radioactive of relative rarity which can be found both on planets, often at the core of larger deposits of radioactives, as well as within asteroid belts. Systems without any significant L-Compound deposits often find it difficult to manufacture J-drives on their own, at least until they reach TL12 (or do trade with TL12+ neighours). The L-Compound (known by the scientific name lancaeum, and known to the Vilani as Val-Riza (World Bridge)) is peculiar in that it produces extra-dimensional effects when bombarded with energy, most notably the creation of J-space holes. It is also noted that bombarding L-Compound with low levels of energy produces significant adverse affects in nearby psions (though the effect has never been noted when high levels of energy are used, and no psion has ever reported issues while travelling in J-space). These effects, which include headaches, vertigo, and hallucinations, occur even while behind shielding (no testing has ever been undertaken unshielded, as the energy involved would fatally irradiate the test subject almost immediately).

Naturally-occurring stores of L-Compound tend to limit Jump-drive production, but given how ubiquitous the technology is and how much the Imperium depends on interstellar commerce (as did the Second Imperium before it, and the Ziru Sirka before them), this became a significant obstacle. Both the League of Sylea and the Ziru Sirka developed, independently, a compound known as G-Compound (synthesized lanceum, or the Gungnir Compound, known as Val-Riza Aeriz (Minor World Bridge) in Vilani). This compound played a singificant role in the Interstellar Wars, allowing the League of Sylea to stand on equal footing with the monolithic Ziru Sirka in regards to war production, and has been a staple of TL12 societies since. There is no functional difference between G-Compound and L-Compound within the context of a J-Drive, but it has been noted that similar low-energy tests with G-Compound produce no notable adverse affects in Psions. Zhodani ships tend to be almost universally fitted with G-Compound drives as a precaution because of this.

The Lanthanum Grid

The second component of a Jump Grid is the lanthanum grid inlaid in the hull of the ship, at about the centre of its thickness. It was found that a side-effect of energizing lanthanum in the proximity of L-Compound while a jump was being initiated would protect the ship within a bubble of N-space. While it's not certain if this is just a property of lanthanum within J-space while being energized, or if it's some sort of interplay between the energy radiated by the L-Compound and the energized lanthanum, the result is a far more energy-efficient, stable and overall safe N-space sphere than would be produced with older methods. (As a note, yes, it is possible to Jump in a ship without a lanthanum grid - most modern J-drives feature lanthanum coils within the drive itself for this purpose, in case damage is sustained to the grid. Even before the discovery of this property of lanthanum, it was possible to create the N-space sphere with L-Compound alone, but the calculations required were extensive and computer or navigator error could cause significant problems.)

The Mechanics of a Jump

While all the above is solidly documented and provable, scientifically, the actual mechanics of J-space and the way in which a Jump is undertaken are far less understood, not least of which is due to the fact that J-space functions in a vastly different way from N-space. It is presently theorized that J-space operates under separate underlying rules to N-space - this is the reason N-space spheres are necessary when travelling. The theory states that because of the inherent real differences between matter types in the two dimensions, J-space matter brought into N-space and vice-versa results in immediate annihilation, in much the same manner as matter and antimatter annihilate each other. However, as it has so far proved completely impossible to ever do any research on objects that leave the N-space sphere (as they are immediately lost, either from perspective or because they've been annihilated) this is merely a working theory. Some question if J-space even has any matter in it, or if something with alien rules governing reality could even be said to possess matter in the sense that we understand it.

However, what is slightly more understood is the actual motion of a jump through J-space. In what is known as the Shackleton Theorem of Jump Space, J-space is acknowledged paradoxically as both a separate dimension and as a sort of hypersphere. In essence - the entry point of the Jump-space "tunnel" as it is referred to is at the centre point of a fourth dimensional hypersphere shape, where all distances within the sphere equate to 1. That is, the distance from the centre to any part on the outside, or within, is exactly the same. In this sense, you could also say that the sphere's diameter is equal to the Jump Time Constant, or 168 hours - as that same amount of time is required whether you are jumping parsecs or making an in-system jump.

However, if J-space is a separate dimension of reality, there is a question as to why it functions in this way. Some suggest it is not J-space itself that acts like this, but the J-drive which creates a hypersphere construct within J-space, in which all distances from the center are equal. Some aspect of J-space prevents this distinguishment from being perceivable, and thus it is instead a mistaken assumption that J-space itself forms the hypersphere. It is believed that more understanding of the actual capabilities and properties of L-Compound will lead to a better understanding of the mechanics of J-space itself, but as yet there have been few breakthroughs.

Regardless, the only perceivable difference in travel between a Jump-6-capable drive and a Jump-1-capable drive are the observed distance travelled after they leave J-space. Whilst in transit, assuming there are no complications with the jump, both ships will experience identical conditions.

The only concrete detail known about J-space is that anyone who's looked out the windows during a Jump can agree that J-space is red.

Information about Misjumps

Misjumps are caused commonly by two different factors, though the end result is the same. The first is Jumping while within 100 diameters of a significant local gravity well, and the second is using improper or impure fuel for a Jump. The first is believed to be a result of interference from the gravity well in the formation of the J-space hole, and the second is a result of the properties of Zuchai crystals - namely that any fluctuation or irregularity in the initial cold-fusion reaction will be replicated when the crystals shunt the power into the L-Compound. This will create an unstable J-space hole, resulting in a wild fluctuation of conditions inside the Jump itself.

Either way, the result is a misjump. A misjump itself is defined as any irregularity resulting from a Jump, and covers a vast plethora of different options. However, the three most common are overjumping (or underjumping), ship damage and the Infinite J-space Phenomenon.

The first is simple enough - a misjump can result in a wildly off-course final destination. This could be anywhere from emerging in the exact spot you left a week later, to appearing multiple subsectors away. The furthest recorded misjump of this sort was a result of poor fuel being sold as premium quality near Capital. A Far Trader using the fuel misjumped, and ended up dropping back into N-space in orbit of Regina in the Spinward Marches. Note, overjumps can result in jumping into presently existing structures, effectively welding together with the extant matter. Sometimes this results in two ships fused together, followed shortly by a catastrophic meltdown of both J-drives, but there are also horror stories of misjumps landing ships in the cores of suns or the mantles of planets.

The second, damage to the ship, is also common. This could be anything from hull stripping to electronic damage to pieces of the ship being torn away to, ultimately, the ship falling apart completely within the N-space sphere while in transit, resulting in only scattered debris being deposited when the ship arrives. While it is theoretically possible to survive in a vacc-suit should this happen, the same tidal forces that tear the ship apart are also acting on the individuals within it - the gruesome typical case is that the crew is shredded with the ship.

Lastly, a ship's N-sphere might hold, but the Jump never completes, resulting in what is known as the Infinite J-space Phenomenon, or in tavern tales, "ghosts in the Jump." This is considered to be compelling evidence of the theory that the hypersphere of J-space travel is a construct of the J-drive, and not a feature of the dimension itself. Effectively, the ship becomes lost, sailing in J-space until it either escapes, miraculously, or runs out of power entirely and is lost permanently in J-space. (While it has never been properly observed, it is believed that for whatever reason, the N-space sphere is a semi-permanent barrier around the ship, and will continue for as long as the ship has power, even if it is not being fed to the lanthanum grid, for whatever reason. Others theorize it is some other factor within J-space that results in long-lasting, stable N-spheres even when lost in jump.) Only a handful of "lost" ships have ever escaped, and the most common tale is two lost ships encountering each other, and somehow rigging their J-drives to shunt them back into N-space.

The above three are not mutually exclusive, and frequently mix, much to the dismay of the crews caught in them. Beyond that, there are various and sundry special cases reported, usually in rumor or bar story, but sometimes reputably. The above three are simply the most common.

There is one other possible misjump symptom, but it is impossible to prove as it would be impossible to survive and report the event. This is the collapse or failure to form an N-space sphere as the ship enters the J-space hole, effectively leaving the ship at the mercy of J-space.

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