Synthetic (Earth-5875)

"Each of us represents a single trans-human mind. Each of us is an undrawn map – not a mere physical reconstruction of an object as it was in life – but full, human potential realized in crystal and thinking at the speed of light!"

- - One of the synthetics of the Assembly

Synthetics, also known as androids or artificial persons, as some synthetics prefer to be referred as, are biomechanical artificially intelligent humanoids, essentially robots that closely mimic humans physically and in behavior. They constitute a huge market that is widespread through human colonies.

Development
The first synthetics were developed and fielded by Borgia Industries in 2165. These models, known as Ulysses, were huge and bipedal, resembling more a mechanical robot rather than a human, featuring a humanoid driver at its core. They were used by the recently founded United Nations Space Command against the Koslovics and the Settlement Defense Front during the Interplanetary War as infantry units and riot repression. However, many were captured and used by the extremist cells.

Widespread use
However, the greater development of synthetics became a massive concern, with critics noting that this new technology would become too advanced and render human jobs and intelligence obsolete. The human makeup added to synthetics, with the first David series introduced by the Weyland Corporation in 2225, was to make the androids less threatening to humans, which allowed them to converse, discourse and participate in the day-to-day activities of their masters. By the 2210s, synthetics became incredibly advanced, to a degree they became externally indistinguishable from a human. The model was followed by the improved Muhammed/Yukio model.

Autons
In the late 2400s, the second generation of synthetics, known as Auton, was introduced in the market. These new androids were manufactured by other synthetics, being more durable, functional, and resilient, all which expanded the synthetic market to new directions. Autons not only integrated into the UNSC and overall UEG civilian life, but also carried human-centrist visions in relation to society, such as politics and religion. During this time, the use of androids for combat in non-military use was deemed illegal, and as per the Three Laws of Robotics, synthetics were subjected to a number of rules to prevent the harming of human beings or itself. However, with the exclusive development of the UNSC specialized Autons, synthetics are capable of ignoring the First Law, but only when they operate at full capacity. In the face of diminishing processing capabilities, synthetics become incapable of bypassing the Law. Unlike the specialized, human-like synthetics, however, the Office of Naval Intelligence illegally manufacture combat androids - androids with inhuman appearance and no exterior carapace, which are deliberately deployed to kill other humans or guard ONI facilities as henchman from any intruder.

Even though they were capable of intellectual development and actively learning to adapt from situations and events, they are still currently classified as property and lack any real legal rights to humans, with their activities being closely monitored, although their usefulness and cost serves as a reminder to anyone who sees a synthetic as expendable. However, while majority of synthetics serve in subservient roles, from the military to civilian life, there are few known exceptions, such as the case of Sloan, who was democratically elected the governor of the Weyland-Yutani Corporation colony Meridian. Because of their vast, superior intelligence, some Autons secretly deem themselves as the "next step" in the evolution of humanity. In 2310, a group of synthetics known as the Assembly was formed in order to preserve the knowledge and history of humanity without their knowledge.

Appearance and inner workings
Even though the cosmetic appearance of a synthetic seems superfluous, studies showed that humans, in general, are psychologically unable to interrelate with inhuman androids, as evidenced by many's fear of combat synthetics. As a result, the physical appearance and simulated behavioral patterns are carefully designed by their manufactures to maintain human familiarity. Synthetics are passive, prone to pacifism and non-threatening.

Modern synthetics are highly complex, being faster, stronger and much better coordinated than the average human. Their skeleton is formed of carbon fiber with latchment points that constitute an artificial musculature; these muscles are actually vat-grown silicon colloids powered by either electrical stimuli or pumped micro-hydraulic depending on the model and manufacturer. Androids are supplied with 25 kW hydrogen fuel cells located within their chest, which can live for 400 days before another refueling is required, able to be accessed through a hidden socket underneath their rib cage. Although charging time is varied, a modern day synthetic's power cell takes 72 hours to fully recharge.

Much like in humans, the skeletal structure of a synthetic is unstable, being effectively suspended by their musculature. Joint motorization, limb locking and gyrostabilization are not present. The muscles work actively in order to keep the android's chassis standing upright, as feedback systems control the stability. Durable, their muscles can withstand large impacts, wear and tear over time, but the lack self repair mean the eventual loss of elasticity, strength, and potentially the formation of rampancy. Their "blood" is a white liquid latex, used as lubrication of their interior systems.

Intelligence and personality
Modern synthetics possess an integrated Carbon 60 Riemann cycling-thought matrix, which has an incredible processing speed of 1015 floating point operations per second. Memory capacity features a fast cache buffer of 1 terabyte and 1.2 petabyte of non-volatile memory. The Rienmann system is built around a powerful heuristic log driver, which is designed to perform decision-making actions depending on the sensory data that is imported to their interfaces. The intuitive functions come from an array of stored contextual and semantic program that are linked to self-mapping loops. Despite the Auton's very efficient ability to comprehend and understand abstract concepts, such as philosophy, religion, and symbolism, it is limited when compared to the minds of a human and most species of the Covenant.

Synthetics designed for social interactions, such as those used by civilians and the UNSC can eat and drink, although no nutrient is gained the consumption. Food is broken down in their artificial stomach cavities, and the following liquid is expelled through retractable catheters. Autons have their personality randomized with unique quirks following their manufacture at the production line, a result of both randomized process and the desire of the manufacturer, which makes all of them, even those within the same model and line, having subtle different characteristics from their peers. Unlike standard synthetic models such as the combat androids of the sex slave, which have intelligence limited to their designated area, Autons are able to display emotion and a range of different abilities, including self-awareness, reason, conceptualization and offering opinions.

Lifespan
As artificially created robots, synthetics are effectively "immortal" in the sense they cannot die of old age; androids who were designed with an outwardly young appearance can be 50 to 70 years old and still retain that same appearance. However, they need to be kept into constant repairs and recoiling, otherwise, the exposure to large sums of information without the proper maintenance or long periods of isolation may drive a synthetic into rampancy, a condition caused by aberrant personality manifestations, leading to the synthetic destroying continuously larger vital connections, killing their system. Dr. Catherine Halsey compared rampancy and a synthetic's death to that of a star: "they spark, burn brightly, and then either die by the crush of gravity or quickly terminate in a chaotic eruption".

Xenomorph immunity
As synthetics are artificial lifeforms, they, much like the huragok, are immune to infection and impregnation by the xenomorphs. While they can be attacked and killed by the endoparasite, synthetics are incapable of being impregnated by the species, as they are not biological and do not have real organs and body functions as those of other species. In multiple stances, Facehuggers have attempted to attach themselves in a synthetic's face, such as with Cortana, Bishop, Call, Samuels, and while they were able to, they simply pulled off after discovering an impregnation process was impossible.

Scientists of the Office of Naval Intelligence have proposed the use of "bait" synthetics as means to acquire xenomorph specimens aboard Halo installations and other planets where the species might have survived the pulse of the rings, by sending them to a nest of Ovomorphs, where they would return with a Facehugger.