What Doesn't Exist

Traditionally speaking there are certain staples in Sci-Fi that people expect when traversing the medium and genre. Below is a list of things that do not exist within the confines of our lore, plain and simply:

Aliens:
Though not strictly technological, Alien life as you'd expect it to be does not exist on our server. Though there are some forms of flora and fauna that exist native to their respective planet, there are no other known humanoids other than humans. This is because evolution would work quite differently on different planets, and if there were alien life out there, they would look nothing like us, act nothing like us, and quite likely be impossible to communicate with.

Personal Shields:
Personal shields, aside from being highly unlikely in creation, allow a lot of room for power gaming and unfair scenarios. Shielding technology at this time is simply not powerful enough to deflect anything coming at high speeds at a specific point (I.E. a bullet or blaster shot)

Force Fields:
Though no force field technology around ships or buildings exists, to reflect or absorb any sort of laser damage or otherwise; ships do come equipped with deflector shields that are capable of pushing away any sort of space debris during FTL travel. These deflector shields however do not protect from any kind of precise laser hit and can only partially protect the ship from things like asteroids, or being rammed by another ship.

Cloaking Devices:
Again one of those objects that allows for unfair situations and powergaming potential. Additionally, cloaking devices are unrealistic by their very nature. In most Sci-Fi cloaking devices are described as being able to bend or distort light around a ship to render it into a state of invisibility. If such a state were even possible to create, it would also mean those inside of those lightless bubbles would be unable to see as well. All inward or outward signals would be blocked. What cannot be sensed, cannot sense as well. It just does not feel wholly realistic.

Teleportation:
Again it falls down to powergaming and missing the point of the server. We do not want players to be able to go anywhere at anytime, which would include secure areas and other ships. Travelling via space ship would be rendered irrelevant and archaic if teleportation were widely available. Quantum physics states the teleportation of subatomic particles is possible, but the human body is far more complicated than a subatomic particle. We have tens of billions of atoms in our bodies, and there just isn't the technology available yet to store all that data, and realistically put it back together once the energy has been transferred to a new location. The process would simply not be precise enough.

"Brain in a jar" Robotics:
Cyborg Prothetics are simply limited in this regard. The technology to simply be a brain in a robotic body is not allowed. At this point it becomes powergaming in the sense that humans are no longer limited by physical weaknesses such as the requirement to breathe, the impact of environmental factors, pressure sensitivity, the affects of heat and extreme cold and so on and so forth. Furthermore, the technology in this universe simply isn't supported. The brain is a very sensitive organ, and it would be extremely difficult to connect to a mechanical body. Anti-rejection drugs would not be a viable choice to help in this process, and the mechanical aspect simply wouldn't be possble. "Ghost limb" could no longer be used as a basis for nerve connection and a computer in the brain is simply not allowed. Even if such a state could be achieved, one would need constant maintenance to ensure the brain tissue does not reject the mechanical hull. There have been no past successes in history of this type of robotics succeeding.