Editing Known Space (section)

==Technology==
The series features a number of "superscience" inventions which figure as plot devices. Stories earlier in the timeline feature technology such as Bussard ramjets and [[Wirehead (science fiction)|drouds]] (wires capable of directly stimulating the [[limbic system|pleasure center]]s of the brain), and explore how [[organ transplant]]ation technology enables the new crime of ''[[organlegging]]'' (as well as the general sociological effects of widespread transplant technology), while later stories feature hyperdrive, [[General Products (Larry Niven)|invulnerable starship hulls]], [[stasis field]]s, molecular [[Monofilament (science fiction)|monofilament]]s, [[transfer booth]]s ([[Teleportation|teleporter]]s used only on planetary surfaces), the lifespan-extending drug boosterspice, and the [[tasp (Known Space)|tasp]] which is an extension of the droud which works without direct contact.

===Boosterspice===
"Boosterspice" is a compound that increases the [[longevity]] and reverses aging of human beings. With the use of boosterspice, humans can easily live hundreds of years and, theoretically, indefinitely.

Developed by the Institute of Knowledge on Jinx, it is said to be made from [[genetic engineering|genetically engineered]] [[ragweed]] (although early stories have it ingested in the form of edible seeds). In ''[[Ringworld's Children]]'', it is suggested boosterspice may actually be adapted from [[Tree-of-Life]], without the [[symbiosis|symbiotic]] virus that enabled [[Hominidae|hominid]]s to metamorphose from Pak Breeder stage to [[Pak Protector]] stage (mutated Pak breeders were the ancestors of both ''[[Homo sapiens]]'' and the hominids of the Ringworld).

On the [[Ringworld]], there is an analogous (and apparently more potent) compound developed from Tree-of-Life, but they are mutually incompatible; in ''[[The Ringworld Engineers]]'', [[Louis Wu]] learns that the character Halrloprillalar died when in [[Amalgamated Regional Militia|ARM]] custody after leaving the Ringworld, as a result of having taken boosterspice after having used the Ringworld equivalent. Boosterspice only works on ''Homo sapiens'', whereas the Tree-of-Life compound will work on any hominid descended from the Pak.

===Hyperdrive===
[[Faster-than-light]] (FTL) propulsion, or hyperdrive, was obtained from the [[Outsider (Known Space)|Outsiders]] at the end of the First Man–Kzin War. In addition to winning the war for humanity, it allowed the re-integration of all the human colonies, which were previously separated by distance. Standard (Quantum I) hyperdrive covers a distance of one light-year every three days (121.75&nbsp;''c''). A more advanced Quantum II hyperdrive introduced later is able to cover the same distance in one and a quarter minutes (420,768&nbsp;''c'').

In Niven's first novel, ''[[World of Ptavvs]]'', the hyperdrive used by the Thrintun required a ship to be going faster than 93% of the speed of light. However, this is the only time that hyperdrive is described this way.

In the vast majority of ''Known Space'' material, hyperdrive requires that a ship be outside a star's gravity well to use. Ships which activate hyperdrive close to a star are likely to disappear without a trace. This effect is regarded as a limitation based on the laws of physics. In Niven's novel ''[[Ringworld's Children]]'' the Ringworld itself is converted into a gigantic Quantum II hyperdrive and launched into hyperspace while within its star's gravity well. ''[[Ringworld's Children]]'' reveals that there is life in hyperspace around gravity wells and that hyperspace predators eat spaceships which appear in hyperspace close to large masses, thus explaining why a structure as large as the Ringworld can safely engage the hyperdrive in a star's gravity well.

One phenomenon travelers in hyperspace can experience is the so-called 'blind spot' should they look through a porthole or camera screen, giving the impression that the walls around the porthole or sides of the camera view screen are expanding to 'cover up the outside'. The phenomenon is the result of hyperspace being so fundamentally different from normal/'Einsteinian' space that a traveler's senses cannot truly comprehend it, and instead the observer 'sees' a form of nothingness that can be hypnotic and dangerous. Staring too long into the 'blind spot' can be insanity-inducing, so as a precaution all view ports on ships are blinded when a ship enters hyperspace.

===Invulnerable hulls===
The [[Pierson's Puppeteer|Puppeteer]] firm, [[General Products]], produces a series of invulnerable starship hulls, known simply as the [[General Products#General Products hull|General Products hull]]. The hulls are impervious to any type of matter or energy, with the exception of [[antimatter]] (which destroys the hull, as demonstrated in "Flatlander"), [[gravitation]] (demonstrated in "Neutron Star"), and visible light (which passes through the hull). While invulnerable themselves, this is no guarantee that the contents are likewise protected. For example, though a high speed impact with the surface of a planet or star may cause no harm to the hull, the occupants will be crushed if they are not protected by additional measures such as a stasis field (''Ringworld'') or a gravity compensating field.

In ''[[Fleet of Worlds]]'', the characters tour a [[Pierson's Puppeteer#General Products|General Products]] factory and receive clues that allow them to destroy a General Products hull from the inside using only a high-powered interstellar communications laser. In ''[[Juggler of Worlds]]'', the Puppeteers, attempting to surmise how this was done without antimatter, identify another technique which can be used to destroy the otherwise invulnerable hulls, one which does suggest some potential defense options.

The strength of the hulls was revealed to be based on the fact that they were essentially one giant molecule.

===Organ transplantation===
On Earth in the mid-21st century, it became possible to transplant any organ from any person to another, with the exception of [[Brain transplant|brain]] and central nervous system tissue. Individuals were categorized according to their so-called "[[Transplant rejection|rejection]] spectrum" which allowed doctors to counter any immune system responses to the new organs, allowing transplants to "take" for life. It also enabled the crime of "[[organlegging]]" which lasted well into the 24th century.

===Stasis fields===
A Slaver [[Stasis (fiction)|stasis field]] creates a bubble of spacetime disconnected from the entropy gradient of the rest of the universe. Time slows effectively to a stop for an object in stasis, at a ratio of some billions of years outside to a second inside. An object in stasis is invulnerable to anything occurring outside the field, as well as being preserved indefinitely. A stasis field may be recognized by its perfectly reflecting surface, so perfect that it reflects 100% of all radiation and particles, including [[neutrinos]]. However one stasis field cannot exist inside another.  This is used in ''[[World of Ptavvs]]'' where humans develop a stasis field technology and realize that a mirrored artifact known as the ''Sea Statue'' must be actually an alien in a stasis field.  They place it with a human envoy, who is a telepath, and envelop both in field. By doing this, they unleash the last living member of the Slaver species on the world.

===Stepping disks===
Stepping disks are a teleportation technology. They were invented by the [[Pierson's Puppeteers]], and their existence is not generally known to other races until the events of ''[[The Ringworld Engineers]]''.

The stepping disks are an outgrowth and improvement of the [[transfer booth]] technology used by humans and other Known Space races. Unlike the booths, the disks do not require an enclosed chamber, and somehow can differentiate between solid masses and air, for example. They also have a far greater range than transfer booths, extending several [[astronomical unit]]s.

Several limitations to stepping disks are mentioned in the ''[[Ringworld]]'' novels. If there is a difference in [[velocity]] between two disks, any matter transferred between them must be accelerated by the disk accordingly. If there is not enough energy to do so, the transfer cannot take place. This becomes a problem with disks that are a significant distance apart on the [[Ringworld]]'s surface, as they will have different velocities: same speed, different direction.

===Transfer booths===
Transfer booths or displacement booths are an inexpensive form of teleportation. Short-range booths are similar in appearance to an old style [[telephone booth]]: one enters, "dials" one's desired destination, and is immediately deposited in a corresponding booth at the destination. Longer-range booths operate similarly, but are housed in former airports due to requiring "equipment to compensate for the difference in rotational velocity between different points on the Earth".<ref>{{cite book|title=A Hole in Space|date=1974|publisher=Ballantine Books|location=New York|isbn=0-345-24011-1|page=29}}</ref> They are inexpensive: a trip anywhere on Earth costs only a "tenth-star" (presumably equivalent to a dime). Introduced by one of Gregory Pelton's ancestors, apparently bought from, and based on, Puppeteer technology.

"A displacement booth was a glass cylinder with a rounded top. The machinery that made the magic work was invisible, buried beneath the booth. Coin slots and a telephone dial were set into the glass at sternum level" (from ''[[Flash Crowd]]'').

===Paranormal abilities===
Some individuals in the stories display limited paranormal or "psionic" abilities. [[Gil Hamilton]] can move objects with his mind using his phantom arm, which he gained after losing an arm in an asteroid mining accident. When he finally had the arm replaced from an organ bank on Earth, the ability persisted. "Plateau Eyes" (introduced in ''A Gift From Earth'') is an ability on the part of some to hide in plain sight, by causing others not to notice them. Population control is tight on Earth, but these abilities can gain the possessor a license to have more children. The Pierson's Puppeteers engineer a lottery for child licenses on Earth to increase the occurrence of "luck", which they think is a paranormal ability humans have that has enabled them to defeat races such as the Kzinti. In ''Ringworld'', the character Teela Brown is said to have this ability (although possibly not to the same extent as others who avoided being included in the expedition).