The device allows for near-instantaneous travel across intra- and even intergalactic distances. Once a destination is selected by the traveler, the Stargate generates a wormhole between itself and a complementary device at the destination, by being supplied with a threshold amount of raw energy. ]Objects in transit between gates are broken down into their individual elemental components, and then into energy as they pass through the event horizon, and then travel through a wormhole before being reconstructed on the other side.
Stargates are usually large rings composed of a superconductive material such as naqahdah or unobtanium. Typically Each Stargate has nine points (chevrons) spaced equally around its circumference which are used to determine the address being dialed. On the inner ring is a set of unique glyphs with one of these representing the planet of origin. The number of glyphs is dependent on the network in which the gate belongs typically numbering between 39 and 36 glyphs. Six of these symbols plus the point of origin serve to map out a specific location in space to which one can dial.
Additional glyphs may also be selected which increase the distance of travel, allowing gates outside the current galaxy to be reached, a process that requires significantly more energy than interstellar dialing, a process often called ‘far dialing’. Eight-symbol addresses allow Stargates to dial different galaxies. The additional symbol acts as a type of “area code”. Nine-symbol addresses act as codes to dial specific Stargates, reguardless of distance. Pairs of Stargates function by generating an artificial stable wormhole between them, allowing one-way travel through. A typical Stargate measures 4.6 m (15 ft) in diameter and weighs 29 metric tonnes (64,000 lb).
Some gate designs forgo the basic design and utilize an ‘internal’ or ‘virtual’ dialing mechanism. While still reliant on a glyph dial system and the same design principles, their control and function differs from the ‘typcial’ gate. Iconian Gateways are large angular structures.
Dial Home Device
There are a handful of methods used to dial a Stargate, and the most common is with the use of a Dial-Home Device. Almost always referred to as the “DHD” for short, DHDs come in many configurations. The most common being pedestal-shaped device with a round inclined control panel on top, consisting of two concentric circles of “keys” and a translucent hemisphere in the center; the keys represent the symbols on the rim of the Stargate. By pressing these keys a traveler builds an address. The central hemisphere serves as an “Enter” key to activate the Stargate once a destination has been dialed.
DHDs can also take the form of a dialing computer, with various keyboard layouts and controls linked to the additional functions of the gates. Every Stargate originally had its own DHD, located directly in front of the gate and facing it. Over time, however, some DHDs have been damaged or lost. This can make return trips difficult for unprepared travelers.
Travelers with advanced gate technology have developed handheld and mobile DHDs for use by explorers and small vessels accessing Stargates remotely.
Once an address is dialed, the gate is said to have created a “stable wormhole” between itself and the gate dialed. The creation process is depicted with great consistency, and hence has become one of the defining motifs of Stargate, at times being central in both the SG-1 and Atlantis title sequences. It involves the generation of the “puddle of water” portal which lasts roughly 2 seconds, and is completed by the ejection of an unstable energy vortex resembling a surge of water or quicksilver, this is sometimes referred to as the “Kawoosh” after the noise the vortex makes.
The actual portal of a Stargate appears inside the inner ring when an address is correctly dialed. This has the appearance of a vertical puddle of water which represents the event horizon. in the show. The wavering undulations characteristic of water represent the “fluctuations in the event horizon”. This puddle may then be entered (usually accompanied by a watery squishing sound), and the traveler will emerge from a similar pool at the destination stargate.
transit though the Stargate is strictly one-way; an attempt to travel “backwards” causes the traveler to be destroyed. As matter is only transmitted through a stargate once the whole object has passed the event horizon, a person or object could be retrieved from the event horizon before entering completely, as the stargate would automatically reintegrate the traveller. Under normal circumstances, a wormhole can only be maintained for slightly more than 38 minutes. Extending the wormhole duration beyond that requires tremendous amounts of power, such as that provided by a nearby black hole
Known Statement about wormhole physics
- Energy to maintain an established wormhole can come from either side, though the energy to form a wormhole can only come from the dialing stargate.
- Substantial gravitational force can pass through a wormhole from either side. (i.e., the effects of a Black Hole).
- Outgoing wormholes can be affected by exterior gravitational and electromagnetic forces, causing them to connect to stargates other than their intended targets.
- When traveling from one gate to another, exterior forces such as solar flares can cause the wormhole to connect to a Stargate in another time period. In this case, the wormhole will then sometimes, under some unknown circumstances, connect to the source stargate or to another gate.
- Matter can only travel one way but weak energy such as radio communication can travel both ways through a Stargate. This can be explained by the hypothesis that the diameter of the wormhole is very small, possibly microscopic in size. Energy would have no problem passing through on its own but matter would need to be converted into energy and then re-integrated at the other side
- Artificial wormholes created by Stargates can only stay open for up to 38 minutes without an extremely powerful energy source powering the dialing gate. Such as “an infinite number of ZPMs or a black hole. After 38 minutes relativistic effects come into play. No matter can be transmitted through a wormhole after 38 minutes as it is presumed unsafe
Complexities of Function
Stargates only transmit entire objects at a time. Matter from an object that is only partially through the event horizon is stored in a “hyperspatial buffer”. Until an object is completely through, it can still be pulled back out of the event horizon. Matter inside a buffer is effectively held in stasis. The buffer is normally wiped clean after the wormhole disconnects, at which time any matter still stored inside ceases to exist. The exception to this is if the wormhole is terminated artificially with an object already en route, in which case it remains stored in the buffer of the receiving Gate until the next wormhole connection. In such a circumstance, the object can be rematerialized by establishing an event horizon without opening a wormhole, done by removing the control crystal of the DHD.
Momentum is conserved through a wormhole, so an object will exit a Stargate at the same speed at which it entered. However, in early episodes (and the film) objects are seen to exit at a faster speed than entry. This is possibly explained by the ‘freezing effect’ also witnessed – heat energy is converted to kinetic energy, both cooling the object and increasing its velocity. These effects were countered during an upgrade of Stargate Command’s dialing computer.
A Stargate is able to discern whether something is “trying” to pass through as opposed to pressure from its ambient environment. Thus, active Stargates in an atmosphere or underwater do not allow gas or water molecules through.
A wormhole is prevented from forming if a significant obstruction is present inside the Stargate’s ring. Consequently, a simple way to seal a Stargate is to bury it. Another way of controlling travel through a Stargate is by placing a barrier just above the event horizon, which will prevent incoming matter from being reintegrated (essentially annihilating it). Many gates have either a physical Iris or a Gate to function in this way. These barriers also prevent the formation of the unstable vortex, although radio communication is still possible.
Power is always required to establish an outgoing wormhole, and is usually supplied by the DHD, but any Stargate can receive a wormhole whether it has a power supply or not; the dialing gate is the one that supplies power to both. In a few cases, Stargates have been dialed “manually” when more sophisticated means were not available. This was accomplished by providing sufficient raw power to the gate and then rotating the symbol ring by hand to encode each chevron.
Power can be fed directly into the superconductor that composes the gate; power harnessed from lightning strikes has been shown to be sufficient, as has the energy from the core of a naquadah bomb. however the minimum requirement for a stable wormhole appears to be a 12 or 24 volt current. The Stargate that establishes an outgoing wormhole determines how long the wormhole is held open, and can generally close the wormhole at will. Under some conditions, a gate only needs enough power to connect briefly, then the receiving gate can provide enough power to maintain the connection. This is often the case with local gates dialing 8 or 9 chevrons, as the rieving long distance gate provides the power for the stable wormhole. The same is true if the outgoing gate loses power while transmitting; if the incoming gate has a DHD, it will take over powering the gate until reintegration is complete.
Some planets are known to possess “secondary” or “backup” Stargates. The second Stargate is normally inactive, with the primary Stargate (defined by the presence of a functioning Dial-Home Device) receiving all incoming wormholes. Seconday gates can be dialed directly if their 9th chevron is known and dialed appropriately.
Stargates are very durable; the oldest in the Milky Way is probably the Antarctic Gate, 50 million years old yet still perfectly functioning; the power source may have been younger.
The Stargates themselves are extremely resistant to damage or destruction: in one documented case, a Stargate survived a direct hit from a meteor, while another was still capable of creating a stable wormhole while on a planet near a newly formed black hole. A Stargate has also been seen to continue functioning while entering a star, though it was protected by a portable forcefield for a portion of its journey. Stargates have survived destruction of planets and massive weapons fire, of the heaviest capital class weaponry.
Stargates and Slipspace
While the physics behind the Stargates operation is widely accepted, some races believe there is a deeper connection between Stargate’s Wormholes and the Quantum threads seen in slip space. Slip Faring races such as the Hengeyokai believe that the Wormholes created or accessed by the stargates are not necessarily temporary, and that the act of connecting worlds with the gates forms a permanent connection one can see in SlipSpace, in the form of Quantum threads or ‘strings’. This theory holds that the connections exist over the millennia, and the gates themselves are opening these pathways or portals into them. Travel via the gates occurs in then ‘thru” the threads, as opposed to when vessels ‘ride’ between and against them.
As travel by Gate increased in the 5th Age bottlenecks developed at the limited number of far dialing gates which served to link the far flung local networks. Several Gate building races collaborated to develop a solution to this issue, and developed Gate Routers. Due to the energy requirements, and complex structure, Gate Routers were never widely deployed. Common only to worlds with large superconducting cores, and bathed in the background radiation from a nearby Slipspace Nexus, Gate Routers allowed a single gate to work as a Network Router for the StarGate Network.
Dialing a Gate Router required 9th Chevron Dialing, once dialed, the receiving gate took over powering the Wormhole and then allowed the original dialer to enter a standard 7 chevron address which the Router would then dial though to. Gate Routers could handle multiple incoming and outgoing requests at a single time, allowing an dramatic increase in Intergalactic traffic.
Only a handful of Gate Routers are known to exist, and their construction has been lost to the ages.
Stargates have been built by many races though out the universe, with some of the more prolific builders being the Anquietas , Iconians, Tollan, Ori and Hengeyokai.
Most of the existing gate networks are millions of years old, relics from the early days of the fifth age. Stargates are known by many names throughout the ‘verse the Anquietas and Hengeyokai refer to them as the “Astria Porta”, Iconian’s are Iconian Gateways, Goa’uld and Jaffer reffer to them as the “Chappa’ai”. Portals are also a common name throughout the ‘verse though thousands of local names exist.
Some advanced cultures possess the means to construct new gates, but no known race has shown the ability or recourses to construct gates on a large scale on in the numbers previous Gate Builds were capable of.