The stargate is a portal, part of a vast network for interplanetary travel, built at least three million years ago by the Ancients. The first stargate on Earth was placed in Antarctica, but it was lost when the continent was covered by the glacier. A second Earth stargate in Egypt was buried about 5000 years ago during an uprising of the ancient Egyptians. It was uncovered in 1928 during an archaeological expedition at Giza headed by Dr. Langford. In January of 1945 a team of American scientists, including Dr. Langford, Heinrich Gruber, and Ernest Littlefield, conducted experiments on the gate for the US government, exploring its possible application as a weapon. The gate was activated manually, and Ernest Littlefield stepped through the gate and was lost. The program ended abruptly, and after the war, all research was shut down and all documentation classified by the Pentagon. By 1969, the gate was locked away in an armory in Washington DC, and the military did not acknowledge its existence. Dr. Langford's daughter Catherine resumed her father's research in the late 1960's, and she petitioned several administrations to restart the stargate program. The stargate was moved to Cheyenne Mountain, and the research under General West eventually led to the first stargate mission to Abydos under Colonel O'Neill and Daniel Jackson. More than a year later, in 1997, the stargate had once again been shut down for lack of funding. However, with the arrival of Apophis through the Earth stargate, the President initiated the SGC under the command of the US Air Force and General Hammond.
Stargates have 39 symbols and use a dialing device, or DHD, to input an address of six symbols plus a point of origin. Typically the DHD buffer holds the last 50 addresses that were dialed. The known stargate network includes thousands of planets, but it is possible to reach certain distant worlds, such as Othala, beyond the known network, by using an address of eight symbols and an additional energy generator. Because stellar drift would cause stargate coordinates to change over thousands of years, the gate network is designed to undergo periodic correlative updates in which the gates dial each other to transmit new coordinates that automatically compensate for stellar drift. Although the stargate was designed to use the DHD as a power source and control mechanism which would allow for safety protocols and stellar drift, it is possible to activate the gate using a power source other than a DHD, as well as to connect to a remote gate that does not have an active DHD. The SGC uses an elaborate dialing computer to control the gate and to initiate additional security protocols. In emergency off-world situations power sources as varied as lightning, cold fusion, or a naquadah generator can power the gate for manual dialing.
Stargates are giant superconductors that absorb energy directly in many forms, including electrical, heat, nuclear, solar, and static, converting and storing that energy in capacitor-like reservoirs, and allowing the inner wheel to spin. As the gate spins, the chevrons lock the address symbols into place in a clockwise sequence, allowing the gate to connect to a remote gate. An artificial wormhole forms between the two open gates and transfers an energized matter stream along lines of force between them, positive to negative, along an extra-dimensional conduit within a subspace field. The wormhole travels in only one direction, however certain kinds of energy including radiation, wave energy, gravity, and audio or video radio transmissions, can be sent back through an outgoing wormhole. The energy required to create a stable wormhole is exponentially proportional to the diameter of the stargate, therefore a much larger gate, such as a supergate, would require energy resources that far exceed that of an ordinary gate.
The kawoosh, or initial unstable vortex of gate activation, stabilizes to form a water-like effect that is the event horizon of the quantum particles that form the wormhole. The event horizon dematerializes an object that passes through it, converting it to energy, and the receiving stargate uses massive amounts of memory, like a computer buffer, to temporarily store the energy signature on a subatomic level within the structure of the gate's memory crystals before reintegrating the matter back into its pre-organized form. The memory buffer is then reset with each new gate activation. Although it feels instantaneous, the journey between gates takes on average 0.3 seconds travel time. An unstable vortex will vaporize objects in its path, but an object can be placed within the threshold of the more stable event horizon of an incoming or outgoing wormhole, and withdrawn again with no effect. However, objects that remain in transit within the wormhole or partially within the event horizon when the wormhole is disengaged would be destroyed.
A stargate cannot engage when it is buried, although it can engage when under water and when a closed iris is placed at least 3 microns from the event horizon, allowing a wormhole to form. A wormhole cannot connect to a stargate that is already active, and similarly, an incoming wormhole prevents a gate from dialing out. Stargate coordinates are not unique to the gate itself, but rather to its location, and because a stargate address indicates a particular point in space, a stargate cannot connect to another gate that uses the same address since the result would be an effect similar to a busy signal. Although a stargate is designed to dial a single gate at a time, it is possible to use the correlative update program to modify the dialing protocol and allow a single gate to dial multiple gates in the network simultaneously.
The stargate has the ability to use density, molecular structure, and the force being exerted on the event horizon to determine whether something is trying to pass through it, and as long as any kind of matter or wave energy is passing through the event horizon, the wormhole can remain active for a maximum of 38 minutes under normal circumstances. Wormholes draw their energy from the originating or outgoing gate, however extreme power fluctuations at the receiving or incoming gate can override normal gate operation and become a secondary power source that will keep a wormhole active beyond its normal limits. A wormhole powered by a black hole at one end can remain active almost indefinitely. A power surge within an outgoing gate can cause an overload that will force the wormhole to jump, or arc, to another gate.
When connected to a DHD, the stargate uses up to 400 safety protocols during a dialing sequence, however many of these protocols have been overridden by the SGC computer that is used in place of the DHD. Wormhole physics dictates that you exit the wormhole at the same velocity at which you enter, however, without a DHD, the Earth stargate required frequency dampeners and adjustments made to the gate and the dialing computers to correct early problems with vibration, rough transit, and the freezing temperatures resulting from the compression that molecules undergo during the millisecond required for reconstitution. Although the stargate was not designed for time travel, the gravitational effect of solar flares and space/time warping can result in wormhole travel both forward and backward in time, however there is currently no means of adapting or controlling this technology with any reliability. Similarly, the gate system isn't designed to transport matter between universes or alternate realities, however it is possible with enough energy to blast a bridge between two alternate realities, allowing an active wormhole to cross over.
Made of naquadah and weighing 64,000 pounds, stargates are nearly indestructible, and have been known to withstand close proximity to a star, the gravitational forces of a black hole, the energy of a nuclear explosion, and a direct strike from a meteor, although a Mark IX naquadria-enhanced nuclear warhead is capable of destroying a gate. Despite the extraordinary complexity of stargate technology, it is possible to build a simple stargate that will dial only once, using materials available online, including 100 pounds of pure raw titanium, 200 feet of fiber-optic cable, seven 100,000-watt industrial-strength capacitors - and a toaster.
See Also: Stargate Glyphs and Addresses
Cross Reference: Abydos Cartouche, Ancients, Anubis's Ancient Weapon, Automatic Correlative Update, Avenger, Beta Stargate, Chaapa'ai, Cheyenne Mountain Complex, Crystals, DHD, Egypt, Iris, Kawoosh, Catherine Langford, Dr. Langford, Ernest Littlefield, Manual Dial, Mark IX, Naquadah, Othala, Ring Transporter, Russian Stargate, SGC, Supergate, Time Travel 1969, Time Travel 2010, Time Travel 3000 BC, Wormhole Arc
First Introduced: Children of the Gods
Significant Episode Reference: The Torment of Tantalus, Solitudes, Touchstone, The Fifth Race, A Matter of Time, Serpent's Song, 1969, Watergate, Ascension, Red Sky, 48 Hours, Redemption, Avenger 2.0, Reckoning, Moebius, Beachhead, Ripple Effect, The Pegasus Project, The Quest, The Shroud