In order to plausibly enable instant travel between star systems that are separated by hundreds or thousands of light-years, some writers have posited the existence of stargates. A stargate is usually an isolated piece of very advanced technology theorized to have been left behind by a star-traveling race of aliens, whose power to move between the stars developed over long periods of time. Step through the stargate and you arrive at a destination very, very far away, sometimes with no easy way to return whence you came.
Operation
The naquadah of which the gate is composed is capable of storing massive amounts of energy from any available source in order to power a wormhole connection to another gate. Typically, power is provided by a DHD or Dial Home Device that enables dialing of the stargate. The origin gate powers and maintains the wormhole connection and determines how long the gate remains open. The maximum period a a wormhole connection can be maintained is thirty-eight minutes. Gates have maintained longer connections but only when supplied with a vast amount of power as in the case of a black hole.
The outer ring of the gate has nine evenly spaced chevrons, each capable of locking on to one of a group of seven of a total thirty-nine constellation symbols decorating the inner ring. As each chevron locks, it lights up. The inner ring is capable of spinning when manually dialed and moves to the specific symbol chosen. In the presence of a DHD, the inner ring does not spin. If a DHD is damaged or absent, the inner ring can be moved manually to the appropriate symbols but the gate then requires an alternate power source if it has not previously stored enough power to engage a wormhole.
A stargate address usually consists of seven symbols; six glyphs representing a point in space and a seventh representing the point of origin. Each symbol can be spoken in Ancient, as in the address Proclarush Taonas. When dialing another galaxy, an eighth symbol is required as a distance calculator. The symbols on the inner ring of the gate are also present on the DHD. When using a DHD, only six of the seven symbols are dialed before pressing the activation button to establish a connection. Once the chevron locks on to the last symbol and a connection is established, a flush of water-like energy (referred to as a kawoosh) rushes out from the center of the gate as the event horizon of the worm hole is formed. Anything caught in this initial flush is destroyed completely. As such, a DHD is typically placed several feet from the stargate. Once the flush settles, the event horizon of the wormhole appears in the center of the ring like a shimmering pool of water.
The gate does not permit two-way travel through a wormhole by solid objects. Once on the other side, the gate must be shutdown and the address dialed to return to the previous location. Radio waves and other forms of energy can travel freely through the gate allowing communication between planets.
Only one stargate can be active on a single planet or star system. Should a planet have more than one stargate, the stargate with the DHD becomes dominant.
Dial Home Device
- also see main article: Dial Home Device
The DHD is a waist high pedestal with a round control panel on top. In the center is a large red activation button ringed by two rows of keys each engraved with a symbol also present on the stargate; there are 38 in total. There is one missing glyph, hidden beneath the pedestal, which one is determined by the position of the Stargate on different planets.
An address is dialed by pressing the keys in the correct order followed by the red (blue in the Pegasus Galaxy) activation button in the center. The DHDs also perform correlative updates, periodically dialing another stargate to ensure all gates have the most updated information on the network.
The Stargate on Earth at the SGC does not have a companion DHD. Dr. Samantha Carter and other scientists studied the gate for several years, trying to interpret its various signals. They managed to create a dialing computer that is capable of dialing the stargate, make the necessary stellar shift calculations and interpret gate feedback.
Sending Matter
When the event horizon is crossed, the person or object going through the gate is converted into its most basic elements and sent to the receiving gate. The information is stored in the hyperspatial buffer of the receiving gate which then reconstitutes matter to its original form. The gate has several safety protocols in place. It requires an object crossing the event horizon to enter completely before it is reconstituted on the opposite side. As such, matter that has not completely crossed the event horizon can be pulled out.
If the gate is shutdown before matter in transit can be reconstituted, the DHD can aid in the reconstitution of the person or object stored in the gate's buffer. If the gate is dialed before this process is complete, the information in the buffer is destroyed.
The gate also prevents air and water from crossing into the event horizon indicating the stargate is able to sense its environment and differentiate between the types of objects entering it. Objects and people crossing the event horizon emerge with the same energy and speed they did when they entered.
Securing the Gate
The only way to prevent an unwanted wormhole from forming is to obstruct the center of the gate. If the event horizon is obstructed, a wormhole will not connect. This method was used on Earth when the Tau'ri rebelled against Ra five thousand years ago. They buried the stargate in Giza and covered it in large stone, successfully preventing the goa'uld from coming through the gate to Earth.
When the gate was uncovered in the 1920s and put to use once more in the 1990s, the Tau'ri protected themselves from goa'uld invasion by installing an Iris over the Stargate. The iris, made of titanium was installed less than 3 micrometers from the event horizon, allowing a connection but preventing matter from reintegrating. The iris is not destroyed by the kawoosh effect during the formation of a wormhole. The SGC's first titanium iris was replaced by a titanium trinium alloy iris after the first was destroyed by the gravity effects of a black hole.
Durability
Like most Ancient technology the stargate is incredibly durable and resists damage and destruction. It is extremely rare for a gate to be destroyed. Gates have been known to survive direct hits from a meteor, extreme heat from close proximity to a star and even the destruction of a planet. The SGC developed a "Gatebuster" naquadah enhanced nuclear bomb designed to destroy gates. It is still unknown if this weapon is successful as the first test occurred under unusual circumstances in the episode "Beachhead" where a Prior protected the stargate.
The power source of the DHDs last for millions of years. The oldest known gate in the galaxy, the Antarctic gate on Earth, was believed to be over fifty million years old. The power source of the Antarctic DHD was depleted shortly after its discovery.
Unusual Situations
The stargate typically operates dependably without problems. Many of the problems that have occurred have been a result of Earth's missing DHD and the substitution of the dialing computer, intentional or accidental interference with its operations, or overriding one of the safety protocols the gate has in place. During its initial operation, travel through the gate was rough and the travelers were expelled from the gate covered in frost. When Dr. Samantha Carter learned to compensate for the planetary shift that had occurred over the thousands of years since the gate was last in operation, travel through the gate became easier, safer, and much more comfortable.
In the episode "Red Sky" Carter overrode the gate's safety protocol and made a connection to the planet K'Tau. The wormhole passed through the system's sun and transferred a super heavy element into the star resulting in what would have been the inevitable destruction of the planet. Carter tried to counteract the element by delivering Malcarium another heavy element into the sun but the plan appeared to have failed. The sun shifted back to its normal state however and the team believes the Asgard may have helped their plan along.
In "1969" Carter's planetary shift calculations failed to fully compensate for a solar flare and the team was transported back in time to the year 1969 on Earth. Calculating the timing of another solar flare allowed them to return to their own time.
In "48 Hours" SG-1 escaped a planet while under attack by the goa'uld. Teal'c was the last to enter the gate just as an Al'kesh crashed into it, prematurely severing the wormhole connection and trapping Teal'c in the gate's buffer. Without a DHD Teal'c could not be reconstituted. The SGC negotiated with the Russians for the use of their DHD and Teal'c was successfully reintegrated, the DHD, however, was destroyed in the process.
In "Redemption, Part 1" Anubis attacked Earth stargate with an Ancient weapon. Small amounts of radiation came through the gate and built up the gates' power reserves. The gate remained open past its 38 minute limit. Once the gates power capacitors reached their limit it would explode obliterating all life on Earth. The planet was saved when the gate was removed from the SGC and transported beyond Earth where it exploded.
Earth's Stargate History
- 5,000 years ago, Earth's stargate was buried after the Tau'ri rebelled against the goa'uld Ra.
- In 1928 the gate was discovered in Giza, Egypt and moved to the United States.
- In 1945, Dr. Earnest Littlefield became the first person to travel through the gate in 5,000 years. He became trapped alone on the planet he nicknamed Heliopolis and wasn't discovered for over 50 years.
- In the 1990s the secret of the Stargate was uncovered and the first trip to Abydos was made by Colonel O'Neill and his team in the movie Stargate. Ra was killed in the movie and the Stargate Program was shut down.
- A year after the events of the movie, Apophis and his Jaffa came through the gate and attacked the SGC. A team returned to Abydos where Daniel Jackson discovered the Abydos cartouche a list of all the gate addresses known to the goa'uld. The program was reopened and exploration of the planets listed on the cartouche began
- In the episode "Solitudes" a second stargate was discovered on Earth in Antarctica.
- In the "The Fifth Race" O'Neill downloaded the Ancient Repository of Knowledge and added hundreds of new gate addresses to the SGC database.
- In 1969 SG-1 was transported back in time when the wormhole was affected by a solar flare.
- In Nemesis The Stargate was transported to The Beliskner to help SG-1 escape the ship's destruction as it burned up in the atmosphere and fell into the Pacific Ocean. The gate survived the ship's destruction and was recovered by the Russians and they started their own program. The SGC replaced their lost gate with the Antarctic gate.
- In Redemption, Part 2 Anubis attacked the stargate and it was destroyed. The SGC leased the Russian's stargate to replace their own.
- In the episode "Endgame" the stargate was stolen by The Trust to use in their plot to launch a chemical weapon Symbiote poison against the goa'uld. The stargate was recovered by the Prometheus
Pegasus Galaxy Gates
When an eight symbol address was discovered at the Atlantus Outpost, an expedition team was formed to visit the Ancient's lost city of Atlantis. Atlantis is located in the Pegasus Galaxy where the Ancients built another gate network. The gates had a slightly different design but function in the same way.
Pegasus gates have no inner ring, and the Chevrons have blue lights instead of red. The gates have thirty-six symbols instead of 39, indicating a slightly smaller gate network than that of the Milky Way. The DHDs also have cosmetic differences with blue activation button instead of red.
The Atlantis gate is the only gate capable of dialing outside the galaxy. The DHD has a special control crystal that enables the connection. The Atlantis gate is also capable of identifying the point of origin of an incoming wormhole and can block a wormhole from connecting.
Like Earth's stargate, Atlantis' gate also has an iris. The iris is an energy shield that covers the gate and prevents matter from integrating.
The Pegasus Galaxy has several gates placed in orbit around a planet and can only be accessed by ship. The Ancients designed small transport vessels known as Puddle Jumpers specifically for gate travel. The Puddle Jumpers have built-in DHDs that allow them to dial orbital gates. The Wraith, a hostile alien species from Pegasus, have also designed ships for gate travel, Wraith darts. Like the PJs they also have built in DHDs.
Dialing Earth's stargate from Atlantis cannot be achieved without the power supplied by a Zero Point Module. Atlantis gained a ZPM and can contact Earth but Earth is unable to connect to Atlantis in return, as a result a trip to Atlantis from Earth takes almost three weeks aboard one of Earth's Daedalus-class vessels. To overcome this difficulty, a plan has been made to harvest Stargates from uninhabited planets and use them in sequence in the void between the Pegasus Galaxy and the Milky Way, enabling quicker travel between the galaxies and relive Atlantis of its power consumption problems.
Supergates
- also see main article Supergate
Season nine of Stargate SG-1 introduced a powerful new enemy known as The Ori. The Ori come from a distant galaxy and have plans to invade the Milky Way and convert its inhabitants to their worship. The Ori share their origin and history with the Ancients and possess vast knowledge of the universe and have mastered wormhole technology. Despite the distance and power requirements, the Ori were able to send Priors to the Milky Way as heralds of their coming and to convert the local peoples.
In order to overcome the vast distance between this galaxy and their own, the Ori attempted to create a massive Stargate in the Milky Way large enough to send their ships through in the episode "Beachhead." They sent the necessary pieces for the supergate through a regular stargate. The pieces encircled the planet and then planet was collapsed into a singularity to power the wormhole connection. Vala Mal Doran succesfully prevented the connection from forming by replacing the last piece of the gate with a Tel'tak.
The Ori eventually created a new supergate and sent their ships through. Carter soon realized the supergate was designed to make a connection from another galaxy. SG-1 visited the Pegasus Galaxy aboard the Odyssey and made a connection to a gate in the Milky Way close to the Ori supergate using the power supplied by a black hole in Pegasus. They attempted to detonate a nuclear warhead close to the gate forcing the wormhole to jump to the supergate. Ultimately, it was the destruction of a Wraith vessel close to the event horizon that caused the wormhole to jump to the supergate as they wished. With the energy supplied by the black hole, the gate can maintain a permanent connection to the Ori supergate preventing them from dialing in and sending more ships to the Milky Way.
