Stargate

A Stargate and it's dug-in DHD

The **Stargates**, also called the **Astria Porta** in Ancient and the **Chappa'ai** in Goa'uld, are a series of devices built by the Ancients that create artificial subspace wormholes, allowing for near-instantaneous transportation between two distant points in space. The Stargates are often considered to be the Ancients' greatest creation, and so the Ancients are often called the Gate Builders.

## Overview

The Stargate is an enormous superconductor composed almost entirely of Naquadah, and is capable of harnessing power from virtually any source, though some sources are apparently inferior to others. Its design renders it incredibly durable; direct meteor impacts have failed to destroy a gate, and they have also survived within a crashing vessel unharmed. The naquadah construction of a Stargate allows it to hold many times the necessary amount of power for a wormhole to form, but it does have a limit. Surpassing this limit will create an explosion of considerable size, enough to potentially kill all life on a planet the size of Earth.

Travel through a Stargate is strictly one-way: from the dialing gate to the receiving gate. This is not a limitation of the wormhole, but of the technology; wormholes will transmit anything that enters them, but no solid matter could survive the process. Thus, each gate in the pair takes on a specific role: the dialing gate converts the traveler into its most basic components (sub-atomic particles) and transmits it, while the receiving gate reassembles the transmitted matter back into its original form. Doing the reverse is not only fatal for the traveler, but would just result in the dialing gate deconstructing the object upon arrival, converting it into energy much like the process of ascension. It is unknown what would happen if someone entered the Stargate via the 'back' rather than the 'front'; Teal'c once stated that he knew someone who attempted that on one occasion and that his death was "most unpleasant", but further details are unknown.

The Stargates within a galaxy are linked to each other in a network, usually by means of a Dial Home Device (DHD for short). This network compensates for stellar drift, allowing every gate with a functioning DHD to properly connect to other gates. In the absence of this, the gate will either fail to connect entirely or roughly eject the passengers due to unexpected deviations in the position of the gate. Known networks include those in the Milky Way, Pegasus, Ida, the Alteran Home Galaxy (through which Priors were sent to the Milky Way), as well as the more primitive gate networks set up by the Ancient Seed ships.

## Networks

### Prototype Gates

The Stargate on the *Destiny*, and by extension those constructed by Seed ships, are suspected to be a prototype version on which all future gates are based. Stargate glyphs do not represent local constellations as the later models do, since they are used in many different galaxies.

The entire Stargate spins when dialing, and locks its glyphs by moving them to the topmost position. The gate rotates clockwise for the first glyph, then changes direction for the next, alternating until the point of origin is locked, much like manually dialing the second-generation stargates.  Planetary gates also have a somewhat more elaborate base than the other models, possessing a large ramp rather than stairs and lights on either side that activate whenever the gate is active, marking the path to the event horizon. Planetary gates and the one in *Destiny* have a chevron in front of the gate that lights up when the gate is active.

Most likely because *Destiny*-style Stargates do not have an external power source, they have a limited range. Unlike Milky Way or Pegasus gates, *Destiny*-style Stargates cannot dial every gate in the galaxy, but instead can only dial gates in relatively close proximity.

The network formed by prototype Stargates functions differently than the full-fledged networks in the Milky Way and Pegasus galaxies. The Stargates are seeded in a relatively straight line, from one end of a galaxy to the other, leaving a course for *Destiny* to follow.

These Stargates communicate with each other constantly and update their positions, and then link up with *Destiny* once it comes into range. Because of the limited dialing range of the prototype Stargates, *Destiny* usually drops out of FTL near the area it wishes to dial, connecting to a few *Stargates* at a time. Though normally out of range, other gates in the chain can be reached by leapfrogging through the gates in-between.

The prototype network has no local Dial Home Device; instead, it links up with *Destiny* and other compatible devices, transmitting the relevant addresses within range for use by the crew. For planetary dialing, *Destiny* has numerous Ancient remote controls, multipurpose devices which serve as hand-held DHDs among other things.

The prototype gates are shown to be far less durable than their successors, having a chunk blown off by a relatively low-powered energy blast from a Berzerker Drone, which may be due to not being made of Naquadah.

### Second Generation - Milky Way/Ida

The second generation stargates are 6.7 meters in diameter and weigh roughly 29 tons. They are dark gray in appearance with red-orange colored chevrons. The triangular lower half of the Stargate's top chevron extends and retracts while locking a symbol. The glyphs are built into an inner ring. Most of the gates are built into a stone platform with a stairway for easy access. Those that aren't have often been moved from where they were first found.

### Third Generation - Pegasus

   Pegasus stargates are the latest model of Stargate and are quite different from their Milky Way counterparts. They are primarily silver in appearance, with a blue inner ring and blue chevrons (larger than those of a Milky Way stargate). They possess no moving parts; instead, each glyph lights up in a circular pattern, staying lit when locked. Unlike Milky Way Stargates, Pegasus Stargates are not built into a platform, and instead are just buried in the ground at about the same level.

Because they have no moving parts, Pegasus Stargates cannot be manually dialed. Pegasus Stargates also have a security feature which renders them incapable of dialing intergalactic addresses without the use of a specific control crystal installed on Atlantis. This crystal can be removed and installed on other Dial Home Devices if necessary. Due to their newer design, Pegasus Stargates also automatically become the dominant gate if placed in the same region as an older model.

Pegasus also has the unique use of **Spacegates**, Stargates which have been placed in orbit above a planet, rather than on the surface. Spacegates have no local DHD, and thus must be dialed remotely by a craft equipped with one (such as Puddle Jumpers and Wraith Darts). They are powered by three power nodes that also serve as stabilizers, keeping the gate in orbit and correcting for sudden impacts.