In these productions, the Stargate functions as a plot device, allowing the main characters to visit alien planets without the need for spaceships or any other type of technology.

In 2001: A Space Odyssey, Arthur C. Clarke uses the term "Star Gate" for the large monolith "sentinel" TMA-2, which is a classic stargate portal to another part of the universe.

[3] The basic stargate concept is that it has at least two devices in distant positions, and when active, the rings of each become similar to a physical, singular gateway or door-frame between the two locations.

[4] Much of the inspiration for the functioning of the device is drawn heavily from theoretical astrophysics, particularly that of black holes and wormholes, a staple of science fiction, often used to create "shortcuts" through space.

Although these may exist in reality, it is not widely held to be true that any such phenomenon could safely transport a human being,[5] as such wormholes would most likely be created by excessive gravity (e.g., from a black hole), which would destroy any potential traveler.

[9] As the Stargate film quickly skips to the "present day" (1994), unsuccessful archaeologist Daniel Jackson is giving a lecture about his outlandish theories that the pharaoh Khufu did not build the Great Pyramid of Giza.

After he is laughed away, an aged Catherine Langford meets with him and recruits his egyptological talent, taking him to a top-secret military base at Cheyenne Mountain, where he is instructed to decipher the unique Egyptian hieroglyphs present on a set of cover-stones.

The majority of these civilizations, descended from former Goa'uld slaves, treat the Stargate as a religious relic, often as a source of long-forgotten fear and evil.

Multiple teams are formed and sent on missions through the stargate, their primary objective being exploration, and through it the discovery of intelligence, technology and allies to help in the fight against the Goa'uld.

For a long time, it was thought that the Goa'uld were the builders of the Stargate network, but it was later discovered that they had merely made use of the relics left behind by a different and extinct race, the Ancients.

Destiny would then extract any relevant data from the planetary stargate in order to further complete research into an apparent signal embedded in the Cosmic microwave background radiation.

In addition, when a dialing sequence commences, the entire ring (as opposed to an inner track, like Milky Way-era gates) rotates clockwise and counterclockwise in an alternating pattern until the final chevron is locked and a wormhole is established.

Rather, explorers from Destiny are required to bring an Ancient remote control that can command the gate to dial an address in addition to other functions, presenting them with a list of accessible Stargates.

[10] Stargates have an inner ring akin to a rotary dial inscribed with a number of symbols, and nine prominent points ("chevrons") spaced equally around their circumference.

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.

The symbols dialed are often referred to as "coordinates", and are written as an ordered string; for example, this is the address used in the show for the planet Abydos: (corresponding to the constellations of Taurus, Serpens Caput, Capricornus, Monoceros, Sagittarius and Orion).

[11] As only a small portion of the possible combinations of Stargate symbols represent valid addresses, dialing the Gate at random is largely futile.

In "Children of the Gods", SG-1 discovers a room on Abydos with a list of valid Stargate addresses and (luckily) a map that allows the SGC to compensate for thousands of years of stellar drift.

[11] It was initially believed that the Goa'uld created the Stargates, but this was proven false in "The Torment of Tantalus" when the SGC discovered that Earth had accidentally dialled an address in 1945 that was not on the Abydos cartouche.

Following this revelation, a larger list of Stargate addresses is provided by Jack O'Neill in "The Fifth Race" from knowledge downloaded into his mind by a repository of the Ancients, allowing them to travel to worlds unknown to the Goa'uld.

Such connections, in comparison to seven symbol codes, require substantially more energy to complete a functional wormhole – much more than any standard dialing method can provide.

The Wraith also travel through Stargates in small spacecraft called darts and have some means of remote-dialing them in a manner similar to Ancient ships.

This has been the source of plot difficulties for the protagonists on several occasions, as it is still possible to travel to a Stargate that lacks a DHD, meaning that dialing home again will be much more difficult, if not impossible.

[22] Any matter that comes into contact with the vortex is annihilated on a molecular level, as is dramatically demonstrated by a pair of smoking shoes in the episode "Prisoners".

[25] Although in the first episode the Goa'uld who come through at the beginning appear to walk back through the event horizon after taking a hostage, in actuality they dialed out again using a hand-held device, as the whooshing sound is audible in the background.

[26] In the movie and early SG-1 episodes, travelers exit from the Stargate covered in frost and at high speed (often being knocked from their feet), feeling as though they have been on a "roller coaster ride".

This is achieved by the use of a specially designed 22-foot (6.7 m) circular gear, which turns the inner ring on a precise pinion drive wheel, using an eight horsepower electric motor.

The top seven chevrons emit laser pulses that are read by a sensor fed into a computer responsible for the gate's movement, which is consequently able to start and stop the rotation very quickly.

The Stargate itself is nearly always filmed against a blue or green backdrop, not only making it easier to paste the vortex imagery onto the scene, but also facilitating the superimposition of the "event horizon ripple effect", which is entirely computer-generated.

Series producer Robert C. Cooper explained that it often costs a lot to erect a Stargate on location, and so in some cases offworld gates are also entirely a visual effect.