As I understand it, to create a wormhole - to pinch time and space together in a nexus point - you need huge amounts of gravity. OK, so far so good, but surely if you get too close, time will get screwed up and you'd get crushed to smithereens...
Well according to StargateSG1/Stargate Atlantis you also need S$%^loads of energy
What is a stargate?
The stargate operated by the U.S. Air Force's Stargate Command (SGC) at Cheyenne Mountain Operations Center near Colorado Springs, Colo., is one of a vast number of wormhole-generating "doors" that allow for near-instantaneous intergalactic travel.
Created millions of years ago by the Ancients, one of the earliest living beings in the universe, they are scattered throughout planets, with each stargate bearing a unique address, similar to a telephone number.
Each is a monumental, roughly circular structure atop a base. The operating portion is composed of giant, moveable inner and outer dials, within which a wormhole entrance appears. Some stargates have an iris that opens and closes over the wormhole entrance. This iris, when closed, rests less than 10 micrometers from the "event horizon" (the two-dimensional energy field forming the passageway to the generated wormhole). This leaves essentially no physical space through which an unwanted object or visitor can materialize.
How does a stargate work? What's it made of?
Stargates are made of the element Naquadah (sometimes transliterated from the original language as Naquada), a quartzite metal not found on Earth. A teleportational wormhole is generated when charged neutrinos are applied to Naquadah, the only known element that absorbs and energizes with neutrinos. This forms a stable, artificial wormhole that connects to another stargate. The derivative Naquadria is a powerful yet unstable fuel source; prolonged exposure to its radiation can cause mental disorders.
How does one travel between stargates?
The monumental inner dial of each stargate has 39 symbols, called glyphs (such as those at left), which correspond to different constellations. The outer dial has nine chevrons. When a combination of the inner dial's glyphs makes contact with seven of these chevrons, a wormhole is activated, connecting the dialing stargate with the one whose code it has been set to just as dialing a seven-digit telephone number makes contact with another telephone. (The last symbol in a stargate sequence is always the point of origin.) When a "puddle" of energy forms from the neutrino-Naquadah interaction, a person or device can pass through the puddle to emerge from the other stargate often on a different planet, but sometimes in deep space or in orbit of a planet.
In the episode "The Fifth Race", an eighth chevron was activated (thanks to the Asgard) and Carter noted, "The extra chevron must add a new distance calculation to the existing points, like a different area code." The purpose or function of the ninth chevron is still unknown.
