In the season 5 episode 20 "Enemy At The Gate", Colonel Samantha Carter mentions she'll be taking over control of the Daedalus-class ship, The Phoenix, which has been renamed The General Hammond. This is in honour of 'Don S. Davis'' character who, similar to 'Davis' himself, is mentioned to have died of a heart attack.
Joe Flanigan (John Sheppard) and David Hewlett (Rodney McKay) are the only actors to appear in all 100 episodes. Rachel Luttrell (Teyla Emmagan) is the only other regular cast member to stay with the series throughout its entire run.
In season1, it is stated that approximately 60 Wraith hive ships exist in the Pegasus Galaxy. Over the course of the series, and including a crossover episode with Stargate SG-1, whether shown on screen or stated by a character, only about 26 hive ships had been destroyed by series' end.
The shooting set of the Stargate Atlantis base, specifically the balconies where the humans from Earth celebrated their first victory as well as several times depicting the outdoor dining area is the exact same location as the Colson Industries' main office building from the Stargate SG-1: Covenant (2004) episode.
Jason Momoa would later go on to succeed Arnold Schwarzenegger as Conan the Cimmerian in the 2011 reboot of the 1982 film "Conan the Barbarian". Jewel Staite's "Firefly" and "Serenity" co-star Summer Glau played Cameron Phillips in the TV series "Terminator: The Sarah Connor Chronicles", based on the films starring Arnold Schwarzenegger. Lena Headey, who played Sarah Connor in that series, would star opposite Jason Momoa in "Game of Thrones" and Emilia Clarke, who stars in "Game of Throne" would go on to play Sarah Connor in the 2015 reboot "Terminator: Genysis".
The machine is a system to open a wormhole. Wormhole is a hypothetical way of space travel too called Bridge of Rosen-Einstein, named after scientists Nathan Rosen and Albert Einstein. According to them, the wormhole should capable to unite two distant points in the universe, altering Space-Time Laws to cross from a point to another in a so brief period of time. The name wormhole was given after a comparative between the universe and an apple, with a worm moving inside. The same concept was used in Contact (1997) as well as Stargate (1994) and their TV series Stargate SG-1 (1997) and SGU Stargate Universe (2009).
The trivia items below may give away important plot points.
A stargate is a ring composed of a fictional superconductive mineral called "naqahdah", marked with 39 glyphs that operates using a combination of 7 glyphs or chrevrons to establish a space route to travel from a point to another. Using mathematical combinatorics, it implies that a single stargate can locate 77,519,922,480 places throughout the galaxy, increased to 45,379,620 if in the combination one of some glyphs can be re-used. Using a 8 glyphs combination for an extragalactic travel, a stargate can locate 2,480,637,519,360 places throughout the universe, increased to 5,352,009,260,481 if one or more glyphs can be re-used.
At a point of the movie, Jackson (James Spader) explains to the staff of U.S. Army that for any space travel, is necessary seven symbols to mark coordinates. Six of them indicate the destination, signing stars or constellations to locate the place where to go. The seven and last symbol indicates the point of origin to start the travel. In the TV series is added an extra glyph, which indicates the galaxy where to go.
Stargate's ring have 39 glyphs or chrevrons. In this TV series as in Stargate SG-1 (1997) and SGU Stargate Universe (2009) is explained that the number of glyphs in a stargate depends of the galaxy where this stargate belongs.