From Stargate Wiki
An alternate timeline is a timeline which has been altered by the changing of an event in the past or future forming a kind of alternate reality where events may be drastically different. This is usually achieved by Time travel where the travelers will either deliberately or accidently change a minute thing resulting in different timelines. Alterante timelines can be restored to their original timeline be undoing or preventing the change of events or ensuring that another later event happens to change the future.
In an alternate 2010, the Goa'uld had been defeated and the Stargate Program was public knowledge. Earth was part of the Aschen Confederacy after forging an alliance with the Aschen. Earth has advanced technology such as public transporters, anti-aging vaccine and anti-cancer vaccine, however these were all simply ploys by the Aschen to slowly sterilize the population and take control of Earth.
This timeline was erased by SG-1 when they took control of the Stargate and sent a message back in time to themselves warning them not to go to P4C-970 and thus would not meet the Aschen, at least not until a year later. (SG1: "2010", "2001")
- The Stargate is located in the J.R. Reed Space Terminal and Cheyenne Mountain Complex was a museum.
- Jack O'Neill and Samantha Carter were no longer part of the United States Air Force.
- Samantha Carter is married to Joseph Faxon.
- Robert Kinsey was President of the United States of America.
- George Hammond died in 2004
- SG-1 are all dead.
In an alternate timeline, the Atlantis expedition arrived to find Atlantis in good condition but they were down to very little power and the shield was failing. The main tower begins to flood and many people drown to death. Several members find shelter in Puddle Jumpers. Major John Sheppard inadvertently activates a time machine in one of the Jumpers and sends himself, Dr. Weir and Dr. Zelenka back in time 10,000 years.
There they find themselves in the middle of the First Siege of Atlantis and are shot down. Dr. Weir survived but the other two are killed. Weir met with the Lantean council and asked to use their time machine to travel forward with a Zero Point Module and save the lives of the expedition members, however the council refuses. The creator of the time machine, Janus, comes up with a plan to extend the life of the ZPM's to save the expedition members however Dr. Weir must remain behind in stasis to facilitate the change. She is discovered by the expedition members, rapidly aged and near death. (ATL: "Before I Sleep")
- The ZPM's in Atlantis are almost completely drained before the expedition arrives.
- The expedition members all die, except for Dr. Weir.
- There is a time machine in one of the Puddle Jumpers in Atlantis.
SG-1: Moebius, Parts 1 and 2
In an alternate timeline inadvertently created by SG-1 by traveling back in time 5,000 years to Ancient Egypt to steal a Zero Point Module from Ra, the Stargate was taken by Ra when he left Earth and the Stargate Program never existed and the Goa'uld were never defeated.
The original SG-1 left behind a video camera in a sealed Canopic jar with instructions on how to find the Stargate and restore the timeline. A new team consisting of Dr. Daniel Jackson, Dr. Samantha Carter, Jack O'Neill, Charles Kawalsky and some marines traveled to Chulak in the Puddle Jumper. They were captured by Apophis' forces and Daniel was implanted with a Symbiote to leanr why they were there.
The team used the video camera to convince Teal'c to help them and he let them escape, killing Daniel and revealing he was a Goa'uld spy. The team used the Jumper to travel back in time and then back to Earth. There they learned that the original O'Neill, Carter and Teal'c were killed trying to kick start the rebellion and Daniel and the rest of the Egyptians were planing another rebellion. The new team helped Daniel take the Stargate and hide it so Ra would not take it when he left. (SG1: "Moebius, Part 1", "Moebius, Part 2")
- Daniel Jackson taught English as a second language.
- Samantha Carter was not a member of the United States Air Force.
- Jack O'Neill was no longer in the Air Force, living on a fishing boat.
- Teal'c was still First Prime of Apophis.
- George Hammond was still in charge of Cheyenne Mountain.
- Charles Kawalsky was still alive.
- Rodney McKay works for the Air Force and is not allergic to citrus.
- Robert Kinsey is President and Henry Hayes is Secretary of the Interior.
- The Stargate was taken by Ra when he left Earth.
Following the gift from the Asgard of all their technology and knowledge, SG-1 on board the Odyssey fleeing from pursuing Ori Motherships. The crew was transported off the ship and SG-1 and General Landry remained behind. The shields were depleted and the only way to save the ship and themselves was to encase the ship in a time dilation field.
The crew spent 50 years aboard the ship before Carter managed to figure out a way to reverse time within the field, however their was no enough power. A plan was developed to let the Ori weapons fire directed at the ship, impact it and funnel it into the generator, but someone had to remain old to change the timeline, Teal'c volunteered. The beam struck the ship, Teal'c was encased in a shield and time reversed itself. This let Teal'c implement Carter's plan to save the ship and themselves. (SG1: "Unending")
Returning to Atlantis Sheppard traveled 48,000 years into the future. From a holographic program of McKay he learned that Michael Kenmore took Teyla's baby and used it to perfect his bybrids, defeated the Wraith and killed millions of Humans. McKay had Sheppard enter into a stasis chamber to keep him alive until an appropriate Solar flare occurred capable of sending Sheppard back in time so he could prevent these events from happening. (ATL: "The Last Man")
- Michael takes over the Pegasus galaxy.
- The Wraith have been defeated.
- Teyla's baby was taken by Michael and she was killed.
- Ronon Dex and Todd die destroying one of Michael's facilities.
- The next 304 in production is called the Phoenix and is destroyed attacking Michael's hive ships.
- Samantha Carter dies on board the Phoenix.
- Richard Woolsey takes command of Atlantis.
- McKay and Jennifer Keller quit the expedition and return to Earth.
- Keller dies from exposure to the Hoffan drug.
- McKay spends 25 years planing to undo the events that happened in Pegasus.
- Evan Lorne is promoted to General and takes command of the SGC.
The System Lord Ba'al traveled back in time to 1939 and stopped the Stargate from reaching America and the Stargate Program from ever existing. Luckily, SG-1, except for Teal'c, were traveling through the Stargate and were unaffected by the changes.
A year after returning to an alternate Earth and settling into new lives, SG-1 must come together when Ba'al's fleet arrives in orbit. SG-1 travel to Russia to use their Stargate to obtain a ship and get to Proclarush Taonas, retrieve the Zero Point Module and defend Earth. Qetesh, Ba'al's queen kills him and takes control obliterating the Antarctic outpost and the Ancient Control chair so SG-1, who meet up with Teal'c, travel to Ba'al's time machine and Mitchell manages to travel back in time and stop Ba'al's plan. (Stargate: Continuum)
- Samantha Carter was an astronaut and died in an accident.
- Daniel Jackson was a reclusive archaeologist.
- General Landry was retired.
- Cameron Mitchell never existed after his grandfather was killed by one of Ba'al's Jaffa.
- Teal'c was First Prime of Ba'al.
- Vala Mal Doran was still host to Qetesh and Ba'al's queen.
- The Goa'uld were never defeated but were under the control of Ba'al
In an alternate timeline a team travels to a Jungle planet and are attacked by nocturnal creatures, several of them are killed and the survivors find out they are infected with a deadly microorganism and they find out the Stargate is incapable of creating a stable Wormhole thus trapping them on the planet. They send through a Kino to see if it is safe but they get no response. When the creatures attack again the following night, Rush makes a run for the gate and flees through it.
In a following timeline created by sending the Kino's through time to be found by the team, they find the virus they are infected with and the footage revealing that the creatures venom is the only cure. A team is assembled to go to the planet to capture some of these creatures to use their venom, however the team is yet again killed by the creatures except for Matthew Scott. Several people on board Destiny begin to die from the virus. Scott records a message on the Kino and send it through the gate hoping to prevent the events from happening again. (SGU: "Time")
- Due to the closeness of these timelines very little, or none, is different between them until the teams go to the planet where they all die and those left on board are all killed by the Hoth virus.
When attempting to dial Earth from the Destiny, the crew are sent back in time 2,000 years and to another planet, before finding a new planet they named Novus, Dr. Dale Volker succumbed to renal failure and died, Matthew Scott and Chloe Armstrong married as do several other couples and started having children. Tamara Johansen died from ALS. (SGU: "Twin Destinies", "Common Descent", "Epilogue")
- Destiny is destroyed.
- Nicholas Rush journeys forward in time several hours and makes contact with the ship before they dial.