The "Time loop machine" was a device of Ancient design built on P4X-639 which continually loops time every ten hours.
Overview[]
The control pedestal of the machine.
The device is powered by static energy in the ionized atmosphere, attributed to the increased solar activity from the resident Star. It is controlled by an advanced panel of cubed "buttons" which emit a complex combination, raising and lowering at various levels, allowing the process to proceed and the static energy to mount.
The 14 planets with P4X-639 in the middle.
Enormous beams of energy would be fired at the Stargate as a means to access the gate's subspace field that is generated when dialed. This causes a time inversion outside of subspace, in effect causing a time loop. The device causes the time inversion by establishing a short outgoing wormhole to 13 gates simultaneous then disconnecting, creating a subspace link and forming a subspace bubble. Everything within the bubble is cut off from the normal flow of time, as well as cutting off these gates from the outer gate network and the rest of the galaxy.
History[]
The Ancient colony was faced with an intergalactic plague which swept the galaxy. Some of the Ancients were determined to beat the plague by attempting to travel in time, so they constructed the loop machine. However, time was looping every ten hours, rather than years. They attempted to increase the loop, but no matter what they did, they couldn't figure out a solution and they all died (apart from those who escaped to the Pegasus Galaxy).
Several millennia later, a scientist named Malakai discovered the device and attempted to finish what the Ancients started in order to succeed, because his wife died and he wanted to return to see her again. However, the time loop not only affected P4X-639, but thirteen other planets relatively close, including Alaris and Earth as well. Through coersion, Malakai shut down the device and left it behind. (SG1: "Window of Opportunity")
After hearing about a lab found by the Tau'ri of an alternate timeline belonging to the Ancient Janus, Daniel tells O'Neill that Janus created the time loop machine. Jade O'Neill states that the machine was one of Janus' experiments into time travel along with the Time Jumper and time travel pods. (SG1: "Relativity")