Ancient time-loop device
A machine of Ancient design on P4X-639 which continually loops time every ten hours. A colony of Ancients, faced with an intergalactic plague which swept the galaxy, were determined to beat the malicious wave. In so doing, they constructed a time machine, and to their horror, discovered it only looped time in ten-hour cycles. Inscriptions on the walls of the alter told that that they tried on multiple occasions to make the device work how it was intended to, by traveling back to a set period of time, but they never succeeded. They eventually gave up and let the plague destroy them.
The device is powered by static energy in the ionized atmosphere, attributed to the increased solar activity from the resident sun. 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.
Enormous beams of energy are fired at the Stargate, which links to fourteen worlds in a relative proximity in the gate network (including Elarus), looping time on each of those worlds. Shortly after, a beam is shot at the altar, and anyone standing in the way is able to retain his or her memories in each passing loop.
The time-loop process can be ended by pushing two specific buttons on the alter controls and a small, circular button on the port side of the device, allowing the static energy to be expelled from the generators, leaving the device dormant.
Theoretically, if one were to avoid an event he or she could return to P4X-639 and loop time back ten hours in hopes of preventing the said event.
KEY EPISODE
Window of Opportunity - SG-1 meets with Malikai, an alien scientist, on P4X-639 in the hopes of observing the sun's coronal mass emissions and uncovering more information regarding a mysterious piece of alien technology. O'Neill, Teal'c and Malikai are caught up in the beam.