Time Dilation Device (Stargate)
In the fictional Stargate universe, a Time Dilation Device is a device that alters the rate of time's passage within an area of effect compared to the rate of time passage outside that area - Either speeding it up or slowing it down.
Variants
Time Dilation technology has only been shown to be demonstated by two species namely the Ancients and the Asgard.
Asgard version
The first such device seen was created by the Asgard to generate a time dilation bubble of radius 0.16 light years. The device was first used by the Asgard to trap the Replicators in a time bubble where time was slowed down by a factor of 104 relative to the outside of the time bubble. This bought the Asgard time to figure out what they could do about the Replicator threat. The Replicators, however, were able to modify the device to speed up time inside the bubble instead. This allowed them to evolve at a faster rate. The Replicators also learned how to create time dilation effects themselves, using it to escape from a black hole. Two years later in the episode Ripple Effect, the time dilation device is used to close an interdimensional gap in a black hole.
The Asgard computer core that was deployed on the Odyssey in the series finale episode Unending possessed a time dilation generator. It was first tested to escape an Ori attack but unfortunately, the Odyssey had no way to escape the field or the blast. After fifty years Carter figured out how to use the device to reverse time to the moment before the device was activated.
Ancient version
The first sighting of time dilation technology in the hands of the Ancients was in the Pegasus galaxy where the Lanteans had constructed a refuge on a planet known as the Cloister which had only one entrance. The entire 'valley' region was engulfed by the time dilation field that accelerated time within its position in order to allow the inhabitants to gain philosophical enlightenment to reach the ultimate goal of ascension. This same field was a potent defensive mechanism as it prevented objects from entering the bubble from orbit as any such object would be destroyed due to the stresses generated by the field.
A second form of the technology was later seen in the Milky way galaxy and was used by Morgan le Fay as one of her tests of a persons prudence in searching for the Sangraal. This model had a set field around the location of the mountain which nearly froze objects that entered its field and was the reason why many human villagers were lost on the quest as they had become trapped within the field. However, as part of the test, a set path was present within the field that allowed movement without being compromised by time dilation. (The Quest)