In appearance, it resembled a pit filled with flowing energy where shapes swirled within the blue-white form. This gave it an almost rolling mist-like appearance or resembled a surge of water currents. Whilst an optical illusion, the patterns formed almost gave it a hypnotic quality. The origin of the name came from the Asgard language where Mimir was "memeera" that translated to mean illusion or duplicate. Within the legends of the Norse people, the Well of Mimir was considered a repository of knowledge which Odin felt was an apt description as it was a means to prevent his people from facing extinction.
This device ultimately employed the use of Asgard holography technology to create a virtual existence for the species. By employing Holograms, Odin intended to allow his people to live virtually yet still interact with the physical reality. Thus, those part of the Well of Mimir, were holographic beings encoded within it. They were not copies but rather expressions of living beings whose awareness was transmitted to portable holographi generators called effectors. These holograms were solid-based allowing individuals to touch them, feel them, hit them or even smell them which provided a real experience to both the generated hologram as well as outsiders. This was part of Odin's intended goal of making holographic existence as real for his kind as possible and providing as close to a physical existence as possible by creating bodies made of energy instead of flesh.
Another benefit of this holographic existence as it allowed the downloaded beings to be seemingly be resurrected. This was achieved through a form of reset that was a crude comparison but accurate. The procedure involved repairing any damaged effector to allow it to function once more and project a hologram along with providing standard maintenance or adjustments. One of the problems with the holo-system was that each hologram generated an electrical field and the culmination of many of them created a combined energy that affected a starships systems where they brought significant damage to them.
The basis of the project came thousands of years ago when the Asgard first restorted to cloning to preserve their species. At the time, they came to realize that there was a limit to how long they could sustain themselves in such a manner as this was based on the limited amount of genetic diversity of their race. Thus, alternative methods were sought with one group experimenting with the creation of artificial lifeforms that would house their consciousness. However, a problem came in the download process as this group struggled to develop an artificial brain that was sophisticated to house the full essence of the Asgard mind. The second group that included Odin instead experimented in the development of a virtual existence for their kind. Odin claimed that he was in part inspired by the Ancient's Ascension though the actual process eluded the Asgard so he sought an alternative means. They learnt to transfer an Asgard's consciousness into a computer-simulated reality that was real in every detail. A problem emerged in this method as it extremely limited their interaction with actual reality once within their virtual realm. This led to the projects termination by the Asgard High Council after they debated on the matter and believed there was little purpose in extending their own existence without being able to act or live within the real world.
Despite the termination of the experiments, Odin decided to ultimately continue on this venture as he believed his kind would never overcome the physical limitations of the cloning process. Thus, he decided to find alternative technological means in preserving his people but at the same time allowing them to exist within the real world. He ultimately took his vessel Yggdrassil to the planet Valhalla where he conducted his experiments in using holograms as a method of living. After breaking away from the Asgard High Council, Odin travelled to Earth where he used his persona as a deity to gather the minds of four hundred fallen Humans from two Norse tribes. His reasons for choosing the tribes was because they reminded him of the Asgard in their earlier existence and offered them a choice to come by his side. Ultimately, the tribes of the Vanir and Jotun accepted whereupon their minds were downloaded into the Well of Mimir upon the death of the physical forms in order to take part in the experiment.
Once on Valhalla, the minds were projected into the landscape where they were allowed to constantly replay battles as part of Norse mythological beliefs. These seemingly Human-like holograms were projected from effectors such as Odin's ovoid drones Huginn and Munnin. There were two reasons for this with the first being that he wanted to recreate the Norse beliefs of Valhalla that was a paradise where they could test their strength and bravery each day. His second reason was because he used the battle conditions to test the speed and complexity of such events to determine the effectice capabilities of the technology's versatility. He also varied the battle conditions allowing the two tribes to progress technologically at different points in order to make events more interesting for the subjects involved. However, Odin began to experience difficulty with the technology as all the subjects accepted the programming except for one; a Jotun named Surtr. This Norsemen desired his freedom and began to exert an abnormal level of control over the Well of Mimir and Odin struggled with terminating the subject program.
To help combat this growing problem, he attempted to contact his fellow Asgard but received no reply. The discovery of the Well of Mimir came when SG-1 arrived on Valhalla where they ultimately met Odin who revealed his attempt at saving the Asgard race. By this point, further problems with the holographic system had manifested such as the damage the holograms did in close proximiation to one another leading to a combined energy that damaged starship systems. Thus, the Well of Mimir option would have left the Asgard as a completely planet bound race as interaction with one another would damage their own technology. Furthermore, the two Norse tribes had been kept as mental patterns for so long to the point that they began to degrade leading to the potential loss of their minds. Following the merger between Surtr and Odin, the Well of Mimir was empty of all mind patterns. (SG1: "Stargate SG-1: Valhalla")