2,410 parallel universes to the right of ours were the alternate realities parallel to the prime reality. In 2373, this parallel universe and thousands of others interesected with one another in the Birsiban system for brief intervals. (VOY novel: Echoes)
During the shifts, the planet Birsiba and its alternate counterparts were visible along an infinite line stretching from left to right from the perspective of a vessel in orbit. Every second universe contained its own version of the Federation Starfleet vessel USS Voyager. When their crews began to interact with one another they needed a way to differentiate between them in a meaningful way. The nomenclature was conceived in the primary universe by Captain Kathryn Janeway and Ensign Harry Kim. (VOY novel: Echoes)
- The designation of the universe is also given at the beginning of each chapter.
Thousands of years before the 24th century, Birsiba was destroyed by an unknown natural phenomenon. The event occurred in 150 parallel universes, ranging from 2,410 to 2,540 to the right ours.
A space-time rift caused a the newly employed transporter technology on Birsiba to shift its entire population from any universe to the next one on its "right". Because there was no planet to sustain them, all Birsibans arriving from the universe 2,409 to the right of ours died in the vacuum of space. Because the shift only transported living organisms, the corpses began to pile up in a spherical shape, outlining where the planet's surface would have been. After 87 shifts, there were more than 300 billion dead Birsibans.
The subspace pulse produced by 87th shift attracted the attention of this universe's starship USS Voyager, whose crew began a desperate effort to prevent more Birsibans from dying. With the help of Voyagers from thousands of parallel universes, the crew succeeded in sealing the space-time rift causing the shifts. Voyager twenty-four-ten, native to this reality, coordinated the interdimensional rescue effort. Eliminating the cause, the entire chain of events was prevented from occurring in the first place. As a result, the Birsibans were able to employ their transporter technology without being shifted, and Voyager was not attracted to investigate the Birsiban system. (VOY novel: Echoes)
Differences between neighboring universes were minute details and increased with greater distance. In the reality 2,410 universes away from the prime reality, the starship Voyager twenty-four-ten had the same design and crew but uniform colors were different. Command division featured orange trimming instead of red. Unlike the prime Janeway, native Janeway (2410) carried her hair in a corona at this time.
Due to this universe being the first in the row from left to right not containing a planet, Voyager 2410 was the only Voyager to receive an away team while not sending out one of its own due to the lack of a planet. The four officers arriving from a reality 2,408 parallel universes to our right were considered guests and the word "two" was attached to their names when addressing them to differentiate them from their native counterparts. (VOY novel: Echoes)