The Enterprise-D uses a subspace differential pulse to scan the fissure
A quantum fissure, also referred to as an interdimensional rift, is a spacetime anomaly which acts as a fixed point across the spacetime continuum, described by Lieutenant Commander Data as a "keyhole" that intersects many quantum realities. In a sealed state, an anomaly of this type remains undetected, and presents no threat to the continuum.
History[]
2370[]
A fissure was encountered by Lieutenant Worf while returning to the USS Enterprise-D from a bat'leth competition on Forcas III. When Worf's shuttlecraft Curie came into contact with the fissure, its warp engines caused a small break in the barriers between quantum realities. Worf was thrown into a state of quantum flux, shifting him into other realities. The quantum flux in Worf's cellular RNA was intensified by the subspace field pulse of Commander La Forge's VISOR, pushing Worf into a new reality every time he was in close proximity to La Forge. The shift caused him a momentary feeling of dizziness, similar to the side effects of a concussion.
Although the fissure could not be seen, Data was able to enhance it with a warp field to make it visible. Using a subspace differential pulse, Data was able to scan over ten million different quantum states within the fissure, but was unable to locate the one which shared Worf's quantum signature. Later, due to an energy surge in the subspace pulse, the fissure destabilized and the barriers between quantum realities began to break down, causing approximately 285,000 quantum incursions by the Enterprise-D to appear from other quantum realities. Eventually the quantum barriers of all the realities intersected by the anomaly would have collapsed and filled the sector where the anomaly was located.
By identifying the Enterprise which shared Worf's quantum signature, they were able to appropriate the same shuttle which Worf had used to traverse the fissure in the first place. By piloting the shuttle into the fissure and initiating a broad-spectrum warp field, Worf was able to seal the fissure before it completely broke down. This also had the effect of transporting Worf and the shuttlecraft back in time to a point before Worf encountered the fissure. Due to the uncertainty principle, Worf could have emerged back into his reality several days before or after the event. (TNG: "Parallels")
2382 Fissures Outbreak[]
In 2382, numerous quantum fissures erupted across the multiverse, which was caused by the then-unknown USS Beagle exploring the multiverse. These quantum fissures emitted radial tachyons that could cause warp engines to explode while traveling at warp.
The USS Cerritos was tasked with sealing up the ones in the prime universe, Captain Carol Freeman referring to them as "space-time potholes". They had sealed up two within a month when they discovered a third. The fissure reacted and pulled the Cerritos inside, where they were greeted by that universe's Cerritos captained by Beckett Mariner. This universe was divergent by .327 percent to the main universe. A plan was devised to reopen the fissure via a gathered energy pulse from the two Cerritos's nacelles, which needed to be hurried as the fissure would be sealed in ten hours.
Problems arose due to the heated tensions between the two crews fueled by superiority complex along with Captain Mariner's tight-fisted rule on the ship. Furthermore, Captain Mariner attempted to switch places with her lower-ranked counterpart as she had gotten tired of being a captain and nearly escaped into the prime universe before the change was made. (LD: "Dos Cerritos")
On the Cosmic Duchess, the Cerritos crew encountered the USS Endeavour, an Intrepid-class starship from another universe that had been pulled through a quantum fissure and gotten stranded in the prime universe for a month. Admiral Milius was assigned to help the Endeavour find a way back to its own universe. (LD: "The Best Exotic Nanite Hotel")
After studying a new quantum fissure in Klingon space with the help of Captain Ma'ah, Mariner discovered that someone had been deliberately creating the recent fissures rather than the fissures being a natural occurrence as it had first appeared. (LD: "A Farewell To Farms")
The Cerritos continued to be sent to close the fissures, at one point being sent to close three in one week. On one occasion, the USS Enterprise-D of a reality where everything was purple briefly crossed through a fissure near Dilmer III "while battling evil clones of Tasha Yar, or something" and left behind Lieutenant Commander Data whose shuttle crashed on the planet. The Cerritos recovered Data's head and launched it back through the fissure in a torpedo casing to be recovered by Enterprise before closing the fissure. (LD: "Fully Dilated")
Quantum Portal[]
Acting on the discovery from Mariner, Section 31 sent Captain William Boimler in the Defiant-class starship Anaximander through the rifts to find the source with William being joined by a crew of "interdimensional castaways" made up of T'Pol, Curzon Dax, Elim Garak, a Julian Bashir who was an Emergency Medical Hologram and several Harry Kim's. The Anaximander discovered that the source of the quantum fissures was the USS Beagle, a ship captained by an alternate reality version Lily Sloane. In her reality, Sloane and Zefram Cochrane had developed the quantum reality drive instead of the warp drive and the Beagle's crew were exploring various alternate realities with their own version of the Prime Directive keeping the crew from contacting societies that couldn't cross realities on their own. Sloane and her crew were unaware that when they crossed realities, they were leaving a second rift behind in a random part of the galaxy that led to an entirely different universe because the Beagle had not accounted for the dissipation of additional energy. (LD: "Fissure Quest")
Although the two crews attempted to work together to return everyone to their own universe, a deranged version of Harry Kim hijacked the Beagle and attempted to return to his own universe with all of the Kims. However, the Beagle's repairs weren't complete yet and the ship wasn't able to handle crossing through another rift, exploding inside after Kim had beamed his alternate selves to the Anaximander. With the coherence of the rift disrupted, soliton waves would spread across all quantum realities. Using the Anaximander's navigational deflector, Sloane created a directed soliton burst that guided the soliton wave into the prime universe. Trusting that his transporter duplicate and friends on the Cerritos could find a solution, William piggybacked a message to Brad Boimler on the soliton beam, warning him of the danger. (LD: "Fissure Quest")
In the prime universe, this fissure opened near the edge of Klingon space and extended a Schrödinger possibility field that remapped matter into other possibilities from the multiverse. Based off of the Anaximander's data, it was quickly determined by Starfleet that the soliton resonance overloading the rift would destroy the prime universe if left unchecked. Starfleet devised a way to seal the rift using a subspace gluonic beam, but the USS Enterprise-E was too far away to reach it in time and the connection between the two Boimlers meant that the Cerritos was perfect for the job. A shield update protected the crew from the transformative effects of the rift as well as a Klingon ship that followed them, but the ships themselves were transformed into various different forms based on what they were in different quantum realities. The Cerritos was eventually able to reach the rift, but too late to seal. Instead, at Malor's suggestion of building a dam, Mariner managed to contain the energy within the rift at the cost of it being left permanently open. The rift transformed from a jagged hole in space into a circular, stable permanent portal.
Subsequently, Starfleet decided to take advantage of the new gateway to explore the multiverse. Because of the increased tachyon density near the rift, only Starbase 80 could be stationed nearby due to its older, outdated systems. The Anaximander returned to the prime universe, and it was stationed at Starbase 80 to take part in the new mission which was overseen by Captain Carol Freeman and her husband, Admiral Alonzo Freeman. (LD: "The New Next Generation")