The Dimensional Drive was thought to be invented somewhere around 100,000, but the earliest possible records go as far back as the 6,000's, as part of an experiment on the asteroid system of 1998 RO1.
The Dimensional Drive was a device used to enter the multiverse. it is prone to malfunctioning, and the only stable version was the 1998 RO1 version, which is a lost technology. it could also re-enter universes at a random point. new universes are almost always searched by unmanned probes first, as different laws of physics or energy can interfere with the operation of the device, leading to the probes being stranded. this procedure was started after the Diamond Incident in 100,820, in which the colony ship "Diamond" got stranded in another universe and malfunctioned, causing deaths of millions of colonists that by looking at the laws of physics of that universe, must have been slow and painful.
1998 RO1 DRIVE
The only stable version of the drive, this was used to transport 1000 colonists to another universe to see if the technology was actually possible. the ship, along with the head scientist working on the project, who was also onboard the ship at the time, was never heard from again. some say that the drive failed and they got stranded, that they ended up in a universe where the ship would not work, or that they were just unable to return for unknown reasons. some even think that the colonists went on to form the mysterious Thesos Empire! however, the universe they jumped into was never identified, and it remains a mystery.