Doctor Paul Manheim was a Human male in the 24th century. He was one of the greatest scientific minds of the time, advancing theories related to time. He was married to Jenice.
In 2342, he was a professor teaching at a university in Paris. Before 2349, he married Jenice.
Despite his brilliance, his theories on time and gravity did not gain widespread acceptance, with the result that in 2349 he left Earth with his wife and a team of fellow scientists in an attempt to test his theories.
After searching for two years for a suitable site, the team settled on Vandor IV, where they built two labs. The dense gravity of the pulsar in that system was required for the time-gravity experiments he needed to be carried out. Manheim believed there were infinite dimensions, and that if the linearity of time could be changed, then a "window" to these dimensions could be opened up. As he came closer to proving his theories, he installed a security system in the lab, as well as a force field. He also made his wife stay in a protected room whenever he performed a new experiment.
He finally achieved his goal in 2364, when he opened a "window" into another dimension. However, this was at a serious cost to his health, as his mind was trapped between the two dimensions, and caused the destruction of one of the labs. He issued a distress call, which was answered by the USS Enterprise-D. Manheim himself was dying, and the temporal distortions caused by the open "window", or the "Manheim Effect", was spreading through the galaxy. The window had to be closed to prevent the other dimension ripping the fabric of the galaxy. This was achieved with the help of Lieutenant Commander Data, causing Manheim to recover completely. Although unable to adequately describe the other dimension, he remained on Vandor IV with his wife to continue his work, saying he owed it to those that died in the other lab. (TNG: "We'll Always Have Paris")
In 2365, when the Enterprise encountered a duplicate version of Captain Picard, apparently transported six hours back in time, the contemporary Captain Picard rejected Manheim's experiments with gravity and time as a cause of this anomaly – noting that the experiments were rudimentary and uncontrollable. (TNG: "Time Squared")
Paul Manheim was played by Rod Loomis.
In the video game Star Trek Armada, the special weapon of the Federation faction is a temporal facility that gives reference to Manheim's name. The facility allows a user to locally freeze time for enemies, while his or her own units remain unaffected.
In Star Trek Online, players who obtain a Mobius class temporal destroyer (the mirror universe counterpart of the Wells-class) also receive a "Manheim Device" which allows them to create past and future duplicates of themselves.