Alternate timeline
(covers information from an alternate timeline)
Temporal theory was an intricate branch of study.
In 2395, when Jean-Luc Picard suggested using an inverse tachyon pulse to scan beyond the subspace barrier, Data was intrigued by the idea, as it was something he did not believe had ever been done with a tachyon beam. He remarked, "I had no idea you were so versed in the intricacies of temporal theory, sir." (TNG: "All Good Things...")