Gallifreyan technology

History of technological advancements

Gallifreyans experimented with tachyonics before abandoning that field in favour of warp matrix engineering (DW: The Leisure Hive). Time Lords also experimented with hyperspace, but finally abandoned it as a theoretical absurdity two thousand years before the Doctor's time (DW: The Stones of Blood)

This information about hyperspace conflicts with several known examples of other species successfully using hyperspace technology (e.g. Humans (DW: Frontier In Space)), suggesting either that there is more than one meaning of the term "hyperspace", or that the Time Lords were less knowledgeable in this field than they thought they were.