This is the best tl;dr I could make, original reduced by 80%. (I’m a bot)
Scorched wooden incense burners unearthed at an ancient burial ground in the mountains of western China contain the oldest clear evidence of cannabis smoking yet found, archaeologists say.
With music as an accompaniment, the heady fumes may have prompted those present to attempt to commune with nature, spirits or the dead. Researchers have found remnants of cannabis at ancient sites in Central Asia before, but the latest discovery points to the intentional use of plants with high levels of the active compound, THC, and to cannabis being inhaled rather than ingested.
The mountainous Pamir region may once have sat astride a busy trade route of the early Silk Road. If cannabis smoking originated there, or nearby, it may have helped to spread cannabis smoking from Central Asia around the world.