By Matt Simon
IF YOU’VE SPENT time with marijuana—any time at all, really—you know that the high can be rather unpredictable. It depends on the strain, its level of THC and hundreds of other compounds, and the interaction between all these elements. Oh, and how much you ate that day. And how you took the cannabis. And the position of the North Star at the moment of ingestion.
OK, maybe not that last one. But as medical and recreational marijuana use spreads across the United States, how on Earth can law enforcement tell if someone they’ve pulled over is too high to be driving, given all these factors? Marijuana is such a confounding drug that scientists and law enforcement are struggling to create an objective standard for marijuana intoxication. (Also, I’ll say this early and only once: For the love of Pete, do not under any circumstances drive stoned.)
Read more at Wired