Today, nearly half of all states allow the medical use of marijuana, and several, led by Colorado, have legalized it completely. In many places, New York being one of them, you can get your pot delivered as easily and quickly as if it were a pizza. I would be happy with that if only I or anyone else knew what it meant to smoke it. But, largely as a result of our government’s refusal to support scientific research on the effects of marijuana, we know stunningly little about what happens when we drop those buds into our fancy new vaporizers. We know even less about the effect of what are called “edibles”—the gummy bears, chocolate truffles, lollipops, brownies, cookies, and other dishes, laced with pot, that are now so easily available to us and, no doubt, to our children. What do we know when we swallow a marijuana gummy bear? Is it like a hit of good pot? Is it like three? For that matter, is a hit of good pot like it was five decades, or five years ago? Or even five months ago? Nobody seems able to answer those basic questions.