For his in-depth investigation of the science behind medical marijuana, University of Pennsylvania physician David Casarett sampled pot-infused wine, smeared marijuana paste on his legs, and took lessons in hash-making—and, of course, talked to a range of researchers and delved deep into the medical literature. We got a chance to talk with Casarett about what he learned and what changes, if any, his medical practice has made in the course of writing Stoned: A Doctor’s Case for Medical Marijuana.

Seven days, lots of science in the news. Here’s our roundup of some of the week’s most notable and quotable items: After its unprecedented flyby, the New Horizons spacecraft started to send back the closest-ever views of Pluto and its moons. Physicists at the Large Hadron Collider have spotted signs of the pentaquark, a rare particle made from five quarks that should help researchers understand how the components of atomic nuclei stay stuck together. Nightmares might actually be good for you. Some pitcher plants are shaped to attract bats, but don’t eat the little critters—just their poop.

You may think the Universe began with a big bang, but really, as World Science Festival co-founder and Columbia University physicist Brian Greene points out, the Big Bang explains how the Universe evolved. A small difference but an important one. Scientists just don’t know what propelled that primordial push that launched the universe on its expansionary path.

First up, the closest view yet of Pluto’s biggest moon, Charon. The scientific team was surprised by the relatively smooth surface of the moon—they were expecting many more craters to dot its surface. Charon’s sleek exterior suggests that it has been recently geologically active. The dark region up top (which the crew has informally dubbed “Mordor”) shows several bright spots, suggesting that it is perhaps a region coated with a thin layer of some dark material. And on the upper right-hand side of Charon, that long notch is actually a canyon 4 to 6 miles deep.

Seven days, lots of science in the news. Here’s our roundup of some of the week’s most notable and quotable items: New Horizons neared its historic rendezvous with Pluto (after overcoming a slight technical glitch) and is already sending images of never-before-seen features on the dwarf planet. (Stay tuned for next week’s scheduled flyby.) The mathematics that describe the pattern of folds in your brain also describe the crumpling of paper. Newly discovered Triceratops cousin Wendiceratops is helping scientists answer the question of why these dinosaurs evolved their distinctive horned and frilled faces. Researchers found five supermassive black holes shrouded behind blankets of gas and dust, leading scientists to think there could be potentially millions of these hidden black holes lurking throughout the universe.