Inflate your pool floaties, prepare a wedding speech, and whatever you do, don’t go in the glowing red cave, because we’re discussing the delightful film “Palm Springs,” starring Andy Samberg, Cristin Milioti, and J.K. Simmons, and currently available (to Americans, anyway) on Hulu. It’s the kind of movie we’ve seen before, but with so many interesting twists on the concept that it always feels fresh. In addition to pointing out what makes the movie work, we’ve got a bunch of nerdy questions about its premise, the multiverse, where you can find C4 and a policeman’s uniform on short notice, and...