All about Groundhog Day. Tetrachromats have an extra photoreceptor that lets them see 100 times as many colors as the rest of us. 7-Eleven is testing touchless “floating holographic displays” for self-checkout. A mistranslated sign inadvertently advertises free alcohol. A gigantic, 60-socket power bank could fully charge 5,000 smartphones with 3,000-mAh batteries. A gallery of “automated furniture.” Enhancing the energy storage capacity of graphene supercapacitors used in solar heating. A search engine that finds full-text public-domain books. Why would anyone program a self-driving car to ignore stop signs? A chainmail cocktail dress made from pennies. All that and more in WhatTheyThink’s weekly wintry miscellany.