Invisibility: After several years of research, it's just gotten weirder

Is it possible to hide something within an invisible cloak? It has already been over four years since the first groundbreaking theoretical papers on invisible cloaking devices were published, stirring up a near frenzy in the physics and optics communities. Since then, new results have come at a rapid and genuinely surprising pace, and news articles on the recent developments have been a bit overwhelming, even for a worker in the field. In this post, I thought I'd take a look at some of the fascinating results that have been published on invisibility, giving some perspective on how far we've come and how far we have to go!