X-ray specs and invisibility cloaks are the stuff of sci-fi and fantasy, but sometimes science is just stranger than fiction. A food dye that helps give certain sodas and snacks their hallmark orange hue renders mouse skin almost completely see-through in a reversible, potentially non-toxic research method that could transform medical and scientific imaging. Because of a counterintuitive fundamental physics principle, Tartrazine, also known as Yellow 5, can temporarily turn biological tissue transparent to the naked eye, as described in a study published September 5 in the journal Science. So far, the scientists behind the new discovery have used the...