There's a whole sea of jellyfish out there ready to sting indiscriminately. So, why do we keep trying to make them? Scientists from Harvard and Caltech have a pretty good reason for creating fake jellies -- they hope to mend broken hearts by adapting their 'pumping' style of movement. Much like our own vital organ, the creatures are a mass of muscle adept at shifting fluid, meaning the research has several medical applications, such as bioengineered pacemakers for busted tickers. In creating the Medusoids, the team used a silicon scaffold coated in functional rat cardiac tissue,
