We are all sure we know what life is, but if you try to actually define it, things get tricky fast. I wrote a feature about the scientific struggle to define life in 2007 for Seed, and I’ve been keeping tabs on the evolution of this metaphysical quandary ever since. I was particularly intrigued to discover recently that one scientist thinks he can define life–and do so in just three words. I’ve written an essay about his short and sweet definition for the web magazine Txchnologist. Check it out.