This week, is there anybody out there? We're pushing at the boundaries of science in the search for ET. We take a magnifying glass to the big questions: what is life, where can we find it and could we ever communicate with it? Plus, the blood test that can tell you how long you'll take to recover from surgery, a new mussel-inspired glue that even works underwater and, 76 years after penicillin was first discovered, how scientists are combating antibiotic resistance