What is love? It’s a question that has befuddled philosophers for millennia, and scientists today still aren’t sure Niall McDiarmid/Millennium Images, UK A smitten couple lean in for a kiss in a hotel lobby as I beeline towards a softly lit conference room buzzing with first-date energy. I am here to attend the Love, Actually and in Theory meeting, organised by the Royal Society, in Edinburgh, UK. As a romantic myself, I am hoping to get an answer to one of life’s biggest mysteries: what is love? Over the next two days, I heard dozens of researchers – from evolutionary biologists and neuroscientists to psychologists – share their perspectives on that instinctive-yet-elusive thing called love, with a heavy focus on the romantic kind. The meeting marked the first time many of the major players involved in love research have been in one room. “This is a big deal for love science. It makes me cry,” Adam Bode at the University of Melbourne, Australia, told me midway through the conference, his eyes welling up.…