This song takes its name from the smallest types of matter in the world of quantum physics. It was inspired by a conversation about science Florence Welch had with her father, a former advertising executive who later ran an organic campsite. "It's actually the name of the two smallest particles that there are when you split the atom, so I wrote a song about it," she told NME. "I even managed to fit the word 'hydrogen' in there."
Science does run in the family; Welch's mother is the Professor of Renaissance Studies and Academic Dean of Arts at the University of London.