At its birth, a new scientific discipline is baptized with the names of the two parent disciplines, Science X and Science Y. Subsequently, usage tends to shorten this compound name by giving preference to one or the other of the constituting terms so that the new term is less disconcerting and novel. Take biophysics, for example. Is it more closely related to physics than to biology, or the other way round? Today this question seems naive but it did not appear so a scarce thirty years ago, that is, at the beginning of the creative activity of the most, eminent scientists in the field of biophysics: it was then the subject of intense discussion.