One of the ironies of scientific progress is the way in which new technologies can sometimes get in the way of each other. This phenomenon is clearly seen in the case of modern city lights causing problems for astronomical researchers, giving rise to a relatively new term that’s used more and more often these days: ‘light pollution’. Jonathan speaks with František Kundracik, a light pollution researcher at the Physics, Maths and Informatics faculty of Bratislava’s Comenius University, about this very modern problem, and what he and his colleagues have been doing to mitigate its impact. Repeat: Are you trying to learn Slovak or some other language? Lýdia Machová – a language teacher who speaks nine languages herself – has some tips for you, in particular how to recognise the crucial difference between expecting to be taught a language, and actively learning one.