There's a great exhibition on city lighting at the Danish Design Centre opposite Tivoli at the moment. Includes some interesting thoughts by light designers about why they don't illuminate buildings the way they do in Amsterdam or Paris. Didn't realise that both the Netherlands and Belgium are one of the worst light polluters in the world. Belgium has lit every inch of motorway and the Dutch have all these greenhouses. If the light is leaking upwards then it is not being used efficiently.