Ice is one of those invisible little gears of the modern, westernized world. We don't notice it when we have it, and as soon as we can't get it we find ourselves desperate to get it back. It wasn't always like this: ice started as a luxury of more northern climates, and the story of how it became more ubiquitous -- including in southern climates where natural ice is rare to non-existant -- is a fascinating one. We speak to writer and author Amy Brady about her new book "Ice: From Mixed Drinks to Skating Rinks - a Cool History...