Deck the pools: Festive divers work at an aquarium in Manila As the lights were switched on in Trafalgar Square last night – and we all start thinking of getting ours in this weekend – other countries were creating their eye-catching variations. The smallest would be pretty tricky to decorate – because it measures less than half the width of a human hair. Little bit of fun: This silicon tree is 0.04mm wide It is made from silicon with an ion beam, normally used on silicon chips, at Britain’s National Physical Laboratory. Meanwhile, Mexico City has gone to the other extreme, hoping to enter the record books with a tree that towers 90m (295ft) over shoppers – beating Rio de Janeiro’s 82m (270ft) effort. Dizzying: Mexico City’s 90m tree dwarfs the traffic passing by Big in another sense is the effort standing in New York’s Rockefeller Center. It has been bedecked with a dazzling 30,000 lights. But lights would be a fairly risky decoration for the tree ...