Where's is the centre of the Universe? Why do volcanoes explode? When God dies, who will be the next God? Why do we have dreams? There are just a few of the questions children ask. But where can they find the answers? Many of you have solved this problem by writing to the famous scientist, Uncle Albert. Here is the first selection of your letters, together with replies from Russell Stannard, the author of the best-selling Uncle Albert books.