tend to think in terms of words and not letters, so it is molecules they count, and these are numerous to say the least. At sea level, at a temperature of 0 degrees Celsius, one cubic centimetre of air (that is, a space about the size of a sugar cube) will contain 45 billion billion molecules. And they are in every single cubic centimetre you see around you. Think how many cubic centimetres there are in the world outside your window--how many sugar cubes it would take to fill that view. Then think how many it would take to build a universe. Atoms, in short, are very abundant. They are also fantastically durable. Because they are so long-lived, atoms really get around. Every atom you possess has almost certainly passed through several stars and been part of millions of organisms on its way to becoming you. We are each so atomically numerous and so vigorously recycled at death that a significant number of our atoms--up to a billion for each of us, it has been suggested--probably once belonged to Shakespeare. A billion more each came from Buddha and Genghis Khan and Beethoven, and any other historical figure you care to name. (The personages have to be historical, apparently, as it takes the atoms some decades to become thoroughly redistributed; however much you may wish it, you are not yet one with Elvis Presley.)