None

Why:

1. If Barbour's theory of Platonia is even roughly correct, then everything exists in a timless universe, and therefore doesn't actually "disappear". Therefore, all questions are always asked, as everything is actually happening at once. I know that doesn't help much, and it dodges the main thrust of the question, but it's one support for my answer, if oblique.

2. Other than forgotten questions that disappear of their own accord, or are in some dead language, or are too personal/particular/atomised (i.e., What did you think of the latest excretion from Hollywood? Is it snowing now? Why is that weirdo across the library reading room looking at me?!?! When will I lose these 35 "friends" who are perched on my belt buckle? etc.) questions don't really disappear. They are asked again and again and are answered again and again, and this is a very good thing. Three Year Olds will always ask "Daddy, where do the stars come fwum?" And daddys will always answer as best they can. Eventually, some little three year old will grow into an adult astronomer and might find even better answers than their daddy supplied them on a cold Christmas night. And they will answer the same simple question with a long involved answer, or possibly, a better and simpler answer. In this way, questions come up again and again, but over time they spin out in new directions with new answers.

3. It's important to not let questions disappear. By doubting the obvious, examining the the same ground with fresh ideas, and questioning recieved ideas, great strides in the collected knowledge of this human project can be (and historically, have been) gained. When we consign a question to the scrap heap of history we run many risks — risks of blind arrogance, deaf self righteousness, and finally choking on the bland pablum of unquestioned dogma.

4. It's important to question the questions. It keeps the question alive, as it refines the question. Question the questions, and then reverse the process - question the questioning of questions. Permit the mind everything, even if it seems repetitive. If you spin your wheels long enough you'll blow a bearing or snap a spring, and the question is re-invented, re-asked, and re-known, but in a way not previously understood. In this way, questions don't disappear, they evolve into other questions. For a while they might bloat up in the sun and smell really weird, but it's all part of the process...

HENRY WARWICK sometimes works as a scientist in the computer industry. He always works as an artist, composer, and writer. He lives in San Francisco, California.