she asked what was the use of prime numbers? (besides being a fascination to math people)
Hardy and Koblitz say,
... both Gauss and lesser mathematicians may be justified in rejoicing that there is one science [number theory] at any rate, and that their own, whose very remoteness from ordinary human activities should keep it gentle and clean. -- G. H. Hardy, _A Mathematician's Apology_, 1940
G. H. Hardy would have been surprised and probably displeased with the increasing interest in number theory for application to "ordinary human activities" such as information transmission (error-correcting codes) and cryptography (secret codes). -- Neal Koblitz, _A Course in Number Theory and Cryptography_, 1987
To me, it looks like Hardy is mostly right, even now. Computer-based communication seems to be the sole killer-application for number theory. Will someone please disagree? -- Don Reble djr@nk.ca -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.