For many years, since 1970 in fact, I have been writing notes on social, mathematical, and other subjects, which I store on index cards.  A collection of several hundred of these notes was published two years ago as Trefethen’s Index Cards: Forty Years of Notes about People, Words and Mathematics (World Scientific, 2011). 

My son Jacob has persuaded me to experiment with posting new cards as I write them in a blog.  So here goes.   I’ll begin with a few notes from recent months.  On average over the years, I have written these at the rate of one or two a month.

As my day job, I am Professor of Numerical Analysis at Oxford University (people.maths.ox.ac.uk/trefethen).

– Nick Trefethen, Oxford, 29 September 2013