RegexTip, a Twitter account for learning regular expressions, starts over today with basics and will progress to more advanced properties over time. SansMouse, an account for Windows keyboard shortcuts, started over with basics two weeks ago. Both RegexTip and SansMouse…
Monthly Archives: January 2011
Scientific results fading over time
A recent article in The New Yorker gives numerous examples of scientific results fading over time. Effects that were large when first measured become smaller in subsequent studies. Firmly established facts become doubtful. It’s as if scientific laws are being…
Weekend miscellany
Music Sacred classical music Free Bach organ recordings Programming Why you can’t hire great Perl programmers 65 attempts at resolving P versus NP Math Math blogs: MathBlogging.org Dynamical systems on a plane Exotic spheres ESP and statistics Sums of cubes…
Posted in Uncategorized
Your job is trivial. (But I couldn't do it.)
Ever had a conversation that could be summarized like this? Your job is trivial. (But I can’t do it.) This happens in every profession. Everyone’s job has difficulties that outsiders dismiss. I’ve seen it in everything I’ve done, but especially…
Posted in Software development
How long computer operations take
The following table is from Peter Norvig’s essay Teach Yourself Programming in Ten Years. All times are in units of nanoseconds. execute typical instruction 1 fetch from L1 cache memory 0.5 branch misprediction 5 fetch from L2 cache memory 7…
Occam's razor and Bayes' theorem
Occam’s razor says that if two models fit equally well, the simpler model is likely to be a better description of reality. Why should that be? A paper by Jim Berger suggests a Bayesian justification of Occam’s razor: simpler hypotheses…
Demand for simplicity?
From Donald Norman’s latest book Living with Complexity: … the so-called demand for simplicity is a myth whose time has passed, if it ever existed. Make it simple and people won’t buy. Given a choice, they will take the item…
Some programmers really are 10x more productive
One of the most popular post on this site is Why programmers are not paid in proportion to their productivity. In that post I mention that it’s not uncommon to find some programmers who are ten times more productive than…
Another math calendar from Ron Doerfler
Last year Ron Doerfler made a beautiful calendar with images from graphical computing, charts used as computational aids before desktop calculators were ubiquitous. Ron has made a new calendar and this year’s theme is lightning computing, tricks for mental calculation.…
Weekend miscellany
Computing The wonderful world of early computing How to design programs Twitter Twitter accounts for all StackOverflow users by reputation and area One fact per day from computer science, math, statistics, etc. Science Elementary mechanics from a mathematician’s viewpoint Using…
Posted in Uncategorized
Three views of differential equations
The most common view of differential equations may be sheer terror, but those who get past terror may have one of the following perspectives. Naive view: All differential equations can be solved in closed form by applying one of the…
Obscenity
Classical Greek dramatists believed that it was degrading to show extreme emotion on stage. Some action had to be implied off stage (ob skene) because it was unfit to display explicitly. The classical idea of obscenity included sexual conduct, but…
Posted in Uncategorized
Three P's and three I's of economics
In the December 27 episode of EconTalk, Pete Boettke summarizes basic economics as follows: If you don’t have the three P’s, you can’t have the three I’s. The three P’s are Property Prices Profit and loss The three I’s are…
Style and understanding
From Let Over Lambda by Doug Hoyte: Style is necessary only when understanding is missing. A corollary to this is that sometimes the only way to effectively use something you don’t understand is to copy styles observed elsewhere. I liked…
Top five non-technical posts of 2010
Most of last year’s most popular posts here were about math and programming. Here are the most popular posts from 2010 not about math or programming. (They may mention math or programming, but they’re not about math or programming.) Write-only…
Posted in Uncategorized
