While at a hotel, waiting for some out-of-town friends to get ready, I went prime number hunting on the 11th floor.
I’m not especially good at factoring, so I just captured numbers that looked prime. I wasn’t thinking too hard about it, so I didn’t notice the one obvious non-prime until later, but the others looked pretty prime to me.
I expected more than one, but at least I didn’t come up empty.
Where are some other good places to go prime hunting?
One of the items on my to-do list was build something. To that end, I spent the afternoon turning a bunch of leftover lumber into a small table.
I’ve always admired those who can build elegant and functional things, but I came away from my project with an even greater appreciation for carpenters, woodworkers, builders, and the like. The measuring: how far are those legs spaced apart? The calculating: when all these pieces get put together, how tall is this thing supposed to be? The engineering: why are things rolling off my table? It’s a set of serious cerebral challenges on top of the obvious physical demands.
One theme that stood out as I slowly assembled my table was that of error propagation. A tiny error at an early stage (a millimeter or two of slant on a “flat” cut on a leg) can produce a sizable error in the end (things quickly rolling off your table).
It put me in mind of the classic differential problems in elementary calculus. For example, suppose you are measuring the diameter of sphere with a margin of error of +/- .1 mm: how much error might this generate in calculating the volume of the sphere? The surface area?
An even more complex problem is understanding how different errors interact with each other, which is something I experience frequently while putting this table together!
I really enjoyed reading Newsweek when I was younger–I loved the political cartoons, the quick-hit section in the front, the in-depth pieces on issues I knew nothing about. So I’ve been watching with interest as the Washington Post Company completes the sale of the news magazine for a reported $1 dollar and assumption of debt. Newsweek–like many print publications–has been losing money for a while, so this is not much of a surprise.
There are a lot of interesting stories going on here: the ongoing saga of print and online media; Sidney Harmon, of Harmon-Kardon audio fame, is the buyer and has no clear media experience; and Harmon’s wife, Jane, is a U.S. Representative. But it was the following analysis of the finances of Newsweek that really caught my interest:
http://www.cjr.org/the_audit/the_newsweek_numbers.php
Someone published a copy of the [presumably confidential] sales presentation on the web, and the revenue and cost data is fascinating: apparently Newsweek spent around $100 million (about 60% of its annual revenue of $160 million) to produce, distribute, and manage the physical magazine. How can a magazine, any magazine, seriously compete head-to-head with an online publication, one that can provide a similar service while avoiding $100 million in such costs?
This drastically changing industry is a good place to look at changing business and finance models.
One of many witty, math-y cartoons from www.xkcd.com:
To create this, I think you’d need to draw panels both on the front and the back of a strip of paper, making sure that the end of one side can precede (or follow) the end on the other side in the story. I imagine it would be best if the circular story had no beginning or end.
This is a lovely three-minute visual homage to the Fibonacci sequence and its relationship to various natural phenomena.