curvature applet

Wed, 2007-10-31 20:15

I wrote this applet for my Calculus I students to investigate, very preliminarily, the curvature of y=x2 at the origin. Notice how the circle is in contact with two points of the parabola until the radius gets small enough, and then it just sits on the origin. Hmmm: what does that tell us?


Tue, 2007-10-30 12:17

I slept late today, and remembered a bit of my dreams.

Jenni and I were walking back to where we were living/staying. There
were threatening clouds, and then it started raining very hard. I pulled
the hood of my "hoodie" over my head, but Jenni had nothing, and was
getting very wet. We stopped under the eves of building to wait for
the rain to stop. But then it seems we were actually in a restaurant,
at a table with other people. There was a large dish of food in the
center of the table that people were serving themselves from.
I tried to eat some of it, but there were long black hairs in it (there
was a woman at the table with long black hair). I tried to take the
hairs out but I didn't want people to see me doing it, and then I noticed
that there were small lobsters or crayfish in the food, so then I
just laughed: this was clearly about the worst food I could imagine.

I was riding my bike on a trail, and came across lots of junk: the
trail was crowded with stuff people might throw away after a garage
sale, or perhaps donate to charity. I had to "jump" my bike over
the junk, and was pretty pleased with my jumping.

I forgot that I had visited India, and then remembered. I thought
it was funny that I could forget such a trip. [I've never been to India].

More dreams.


Fri, 2007-10-19 17:45

This week I've been thinking about weird numbers, a number theoretic concept that, it turns out, hasn't been investigated nearly as heavily (from a computational point of view) as one might think it would have. With another editor at Wikipedia, I've been looking for better lower bounds on odd weird numbers (i.e., a value x that we can be sure that any odd weird number n must be greater than: n>x). I found a paper from 1976 that gives a method for calculating rather large weird numbers, but it says nothing about odd weird numbers. I might try some computations this weekend.

Also this week, I had an MRI on Tuesday. This was my first MRI. My liver doctor wants me to have them once a year to make sure we detect any anomalies (read: tumors) in my liver as early as possible. I've been having liver ultrasounds every siz months since my interferon treatment for hepatitis C, but now he wants to replace every other one with an MRI. I have to say, ultrasounds are more fun. The MRI required an IV, and although I'm not claustrophobic per se, it was a bit unpleasant being in the tube and subjected to quite loud noises (actually, it was kind of funny, too). On the plus side, the MRI is quite short, so it's really not that bad.

a panorama

Tue, 2007-10-09 19:52

Last September I did some bicycling in France. I took some pictures. This is my first successful-ish panorama done with the open source Hugin panorama software.

About the image: When descending the D1091 highway down toward Le Freney-d'Oisans, you run into a few tunnels. That water is the Lac du Chambon.

best September

Sun, 2007-09-30 23:04

I rode a quick 23 km today in the rain (I put the fenders back on a week ago), just to get my total for September up to 749.39 km and break my previous best September of 739.5 km (set in 2003). This is the kind of silliness I engage in, since I can't seem to come up with other short-term cycling goals to keep me riding after the boredom sets in.

This year has been quite good in this regard. Every month, except April, has been a "best ever" month. I should easily make this the best year ever: I'm only 300 km away from that record, with three months left.

books! books! books!

Fri, 2007-09-28 22:33

Today was the Friends of the Seatle Public Library book sale at Magnuson Park: twice a year, they fill a giant airplane hangar with tables covered with books, and hordes of rabid book buyers descend on it. It's great. Today was actually the preview night, where you pay for a card that allows you to buy up to 25 books. Here's what I got:

  • Socialism for Beginners, by Anna Pacuska

    A bit more light-hearted than most of the socialist stuff I get at these sales. Nicely illustrated by Sophie Grillet

  • Does it Matter? Essays on Man's Relation to Materialism, by Alan Watts

    Alan Watts is pretty awesome.

  • A Grammar of Dreams, by David Foulkes

    I'm interested in dreams. This book looks quite interesting, with diagrams, and "a scoring system for latent structure" which sounds cool.

  • A Tale of Two Cities, by Charles Dickens
  • Our Mutual Friend, by Charles Dickens
  • The Pickwick Papers, by Charles Dickens

    I've set myself the goal of reading every Dickens novel, so I picked up some at the sale.

  • One Hundred Years of Solitude, by Gabriel Garcia Marquex

    People seem to like this book.

  • Lord of the Flies, by William Golding

    I've never gotten around to reading this. Maybe now that I have a copy...

  • Anarcho-Syndicalism, by Rudolf Rocker

    Apparently a classic of anarchist writing.

  • The Courage to Be, by Paul Tillich

    "This book is concerned with anxiety and its conquest."

  • Tertium Organum, by P. D. Ouspensky

    Some philosophical writings.

  • A Guide for the Perplexed, by E. F. Schumacher

    I love this book's title.

  • Data Book for Civil Engineers, Volume One: Design

    This book's awesome. From 1947, it is filled with tables, diagrams, and specifications, almost entirely written with hand lettering and hand drawn figures. Just beautiful. (Listed at various online seller anywhere from $50 to $1600 !)

  • Manual of Mechanical Movements, by Henry T. Brown

    This little book is filled with small diagrams showing "mechanical movements", i.e., mechanical arrangements of gears, belts, pulleys, etc. for all kinds of purposes. It accompanied a travelling exhibition called "Mechanical Wonderland", which was a "collection of over 200 moving models: Electrically drive, in slow motion, showing all the movments used in the art and science of mechanics". Fantastic.

So there you have it. Not a bad catch.

two more photos

Tue, 2007-09-25 00:24

Two more photos added to the website.

A moth, and a glass of blue water.

Click for bigger images.


Sat, 2007-09-22 10:22

This blog's been spammed: someone added 21 comments to one entry, each with a link to some unsavory site. So, I've turned the approval queue on: comments won't appear until I approve them. This is rather a lame system, so I'll have to look around and see what other options Drupal offers.

Mr. Visconti and Mr. Dovzhenko

Thu, 2007-09-20 12:07

Two more films viewed from directors on this list.

La Terra Trema is an awesome, commi-tinged non-romp around a Sicilian fishing village. Great acting by a bunch of non-actors. Really excellent film. Directed by Visconti, who is the answer to a question posed on one of Monty Python's records, "What famous person is this, getting up in the morning?", followed by sounds of an alarm clock, yawning, using the toilet, etc. "An italian film director" is not sufficient.

Earth has some similarities, being about poor, working folk, but it is more commi-tinged, being set in early Soviet Russia, with discussion of farm collectivization and such. They sure do love their tractor, boy. Lots of close-ups.

So, only a few directors left:

  • von Stroheim
  • Marker
  • Flaherty
  • Rocha

Mr. Mankiewicz and Mr. Tarkovsky

Mon, 2007-09-17 22:45

Two more films from this list of directors.

I watched Stalker, by Andrei Tarkovsky. Extremely impressive visually, it looks like nothing else I've ever seen. A little like Eraserhead, kind of like a Joel Peter Witkin, but not so human. He does these long shots with the camera looking straight down into shallow water containing all kinds of interesting things. Very impressive to look at, but rather thin on content: some heavy philosophy, but philosophy we've all thought about before, and it's not as fun to think about it so slowly and quietly.

Definitely is not dated. I didn't realize it was made in 1979 - it feels very modern.

I wasn't terribly surprised to find out that the film actually was shot in a hazardous environment: several of those involved in the film (including Tarkovsky) died of the same cancer.