Monthly Archives: May 2003

Fun with PyEphem…

I’ve been trying to tune up some of my telescopes for the upcoming Mars event. In late August, Mars will be closer to the earth than it has been in all of recorded history. While surfing around, I noticed that there was a Python package called PyEphem
which provided Python bindings for the popular Xephem program. It’s remarkably easy to deal with, in a few minutes I had a script which computed the apparent size and magnitude of Mars and printed them out. A much longer time was spent trying to understand how to use the gdchart module, but the results turned out the nice charts you see here.

The apparent brightness is in apparent magnitude, where negative numbers are brighter. When Mars is at its closest approach, it will outshine everything in the night sky except the moon. (I wasn’t able
to figure out how to get Python’s gdchart module to display the graph
with the yaxis reversed. I’ll keep at it.


Finding Nemo released


Well, it’s that time again, I’ve got another production credit on another movie.
Pixar is releasing Finding Nemo, starring a young clownfish named Nemo and his dad Marlin. Nemo is captured by divers and put in a fishtank in a dentist’s office, and the movie highlights their parallel adventures to be reunited. I can’t be impartial, but I think it’s a pretty good movie, and it looks beautiful. So get out there, drive our stock price up, and enjoy.


Narrowband Television

The problem with the web is that sometimes you hit a website that drags you off into a direction completely unrelated to anything you’ve really considered before.
This happened to me most recently when I encountered a site which described
the work of John Logie Baird, a Scottish engineer who designed a television system that transmitted 30 line images and was used in the first public broadcasts by the BBC. Some of these early transmissions have been restored and documented in a rather interesting looking book entitled Restoring Baird’s Image by Don McLean.

Curiously enough, there are still amateurs who are devoted in building replicas of these early mechanical televisions. Some links:

Moon picture…


Well, I didn’t try to take any pictures of the lunar eclipse, but I did try to take a picture of the post-full moon using the maximum zoom setting on my Nikon 4500. Exposure was for 1/60 second at f/5.1, and was a simple handheld exposure. The image was cropped from the normal 3.8 megapixel image. Not stellar, but not bad.


More fun with fingerprints

I have to admit that I’m a pretty big fan of CSI. Not the crappy new
CSI: Miami, but the original one. It gets Tivo’ed at my house all the time, as well as many CourtTV shows like Forensic Files.

The previous blog entry got me thinking about aquiring fingerprints clandestinely, and I thought about CSI. Often you see them place some fuming substance under a fume hood and it brings out fingerprints. I did a bit of digging, and found out that the fuming substance is cyanoacrylate glue, better known as Superglue. The fumes
interact with the fats and acids in fingerprints, and cling to them, resulting in
a white residue that is both permanent and can be easily photographed.

Using Matsumoto’s technique, one could probably construct fairly accurate forgeries of fingerprints, which is part of the reason why I detest these attempts
at biometrics.

If your interested in doing this yourself with minimal equipment, you can check out this link for the rather
simple instructions.

Fun with Fingerprint Readers

Bruce Schneier is the author of Applied Cryptography, the incredibly useful encylopedia of modern cryptographic algorithms. He also publishes the Cryptogram, an electronic
bulletin involving computer security, privacy and cryptography. Today I received the latest issue, which includes an article on fooling biometric fingerprint scanners. Tsutomu Matsumoto tried several techniques to create phony fingers that the fingerprint scanner would accept as real. Nifty!

Addendum: You can click here
for some slides that Matsumoto did detailing his work.

phlog — a photo weblog

Since Carmen and I both just got new digital cameras, we are taking a lot more photos and Carmen wanted me to create a simple way for her to put her photos on the web and to organize them. I used some of the ideas that I got from writing my primitive blosxom clone, and create a photo weblog script that I call phlog. It’s very simple, but will grow in functionality. Try checking out my gallery to see what it is all about.

New Digital Camera


I’m planning an anniversary trip to Paris with the missus, and decided that it was time to retire our aging Kodak 210+ camera and buy something new. We decided that we would each buy each other a new camera: I got Carmen a Canon A70, a very nice 3M pixel camera that is both small and easy to use, but also has full manual controls. Carmen got me the spiffy Nikon 4500: a 4M pixel camera with a split rotating design and very cool macro features. I shot about 100 pictures with it, and picked a few as examples. I’m very pleased.