May 29,2001: I'm taking a break from
Astronomy - hung up on getting eclipse prediction working. So
here's a Measuring Cups
program. It was prompted by this puzzler from a recent edition
of the Cartalk radio show: You have a four-ounce glass and a nine-ounce glass.
You have an endless supply of water. You can fill or dump either glass. It turns out that it's possible to measure six ounces of water using just these two glasses. What's the fewest number of steps in which you can measure six ounces?
Tom and Ray Magliozzi, two of the smartest, and jolliest,
mechanics you'd ever care to meet produce Cartalk weekly on National
Public Radio. The Puzzler is a regular feature and also available
online at cartalk.cars.com.
May 26,2001: We'll just make this Astronomy
month. I'm finishing up the TAstronomy class which includes Moon and
eclipse information, maybe planets too if I get real ambitious. In
the meantime, here's a
Draw the Moon page in the Delphi-topics section which describes
one way to draw phases of the moon on the screen. Mainly an
illustration of using Arc and Floodfill procedures along
with a little bitmap pixel manipulation. Source code available
for download of course.
May 20, 2001: "Hour
angle", "solar time", "declination", "right
ascension" "ecliptic coordinates", "nutation in
the obliquity of the ecliptic" ---- just a few of the many concepts a budding astronomy
student must learn. But if you just want to fool around with sun positions for any
location, date, and time of day - here's a Solar
Position program that will provide that information. The only
required concepts are latitude/longitude for where we are on earth and
azimuth/altitude for the Sun's location (angle clockwise from North and angle up
from the horizon). As a bonus, we'll throw in sunrise and
sunset information and a plot of the "analemma" for your
location (and even tell you what the heck it
May 13:2001: Here is Tangram
2, the "final" version of the Tangram puzzle.
A challenging project based on a version written by Dr. Mark
University of Utrecht, NL. His version is better than this one
(It includes an Editor to build new figures and a Help file!). But
mine runs the same figure files and includes Delphi source (of
course). A good exercise in Computational Geometry, a
field I didn't even know existed until last week. There are
close to 1000 lines of code here, so plan on spending several lunch hours
if you want to understand how it works.
May 9, 2001: Tangram1
was posted today. It's a partial version of the classic
Chinese Tangram puzzle. A square cut into 7 pieces is to be
reassembled to match a given figure outline. In this version, the
pieces are defined and can be moved and rotated to form figures.
There's even an option showing the original square figure as a
pattern. (But assembling the square without the pattern can be
a challenge the first time you try it.) Flipping of pieces and
figure handling are still to be completed.
If you are just interested in playing with a finished
Tangram, I recommend Professor Mark Overmars' excellent version available here.
May 6,2001: It's been one of those weeks with
a not much to show for it. I'm working on a Tangram program and a
Solar position program - figured a couple of days for each. Well, a
couple of days barely scratched the surface. Maybe next week.
In the meantime here's one examining an excellent Bad
DNA Theory, prompted by a book I'm currently
reading. After Francis Crick and his associate, James Watson,
came up with the double helix explanation for the structure of DNA, Crick developed this theory to
explain why the 64 three-letter words formed by the 4 bases (A,C,G,T)
would only produce the 20 existing amino acids. A 25 line Delphi program
illustrates the theory. Brilliant, simple, and elegant, ... but
wrong! The book, by the way, is "Genome" by Matt
Ridley. I'm finding it a fascinating story.