What's New - May 2001

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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 is).      

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 Overmars, 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.