What's Your Internet Birthday?

I was doing some vanity surfing the other day and started wandering what the earliest surving pmk Internet “footprint” (email, Usenet post, etc.) was.

After much digging, I found this post on Usenet, dated 1992-11-08 22:09:08:

Subject: Newton’s Method

I recently read the book FRACTAL PROGRAMMING IN PASCAL and have a question relating to the generation of Newton’s Method fractals. The following code fragment iterates the equation z^3-1=0:

xsquare= x * x
ysquare = y * y
denom = 3 * ((xsquare - ysquare) * (xsquare - yswaure) - 4 * xsquare * ysquare)
IF denom = 0 then denom = 0.0000001
x = (2/3) * x + (xsquare - ysquare) / denom
y = (2/3) * y - (2 * x * y) / denom

This does, of course, work beautifully. However, with my high school calculus skills, I am unable to understand WHY. Could someone please e-mail or post a step by step explanation of each part of the above fragment? Any help is appreciated.

There must be slightly earlier stuff floating out there, some of it from gagme and others from “borrowed” accounts, but this was the best I could do.

What’s your Internet birthday? Did you come into the online world with a whimper or a primal scream? Or a nerdy maths question?

Posted by pmk at June 16, 2004 12:38 AM | TrackBack