🚀 go-pugleaf

In article <1993Aug26.191358.13167@ast.saic.com>, 
   hilljr@jupiter.saic.com (Jay R. Hill) writes:
|> So near the Feigenbaum point which I place near -1.401155189092116 
|> we will find very nearly

            Universal constant not universal?

The 'Universal' constant, whose value was first reported in 1977 by
Grossmann and Thomae and which was found by Feigenbaum to be in many 
nonlinear processes, seems to change with each new publication 
appearance!

It takes on at least three different values in the first 3 books
I found it in.

In 1986 Peitgen and Richter report the value on page 7 of The Beauty
of Fractals as 4.669201660910...
                        ^
The 1990 edition of Dynamical Systems and Fractals by Becker and
Dorfler (p48) puts delta = 4.669201660910299097...
                                    ^        ^^
But in 1992 Peitgen, Jurgens and Saupe's Chaos and Fractals New
Frontiers of Science, page 612, list the delta at 4.6692016091029...
                                                          ^      ^^
I have calculated it and submit for your consideration for 1993 this
value for delta: 4.66920160910299067197...        ;-)

BTW I get -1.40115518909205060052382678789... for the Mandelbrot Set
Feigenbaum point.

Warmly,
Jay 'Not tonight honey, I'm changing the Universal Constant' Hill
-- 
{ hilljr@jupiter.saic.com } begin writeln(3*ln(640320)/sqrt(163):17:15) end.
void main(){double sqrt(), y=1/sqrt(2.), a=.5, m=1,z; int n=0;
for(;m*=2,z=sqrt(1-y*y),y=(1-z)/(1+z),a=a*(1+y)*(1+y)-m*y,n<4;n++);
printf("%17.15lf\n",1/a);}