So I'm reading along in the Pixaxe book (yet again), and I am told
how genuinely object-oriented Ruby is and how in Java I would have to
invoke a function like

  Math.abs(number)

whereas with Ruby I merely pass a message to the number, i.e.,

 number.abs

But then later I find out that I need to do things like

 Math.sin(number)

which looks alot like Java.

What happened? Why did the idiom change?  Why isn't Math
implemented as a mixin for the Numeric class a'la Enumerable
or Comparable or Kernal, etc.?

(I couldn't find this discussion in the archives, but I would
suspect it's already in there somewhere so I'd be obliged for
a lead...)

-- 
Bil Kleb
NASA Langley Research Center
Hampton, Virginia, USA