🚀 go-pugleaf

I wrote:
>Note: neither Cooley nor Tukey nor Gauss INVENTED the FFT; they discovered it.

Dave Sill writes:
|> What's the difference?  Isn't invention the discovery of a
|> configuration or procedure that was previously unknown?  Would not the
|> light bulb have been invented by someone else if not Edison?

Did Edison find a light bulb lying on the ground?  No, he tried several
thousand different filament materials and did lots of other work until
he found something that would work (and yes, someone else would have
invented it eventually).

With the FFT, on the other hand, given the specification for the digital
Fourier transform, the FFT already exists, in a sense; as soon as someone
looks at the relationship between the transform of a sequence and the
transform of every other member, the FFT appears.

Now, if someone finds a program listing by Cooley and Tukey lying on the
ground, that's a different matter; copying that program without permission,
even if you change all the variable names, is a violation of copyright.

Of course in some cases the distinction between invention and discovery
is difficult to draw cleanly.  But then, the "Hartley Transform" patent
should have been laughed out of the Patent Office.
--
Joe Buck
jbuck@galileo.berkeley.edu	 {uunet,ucbvax}!galileo.berkeley.edu!jbuck