Steven Lumos wrote:
> "Francis Cianfrocca" <garbagecat10 / gmail.com> writes:
>   
>> Even though the Church and Turing models of computation are unified
>> (and were unified long before digital computers existed), there still
>> seems to be something intuitively attractive to many programmers about
>> stuffing values into little boxes and being able to go get the values
>> out of the boxes later. I'm not sure if this is fundamental, or a
>> side-effect of the fact that our practical computing machines are all
>> Turing machines and most programmers learn something about "memory"
>> and "secondary storage" early in their training. This explains why
>> pure functional programming is stylistically so challenging in
>> practice, whether or not you believe it's challenging in theory.
>>     
>
> Turing machines derive from a model of a human working with pencil and
> paper.  That's pretty fundamental.
>   
First of all, while a Turing machine is a great "experimental animal", 
our "practical computing machines" are Von Neumann machines rather than 
Turing machines. And Von Neumann machines derive from a model of a human 
working with a mechanical desk calculator. In fact, the people -- rooms 
full of people -- who operated them were called "computers". Properly 
speaking, a Von Neumann machine is an "electronic" computer or 
"automatic" computer -- a machine doing what people used to do.

Second, I don't think the actual unification of Church and Turing models 
occurred *long* before digital computers existed. The basic Turing and 
Godel and Church papers were written in the early 1930s, and by the late 
1930s there were working relay-based digital computers. Vacuum tube 
machines started showing up (in public, anyhow) in the early 1950s and 
in "war rooms" shortly after the end of WW II.