Formal-ity and the Church-Turing thesis

[Steven D'Aprano]

On Tue, 08 Oct 2013 18:16:01 +0530, Ravi Sahni wrote:

>> So in that sense, computers are Turing Machines. Anything a physical
>> computing device can compute, a Turing Machine could too. The converse
>> is not true though: a Turing Machine with infinite tape can compute
>> things where a real physical device would run out of memory, although
>> it might take longer than anyone is willing to wait.
> 
> Thanks Sir the detailed explanation. You are offering me many thoughts
> inside few words so I will need some time to meditate upon the same.
> 
> Presently Sir, I wish to ask single question: What you mean "wave our
> hands"??

It is an idiom very common in Australia. (It may not be well known in the 
rest of the English-speaking world.) It means to figuratively flap one's 
hands around in the air while skipping over technical details or 
complications. For example, we often talk about "hand-wavy estimates" for 
how long a job will take: "my hand-wavy estimate is it will take two 
days" is little better than a guess.


-- 
Steven