Thursday, June 8, 2017

June 08, 2017 Thursday

Bedtime Story 


Gödel Numbering Series of Formulas


Now we are very adept at assigning Gödel numbers to any one formula or a theorem.

The question we were pondering last night was that having assigned Gödel number to a series of formulas, how do we handle them?

Can they cumulatively all be assigned one number?

Is it possible to do that kind of feat involving a string of 10 or 20 such formulas?

Yes, it is possible using the exact same technique; generating a new number which will be the product of first two primes, each raised to the power that corresponds to the Gödel number.

So if, say, we assign a number k to this series of two formulas, it will be written as:

k = 2m x 3n 

This same process can be repeated for as many formulas as needed.

All this now should surely convince you that Gödel had devised such a system for his proof that any expression of his formal calculus - may it be an elementary sign, a string of signs comprising a formula or a sequence of such strings representing sequence of formulas – all could be assigned a unique Gödel number.

So with his unique numbering system, Gödel was successful in establishing a one-to-one correspondence of every expression of his formal system with a distinct number.

Now don’t get the wrong idea that given such a system, every natural number by default will end up becoming a Gödel number.

(Just consider the simple number 100, and think whether it can be a Gödel number or not).

Yet the fact remained that given any expression, it would be possible to figure out its corresponding Gödel number which had to be special and unique.

Mathematicians as I have told you earlier are never satisfied with what they have.

They try to look at it in a reverse way or extend it further, anything to make your and my life miserable.

So let us try to think like them for a while and share their agony.

What if you are given a Gödel number and asked to decode it and retrieve the expression that it represents; can it be done?

Yes, that too is possible.

In our formal calculus that we have been considering, any number from 1 to 12 would represent the elementary signs.

But what about Gödel numbers greater than 12?

How can we decode them to arrive at their underlying formula?

We shall be tackling this troublesome issue in the nights to come.

Stay tuned to the voice of an average story storytelling chimpanzee or login at http://panarrans.blogspot.in/
                              
Good night mon ami and my fellow cousin ape.
                           
  
                

             












Advertisements

Another great educator and a teacher that I am aware of is Professor Subhashish Chattopadhyay in Bangalore, India.

While I narrate stories, Professor Subhashish an electronic engineer and a former professor at BARC, does and teaches real mathematics and physics.

He started the participation of Indian students at the International Physics Olympiad.

Do visit him here:


All his books can be downloaded for free through this link:


For edutainment and English education of your children, I recommend this large collection of Halloween Songs for Kids:

https://www.youtube.com/channel/UCd14DRdYKj454znayUIfcAg

No comments:

Post a Comment