Originally posted by buddhasystem
This in no way establishes any kind of equivalence. The parity bit in many storage systems that
employ it does not carry any special significance. I'm not holding my breath that Mary would understand any of that stuff, but then again, what does
she?
When I built this computer, I had to decide whether to install parity memory modules, or non-parity memory modules. I had to try to
determine what the significance, if any, was. Here's another Wiki link related to that topic:
RAM parity
In the case of the home PC where data integrity is often perceived to be of little importance—certainly true for, say games and web browsing,
less so for Internet banking and home finances—non-parity memory is an affordable option. However, if data integrity is required, parity memory will
halt the computer and prevent the corrupt data from affecting results or stored data, although losing intermediate unstored data and preventing use
until any faulty RAM is replaced. For the expense of some computational overhead, of negligible impact with modern fast computers, detected errors can
be corrected—this is increasingly important on networked machines serving many users.
I suppose my decision to buy non-parity memory for my home PC shows that I tend to agree that I didn't find the significance particularly
earth-shaking and my PC is still relatively reliable.
Had I been building it for a server application, I probably would have installed parity memory modules as the above quote suggests may be prudent for
server applications.
But this is binary parity.
The UPC symbol you see on all the products you buy in the grocery story uses something called a "check digit". Be careful how you use this math
because I can't guarantee it won't create black holes or vortexes, though in all the work I've done with UPCs I have yet to see such a thing:
Universal_Product_Code
In the UPC-A system, the check digit is calculated as follows:
Add the digits in the odd-numbered positions (first, third, fifth, etc.) together and multiply by three.
Add the digits in the even-numbered positions (second, fourth, sixth, etc.) to the result.
Find the result modulo 10 (i.e. the remainder when divided by 10.. 10 goes into 58 5 times with 8 leftover).
If the result is not zero, subtract the result from ten.
For example, a UPC-A barcode (in this case, a UPC for a box of tissues) "03600029145X" where X is the check digit, X can be calculated by
adding the odd-numbered digits (0 + 6 + 0 + 2 + 1 + 5 = 14),
multiplying by three (14 × 3 = 42),
adding the even-numbered digits (42 + (3 + 0 + 0 + 9 + 4) = 58),
calculating modulo ten (58 mod 10 = 8),
subtracting from ten (10 − 8 = 2).
The check digit is thus 2.
In this example we could say the parity digit of 03600029145 is 2, though in this case it's called a "check digit" in
UPC terminology.
If I follow Mary's lead and substitute "equals" for the word "is" can I write 03600029145 = 2?
No I don't think so. The math for calculating the 2 is clearly shown above. And you will find the equals sign is used numerous times, but nowhere is
it used to claim that 03600029145 = 2.
This could be called a sort of hash function as you suggested, though numerous other hash functions could be used. Without specifying what the hash
function is, (such as the math in the above UPC example), the relationship between the parity digit and the number that created the parity digit is
undefined.
I would also add that while I could probably write an entire book on how this parity check digit on UPC codes helps us in real life reality, I see no
application where it helps with the number Pi.
However Mary, if you would like to elaborate on how this might be so, please feel free to elaborate. In the absence of such response I'll just
conclude that you are speaking of things which you know absolutely nothing about, while at the same time claiming that people who do know about such
things are brainwashed by mainstream science. Which leads me to this cartoon:

I can try to lead people to reality, but I can't make them get a grip. In your case Mary, I'm not sure you want one. Your decision to constantly
ridicule all things mainstream, and instead choosing to believe any and every crackpot whose only common thread seems to be that they disagree with
mainstream, even when they disagree with each other, tells me you don't. I'm not saying you should automatically believe everything mainstream
says...I don't. Some skepticism is healthy, even skepticism of mainstream views. But to just trash everything mainstream when you don't even
understand what it is that you're trashing, is not healthy.
edit on 12-2-2012 by Arbitrageur because: fix typo