Comment on Am I entitled to compensation?
hakase@sh.itjust.works 1 week ago
I thought pi hadn’t been proven to be normal, only conjectured to. My phone number isn’t in the digits of pi that we’ve discovered so far, for example: www.angio.net/pi/
I checked a couple but none were found if I included the area code.
Based on my sample size of half a dozen phone numbers, it doesnt seem to have numbers once they are more than 8 digits.
Seems like there should some formula to determine how long the normal number needs to be to have all digits go to a certain length.
Reminds me of the formula for calculating the shortest path to watch all episodes in a tv series in all possible orders.
If you explore compression using pi - i.e., giving an index and a length of pi as your compression method - what you’ll end up finding is that the length of the data you want to compress is about the same as the length of the index in pi your data is at.
So if you wanted to “compress” five digits by just linking to its index in pi, you would most likely need a five-digit index into pi to find the spot where pi has that number. So, you save nothing on average.
There’s a good blog post that goes into this, but I’m having trouble finding it. The rough explanation I can remember is: if you have every permutation of a given length n in a row with an even distribution, then a random string you choose is likely to be in the middle of that length. Using our numbers 0-9 as our base, that puts you at index 10^n/2. Given our example of 5 digits, that’s 100000/2 - 50000, itself a 5 digit number, saving us no space.
In the mean time, you can use pifs to “store” your data using similar ideas.
Didn’t say anything about compression.
Indexing and compression are not the same concept.
If there was an index for all 5 digit sequences and their locations, it wood reduce the search space for finding a 6 digit number.
This is about look up speed not saving space. Indexes always increase storage requirements. Always.
The question being asked here is does pi contain my phone number? Not does pi contain my phone number with an index location whose numeric value is shorter than my phone number?
Does pi contain my phone number?
We can’t yet answer this because we don’t actually know whether or not Pi contains all permutations of all numbers. It’s conjectured that it does, however.
Didn’t say anything about compression.
You didn’t, but “compression” using pi actually asks the same question you do, iiuc, of " How far do I have to search in order to find a thing of a given length?" And the answer is - if pi truly does contain all permutations of all numbers - probably 10^length/2 - for phone numbers, 10^10/2, or half the length of all of the permutations of 10-digit phone numbers next to each other.
Which, coincidentally, and the reason I was aware of this, is why indexing into pi doesn’t save you space on average if you’re being a nerd and trying to use it for compression.
Sorry for the AI slop. I am not an artist and just thought this was kind of funny. I like that Ω is hidden in her hairstyle.
::spoiler::
What does Omega mean?
Chaitin’s constant also known as Chaitin’s Ω is transcendental, uncomputable and algorithmically random. Also normal in every base. I don’t know how or what any of it means, but it’s a probable, normal number.
Yes, I’m aware of that, but I’m not sure how it’s relevant. There are an infinite number of irrational base-10 numbers that only contain combinations of 0 and 1, for example, and none of them will contain my phone number, credit card, etc.
Not all irrational numbers are normal numbers, and only normal numbers are guaranteed to behave as described in the OP.
It doesn’t contain your phone number when read as a base 10 number! Checkmate, I got your phone number!
Sorry…
How about if it’s read as a base pi number?
is 200m what’s been discovered, or just what was worth putting into this program? Not a huge expert but I thought it’s all fairly easy to get the next number of pi, just seemingly never ending.
We currently know about 202 trillion digits of pi. As for your other question: it is easy to get the next digit of pi from a “mathematical” point of view. By this I mean that we know functions that will approximate pi with as much precision as we want, but actually having a computer do it is very hard. The digits we know today took 3 months and needed 1.5 petabytes of high end storage.
Apparently it’s been calculated to trillions of digits so a bit lacking.
The search on that length would need an optimized index.
emeralddawn45@discuss.tchncs.de 1 week ago
Plot twist: the websites that check if a given number has been found in pi are actually just data mining operations looking for credit card numbers and phone numbers.
hakase@sh.itjust.works 1 week ago
That did occur to me, so I only gave them my old number.
CrayonRosary@lemmy.world 1 week ago
Well obviously that’s not in pi. Pi only tracks current phone numbers.
ChilledPeppers@lemmy.world 1 week ago
There is a website that just has like, a million digits of py in plai text, you could go there and ctrl+f