1.7 Billion Digits Of Pi On CD

H0ek writes "Not that there is any use for this whatsoever, but there is a torrent available for 1.7 billion digits of pi on a CD. The data is everything after the '3.' on one line, bzipped. There are a couple of the Cygwin tools on the disk as well as source for a small search tool (because grep just didn't cut it this time). Inside the ISO there's links to the source of the data, in case you want the rest of the 4.2 billion digits available. Wear your geek badge with pride! Be the first kid on your block to have the entire set!"

Comments

Unlikely!

[JaxWeb]

Be the first kid on your block to have the entire set!

You're unlikely to be the first kid on the block to have the whole set of Pie digits...

Shouldn't compress well

[crow]

At first, I was thrown off by the idea of compressing something like pi, as it shouldn't compress. The answer is that they're storing ASCII decimal digits, which require less than 4 bits per number, instead of 8. So you should get at least a 50% compression ratio, which would be 850 million bytes. But it's actually 3.something bits of information per byte, so they're able to fit it on a CD. I would be surprised if bzip could do any better than that.

Re:Shouldn't compress well

[EnronHaliburton2004]

I would be surprised if bzip could do any better than that.

Out of curiosity--

Bzip could could only improve on that if it found some repeating data the stream, right? Any improvement beyond the 50% compression ratio would be pretty revolutionary...

Who uses PI?

[vettemph]

I use pie all the time in an Engineering lab. typically out to 3 or 4 decimals. Does anyone NEED to use PI to a greater level of accuracy? If so, what application and how many decimal places do you require?

Re:Useless?

[WolfWithoutAClause]

And a statistical analysis of the digits of Pi would be useful because? :-)

Re:Useless?

[Zocalo]

Interesting, and a step beyond just using Pi (or e, or...) as a source of sequences of random numbers but I can't help but feel that there is an element of "Bible Code Syndrome" here. There seems to be a similar obsession with finding a pattern in Pi as some have with finding messages from God in the Bible. What happens if we do a statistical analysis of every nth digit? What happens if we do an analysis of all the odd digits? Or even digits? What if we reverse the sequence and try again? Try again in other number bases?

It's an infinite data set; apply an infinite number of methods of analysis and the odds are good that some of them will give results that might be considered meaningful. Even if you do find something, whether it's a something profound about the structure of the universe or even a message from God, you then have another problem. How are you then supposed to prove that it's not a statistical fluke keeping in mind that an infinite random data string will contain within itself every possible sequence?

Re:Useless?

[illuvata]

Why wouldn't they just generate it themself? For most people, downloading an ISO and extracting the archive would be slower than just to use something like this.

Compressing Pi

[rdwald]

The data is everything after the '3.' on one line, bzipped.

So, in order to reduce the space on the CD, they bzipped it? I could see that helping for the search code, etc., but for pi itself, isn't it impossible to represent it in less space than it already takes without actually using a mathematical formula which defines pi? I would think the only way to actually save space would be to use some non-ASCII encoding scheme such that each byte could hold two digits, not one. Or encode it in hexadecimal, and use five bits per digit.

Re:I've got a bunch of digits of pi

[mdielmann]

I'm pretty sure that the data on every CD I own appears somewhere in pi.

Oh great, just what I need. Now every time I see a circle, I'll be reminded that pi contains Britney Spears' Greatest Hits. Bastard.

On the plus side, it also contains every snide remark made about her. Including this one.

Re:I've got a bunch of digits of pi

[DustMagnet]

Since pi is infinite and irrational, I'm pretty sure that the data on every CD I own appears somewhere in pi. So, can I distribute these too? :)

Cute concept.

Of course you mean that the number of digits in pi is infinite. We both know pi isn't infinite since it's greater than three and less than four. Of course all irrational numbers have an infinite number of digits, so it works better to say, "Since pi is irrational, etc".

While I don't know about pi, an irrational number does not have to contain every combination of digits. For example, take this irrational number:
3.131131113111131111131111113111111311111113...
While irrational, it doesn't match any of your CDs. At least, I hope it doesn't.

Re:Useless?

[Zocalo]

Yeah, I'd come across that formula before which is where my reference to trying other numeric bases came from. Similarly the reference to the message from God in Pi was from "Contact" by Carl Sagan (the book, rather than the film, as well as a nice link back to the Bible Code. And that's where I have a problem; the usual approach is more akin to looking for a hidden message rather than finding a reason *why*.

My own personal view is that few, if any, of these universal constants, whether mathematical like Pi and e, or physical like the speed of light and Plank's constant, are entirely arbitrary. There is a *reason* why Pi is 3.14159... instead of some other constant value, a reason why light travels at the speed that it does in a vacuum, and so on. While some of those reaons may be quite mundane, I think there are some profound insights into the nature and underlying structure of the universe hidden behind all those digits. Whether you would want to see that as pure science or looking for God's signature is entirely up to you.