Pi Explorer

Are the digits of Pi random? 

Maybe.  Mathematicians have calculated five trillion decimals of Pi (that’s 5,000,000,000,000!), and so far, they appear to be random, but that’s no guarantee that this trend will continue.  We know that Pi is irrational, meaning that it can’t be expressed as a fraction m/n where m and n are integers. This tells us that its digits will go on forever without repeating, but that's not the same as being random.  Mathematicians have not been able to prove that Pi is random nor that it is even a "normal" number.

Ultimately, the value of Pi is determined by the physics of our universe. So from a philosophical point of view, there is nothing random about it.  The fact that you have to walk 3.14 metres around a manhole cover with diameter 1 metre is strictly determined by physics, not chance.  Yet, those five trillion digits have no apparent pattern, and this makes Pi intriguing.  Perhaps some meaningful message is encoded in Pi.  That’s the premise of Carl Sagan’s book Contact, where the universe’s creator has buried a message deep inside Pi and hence into the fabric of space-time.  It’s also an idea in the movie Pi, which weaves the story of the search for meaning in numbers with the story of Icarus.  What can you find in Pi?  Let the Pi Explorer, the Internet's biggest Pi search program, help you with your search.

How to use the Pi Explorer:

• To search for number strings, just click on the entry field and start typing, or click on the digits.
  • The ticker at the top will show your string with proceeding and trailing decimals around it. The index number shown in the middle is the location of your string in Pi.  For example, type 314 to find that the first occurence of “…314…” in the decimals of Pi is at the 2,120th decimal place.
     
• To search for words, click on LETTERS and do the same.
  • This switches the explorer to binary digit (bit) mode where each letter of the alphabet is encoded in base-32 using five binary digits (giving 32 combinations).  For example, P and I are the 16th and 9th letters of the alphabet, and since 16₁₀=10000₂ and 910=010012, the Pi Explorer tells us that "PI" (10000001001) can be found in the 852nd position of the base-32 Pi.

• If digits or letters appear in grey, you cannot click on them because that string does not appear in the database
• Click on the arrows to move to subsequent and earlier occurrences of your search string in Pi.
• If you type quickly, it will take a moment for the Pi Explorer to catch up with you—just wait a few seconds.  If it pauses after you type the 5th or 6th character, just wait five seconds while the hamsters spin up the hard drive holding Pi.  It will work fine after that.

Learn more about the brains behind the Pi Explorer!