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http://www.angio.net/pi/

My 11 digit phone number occurs around the 115 millionth digit, a grand saving of two digits.




Wow, isn’t there a really low probability of finding your phone number in the first 200m digits of pi? (0.09995% in first 100m) I’m tempted to start throwing a dictionary of phone numbers through this pi lookup to find your number, call you, and verify, I think you could quickly narrow in on your phone number given the information above.


I think you'll have trouble. Assuming the first digit of the phone number is somewhere between 114.5 million and 115.5 million, you have 1 million potential 11 digit numbers to check.

There are 10^11 sequences with 11 digits. The number of people in the USA is 3×10^8, and we can assume there is roughly 1 number per person (some people don't have a phone number and some people have more than one, but it turns out that the exact approximation won't matter unless we're a few of orders of magnitude off). So about 0.3% of 11 digit sequences are valid phone numbers.

So there are approximately 0.3% × 1000000 = 3000 people with phone numbers around the 115 millionth digit of pi. You have no way of knowing which one of those people is sjcsjc.


It'd be a great 1 person-audience magic trick to call up all 3000 of those people and say, "Hi sjcsjc, I found your phone number in Pi".


Derren Brown did a great series of tricks based on probability.. your comment reminded me on the one that showed a video of him flipping 10 heads in a row on an unbiased coin. He revealed them that he had done it by flipping a coin for hours until he got that sequence.


Teller has made a similar statement, about practicing something more than anyone would find reasonable, so the trick is just in being able to do it.




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