Pi: Less Random Than We Thought
Link: http://slashdot.org/article.pl?sid=05/05/01/1759240 Posted by: timothy, on 2005-05-01 18:26:00 from the at-least-statistically dept. [1]Autoversicherung writes "Physicists including Purdue's Ephraim Fischbach have completed a study [2]comparing the 'randomness' in pi to that produced by 30 software random-number generators and one chaos-generating physical machine. After conducting several tests, they have found that while sequences of digits from pi are indeed an acceptable source of randomness -- often an important factor in data encryption and in solving certain physics problems -- pi's digit string does not always produce randomness as effectively as manufactured generators do." References 1. https://autoversicherung.einsurance.de/ 2. http://news.uns.purdue.edu/UNS/html4ever/2005/050426.Fischbach.pi.html ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> ______________________________________________________________ ICBM: 48.07078, 11.61144 http://www.leitl.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE http://moleculardevices.org http://nanomachines.net [demime 1.01d removed an attachment of type application/pgp-signature which had a name of signature.asc]
[1]Autoversicherung writes "Physicists including Purdue's Ephraim Fischbach have completed a study [2]comparing the 'randomness' in pi to that produced by 30 software random-number generators and one chaos-generating physical machine. After conducting several tests, they have found that while sequences of digits from pi are indeed an acceptable source of randomness -- often an important factor in data encryption and in solving certain physics problems -- pi's digit string does not always produce randomness as effectively as manufactured generators do." 1. https://autoversicherung.einsurance.de/ 2. http://news.uns.purdue.edu/UNS/html4ever/2005/050426.Fischbach.pi.html
This doesn't really make sense. Either the digits are random or they are not. You can't be a little bit random. Well, you can be, but the point is that you either pass the test or you don't. If pi's digits fail a test of randomness in a statistically significant way, that is big news. If they pass it, then there is no meaningful way to compare them with another RNG that also passes. It's just a statistical quirk due to random variation as to which will do better than another on any given test. The bottom line is still that either an RNG passes the tests acceptably or it does not. From what they say (or don't say), pi does pass. It doesn't make sense to say that other RNGs do better. CP
participants (2)
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cypherpunk
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Eugen Leitl