On 29 Dec 2013, at 11:37, LizR wrote:

## Advertising

On 29 December 2013 13:11, Edgar L. Owen <edgaro...@att.net> wrote: Jason and John,If something is random it can't be computed by any deterministicprocess. That's the meaning.I thought the digits of pi were random, but computable by adeterministic process?

`Well, this is just a question of vocabulary, and we have to agree on`

`some definition.`

`Empirically, we know that pi pass the statistical test of normality,`

`and so it is random in that sense (but this is empirical, and the`

`question of pi being normal is an open problem in math).`

`Of course the digit are computable, and so pi is not random, in the`

`incompressibility sense.`

`"random" is just a fuzzy terms which can have different meaning in`

`different context. Passing normality test is a weak notion of`

`randomness, compatible with computable. Being incompressible is a`

`stronger form of randomness. The second notion implies the first, but`

`the first does not imply the second, like pi illustrates indeed.`

Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.