On 17-Nov-98 Dennis R Redmond wrote:
>On Tue, 17 Nov 1998, Les Schaffer wrote:
>
>> incidentally, i just read a paper yesterday by a group at CERN
>looking
>> at violations of time-reversal symmetry (the T in CPT) in
>neutral-kaon
>> experiments. because they had to look at large numbers of particle
>> track data (over 1 million) they used a neural network trained to
>> search for particular sub-atomic reactions in the data.
>
>Is that like a search engine or something, i.e. a search engine which
>can modify the parameters of its search independently, depending on
>what
>it finds? Like Yahoo on steroids or something?
>
>-- Dennis
No. I suspect Les is referring to the grad student population who sit for days on end in front of streams of digital images, running the co-ordinate trace programs. You visually scan the images looking for particular patterns and when you find anything near what might be worth recording, you click on the beginning and end points, an auto-trace routine follows the particle lines and records the numerical co-ordinates. It takes months and years to get these numbers into a giant database.
Then, another whole crew of grad students and postdocs write and run statistical packages on bank after bank of this data. I am guessing now, but I also suspect nobody sees a particular event--rather there are numerous other mathematical steps that uncover a strong or weak likehood that temporal asymmetry exists because such and such a path should be like X, but every so often it does a Y.
Chuck Grimes .