Wednesday, July 13, 2005

Just a bit on random things

There has been a lot on other sites about "random" in connection with evolution and God. I wanted to give just a little about the idea of "random," and went to look it up, and found that it will be HARD to say just a little, and be precise. The word can be given a precise meaning in mathematics, but it is neither easy to write in ASCII (so I cannot post it) nor easy to explain (so I will not post it). Another part of the problem with this word is that we have an "intuitive" sense of its meaning which may not agree with an actual sample...

In computing, there are tricks which we can use to make "random" numbers (they use timers, or Geiger tubes, or something dealing with physical phenomena) But the usual way most software libraries use is called a "random number generator" - which is pseudo-random - that is, it is NOT random at all, but computed using a rather strange function. Since it is computed, it can be predicted! But unless this is the function they use for making the lottery numbers, there is not really any reason to predict the next value from a given generator. (They have very interesting uses, which I cannot take the time to explain just now!) The nice thing about them is their results "look" random to the "casual" or "untrained" eye...

If you have a library nearby and want a starting point to see a little more, check for Knuth's The Art of Computer Programming, Volume II: Semi-numerical Algorithms, page 142-166. Even just to do the math, or to set up a program to make "pseudo-random" values, will be seen to take quite a lot of orderly effort...

2 Comments:

At 14 July, 2005 19:49, Blogger Dymphna said...

Your are over my head here...but I point you to a post of the Baron's that you might enjoy:

Race Against Time

Also see his Fibonacci Spirals at www.chromatism.net

Some mathbook co. emailed him yesterday with a request to use one of them in a new college text.

But I really came over to say the link to sigma to order the poster keeps giving me an error message.

 
At 14 July, 2005 20:22, Blogger Dr. Thursday said...

Odd - it worked OK for me. Then start with http://www.sigmaaldrich.com and then do a search for "metabolic pathways"... It's not my web page, so I cannot help you more than that.

 

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