Since noise is essentially an arrangement of electrons in a device across which a voltage potential exists, it seems logical that there is an infinite possible amount of states the electrons can exist in, which implies an infinite number of inherently random states. However, there is a limit to the amount of states the electrons can exist in a substance, which is related to (I believe) quantum mechanics and the "size" of the electron. I remember reading last century that Poisson, the French mathematician, calculated a number pertaining to the amount of states a certain volume of gas can exist in. While finite, the number is so large that each state simply cannot have existed yet! Therefore, each new state is a new (random) position. So there is a finite amount of random states, and so eventually a random sequence can be repeated. For true randomness, try atmospheric noise. There is far more randomness in nature, related to potentials created by cosmic radiation, background radiation and the like. Since each is continually changing randomly, the randomness of atmospheric noise is quite high. Something like this is supposedly used in one time pad ciphers used by the military/intelligence units. You might like to try this. Record a noise source from shortwave radio or similar, and encode it in a sound format on your computer. (Make sure your computer is off while recording, or you'll get lovely RFI from Memory, Monitor (Especially on 14MHz) and CPU, not to mention 50/60Hz Hum). Use the binary values from that as a random sequence of values. I haven't tried this, nor can vouch for how much random data this produces, but it could be quite interesting. As for quantifying randomness, we are doing just that. By discussing "randomness" we assign a mythical qualitative value which implies disorder in our system. This sounds like chaos theory, and I suppose it is. But I'm just a lowly first year Uni student, and Physics bores me to tears. ;) Please, no flame mails for incorrect data, this is jsut my thoughts on the matter. Andrew Ryan =============================================================================== Andrew Ryan RMIT - BEng/BApp.Sc. 1st Year anryan@cs.rmit.edu.au http://anryan.tsx.org OR http://yallara.cs.rmit.edu.au/~anryan/ Program (pro -gram) [n] A magic spell cast over a computer allowing it to turn one's input into error messages. [vi] To engage in a pastime similar to banging one's head against a wall, but with fewer opportunities for reward. =============================================================================== On Mon, 18 Oct 1999, Wesley Moore wrote: > > > ___________________________________________ > Wesley Moore > RMIT - BEng/BApp.Sc. 1st Year > > wmoore@cs.rmit.edu.au > http://wmoore.tsx.org/ > > ---------- Forwarded message ---------- > Date: Fri, 15 Oct 1999 20:24:05 +0100 > From: Michael Lee > Reply-To: pic microcontroller discussion list > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: "Real" Random sequence sought > > ----- Original Message ----- > From: Wilhelm Erouve > To: > Sent: Friday, October 15, 1999 5:47 PM > Subject: "Real" Random sequence sought > > > > Looking for examples of a real random sequence for use with the 16f84. > Have > > generated a succesful psuedo-random routine and would like to work with > the > > real. > > This can easily be acheived by amplifying the shot noise across a PN > junction. Zener diodes are a particularly good source of noise. This is > random to the same degree as the radioactive decay method already suggested, > but obviously much more practical. > > Once recorded, does a random sequence cease to be random as can now be > repeated at will, and is surely now - by definition - deterministic? Can > randomness be quantified? Any mathematicians out there care to enlighten > me? > > Regards > > Mick >