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Mysterious Random

Posted: Sun Jan 09, 2011 9:15 pm
by Rabalder
I have been wondering about this for quite some time but havent really made an effort to find the answer.
If someone could explain this to me, I would be grateful.


How can random be?
Lets say you have some effect device with a random-button on it.. When you push that button everything
is supposedly randomized. But down to the most basic level, a computer cant produce anything in a random
order!! (i think).
How can something that deals in math, make something thats not math??
Computers are logical right? Than how can you program something that deals in logic, not to be logiacal??

I talking about the most basic level in computer programming.. How is Random borned?

The only thing I can think of is running several clocks at different speeds and somehow make something "random" out of that..?

If you had access to the math behind a random-button, you could theoretically calculate every piece of random
number the button is ever gonna produce..

Nothing cant really be 100% random in a coumputer!!?!!??

Get my drift??

Any smart people out there???

Re: Mysterious Random

Posted: Sun Jan 09, 2011 9:19 pm
by TenSquare

Re: Mysterious Random

Posted: Sun Jan 09, 2011 9:20 pm
by Theo Void
I think you may be a bit smarter than I. Or at least have eaten more LSD than I.
We're getting into semantics here. Of course, I think you're absolutely right, but what I think "random" means is that it sets the device to parameters that were not set by YOU(a human.) The machine chooses a "Random" set of paremeters. Feel me?

Re: Mysterious Random

Posted: Sun Jan 09, 2011 10:52 pm
by fx23
exactly, what matters is you, final user, perceive it as random.

random probably don't exist in the whole universe, still you perceive lot of things has beeing apparent random,

when you drop a dice it's said random, but if you were smart enough to analyse velocity, atoms shapes of dice and table,

air friction ect the result is a fairly predicable and static mathematic/physic equation with static result.

the fact is we are not brained enough to compute that, so as you can't predict what will be the result, it can be

considered as random.

Re: Mysterious Random

Posted: Mon Jan 10, 2011 12:32 am
by andrewbrewer
pseudo-random. real and very important word.

Re: Mysterious Random

Posted: Mon Jan 10, 2011 12:36 am
by moonpie
Yeah, what the other posters said - random doesnt exist in computers. You create an Algorithm that will repeat events, but the time before repetition is so long that human perception cant see it. You could program a computer to pick a number, every day of your life between 1 and a billion by some extremely long mathematical function, and not to be morbid, youll be long dead before the pattern becomes apparent and you can figure out the initial equation.

Its the weakness of human perception. We only live so long. For example: Took quite a while for us to figure out the earth wasnt the center of the universe. You need lifetimes upon lifetimes to see the subtle changes. And make sense of the patterns.


Re: Mysterious Random

Posted: Mon Jan 10, 2011 12:38 am
by Simbosan
Random is a pragmatic description, not theoretical. You can buy special plugin cards for computers that use thermionic valves to create analogue noise which is 'more random' than anything a chip can produce, but that's kinda nutty. There's probably other ways that are more 'quantum'.


Re: Mysterious Random

Posted: Mon Jan 10, 2011 8:55 am
by Rabalder
An alogarithm that repeats itself. - Good
Thermionic valves that create analogue noise. - Good

The above (and google in general) describes "random" in very complex ways..
I know about random/probability in real life, but its the basics inside a computer I was curious about.
Something like a prinsipal, the leading textbook example of random.
Are there several prinsipals or one leading prinsipal?

If I were to create a random generator from scratch, what would I need and how would that work??

Usually you just use a "random generator" to generate random, but what generates the random inside the random generator?

Re: Mysterious Random

Posted: Mon Jan 10, 2011 9:46 am
by Simbosan
Every programming language under Gods Earth has a random generator. To create one from scratch would require understanding these very complex issues you are trying to avoid. They are simply mathematical functions that produce very very long sequences of seemingly random numbers. E.g. PI for example, produces an infinite number of digits that never ever ever repeat. Random generator math functions are chosen for their speed and even spread and are written by crazy geeks who really grok this kinda thing. You could use a PI generator but they are horrifically computationally expensive.

Random generators in all languages are perfectly suitable to all but scientific purposes. To make them appear more 'random' you kick them off with a number of your own choosing, the common choice is the current time in milliseconds. That means that to get the same sequence exactly in two process you would need to start the random generator at precisely the same millisecond. So it's for all intents and purposes random.

Not sure what else you are after, but if you are trying to create a truly random generator, you are getting into some VERY deep philosophical water. What is random on a PC, maybe you could get a handle on hiss/static from your soundcard, white noise from a TV card. You need something analog basically.

Just use the functions provided.


Re: Mysterious Random

Posted: Mon Jan 10, 2011 10:19 am
by Rabalder
Thanks for your explenation..
This is just a question Ive been wondering about for some time. No purpose really.
I just couldent understand how a digital computer could create REAL randomness.
So I suppose it cant then.. Its all just probability in cycles..

Re: Mysterious Random

Posted: Mon Jan 10, 2011 10:59 am
by polymer
You are quite right about computers not being able to produce a proper random number
they have invented a new way of creating a true random number device at a quantum level ... thing.html

Re: Mysterious Random

Posted: Mon Jan 10, 2011 11:32 am
by Simbosan
There ya go! Quantum!


Re: Mysterious Random

Posted: Mon Jan 10, 2011 1:31 pm
by Rabalder
Thanks everybody!

Case closed.

Re: Mysterious Random

Posted: Mon Jan 10, 2011 2:16 pm
by Captain Johnson