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Is anything Random?

M600

Sock Hats are Cool!
Jan 4, 2008
894
70
63
true, i totally agree with you
but some things are still random no matter how close or accurate predictions can get
anyway
interesting convo :)
 

Robbo

Owner of this website
Jul 5, 2001
13,114
2,157
448
London
www.p8ntballer.com
true, i totally agree with you
but some things are still random no matter how close or accurate predictions can get
anyway
interesting convo :)
M600, I think you have missed my point again; the only thing that is truly random is .......... the mind of God - everything else is predictable if we know the rules and the initial states, this is my point mate.
 

Duncan Berry

London Tigers 2
May 27, 2008
83
1
28
39
Cambridge
Now i dont know too much about this but some clever boffins somewhere are studying quantum physics and at the the most base level they say the entire universe is random.
 
John, I was gonna let this post go but I just can't ....sorry mate.

Some people may think my reply is pedantic but I am sure you are aware, if you jump into this thread, or in fact into this forum, when you state something, then it has to be as near as one can make it, skeptic resistant.

The idea of anything being random is something that is in my understanding, pattern free.
It seems ironic to me that you quote the background radiation interference from the big bang as random when it was a bunch of scientists looking for the smoking gun of a 'pattern' in the sky to finally validate the big bang.

It could be argued, that if we knew the initial conditions, we could well predict the interference 'seed' you would look to as your random input.
Im glad you didnt let it go. How boring would that be?


My original post was mainly pointing out that conventional electronics (computers) cant just pick a random number.


'Random' noise can be observed in some semiconductors based on Quantum mechanics.
The origin of this noise is the same data that the SETI program has been processing for years, yet failed to find any pattern whatsoever.

I understand quantum mechanics accepts randomness as a property of the universe.
If you accept that you can have a situation where one seed produces more than one possible outcome even when all else is equal.

You may not accept that. You could say that any apparently random variation is innacuracy due to our limitations (of understanding or of measurement).

At this point, that is more a debate of belief and faith rather than science.
At least it is with me as Im far from qualified to argue the validity of quantum theory.
 

Bedlam

Gone crazy, back soon...
Randomness denotes a lack of predictability not a lack of probability. Given todays current thinking on this subject (Which has changed over the years), even seemingly chaotic functions have an element of predictability.

So, while we can posit examples of randomness, there is an school of thought that sets out to determine predictability from the chaos. For some, that may fly in the face of common sense. For example, the law of entropy determines the measure of randomness or disorder within a closed system. When I was taught thermodynamics and we discussed entropy, it was taken that all systems will tend to a more chaotic or random state. I am not so sure that that is current thinking though.........look at chaos theory. That builds upon the idea of entropy but bases its randomness on the initial state of the system and then determines the systems state at a distant point in time.

So, whats the point? Well, essentially, randomness is not as chaotic as we first thought and the more we understand any given system, the more we move from probability to predictability.

The only danger I have with this line of thinking is that it means that nothing I do in my life is truly random. That means, as a system, my life (while appearing chaotic) is predictable, which then means I have no true free will. Oh crap.......and here's me thinking I was in control :p
:cool:
 

Rabies

Trogdor!
Jul 1, 2002
1,344
8
63
London, UK
Randomness is determined by the entropy in a system. A computer, with no external stimuli, cannot generate randomness, only pseudorandomness. That is, it may to all intents and purposes appear random, but it follows a predictable pattern. In many cases, by observing a sequence of pseudorandom data, one can determine what will follow. Thus it obviously can't be random, because randomness must be unpredictable. The most common use of randomness in computing nowadays is cryptography, which requires that the randomness is, as far as possible, entirely unpredictable; otherwise the potential exists to determine what the content of the encrypted data is, or to forge an encrypted message.

So mechanisms exist to introduce entropy into the equation. Entropy in this context means unpredictability -- it is the amount of "unguessable" data which has been fed into a system. Computers often generate entropy by using the timing of unpredictable external stimuli, such as keystrokes or network activity. Feed these into the pseudorandom number generator, and what comes out is significantly more random (i.e. less predictable) than the basic pseudorandom number generator. But it is (theoretically) possible to influence the random output by controlling the entropy going in, which must be a consideration in any case where true randomness is needed.

Electronic circuits needing randomness sometimes use semiconductor junctions known for their noisy behaviour (usually an undesirable characteristic!), and feed the entropy from this noise into the generator. But these methods are prone to producing biased results, which may be unpredictable but not statistically well-distributed. They can also be affected by external sources such as electrical interference, which again makes them less suitable where a high degree of randomness is essential.

If you want real randomness, you want one of these: http://www.idquantique.com/products/quantis.htm

This device works, in simple terms, by firing individual photons (light) at a partially reflective surface. About half the light will be reflected into one sensor, the rest will pass through the surface into a second sensor. But an individual photon cannot do both; it will either be reflected or it won't. Now, quantum theory tells us that it is not possible to predict in this case which individual photons will go which way. We know that about half will go each way, but where each individual photon ends up cannot be predicted.

This is where we finally meet true randomness. Randomness, of the true variety, is very important to quantum physics. For instance, Heisenberg's Undertainty Principle tells us that we cannot predict both the position and the momentum of an electron at the same time. In other words, you can calculate one property, but the other is unpredictable, i.e. truly random. So, in the quantum world, randomness really does exist. Einstein struggled with this concept for a large portion of his career, when the new generation of physicists developed the field of science he had largely created. He could not accept that there came a point at which things could not be determined mathematically, hence his famous (paraphrased) quote, "God does not play dice with the universe." However, it seems, God does play dice with the universe, and some things truly cannot be predicted.