What is random?

Started by: Skeletonxf | Replies: 4 | Views: 1,144

Skeletonxf
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Feb 16, 2014 4:05 PM #1159723
A truly random process does exist, such as radioactive decay - which can be averaged and follows a pattern but no scientist can pinpoint the exact time of the decaying

My question is, at what point do we decide a process is random?

I can roll a die and if I had enough data and put it all into a simulation sophisticated enough I could predict the way the die will land at the time I toss it into the air, the die is perfectly predictable but not for a human alone. Thus, I can randomly allocate things to a die roll, but is my die roll random? There is a totally predictable method to my die roll.

Studying psychology gave me a definition of random allocation as being 'everything having an equal chance of being selected' which my die roll would have as each side has a 1/6 chance. Or at least it should, but if I weigh a die to make the 1 face heavier to get more 6s (opposite die faces add up to 7) then my chances aren't equal any more, but surely they're no more or less random than before, just with different odds?

Thus, were radioactive decay to be found to have some way of predicting it, would that also have to be considered no longer random or can I still consider a process random if I can't work out the outcome prior to the event (at that time) even if I could with enough data?

Random:
made, done, or happening without method or conscious decision.


Edit: It is usual for no one to chip into these discussions or have I not typed something right?
Edit2: @Syber (I do suspect replying would infract me because of the bump), thanks, but I actually am subbed to those channels and saw the videos on release, so I guess I had my answer long before you posted. Either way, that does indeed answer everything so I guess that's the end of the debate.
Syber
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Nov 16, 2014 12:55 AM #1269334
https://www.youtube.com/watch?v=9rIy0xY99a0

This will answer everything
En
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Nov 17, 2014 7:38 AM #1269840
I think you already answered the question. We no longer call something random when we are able to predict its outcome before the outcome can occur. When there is 100% possibility that something will occur, it is considered not random. We know that the sun rises and falls every day, so therefore it is not random. We know that following winter, spring will come therefore it is not random.

Games like gambling however would be considered random regardless of your advantage as there is some degree of uncertainty. While you may have %99.9 chance of winning, that is still not a certainty but just highly probable.

Probability is also not the same as randomness though related. Probability gives you an indication of the frequency to which a random event is likely to occur.

Something that might be of interest to you is entropy, relating to thermodynamics. I was taught it in first year chemistry and it is a real brain bender but I'll try my best to explain. So what is entropy first of all? Entropy, in layman terms, is the amount of randomness and disorder within a system. Say for example you have two containers, left and right, that are connected by a pipe, but this pipe is currently shut; stopping the movement of any molecules across the containers. Say you were to place two gas molecules, A and B into one of the containers and then open the pipe to let them freely move. Basically you will end up with 4 configurations.
Image
Now let's ignore what the specific molecules and just look at there position. Clearly having one molecule on either side is the most likely configuration right? So if we were to determine the probability it would go 1/2 for both sides, 1/4 for all left side, 1/4 for all right side. But that's not how the world works and you very rarely get anything with just two molecules. What you will find that by increasing the number of molecules in the system the probability of even distribution on both sides will increase dramatically and that the other configuration become extremely improbable (all on one side for example)

So how does this relate to the topic? Well in the scenario I described, we were able to see that with a large enough sample, something that may seem random is now considered highly probable to the point where it is almost a certainty. But we still consider the process random if we look at it really really closely, only we say it is highly probable.

I hope I didn't muck up the explanation or misinterpret the theory so feel free to call me out on bullshit.

edit: fucking ipad, I'll fix this shit when I get home.
Skeletonxf
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Nov 17, 2014 4:59 PM #1269978
xD No, you didn't mess it up, nice post. I also found this article on how probability is not something you should assign to an object quite interesting and related.

The probability of something can change, and the article had a few good examples with how finding out something changes your probabilities in the same scenario of the same question. Hence the randomness of something is only something we can assign to the object based on what we know.

The chance of rain tomorrow would be 'random' 1000 years ago without all the equipment we now have, because the probability is only based on what we know, not the object/event we talk about. :P
Skeletonxf
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Jan 15, 2015 6:25 PM #1295746
What's it?
You haven't provided a link to the thing you're talking about.