Does random have rules?

[robvalue]

It's a very interesting subject. My intuition tells me that if we think it's random, it must be because we just don't understand it fully yet.

But as I've learned, QM and intuition really don't mix! So I tell my intuition to shut it.

You can't even apply very basic rules of probability, like if it's come up red 30 times in a row, it's virtually guaranteed to be black this time so sell your house and your kids and pile it all on. And always take a bomb with you onto a plane, because the chances of there being two bombs are much less! Also, avoid really unlikely lottery combinations like 1,2,3,4,5,6.

Just having silly fun.

I need to learn more about QM, sadly my brain isn't up to it at present. God damn it's weird.

[downbeatplumb]

The one thing I have been told is "real randomness clumps things together".

[Alex K]

I think in principle that should be possible. Consider bohmian quantum mechanics. It is a deterministic interpretation, and even though that doesn't mean that the randomness which occurs can be calculated by a simple formula(it is akin to a chaotic system where arbitrarily small changed in the initial conditions can have huge effects), it nevertheless is only pseudo random because it is uniquely determined by the starting conditions of the hidden variables.

[Homeless Nutter]

[...]'entropy' is a cop out term that describes a given indivisuals limited understanding, of what he can not explain.
[...]

Nope. What you're thinking of is 'God'.
Stick to bothering Jesus and quoting fairy-tales, you're obviously out of your depth here.

[robvalue]

The first rule of quantum mechanics is if you think you understand it, you don't understand it :p

[watchamadoodle]

The one thing I have been told is "real randomness clumps things together".

Hmmmm.

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I think in principle that should be possible. Consider bohmian quantum mechanics. It is a deterministic interpretation, and even though that doesn't mean that the randomness which occurs can be calculated by a simple formula(it is akin to a chaotic system where arbitrarily small changed in the initial conditions can have huge effects), it nevertheless is only pseudo random because it is uniquely determined by the starting conditions of the hidden variables.

If QM was ultimately deterministic, what would that say about entropy?
IMO, thermodynamics wouldn't work unless randomness is as "real" as energy, mass, etc.
Like in your example in an earlier thread of the 3-body problem and the arrow of time, that was not "real" entropy IMO, because everything was deterministic forward and backward in time.

[Little lunch]

I can't understand anything anyone's talking about. (Ohoh, I'll be put in Drich's dumb person file). :-)

But if I was rolling dice, nothing would affect the outcome except gravity and hitting the table or each other.
I couldn't believe that some law of randomness would have any effect.
I'm clearly missing something.

[downbeatplumb]

[quote='downbeatplumb' pid='908722' dateline='1427444698']
The one thing I have been told is "real randomness clumps things together".

Hmmmm.

Ask people to spread themselves out randomly and the will spread out almost equidistantly around the space. Real randomness would have clumps of people together.

It's the same with coin tosses. people assume that because heads has come up twice tails is more likely but it isn't.

[Alex K]

The one thing I have been told is "real randomness clumps things together".

Hmmmm.

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I think in principle that should be possible. Consider bohmian quantum mechanics. It is a deterministic interpretation, and even though that doesn't mean that the randomness which occurs can be calculated by a simple formula(it is akin to a chaotic system where arbitrarily small changed in the initial conditions can have huge effects), it nevertheless is only pseudo random because it is uniquely determined by the starting conditions of the hidden variables.

If QM was ultimately deterministic, what would that say about entropy?
IMO, thermodynamics wouldn't work unless randomness is as "real" as energy, mass, etc.
Like in your example in an earlier thread of the 3-body problem and the arrow of time, that was not "real" entropy IMO, because everything was deterministic forward and backward in time.

The concept of entropy was invented in the context of classical mechanics, which was perfectly deterministic.

I think one of the important aspects is the ergodic hypothesis

http://en.wikipedia.org/wiki/Ergodic_hypothesis

which allows you to look at the system averaged over time as if you had many different copies of the same system with randomized initial conditions. I have the suspicion that this might open up the possibility to talk about probabilities and such in a deterministic system. But I haven't thought about it in detail, and this is just what I came up spontaneously. If I meet a statistical physics person in the coffee room later I shall ask.

[watchamadoodle]

The concept of entropy was invented in the context of classical mechanics, which was perfectly deterministic.

I think one of the important aspects is the ergodic hypothesis

http://en.wikipedia.org/wiki/Ergodic_hypothesis

which allows you to look at the system averaged over time as if you had many different copies of the same system with randomized initial conditions. I have the suspicion that this might open up the possibility to talk about probabilities and such in a deterministic system. But I haven't thought about it in detail, and this is just what I came up spontaneously. If I meet a statistical physics person in the coffee room later I shall ask.

It seems to me that if you tried to derive the thermodynamic laws bottom-up from a deterministic model of particle behavior, then your laws would not be laws. The thermodynamic laws would need to say "this is almost always true for a large population of particles." instead of "this is always true".

I have read that many physicists think entropy and thermodynamics are the most trustworthy ideas in physics, so I think that means randomness must be a real thing.

I think it would be really neat if randomness is a real thing, because so many ancient cultures believed that the world was created in a battle between a god of law and a god of chaos.