The Meaning of "Random"

Well, my type of physicists care a lot about deterministic systems, but a lot of physicists spend their lives working on stochastic systems that are inherently random. I don’t want to discount their work by saying that physics don’t really care about them :yum:

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What would you characterize Brownian Motion?

It is clearly theoretically deterministic, but certainly not so in practice. It can be modeled as a random walk (an ergodic process). It turns out this is very hard to even simulate directly in molecular dynamics as a deterministic process. So it may not even be deterministic in the context of simulation. Still, it apparently follows classical physics and should be in principle reversible and deterministic.

Is that a random or a deterministic process?

This is a philosophical question :yum:

I would say that the mathematical model of a Brownian motion model is stochastic and random. Real life Brownian motion is classical and not random. In the limit of large number of particles, the stochastic mathematical model of Brownian motion approaches the deterministic real life Brownian motion.

So I would say that it is both random and deterministic, depending on whether you are talking about the mathematical model or the IRL version.

I suppose that is my point exactly.

Or just a a causal pattern we cannot practically model, as in the case of Brownian Motion, even though we know in fact it is there.

What about when there is no causal pattern, like in quantum mechanical collapse?

We don’t know yet, do we? As I understand it, collapse can still be explained by a Bohmian mechanics. There have been some very interesting experimental results on this recently too, out of MIT I think. So it is possible there is a hidden deterministic process governing collapse, right?

Regardless, even if there is not, it might still be deterministic from God’s point of view.

Yes, but for Bohmian mechanics to be true we need to give up locality. This is not easy for a physicist to give up - perhaps even harder than determinism. Further, the relativistic generalization of Bohmian mechanics relies on an unobservable preferred frame - which in its own way runs contrary to the spirit of relativity. The field theory generalization (to bring QM->QFT) as I understand it is not fully understood and is still a topic of active research.

If one can even define a notion of determinism for a being outside of time like God, I suppose this could be true.

@nwrickert

This is a lot of discussion to support a favorable view of “randomness” … whuch is conpletely beside the point here at PS.Org: we dont have to defend randomization because we dont need an unguided Universe.

We have already signed-up for a “god-guided” universe!

Some of us have. Some us haven’t.

I think most people here would agree that god-guided is not in conflicted with evolutionary science, even if that isn’t their personal opinion.

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It was mostly for a small number of people who have seemed confused about randomness.

@swamidass

So… you can definitely say that from a theoligical perspective, that there are things In The Universe that are RANDOM to God as you would understand God?

Just say yes, and ill re-adjust the wording of my complaints!

Yes - that amounts to the same thing: a lack of full knowledge. The molecules know exactly where they’re going, at least at the Newtonian level.

What’s our problem, then? Simply that we are not closely in touch with the molecules. We’re not even fully in touch with ourselves. If it was the case that we knew ourselves perfectly, and that in us the molecules lived, and moved, and had their being, it would be a different epistemological universe.

Stirring custard would then be reasonably analogous to lining up counters in a row.

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Still a big fan of ‘stochastic’ as a good enough term…

‘Ergodic’ seems unnecessarily ‘fussy’.

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Isnt stochastic just random too?

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I agree with this statement. I see no conflict between the randomness described by science and the theological belief that God is involved in the process in some way, even though I lack a belief in God. This non-conflict has existed within the sciences for a long time now, and I am quite proud that it appears to be continuing into the future.

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Science doesn’t make claims about God so it certainly doesn’t claim that anything is random from the perspective of God. Science is silent on this matter.

Theological, what we can random may not at all be random to God. At least it may be no more random than free will.

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@gbrooks9 I think the way the wording could be improved is to state it similar to how I did. We don’t care if people personally agree evolution is guided or not. However, when they state their opposition we just want to clarify they are opposing it on personal, not Scientific grounds. As long as they are tolerant of other views I have no quarrel with them stating their won view.

Goin forward, you can even just quote @T_aquaticus and myself:

Quote that when ever you are frustrated by people declaring for unguided evolution, and you will do a lot of good, and encounter very little resistance from the atheists and agnostics here.

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It carries a slightly different nuance because ‘random’ is freighted with so much baggage in colloquial use, to me. For example, if you described to a layman that an electron’s position can be distributed randomly around a nucleus, and then show them a picture of a pi orbital, they’re going to suggest that’s not what they initially envisioned by ‘random’ (Something like an s-orbital might match their expectations better). You and I know that a description of something being ‘random’ needs to include information about distribution. But to laymen, the first thing people think of is an equal distribution – all outcomes equally probable. “Stochastic” also tends to invoke a process in people’s minds. That’s why I like to use ‘stochastic’, particularly when discussing a process, like evolution. I wouldn’t characterize many of the mechanisms and processes in evolution as being ‘ergodic’. Makes sense for use in statistical thermo…

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@gbrooks9 responds:
"This is a good benchmark sentence, @swamidass. If we can get @T_aquaticus to use it… the people he chats with will not only understand him better… but they will also know better that G.A. has the capacity to treat Randomness from a Theological perspective… rather than from a purely scientific one.

I’m inclined to see that as an unreasonable request.

Looking at it from my agnostic perspective, I do not have a problem with the view that god-guided is not in conflict with evolutionary science. But it would be inappropriate for me to argue that view. I can accept it, but because am not a theist, I cannot argue it. And I suspect that also would apply to @T_aquaticus.

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