[Garrett]

Some systems which appear to behave randomly or probabilistically may be highly sensitive to initial conditions - a small change in initial conditions may lead to large changes in outcomes. Weather, for example, or a die-roll. In theory, the behavior of such systems could be entirely deterministic with no "random elements" at all.

But what if the small change in initial conditions is provided by the probabilistic behavior of quantum events?

Then we have an interesting situation where the deterministic explanation for an apparently probabilistic event depends on probabilistic events!

For a specific example, imagine controlling all the initial conditions of a die-roll. Toss it from enough height and with enough spin so it seems to behave probabilistically. An edge or corner would eventually strike the surface of the craps table - maybe the position and velocity of an electron at that edge or corner would be the "butterfly" which determines the resulting trajectory, velocity and spin of the die - which ultimately determines which face would end showing up. But those factors - the position and velocity of that electron - are fundamentally indeterminate!

Iow, even though we exactly control the initial conditions, and assume a deterministic explanation for the behavior of the die, it may still behave probabilistically. (!)

I'm wondering two things here: how stupid is my idea, and have you ever heard of a similar idea?

[Quizalufagus]

Not at all, and yes.

The study of differential equations containing functions of random variables is a growing research area right now, and that seems to relate to this idea. Differential equations are usually thought of as a deterministic model when applied to real world problems, but throwing a random variable into the mix challenges that assumption (obviously).

[Rilx]

If we exactly control the initial conditions in tossing die-rolls, the whole event has nothing to do with the general meaning of the die-roll game. The large random variation in initial conditions creates the characteristic indeteminism to the game.

I don't see that the butterfly effect could be applied in the die-roll case. The effect doesn't belong to the initiation of a whole process, but to the occasional change in the middle of some complex system of continuous processes, like weather.

If I interprete your purpose right, you are searching for an explanation (or even proof) to the probabilistic nature of some events (die-rolls) which you experimentally and intuitively know probabilistic. I think the problem is in the method: you assume first that the process is deterministic and then try to find contradiction with determinism...? When tossing a die-roll your breathing and circulation and metabolism takes care that initial conditions are never the same. And you may have butterflies in the stomach, too.

[Quizalufagus]

Indeterminism isn't the same thing as true randomness, though. As I read it, Garrett's point is that even if we could take care of sensitivity due to initial conditions, some macro phenomena may still be indeterminate due to randomness in some components.

[Rilx]

Yep, I understood Garrett's point. He also asked for a general evaluation of the idea. In every material phenomenon we can go to quantum level and - by the definition - conclude that every material phenomenon is indeterminate. The concept loses its meaning.

[Garrett]

Quizalufagus
As I read it, Garrett's point is that even if we could take care of sensitivity due to initial conditions, some macro phenomena may still be indeterminate due to randomness in some components.

Yes, although I wouldn't use the word "randomness" since it is too ambiguous.

The op idea is new to me, and one which I think I thought up on my own. Maybe I encountered it somewhere and just don't recall, which explains my second op question.

What is especially interesting to me is that chaos theory, which is designed to provide a deterministic explanation for apparently-probabilistic events, may actually fail in that regard!

"Indeterminism", btw, is the idea that some events are not caused. I really have no idea how that can be taken seriously - it amounts to saying that we are unable even in theory to ever understand our universe. I think science must assume that events are caused.

Determinism seems to be a very confusing subject. People tend to treat it as if it merely says that all events are caused. However, I think it makes at least three distinct claims: all events are caused, all causes are antecedent, and no causes are probabilistic.

I've been becoming more and more fond of the idea of probabilistic causation. Right now I'd say that all events are caused, all causes are probabilistic, and some causes may not be antecedent.

[Garrett]

Rilx
In every material phenomenon we can go to quantum level and - by the definition - conclude that every material phenomenon is indeterminate. The concept loses its meaning.

I don't understand why you say that would mean it "loses its meaning".

Anyway, are all macro events directly influenced by quantum behavior? Gravity always pulls the apple down to the earth - no apple can ever suddenly be pulled sideways or upwards by the earth, if you see what I mean. The behavior of gravity-events don't seem to submit to any sort of quantum indeterministic behavior.

I don't see that the butterfly effect could be applied in the die-roll case. The effect doesn't belong to the initiation of a whole process, but to the occasional change in the middle of some complex system of continuous processes, like weather.

That's interesting, but I don't think it is accurate. Putting the butterfly effect at the start of a chain of events, where no other link in that chain is another "butterfly", is just a conceptual tool.

Read the fourth paragraph in the op again. The moment the edge strikes the surface could be an "initiation", and when it bounces and again strikes an edge there is yet another "initiation" - so there is an sequence of butterfly effects, escalating and magnifying the range of possible outcomes, so to speak.

[Quizalufagus]

Originally Posted by Garrett

Yes, although I wouldn't use the word "randomness" since it is too ambiguous.

"Randomness" can actually be made very precise--indeed, mathematically precise.

"Indeterminism", btw, is the idea that some events are not caused. I really have no idea how that can be taken seriously - it amounts to saying that we are unable even in theory to ever understand our universe. I think science must assume that events are caused.

It seems to me that there are well-documented phenomena on the quantum level which aren't at all caused. How can fundamentally probabilistic behavior be thought of as caused in the usual sense, anyway?

[Garrett]

Quizalufagus
It seems to me that there are well-documented phenomena on the quantum level which aren't at all caused.

Not caused in the usual (classical, deterministic) sense.

Do you really believe that nothing makes them happen? That there is no reason for such events to occur?

I think that if you ask scientists what causes quantum events, they won't say "nothing". I think that when they say they are "uncaused", they are speaking loosely, and if you question them closer it will turn out they merely mean there is no known deterministic cause for those events.

How can fundamentally probabilistic behavior be thought of as caused in the usual sense, anyway?

It can't. But so what - the "usual sense" is classical deterministic causation - which is by definition not probabilistic.

I think probabilistic causation makes more sense than deterministic causation. Oddly enough, the determinist can't claim that sex causes pregnancy, or that war causes deaths, or that smoking causes cancer, etc.

[Quizalufagus]

What does "probabilistic cause" mean?

[Pyrogenesis]

It's when you add "...or not" at the end of every causal claim. "Peter liking the hawt chixxor Mary causes Peter's pants to itch or not."

[Garrett]

probabilistic causation (Stanford)

probabilistic causation (Wikipedia)

[Gurdur]

Originally Posted by Garrett

..... I'm wondering two things here: how stupid is my idea, and have you ever heard of a similar idea?

If I may say so, the quantum butterfly is an idea a few people have had (as so often, with every good idea, a lot of people get it simultaneously) -- it's usually expressed in two different ways:

1) The stochiastic butterfly whose wingbeats over (say) Argentina eventually cause a typhoon over China (Terry Pratchett, BTW, includes this in one of his novels; he's very fond of including all the latest scientific ideas in his books)

2) The Butterfly Effect, which is a named thingy in Chaos Theory.

[Rilx]

Originally Posted by Garrett

I think that if you ask scientists what causes quantum events, they won't say "nothing". I think that when they say they are "uncaused", they are speaking loosely, and if you question them closer it will turn out they merely mean there is no known deterministic cause for those events.

I agree. Generally, when something has happened there must always exist causes because of conservation of energy. Otherwise the event had got its energy of birth from nowhere.

The nature of matter/energy is actually unknown in the quantum level. All we know are explanatory models derived from secondary observations. The radioactive decay could (IMO) be modelled by vaporization of water essentially below its boiling temperature. Some vaporization happens in normal room temperature, say 22 deg/Celsius. Though we can imagine determinism, it's practically as random as radioactive decay to determine which water molecule reaches the vaporization energy (corresponding 100+ deg/C) and leaves water container like a particle from radioactive matter.

If the liquid were deadly poison which killed when breathed a certain amount, it could be used to perform the Schrödinger cat experiment.

[Rilx]

Originally Posted by Gurdur

2) The Butterfly Effect, which is a named thingy in Chaos Theory.

It must be over 30 years when I heard a radio play which first introduced the butterfly effect. I can't remember name or author, but this is what happened:

It happened in far future. The world was developed both technically and socially. Time was happy and peaceful, life was easy because of technical development. Time machine was invented and tours to past were organized.

A tourist group travelled to the stone age. It was like a nature reserve: tourists were allowed to use only certain paths. A person slipped and accidentally hit a butterfly, breaking its wing.

When the group returned home, they found themselves in the middle of world war.

[Gurdur]

Originally Posted by Rilx

It must be over 30 years when I heard a radio play which first introduced the butterfly effect. I can't remember name or author, but this is what happened:

It happened in far future. The world was developed both technically and socially. Time was happy and peaceful, life was easy because of technical development. Time machine was invented and tours to past were organized.

A tourist group travelled to the stone age. It was like a nature reserve: tourists were allowed to use only certain paths. A person slipped and accidentally hit a butterfly, breaking its wing. ...

I don't know the radio play, but I do know the very original SF story it's based on. The story ends with the group returning to find a kind of fascist regime in charge, instead of the democracy they had when they left on their trip.

I can't remember the author either *, but I think the name of the SF short story was "A Sound Of Thunder", and I will look it up.

____

* It's been 3 decades since I read it.

[Gurdur]

Bingo!!!

The SF short story on which the radio play was based is A Sound Of Thunder, written by Ray Bradbury, and you can get it here along with other short stories by Bradbury.

[Gurdur]

And there is a whole Wikipedia entry on that SF short story.

Interestingly, Bradbury seems to predate anyone else using the butterfly metaphor, so the Butterfly Effect seems to be so-named bacuse of the Bradbury-created meme.

[Garrett]

Gurdur

I think you miss my point. I know about the butterfly effect - that isn't the 'new' idea I'm talking about.

[Rilx]

Originally Posted by Gurdur

Bingo!!!

The SF short story on which the radio play was based is A Sound Of Thunder, written by Ray Bradbury, and you can get it here along with other short stories by Bradbury.

Thats the same play I remembered, and I remembered the end wrong, it wasn't war but fascist regime. 30 years really means something.

[Gurdur]

Originally Posted by Garrett

I think you miss my point. I know about the butterfly effect - that isn't the 'new' idea I'm talking about.

My apologies, my brain during this period is sadly defunct. I do agree completely with your actual point.

[Garrett]

I don't believe I'm the first to have that idea, but so far, I'd say finding swag no one knew was there is something to smile about.

Afaics, I just kicked the last leg out from under determinism. Not unlike helping to slay the Trickster god!