Is there such a thing as chance?

There is a lake, and there is a (suspended)chemical in it of 2 ppm. There is a stream pouring into it, and a dam that forms it. It doesn't matter the size of the lake, or amount of water pouring into it. But eventually this chemical would be washed out, or would it.The amount of time it washes out, is that chance. The fact that maybe a molecule might not ever get washed out, is that chance, or the fact that it may indeed get washed out, is that chance. Is it chance that any three of these options would happen.Are any of these chance?
Does chance really exist?
Or is chance a word we use to explain what cannot be explained because we don't know how it all works, or we don't really understand the laws of the universe?I am no scientist, and this topic may have been covered already, but I would like to discuss it, and share knowledge/thoughts about it.:note to admin, I am not sure what forum to suggest, but please not the coffee house.

Thread moved here from the Proposed New Topics forum.

It's an interesting question but your first example seems to have little to do with the question. If you are defining the chemical as 2 ppm, then as long as we know the variables involved, we can model the outcome. The amount of time it would take to "wash out" the chemical would have nothing to do with chance but all do with the variables involved (the size of the lake, the amount and speed of water pouring into it).

Good point, it is in the direction I am going with this.
So then with that kind of thinking, looking at this part of the definition of chance: A better question would be then, just what do we see in the universe that could be considered chance according to this definition?Keep in mind, as complicated as it would be to find all the variables in the lake example, and then calculate the predicted outcome, it would be considered only a uncomplicated example, compared to everything else we see.I used the lake example, because I vagely remember being taught about that scenerio. I believe that the outcome would always be that the chemical would eventually be washed away completely.

Well... right now, modern physics seem to imply there really is such a thing as chance.
"Something that happens unpredictably without discernible human intention or observable cause"? Radioactive decay seems to fit the bill here. As it is right now, we simply cannot predict when a nucleus will decay. We can calculate the probability that it will within a given time interval, but that's it.
Maybe this is just a result of our limited knowledge of the laws (and I use the word losely) of nature, but this only means we'll have to accept the concept of chance tentatively.
As long as the explanation of chance is the best one available for the phenomena we observe (in terms of accurately describing reality), it's the one we'll use.Phenomena on a quantum level are the only ones I know of that currently can be seen as the product of "true" chance. In all other cases I can think of chance is simply a model we use because it's convenient. Take your lake example for instance. We could, theoretically, sit down and calculate the motion of every single particle in this lake. It would however be an incredibly complex system (with a lot of initial values that would be extremely hard (or impossible) to find) that would be taxing even for our fastest computers to solve in any reasonable ammount of time.
Instead, we create a "fluid model" which makes some observations about the way large collections of particles behave on a macroscopic level, these observations are largely statistical, and thus use the concept of chance.
So no, your example doesn't really involve "true" chance, as we understand it right now, but chance is the best model to use, because it gives us a great degree of accuracy as well as a pretty short time for solving problems.Whether true chance really exists though... we really can't say, and the tentative nature of science tells us we never will.

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"tellement loin de ce monde..."

I understood that atomic decay is basically true chance. That is that while you can predict that some degree of decay will occur over time, you cannot predict which atom will decay when.

There are already a number of threads on this topic, mostly framed in terms of determinism and indeterminism, be warned however, Syamsu is a major contributor to these threads, so how much you will get from reading through them is debatable. I think the most recent one is Syamsu's thread about probability terminology.TTFN,WKP.S. I mean the topic of the OP, not radiactive decay specifically.This message has been edited by Wounded King, 01-11-2005 05:27 AM

Chances are that chance needs to come up with that very first ingredient to chance a chance. Even chance has no chance without that and it doesn't have that first ingredient and, therefore, has no chance.
I wouldn't mind billions of years of this and that, if there were an explanation of where that very first thingie came from that allows the rest of the story. And none of the erudite of science have been able to tell me what chance does chance have without that first thingie.
It's enough to make one believe in God.

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"Let us cleanse ourselves from all filthiness of the flesh and spirit!"
2 Cor. 7:1

The only thing I feel right now which can induce chance would be our own free will.The rest of it like someone just said is ignorance of just how things work.

Forgive my ignorance, but isn't that how we carbon date things?

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I wouldn't mind billions of years of this and that, if there were an explanation of where that very first thingie came from that allows the rest of the story.

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Ah, so it's uncertainty and a lack of knowledge that makes you uncomfortable, then?

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And none of the erudite of science have been able to tell me what chance does chance have without that first thingie.
It's enough to make one believe in God.

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...and since you are uncomfortable with uncertainty, you plug "god" into that gap in our knowledge.Tell me, is everything we don't understand caused by God?

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The only thing I feel right now which can induce chance would be our own free will.

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What do you mean by "induce" chance?

No, not really.We carbon-date things (and do other kinds of radiometric dating) by measuring how incredibly large numbers of unstable nuclei act. But we do not carbon-date things by looking at one particular unstable nucleus.If you have one atom of carbon-14, you cannot predict when it will decay. You can calculate a probability that it will decay in some specified time period, but for that one nucleus that's the best you can do. It may or may not actually decay in that time period.However, when you have trillions of carbon-14 atoms, or (as is more usual) trillions of trillions of trillions of carbon-14 atoms, you can predict extremely precisely how many of those nuclei will decay in any specified time period ... but you cannot predict which of those nuclei will be the ones that decay. You know that some of them will decay but not the particular ones that will decay.Radioisotope dating methods work because any samples we take, even the ones that are incredibly tiny by our everyday standards, have enough atoms in them that the large-number-of-atoms statistics work very precisely.Or, as it says at The Law of Radioactive Decay:"You can't, however, predict the time at which a given atomic nucleus will decay. For example, even if the probability of a decay {of one particular nucleus - JRF} within the next second is 99 %, it is nevertheless possible (but improbable) that the nucleus decays after millions of years."That site has a nice Java applet that simulates decay.

We carbon date (or date using radiometric methods in general), not by knowing exactly when a particular nucleus will decay, but by knowing how many nuclei will decay, on avarage, over a large ammount of time.ADDED BY EDIT:
Or, like JonF mentions, by using an avarage over a lot of particles, which actually makes more sense. This message has been edited by Maxwell's Demon, 01-11-2005 09:03 AM

riVeRraT Individual decay events have an equal probabilty of occuring at any time, so, it is impossible to say when that event will occur for a given particle.