Random?

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Borommakot
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Random?

Post by Borommakot »

If one being knew the past and present of everything, would he be able to know the future? I've heard about quantum mechanics, and "stuff" like that, but I don't belive any of it. I completely agree with Einstien. I don't think that there are any random events. None.
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Dan Rowden
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Post by Dan Rowden »

Since one cannot know the present of everything, the whole issue is moot.
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Shahrazad
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Post by Shahrazad »

If one knew the exact position and state of each and every particle in the universe, one could know the future. Assuming, of course, that we live in a deterministic universe.
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Dan Rowden
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Post by Dan Rowden »

That has 3 faults. Can you guess them?
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Shahrazad
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Post by Shahrazad »

I'll try.

(1) A person will never know the position of every particle.

(2) The universe could be in part random.

(3) We don't have perfect knowledge of laws of nature.

.
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Katy
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Post by Katy »

How about the entire thing could be an illusion?
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DHodges
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Re: Random?

Post by DHodges »

Borommakot wrote: I don't think that there are any random events. None.
"Random" means you can't predict something ahead of time. Usually this is due to limited information. For instance, you can't predict the roll of dice because you don't have perfect knowledge of the initial position of the dice, the force with which they are thrown, the friction at each point on the table, and so on.

In quantum mechanics, there are some other issues when you get to small scales - the main one being that at very small scales, a "particle" is not at a "point" - at a small enough scale, a "particle" is a wave smeared out over some region, and you can only gain information about the wave by changing the wave in another way. So you have theoretical limits on the knowledge you can possibly have on a "particle" - you can't know everything about it at once.

"Random" does not mean something outside causality. Everything is subject to causality, but that does not mean that someone can know all the causes and predict what will happen. We always have limited information.
Borommakot
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Post by Borommakot »

My problem is this. Someone who knows a fair amount of quantum mechanics told me that everything is a probability. But what confuses me is that that probability is caused by something else defying the laws of nature, which is caused by the same.

For example: if one dropped a pencil, there is a possibility that it would float. I think that if we knew the reason that it would float, and the reason for that, and so on, we could predict the future from one event. well, the last thing i said isnt practical, but my point is that the common term "random" is impossible.
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Jamesh
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Post by Jamesh »

You folks need to think a hell of a lot more about what a thing is and isn't. Think about the interconnectedness of all things.

It is definitions that create things. All definations are limitations of reality. Calculations based on these definitions/limitations can never be absolutely predictively determined, as their nature arises from changes that occur at lower (and higher) levels from whatever has been defined as a particular thing.
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