Does randomness exist?

I just want to say up front that I am a ardent NON-determinist. So of course am bias. I was always under the impression that the behavior of our physical world all the way down to the atom and then down to the wavefunction was not totally predictable. This has very important ramifications. A clock-work universe negates freewill.The only thing that keeps me personally out of the pit of nihlism is the concept that I, on some level I have control over my decisions and destiny. Congito ergo sum.I can decide ...I can decide not to decide. And hence made a choice.My thoughts manifested through biochemical reactions in my brain give rise to ideas, and manifest my will on the physical world which in turn changes everything.Illusion? Perception? Determined? Or Choice.
I Prefer the latter. In my opinion if it can not be calculated experimentally or mathmatically to be 100 percent accurate then it is not fully deterministic.
And the smallest margin of error can change the data. If the data is not fully reproducible then the event is not either. Will it rain tomorrow? What is your prediction?

It is totally deterministic. Given the initial wavefunction and a description of the system, I can give the final state with toal accuracy.Now measurement is a different story.

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Once and for all There is a element of complete and total randomness ingrained into the fundalmental elements of existance. Get that ?

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I understand the reasons you have given to come to your conclusion. But even so, I am not ready to totally commit to the existence of true randomness for the same reason I am agnostic rather than atheist.I don't believe for a second that we've figured out all there is to know about the universe quite yet.And on the issue of free will. We don't have any, but that makes no difference to you or me.[edit]To clarify: I am not some sort of dualist. I believe that if there is some sort crazy, very powerful God, it will be a physical thing. I'm only saying that the possibility, no matter how infinitesimal, still exists.This message has been edited by Drewsky, 04-07-2006 01:06 PMThis message has been edited by Drewsky, 04-07-2006 01:09 PM

Thanks for your reply given the intial wavefunction and a description of the system would yield a totally accurate prediction. But still the calculation would be based on prediction and not on a predetermined outcome. Is this correct? *edit to add imageThis message has been edited by 1.61803, 04-07-2006 02:19 PM

Well since you do not state what those reasons are I am at a loss of what this statement even means. As for your statement "true randomness"...please define your term. Stochiastic behaviors? or Quantum randomness? Classical theory of chaos of finite-dimensional systems? What would you consider is a example of something that is not truly random and why do you consider it not be be random? Really? Jeeze....I am sure glad I finally met someone who has all the answers and the balls to post them without supporting evidence. Since you have elected to speak for me and the rest of mankind we can all just listen you and your psuedo-enlightened rhetoric.

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Well since you do not state what those reasons are...

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My reason was:

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I don't believe for a second that we've figured out all there is to know about the universe quite yet.

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Really? Jeeze....I am sure glad I finally met someone who has all the answers and the balls to post them without supporting evidence.

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Yikes, that stings. Now I know what it feels like for the theologists on this site! You are right, though. It is an unsupported claim that relies soley on "what feels to be the truth". I should have mentioned that I didn't intend it to be taken as fact.We were having such a good debate. I never wanted emotions to start showing through like this.

Hi Drewsky. The question of whether there is such a thing as randomness or not is fundalmental to the concept of freewill. You stated emphatically we have none. And that it does not matter to you or for me. I respect your opinion but do not add me into it. I posted earlier being very clear that the idea of freewill is extremely important to me personally. Now I felt like you either gave a shit or did not read my post. Or added that statement to dig at me. Either way I wanted to make clear that It is not crazy or silly to think that randomness exist in the universe.(however slight or in what ever form) There is more at stake than just winning a argument. People read these post and draw conclusions from them. I apologize for being an ass. Peace be with you.

That's alright, I can agree to disagree. I personally found this thread to be useful to me. I hope it was for others as well.

Just rephrase this line, I want to make sure I'm answering correctly.

In other words: Schrodingers equations can extract data from the wavefunction to such a precise degree that things such as PET scans and MRI are possible. But the data is approximated based on what the computer thinks the image will look like and not based on something that can be measured as a something that is static and fully deterministic.
Also the stochiastic behavior of some elements in nature are indeed random and not deterministic in the sense that there are so many variables 100% accuracy in outcomes is impossible and the intial conditions can ever be duplicated anyways. In my opinion, nature is both deterministic and random.

Schrodinger's Equations govern the evolution of the Wavefunction from time A to time B.
A different set of tools is used to describe measurement.
When you measure a quantum mechanical property the wavefunction jumps (not collapses like people always say) to a wavefunction which is classically sensical.However measurement isn't what Schrodinger's Equation talks about. Many variables actually doesn't cause that much indeterminism. It just means the system is complex.
A much bigger source of indeterminism is Chaos.
Even worse than Chaos is stuff like the Navier Stoke's Equations.
(Probably the most unpredictable things in nature are governed by this)
Believe or not, some physicists think we'll have a working theory of Quantum Gravity before we understand fluid flow, even though we already have the equations that govern fluid flow.

Nicely put. I would perhaps dare to go one step further and replace "jumps to" with "evolves into" which then really gets us back to one process, not two, which is more the basis of decoherence. What do you think? The Part III High Reynolds Number Flow exam: open book, average mark 16% Stay well clear of fluid dynamics and stick to the easy stuff...

To be honest, I think "evolves into" is the correct wording, as I believe that, fundamentally, something does happen during measurement which causes the state to go from |A> to |B>.
I also think this is due to decoherence.[musing]Although I still haven't made up my mind as to what decoherence is. I'm not sure if it's just environmental interaction.[/musing] Imagine, some think that solutions to the Navier-Stokes equations don't even exist.
Just like nature to make something like a river more unpredictable than a black hole.

Thank you for the reply,
mathmatically expressing a rock skipping on a pond is no simple task either. How wonderfully simple and yet tremedously complex our blue marble..

Exactly.Simulations for a rock skipping on a pond make huge simplifications.
(Incompressible fluid, very smooth rock, e.t.c.)