The existence of random

The laws of physics apply on all the matter in the universe. Therefore it could be resonable to expect that knowing the current state of the universe including all its matter, energi, position etc. etc. would give you (in theory) enough info to foretell how the universe would be in 1 day or 10000 years as all the universe is bound up in the laws of physics. That would imply that if the universe could travel back in 1 million years back in time, it would end up here with me typing this message in 1 million year. I do believe this is called determination. This would eliminate the possibility for randomness, and we are all robots with no controll over our own lives.

I dont believe in the determination theory cause I dont want to beleive in it. With no determination and the universe "rewinding" 1 million years back in time and than we pushed "play" again, the end of the story would NOT be me sit here posting this [censored].

So - how can something random happen? Is it proof of Gods excistence or is it incorporated in the laws of physics in some unexplainable way? Could TWO PLUS TWO BE FIVE once in a while [img]/images/graemlins/shocked.gif[/img]

[Brom]

[ QUOTE ]

So - how can something random happen?


[/ QUOTE ]

Randomness comes from our inability to know the exact position and velocity of particles due to the Heisenberg uncertainty principle. We can have vague ranges to place these values in, but never exact numbers. We can assign probabilities that the particle will be at any particular velocity and/or position at any given point in time from those boundary conditions. It will "randomly" be one of these values with it being more likely that it will be one of the values of higher probability.

You are right in that true "randomness" can not occur. It is always taken from some subset of values.

PS We also don't know any of the formulas for complicated sub-atomic particle interactions (or atomic particles for that matter). Therefore more things seem "random" because we can not come close to predicting their behaviour or probability distribution ranges.

[KenProspero]

[ QUOTE ]
The laws of physics apply on all the matter in the universe. Therefore it could be resonable to expect that knowing the current state of the universe including all its matter, energi, position etc. etc. would give you (in theory) enough info to foretell how the universe would be in 1 day or 10000 years as all the universe is bound up in the laws of physics.

[/ QUOTE ]

In fact, based on our best current understanding, it appears that the laws of physics say the exact opposite.

The view you state is generally attributed to Laplace. "In effect what he said was, that if at one time, we knew the positions and speeds of all the particles in the universe, then we could calculate their behaviour at any other time, in the past or future." (Quoting Stephen Hawking Hawking Lecture

Laplace's view of the Universe was generally accepted throughout the 19th and early 20th centuries. However, the development of Quantum Mechanics by Planck had implications that are inconsistent with Laplace's view. Specifically, Heisenberg demonstrated that if quantum mechanics is correct, it is impossible to measure both position and the speed of a particle precisely. This is called the Heisenberg Uncertainty Principle.

(Again, quoting Hawking)"Laplace's vision, of scientific determinism, involved knowing the positions and speeds of the particles in the universe, at one instant of time. So it was seriously undermined by Heisenberg's Uncertainty principle. How could one predict the future, when one could not measure accurately both the positions, and the speeds, of particles at the present time? No matter how powerful a computer you have, if you put lousy data in, you will get lousy predictions out."

Now, if you want, you can choose to not believe in quantum mechanics as a law of physics. And take heart, if you do so, you're in good company -- Einstein, was unable to accept the implication of the Heisenberg Uncertainty Principle of the randomness of nature. His view is often summarized by his famous quote "G-d does not play dice."

(quoting Hawking)"He seemed to have felt that the uncertainty was only provisional: but that there was an underlying reality, in which particles would have well defined positions and speeds, and would evolve according to deterministic laws, in the spirit of Laplace. This reality might be known to God, but the quantum nature of light would prevent us seeing it, except through a glass darkly."

However, experimental science seems to show that Einstein was wrong on this point. The best scientific evidence to date is that Heisenberg is correct. Based on this evidence, it appears there is a randomness in nature, and G-d does,in fact, play dice.

(Most of this post is a truncation of the Hawking lecture, for which a link has been provided. If you're interested in the subject, I highly recommend the lecture in its entirety.)

[Trantor]

[ QUOTE ]
[ QUOTE ]

So - how can something random happen?


[/ QUOTE ]

Randomness comes from our inability to know the exact position and velocity of particles due to the Heisenberg uncertainty principle. We can have vague ranges to place these values in, but never exact numbers. We can assign probabilities that the particle will be at any particular velocity and/or position at any given point in time from those boundary conditions. It will "randomly" be one of these values with it being more likely that it will be one of the values of higher probability.

You are right in that true "randomness" can not occur. It is always taken from some subset of values.

PS We also don't know any of the formulas for complicated sub-atomic particle interactions (or atomic particles for that matter). Therefore more things seem "random" because we can not come close to predicting their behaviour or probability distribution ranges.

[/ QUOTE ]

You are desribing chaos theory as applicable to classical sytems.

On the poster's point, the fact is all the evidence is consistant with inherent randomness at the quantum mechanical regime and it is sciences job to find out why or find contrary evidence to show it is not the case.

The fact there is no reason as to why something is the case doesn't doesn't mean it isn't so.