Destiny or random chance

[trevor999]

Hello all

 

Recently I finished Brian Greene's book "The Fabric of the Cosmos". One statement stood out that said that if one could plot the motion and position of every quantum particle in the universe (impossible I know, because of the Heisenberg Uncertainty Principle, but mechanics aside) one could predict the future with 100% accuracy, or words to that effect. Does this mean that random chance and freedom of choice are illusions because that whatever happens happens because it must happen?

 

Thanks in advance.

[swansont]

No. The statement boils down to "if you could do something that is impossible, you can do X." Since you can't actually do the impossible thing, you can't draw any conclusion from it.

 

e.g. "if you could go faster than light, you could send information into the past" doesn't mean we can send information into the past.

[ajb]

Does this mean that random chance and freedom of choice are illusions because that whatever happens happens because it must happen?

 

If we were to know all the degrees of freedom in the universe at a given instant then one could describe the time-evolution exactly. This would correspond to knowing the wave-function of the universe (something like Hartle-Hawking ) and the Hamiltonian for quantum gravity + the other forces. Look up the Wheeler–deWitt equation.

 

Of course, as we have a covariant theory it is not really the "global time-evolution", but not to worry too much about this. Time evolution is really just a gauge transformation or the "Hamiltonian constraints". This all gets difficult quickly.

 

This also reminds me about time travel. Similar questions arise here.

[Severian]

I think Greene's point was that if the universe were deterministic, knowing the initial state of a system means that in principle we can calculate exactly where every particle will be a fixed time later. If that system then includes human beings (who are governed by the same laws) then we could also predict their actions.

 

I agree with this statement and I agree with your interpretation that there can be no free-will in such a situation. I have said so in these forums before.

 

I would take it further. In quantum mechanics, the universe evolves in a way which is statistical. Essentially, when each measurement is made, the universe rolls a metaphorical dice and uses the result to modify our answer. This is sometimes regarded as a way around the free-will dilemma. After all, we can no longer make absolute predictions of the state of the system after a given time.

 

However, I would also not class this as free-will since the divergence between different final outcomes is determined by the roll of a dice - a random number. If, every time I need to make a decision, I had to roll a dice and was forced to stick to the decision made by the dice roll, I would not regard myself as having free-will.

 

So, I contend that our current theories of the universe (quantum field theory) have no room for free-will at all. The only way one could object to my assertion would be to have a different definition of free-will.

[Farsight]

Severian: when you calculate the "in-principle" position of those particles, you can only do it by moving particles around. So you have to account for your calculation in your calculation, which leads to a recursive state which breaches the principle.

 

Another way to object to your assertion is to assert that those current theories of the universe are incomplete. For example, those rolling-dice quantum fields, in the guise of a man, can calculate.

[ydoaPs]

there can be no free-will in such a situation.

I think that free-will is actually dependent upon some level of determinism.

 

If, every time I need to make a decision, I had to roll a dice and was forced to stick to the decision made by the dice roll, I would not regard myself as having free-will.

Quite so.

[Mr Skeptic]

I think Greene's point was that if the universe were deterministic, knowing the initial state of a system means that in principle we can calculate exactly where every particle will be a fixed time later. If that system then includes human beings (who are governed by the same laws) then we could also predict their actions.

 

I agree with this statement and I agree with your interpretation that there can be no free-will in such a situation. I have said so in these forums before.

 

I would take it further. In quantum mechanics, the universe evolves in a way which is statistical. Essentially, when each measurement is made, the universe rolls a metaphorical dice and uses the result to modify our answer. This is sometimes regarded as a way around the free-will dilemma. After all, we can no longer make absolute predictions of the state of the system after a given time.

 

However, I would also not class this as free-will since the divergence between different final outcomes is determined by the roll of a dice - a random number. If, every time I need to make a decision, I had to roll a dice and was forced to stick to the decision made by the dice roll, I would not regard myself as having free-will.

 

So, I contend that our current theories of the universe (quantum field theory) have no room for free-will at all. The only way one could object to my assertion would be to have a different definition of free-will.

 

I've concluded exactly the same. There doesn't seem to be anything not covered under chance and determinism, or some combination thereof. Free will as I imagined it seems impossible. (For extra fun, this also means God has no free will. Or, more likely, we need a different definition of free will.)

[Severian]

(For extra fun, this also means God has no free will. Or, more likely, we need a different definition of free will.)

 

Or the universe works a bit differently from what we think.

[Cap'n Refsmmat]

(For extra fun, this also means God has no free will. Or, more likely, we need a different definition of free will.)

Or, to be more theologically correct, God is not a part of this universe.

[Mr Skeptic]

Or, to be more theologically correct, God is not a part of this universe.

 

And you would describe something not part of this universe how? Wouldn't we still describe things via chance and non-chance?

[Zolar V]

I believe the best definition of free-will is one that implies that you have the "free will" to act within a set boundary.

 

Secular EG: An atom is not going to violate laws of physics because it can, it is going to act as it can under those laws

 

Theologically EG: We cannot think a thought that God(s) have not thought of first.

of course theologically it does depend on which religion your talking about.

[Cap'n Refsmmat]

And you would describe something not part of this universe how? Wouldn't we still describe things via chance and non-chance?

 

Not necessarily. Anselm of Canterbury, for example, attempts to describe what God must be like, using a priori logic and reason alone.