Oxymoron

Surely. Take any particle - electron, proton, etc. Do an experiment on it which would indicate that it is a wave (ie spread out in space with a length between peaks and an amplitude), and lo! it is a wave. In this way, a single particle can "interfere" with itself by the addition of waves - if a peak hits a trough, the wave vanishes. Hence the slit experiment working on particles as well as light.

Now if you do a "particle" experiment on light, guess what happens? Maxwell's waves start behaving like they're miniature billiard balls. Ain't it grand?

Oxymoron

Dynamical systems are not quantum, are fully determined, yet utterly undeterministic. A Dynamical System is usually goverened by a non-linear set of equations that have the effect of magnifying errors over time. No matter how small the difference between two states in a near-identical state, there is a finite time after which the behaviours will diverge. Since we can never specify numbers to infinite precision (it would take infinitely long to do so), it follows that these systems can be utterly unpredictable for a given set of starting conditions.

For example, we have no idea whether our solar system is stable. All the solutions to Newton's equations of motion for 4 (or more) planets have nasty singularities (non-linear terms) that can be swept under the carpet but never fully hidden. Given a long enough time (we don't know how long), there is nothing stopping the whole thing falling apart.

These - and Quantum Mechanics - aren't just about humans with their puny tools; they are fundamentally unknowable by anyone no matter how clever they or their science is.

Oxymoron

It's a bit clever and cunning (which is my way of saying I don't understand the details), but it involves entanglement, which means that two particles are in a special state by which if you do an experiment on one, the other one will "know" the result and adjust itself accordingly. This works instantaneously no matter how far apart the particles are.

(Ducks for cover).

PotatoError

Oxymoron said:
"These - and Quantum Mechanics - aren't just about humans with their puny tools; they are fundamentally unknowable by anyone no matter how clever they or their science is."

I was asking if quantum theory proves that there is true randomness at the quantum level. I realise that it proves events are totally unknowable. But totally unknowable isn't the same as random.

Someone told me a few posts ago that quantum theory proves true randomness. In light of what I have said above, does their assertion still hold? (sorry about my grammer btw). I will learn quantum theory soon but for now I just want to know if it really does prove randomness.

Starboy

PotatoError, I cannot speak for Oxymoron, but what I think he was trying to say is that much of our confidence in being able to predict the future is hubris. Even in the case of “classical” determinism there are systems that can behave chaotically. In other words these systems are soooooo sensitive to their initial conditions that just the smallest currently unmeasurable difference can cause wildly different results in the matter of a fraction of a second. When this is compounded on itself it leads to a result that for all intents is uncomputable. And this is without taking into consideration the inherently random nature of motion at the Plank scale. A classic example of this is turbulent flow, the kind you might see in a rapids. And yet if you observe a rapid long enough it does appear to have order, it’s just that computing it is intractable.

The other reference that Oxymoron was making concerned the solar system. It is an old problem involving Newton’s equations of motion called the n-body problem. It turns out that for a simple system involving only two bodies it is very easy to solve for the motion of the system under any combination of initial conditions that can be imagined. Add just one more body and it can now only be solved for a few special cases. Increase the number to nine such as seen in our solar system, and it can only be computed with some accuracy for a relatively short period of time. And nine bodies doesn’t even begin to cover the complexity introduced by asteroids, comets, moons, other stars, the Milkyway and so forth.

So even though the universe does appear to be random at the smallest scales and therefore unpredictable in detail, at the largest scales where it doesn’t appear to be random it is also unpredictable.

Starboy

[ December 16, 2002: Message edited by: Starboy ]</p>

PotatoError

Sorry I understand chaos theory and what Oxymoron was saying. But chaos theory is to do with determined systems isn't it?

Motion at the plank scale might be chaotic but is it really random?

By random I mean that if you rewound time the movement would be different.

Starboy

PotatoError, as far as any scientist can tell at the plank scale the universe is random in the sense that you describe. Oh there would still be stars and galaxies and possibly planets such as Earth with life, but it would be an entirely different history.

Starboy

[ December 16, 2002: Message edited by: Starboy ]</p>

Starboy

Devilnaut, you have hit upon what appears to me to be the most difficult part. Quantum randomness does demonstrate that unrestrained freedom can exist. The question comes back to what does the “will” in “free will” mean? The will to do what? Many here seem to want to cast will as something selfish, such as the will to do what I want? If so, why couldn’t I want to choose something randomly? If for no other reason then to demonstrate that I have free will. Without a clear understanding as to what “will” is, the best one can do is show that by choosing randomly at least there is complete freedom if not “free will”.

Starboy

Kharakov

Calling the universe random is not technically correct. Stating that the observables we can detect appear to be random in some situations is correct.

PotatoError- note that it is entirely a matter of personal opinion when we deal with non-observables. Any speculation as to the actual reality behind the apparent randomness is just that: speculation.

Kharakov

Actually it just indicates lack of knowledge about quantum phenomena.

I always felt that will implied intent (which indicates a lack of randomness and freedom).