Is quantom mechanics realy random?

[jutntog1]

I have seen a few shows on quantom mechanics and done a little research and everthing that i have seen talks about some amount of randomness at a quantom level, this doesnt make sence to me, is what its trying to say is that we cant predict it or understand why it reacts the way it does? becouse it is imposible for something to be compleatly random isnt it?

[Meir Achuz]

QM is not random. If the wave function is given at one time, it is uniquely determined at a later time. Position and momentum are not suitable variables for getting a definite future prediction, but that is their fault, not QM's.

[swansont]

QM is not random. If the wave function is given at one time, it is uniquely determined at a later time. Position and momentum are not suitable variables for getting a definite future prediction, but that is their fault, not QM's.

 

How are you defining 'random' ?

[jutntog1]

ill state what im asking a little diffrent instead of answering your question:

 

hypotheticaly if you were able to know everthing and could stop time to give you time to figure it out, could you predict all aspects of qm

 

i hope that clears up what im saying

[J.C.MacSwell]

ill state what im asking a little diffrent instead of answering your question:

 

hypotheticaly if you were able to know everthing and could stop time to give you time to figure it out' date=' could you predict all aspects of qm

 

i hope that clears up what im saying[/quote']

 

I don't think anyone knows.

[jutntog1]

yeah i havnt seen anyone with a solid theory but i dont think it is posible for something to be random is it?

[swansont]

ill state what im asking a little diffrent instead of answering your question:

 

hypotheticaly if you were able to know everthing and could stop time to give you time to figure it out' date=' could you predict all aspects of qm

 

i hope that clears up what im saying[/quote']

 

But you can't know everything.

[[Tycho?]]

ill state what im asking a little diffrent instead of answering your question:

 

hypotheticaly if you were able to know everthing and could stop time to give you time to figure it out' date=' could you predict all aspects of qm

 

i hope that clears up what im saying[/quote']

 

Look up Heisenburgs Uncertainty Principal. Basically it says you cant know everything about a particle; the more you know about one aspect of it (like its momentum) the less you would know about another aspect (like its position). So we are unable to find out everything about a given system.

[jutntog1]

cool thanks for the info ill look it up

[Meir Achuz]

Swansont: In any given theory (even classical mechanics) you have to determine a complete set of variables. Then "not random" (easier to define than random) means that knowing the value of each of these variables at one time, you could tell the value at any future time (assuming causality). For CM, those variables are the momentum and position of a particle (doing one particle for now). If you chose momentum and temperature, it would look like a random theory. Just look at the 5 day weather forecast. That does not mean CM is random, but just that you picked the wrong variables. In QM, momentum and energy are the wrong variables. If you pick the wave function at one time for all space, you can uniquely predict the wave function at a future time. That is what I call "not random".

[swansont]

Swansont: In any given theory (even classical mechanics) you have to determine a complete set of variables. Then "not random" (easier to define than random) means that knowing the value of each of these variables at one time, you could tell the value at any future time (assuming causality). For CM, those variables are the momentum and position of a particle (doing one particle for now). If you chose momentum and temperature, it would look like a random theory. Just look at the 5 day weather forecast. That does not mean CM is random, but just that you picked the wrong variables. In QM, momentum and energy are the wrong variables. If you pick the wave function at one time for all space, you can uniquely predict the wave function at a future time. That is what I call "not random".

 

Knowing the wave function doesn't tell you exact position and momentum, it tells you a distribution of possible values.

[bascule]

Probabilistic behavior is engrained into quantum mechanics at the most fundamental level, namely through the Heisenberg Uncertainty Principle and the Scrodinger Wave Equation. However I (and string/M-theory) blame this on our rather limited 4 dimensional perspective of observation... as events transpire on a level which closes in on the size of the extra compactified dimensions, their significance in events rises rapidly, and particles in other dimensions begin interacting with single particles from ours, when a collision with a particle from our everyday 4 dimensional space would destroy such interactions.

 

In an experiment like the double slit experiment, when an interference pattern is observed even if only an electron/photon every few seconds is fired, the culprit may indeed be interference with entangled extradimensional particles, rather than the (somewhat contrived) quantum explanation of "interfering probability waves." So they universe may yet prove deterministic, and the probabilistic nature of quantum may merely prove to be a lack of (fundamentally unobtainable) information. Personally I still espouse causal determinism.

[jutntog1]

Swansont: In any given theory (even classical mechanics) you have to determine a complete set of variables. Then "not random" (easier to define than random) means that knowing the value of each of these variables at one time, you could tell the value at any future time (assuming causality). For CM, those variables are the momentum and position of a particle (doing one particle for now). If you chose momentum and temperature, it would look like a random theory. Just look at the 5 day weather forecast. That does not mean CM is random, but just that you picked the wrong variables. In QM, momentum and energy are the wrong variables. If you pick the wave function at one time for all space, you can uniquely predict the wave function at a future time. That is what I call "not random".

 

 

thats what i was wanting to know exactly thank you.

[swansont]

thats what i was wanting to know exactly thank you.

 

Except that it's wrong. Knowing the wave function at one time only allows you to determine the wave function in the future, barring interactions, but does not allow you to predict everything about the particle.

 

MA did not do a very good job of defining random, and this is a topic that has arisen in various threads. Random does not necessarily mean all outcomes are possible, or that outcomes are equally probable. And a wave function can describe more than one state.

 

I know that the roll of a die will give me an integer result of 1 to 6. So I toss the die, and now it has a wave function that represents an equal probability of each of those numbers (or not - it really doesn't matter, as long as more than one outcome can occur) Knowing the wave function later on doesn't mean that I can predict the outcome. The outcome - the one state it's in when I measure it - is still random.

[unknow force]

random QM= we dont understand QM

[geistkiesel]

Spin 1 particles can have either +1, -1 or +-1 spin states. Some have modeled the spin-1 particle as being rigidly polarized when bolied off gthe "tungsten filament". The model is far from the truth. The spin states are generated in every p;artricle in the ordwer of , +1, -1, +-1, +1, -1, +-1,+1, -1, +-1, +1, -1, +-1, ...etc. Only when polarized by a magbnetic field does this switching of states cease. But ask yourself, which is more natural a condition, a random number generator producing random numbers of 1 to 3? or the generator producing the numbers sequentially? If I were you and had this problem I would always opt to assume the ordered state as the physical reality, why? Because as accurate as I can measure spin 1 particle states from virgin polarized particles, I will always get the same statistical spread, and this because millions of particles are measured one time instead of one particle being measured a million times.

 

Geistkiesel

 

Geiosgtkuiesel

[BlackHole]

I think the OP is talking about the wave-particle duality and quantum superposition. QM has taught us that an interaction is an imbalance, i.e., a violation of a conservation principle which must be corrected.

 

Theoretically i think it's possible to travel great distances in the universe by quantum jumps.