Quantum Mechanics: Equal Probabilities Explained

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Discussion Overview

The discussion revolves around the concept of equal probabilities in quantum mechanics, particularly in relation to the behavior of subatomic particles and the implications of tunneling over large distances. Participants explore the nature of probability fields, the effects of decoherence, and the quantization of time.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions whether the infinite possibilities for a particle's location imply equal probabilities for its presence in any location over time.
  • Another participant argues that while pure calculations might suggest such possibilities, real-world conditions involve complexities that prevent such events, emphasizing the role of decoherence.
  • A subsequent reply challenges the assertion that decoherence would prevent tunneling over large distances, suggesting that the probability of such events is already extremely low.
  • One participant posits that if tunneling could occur an infinite number of times in a second, it might raise the probability of such an event happening, despite its low likelihood.
  • Another participant counters this by stating that the probability does not increase simply due to the number of attempts, and emphasizes that quantum mechanics shows time is quantized, limiting the number of events that can occur.
  • There is a mention of the Planck Time as the smallest meaningful unit of time, suggesting that even with many attempts, the probability of tunneling to distant locations remains exceedingly remote.
  • A later reply expresses gratitude for the clarification regarding the non-infinite divisibility of time.

Areas of Agreement / Disagreement

Participants express differing views on the implications of infinite possibilities and the effects of decoherence on tunneling. There is no consensus on whether the number of attempts influences probability or on the feasibility of tunneling over large distances.

Contextual Notes

Participants acknowledge limitations in their understanding of quantum mechanics, particularly regarding the mathematical and conceptual frameworks involved. The discussion reflects varying interpretations of quantum behavior and the assumptions underlying those interpretations.

fireball3004
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I have a question about quantum mechanics. I was reading up on probability fields and it occurred to me that if there is a possibility that a subatomic particle may exist in a very unusual place like say jumping from Utah to Ohio in any give frame of time that has yet to happen and you can divide any give portion of time into an infinite number of frames. Does this mean that there are an infinite number of changes for that particle to be in any location and does this mean that the probabilities are equal?
In addition I would like to ask the question if physics equations can make no distinction between past and future does this mean that it is also a mater of guess work where things were?
Note: I still don’t understand the equations yet so please put in lays-man terms.
 
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If you make really "pure" calculations, where you include some nice potential and only one particle, then yes, you find that situations like this can occur.

But the biggest mistake you make there is that you actually make a way too many simplified assumptions. Fact is you don't have just one particle, or some smooth potential. The environment is so full of "junk" which will disrupt your system continiously, that stuff like tunneling over 1000 miles simply can not happen.The keyword here is decoherence.
 
xepma said:
simply can not happen.The keyword here is decoherence.

How exactly do you think decoherence prohibits or affects tunneling over large distances?

In any experiment the total probability of detecting such an event would already, by definition, be immeasurably close to zero.. so I really see no call to suggest additional mechanisms of avoiding it outright.
 
But the point was that it could happen an infinite number of times in one second doesn't this raise the probability so that no matter how close to zero it is in one frame that it is extremely of probable. I mean I know tunnling that far in extremely improbable but i was just confused because if you do something an infinite number of times un less it is infinitely imporbable
 
fireball3004 said:
doesn't this raise the probability
No it does not.
 
fireball3004 said:
But the point was that it could happen an infinite number of times in one second doesn't this raise the probability so that no matter how close to zero it is in one frame that it is extremely of probable. I mean I know tunnling that far in extremely improbable but i was just confused because if you do something an infinite number of times un less it is infinitely imporbable

something like that would only be possible IF there were an infinite number of divisions/events per unit of time- but QM shows us that time is not continuous- it is quantized and the smallest instant of time that has any physical meaning is the Planck Time: 10^-44 sec- the probability of a particle tunneling to Andromeda [or Ohio] is so remote that with only 10^44 'changes'- as you say- per second- it would still take googolplexes of giga years before such an event would be observed- however that doesn't mean that such an event could not be technologically harnessed- it may be possible to artificially manipulate a particle so that this remote probability becomes a certainty- quantum computers are an example of that sort of idea
 
Last edited:
Ah, thank you. I did not realize that time could not be devided infinitely.
 

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