Quantum tunneling instantaneous

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Discussion Overview

The discussion revolves around the concept of quantum tunneling, specifically addressing the nature of tunneling time and the behavior of electrons during the tunneling process. Participants explore whether tunneling implies instantaneous movement or if it involves wave propagation and localization upon observation.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants question whether tunneling time is effectively zero, suggesting that electrons might 'skip' over barriers or experience instantaneous jumps.
  • Others argue that electrons do not have well-defined positions or speeds, emphasizing that any propagation is constrained by the speed of light and rejecting the notion of instantaneous jumps.
  • A participant describes the electron as a "fuzzy ball of probability," localizing only upon observation, and notes that simulations may not accurately reflect experimental realities.
  • Concerns are raised about the interpretation of popular science articles, which may oversimplify complex issues and lead to misconceptions about scientific theories.
  • One participant references a quote from Dr. Igor Ivanov regarding the possibility of electron velocities exceeding the speed of light during tunneling, while noting that such velocities are described as imaginary and do not violate relativity.
  • Another participant firmly states that electrons do not skip over barriers, reinforcing the need for careful interpretation of tunneling phenomena.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the nature of quantum tunneling, with no consensus reached on whether tunneling involves instantaneous movement or is better understood through wave propagation and localization.

Contextual Notes

Participants highlight limitations in current understanding, including the dependence on interpretations of simulations versus experimental data, and the potential for misrepresentation in popular science communications.

God Plays Dice
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The electron does not have a well-defined position or speed. There are no instantaneous jumps, and the propagation of any signals is limited by the speed of light.
 
God Plays Dice said:
http://m.phys.org/news/2015-05-physicists-quantum-tunneling-mystery.html

Does this mean that the tunnelling time was actually zero, and the electron 'skips' over the gap, or does it mean that the electron wave traveled at the speed of light followed by an instantaneous jump later on
The way I look at it (which is probably wrong) is that the electron exists as a fuzzy ball of probability. It only localizes when "observed" (for some value of observation that I can't define). Thus the electron is on both sides of the barrier. The article you linked seemed to be a computer simulation that claimed the observation localized it in zero time. That is not the same as the electron moving.

There are some important caveats: Most importantly, simulations are not experiments. They may lead to experiments, but until they do, they are just a new and potentially wrong (if the simulators missed something) way of looking at the model they are simulating. They can add insight, but they have lots of weaknesses.

Second, this seems to be a popular press release. The popular press is notorious for making complex scientific issues into simple pissing contests (look, FTL electrons!) between scientific theories. Science facts are often left to fend for themselves.

I will say the link you provided gives rise to some deep thoughts. It could easily lead to a testable hypothesis and new knowledge. It sounds like someone is doing good work.
 
God Plays Dice said:
does it mean that the electron wave traveled at the speed of light followed by an instantaneous jump later on
Despite the seemingly lack in the firm theoretical description of tunnel ionization, hasn't the article itself already anticipated the rise of such notion in the reader's mind by quoting Dr. Igor Ivanov, "A very interesting paradox arises, because electron velocity during tunneling may become greater than the speed of light. However, this does not contradict the special theory of relativity, as the tunneling velocity is also imaginary."?
 
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