What Makes Quantum Tunneling Possible Despite Classical Physics?

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Discussion Overview

The discussion revolves around the concept of quantum tunneling and its implications, particularly in relation to classical physics. Participants explore the nature of quantum tunneling, its acceptance in scientific applications, and its relationship with concepts like the weak force and radioactive decay. The conversation includes both theoretical inquiries and practical examples.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants express confusion about how quantum tunneling occurs, questioning its compatibility with classical physics and causality.
  • Others assert that quantum tunneling is indeed supported by physical laws, citing its applications in semiconductors and tunneling microscopes.
  • A participant raises a hypothetical scenario about jumping into a black hole, prompting discussions about the differences between quantum tunneling and quantum teleportation.
  • There are claims that quantum tunneling allows particles to pass through barriers that classical mechanics would deem insurmountable.
  • Some participants discuss the weak force in relation to atomic decay, suggesting a connection to quantum tunneling, though this is met with skepticism and calls for clarification.
  • Concerns are raised about the validity of external resources referenced in the discussion, with participants expressing uncertainty about their authenticity and relevance.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the relationship between quantum tunneling and classical physics, nor on the relevance of the weak force to the topic. Multiple competing views remain regarding the interpretations and implications of quantum tunneling.

Contextual Notes

Some discussions involve assumptions about the nature of quantum particles versus classical particles, and the complexities of the weak force are acknowledged but not fully explored. There are unresolved questions about the accuracy of external references and their connection to the main topic.

Who May Find This Useful

This discussion may be of interest to those exploring quantum mechanics, the implications of quantum tunneling, and the interplay between quantum and classical physics, as well as those curious about fundamental forces in physics.

superweirdo
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Ok, I understand that it is about those negligable probabilities that end up happening, but b/c we don't live long enough to see these probability happen in our real life(big objects take longer time), we have seen that quantum tunelling exist on nanoscopic level. Now, what I don't understand is that how is it possible? I know it has been proven, and makes sense by probability but still. I guess it just bothers me to see something happening that is not supported by our physical laws. I believe everything happens for a reason(causuality) but this counters it.
 
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superweirdo said:
I guess it just bothers me to see something happening that is not supported by our physical laws.
Who said tunneling was not supported by physical laws? If it isn't, semiconductors and scanning tunneling microscopes would be something out of science fiction.
 
then could you explain to me how is it possible for me to jump here and vanish and go inside a black hole?
 
superweirdo said:
then could you explain to me how is it possible for me to jump here and vanish and go inside a black hole?

are you sure you want to do that? , actually quantum tunneling is a phenomena in which a quantum particle can enter a classically forbidden region , and this isn't as weird as it seems to you , infact it has been already put to use in tunneling microscopes with high results.
You can read about it here:
http://en.wikipedia.org/wiki/Quantum_tunneling
 
That was a good read, Zap.
 
Yeah, that zap post got me, thanks a lot guys
 
superweirdo said:
then could you explain to me how is it possible for me to jump here and vanish and go inside a black hole?

That's not quantum tunneling, that's quantum teleportation! :smile:
 
superweirdo said:
then could you explain to me how is it possible for me to jump here and vanish and go inside a black hole?
It would be possible for you to jump over classical barriers if you were a quantum particle. I.e., a particle that obeys rule of quantum mechanics and doesn't care about classical mechanics.
Quantum mechanics, in contra to classical mechanics says that any waveform of any particle may go through barriers that classical particle with same properties can't go through.
So, yes, this effect is described by laws of QM.
 
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  • #10
Chipset said:
It would be possible for you to jump over classical barriers if you were a quantum particle.
I am not sure this is really necessary. I suspect theoretically you can jump over a classical barrier having lesser kinetic energy than the potential energy your mass would have at the top of the barrier. In fact, in the course of a high jump you can bend over the barrier in such a way that your center of gravity will be outside of your body and pass under the barrier.
 
  • #11
That's a nice way of putting it, akhmeteli.

I thought this "Quantum Tunneling on your Kitchen table" looked interesting. I don't know if it's genuine though.

http://www.altair.org/Qtunnel.html

But anyhow, IMHO quantum tunneling is only weird if you think of things like electrons as billiard-ball particles.
 
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  • #12
Wow, that's an interesting site you listed, Farsight. You mentioned that you are not sure of its genuiness, so I hope that others can jump in and clarify that aspect.
 
  • #13
I'm not too sure about that site. Someone with more knowledge will have to look at it. For one thing, it even says that quantum physics "superceded" the physics of einstein; never mind that Einstein was one of the most important contributors to quantum theory in the beginning of the 20th century.
 
  • #14
The weak force

Superwierdo, you are asking about the weak force. That is the force that causes atoms to decay. You see, certain atoms know as isotopes, are radioactive because they contain one or two less neutrons or one or two more protons then there stable counterparts. If you look at the periodic table, you will find that each element has a mass number. This is the total number of protons and neutrons in each atom. Carbon, for example, has a mass number of twelve, while there is an isotope known as carbon-14 which is used in carbon dating.
Now the nuclei of non-radioactive atoms are held together by the strong force. But when the atom is missing neutrons or in excess of protons then the strong force breaks down and the protons, due to their like charges, repel. It is not the protons repelling which causes the nuclei to dissolve slowly, it is the replacing of the strong force with the weak force.
 
  • #15
But where is the weak force? All I see is repulsion.
 
  • #16
Quantum tunneling and the weak force

I don't know exactly where the weak force comes from. I've never read anything that has the answer. I don't think modern science has found a way to accurately describe it.
 
  • #17
baryon said:
I don't know exactly where the weak force comes from. I've never read anything that has the answer. I don't think modern science has found a way to accurately describe it.

No, I thnk it was rather strange that you introduced the "weak force" in this thread. I'm not sure what you were trying to explain, even after re-reading your earlier post.

There there have been description of alpha decay via the tunneling through the electrostatic potential barrier. However, this doesn't mean that all radioactive decay is a governed by such a process. The weak interaction is much more complex and "powerful" than this. And yes, "modern science" does know a lot about this process. We may not know all of it yet, but the same can be said about almost anything. Still, we know that the weak interaction can have a CP-violating component, and other characteristics, enough that we have a consistent electroweak description.

Zz.
 
  • #18
So sorry. won't do it again. You're right, it's not pertinent.
 
  • #19
superweirdo said:
not supported by our physical laws... counters it.


Just remembered why I thought about it though
 
  • #20
I know this is kind of offtopic but since we are already there and my purpose is solved in this thread, could someone explain to me what is weak force?(more than that it causes alpha decay)
 

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