4 ms·
"Tunneling" refers to the process by which a particle may pass through a classically-forbidden potential barrier. It is like bowling, and finding your ball in t
by millstone 6y ago
"Tunneling" refers to the process by which a particle may pass through a classically-forbidden potential barrier. It is like bowling, and finding your ball in the next lane over. You didn't throw it hard enough to hop the lane barriers, but there it is.
> particles can exceed c0 (the speed of light in a vacuum) during tunnelling
No particle's speed is measured here, so it cannot exceed c.
What does "during tunneling" mean? Tunneling means measuring its position here, and then over there. You can't do that simultaneously with measuring its speed in between, because of the uncertainty principle.
The wavefunction can be thought of as a probability distribution. That can be updated instantly, even if it becomes very bimodal, because it's just a change in knowledge.
- hilbert42 6y agoAs I mentioned elsewhere, some months ago there was report that the time that an electron takes to jump from one shell to another was measured for the first time. If true, then it seems to me this changes things. When I was leaning physics I was told that this was either infinitely fast or indeterminate (in keeping with QM). By this account, same would go for tunnelling I'd reckon (that's just my extrapolation from that report). We'll just have to wait and see whether it's fact or not.
- hilbert42 6y agoJust found hese references, they may help: https://www.discovermagazine.com/the-sciences/scientists-catch-a-quantum-jump-as-it-happens https://www.discovermagazine.com/the-sciences/scientists-cat... http://qulab.eng.yale.edu/documents/papers/zlatko_paper.pdf http://qulab.eng.yale.edu/documents/papers/zlatko_paper.pdf
- andreareina 6y agophysics. SE disagrees with the popular media on the interpretation on the quantum jump result: https://physics.stackexchange.com/questions/484675/does-the-new-finding-on-reversing-a-quantum-jump-mid-flight-rule-out-any-inter https://physics.stackexchange.com/questions/484675/does-the-...
- hilbert42 6y agoHa, not a bit surprised. If every one agreed or did so quickly, then it would violate fundamental principles of the Quantum Disagreement Theory. ;-)