Can the laws of physics be violated?

[CarlosLara]

Hello. I read recently that the law of conservation of energy can be violated for very short time intervals, according to the uncertainty principle. Apparently, this fact gives rise to virtual particle production from the vacuum. Once we accept that the uncertainty principle allows the laws of physics to be broken, even for a very short time, then what is the uncertainty principle? Is it a law of physics, or a "super law" beyond all others? Most importantly, I want to know if the uncertainty principle allows the Pauli exclusion principle to be violated, if even for an extremely short time. According to the principle, if all electrons in the universe are "aware" of the quantum states of all other electrons, what happens when virtual particles are randomly created close enough to an electron in an atom to affect its energy? (The Lamb shift is proof that virtual particles have a real impact on the energy levels of atoms). If the exclusion principle cannot be violated at all, then spacetime itself has to "be aware" of the quantum states of all electrons contained within it to make sure that the virtual particles it produces do not impart energy to an electron so that its new energy coincides with the energy that any other electron in the universe already possesses. What are your thoughts on this?

Thank you in advance.

 

[Demystifier]

I read recently that the law of conservation of energy can be violated for very short time intervals, according to the uncertainty principle.

I've seen that claim many times in popular-science literature, but it is simply a nonsense. Total energy is exactly conserved in quantum mechanics, even during a short time.

 

[ZapperZ]

Hello. I read recently that the law of conservation of energy can be violated for very short time intervals, according to the uncertainty principle. Apparently, this fact gives rise to virtual particle production from the vacuum. Once we accept that the uncertainty principle allows the laws of physics to be broken, even for a very short time, then what is the uncertainty principle? Is it a law of physics, or a "super law" beyond all others? Most importantly, I want to know if the uncertainty principle allows the Pauli exclusion principle to be violated, if even for an extremely short time. According to the principle, if all electrons in the universe are "aware" of the quantum states of all other electrons, what happens when virtual particles are randomly created close enough to an electron in an atom to affect its energy? (The Lamb shift is proof that virtual particles have a real impact on the energy levels of atoms). If the exclusion principle cannot be violated at all, then spacetime itself has to "be aware" of the quantum states of all electrons contained within it to make sure that the virtual particles it produces do not impart energy to an electron so that its new energy coincides with the energy that any other electron in the universe already possesses. What are your thoughts on this?

Thank you in advance.

Please read this entry in the FAQ subforum in the General Physics forum:

https://www.physicsforums.com/showthread.php?t=511176

Furthermore, "I read recently" is not an acceptable source citation. We require that sources be clearly cited. If this is from a paper, cite the author, journal, volume, and page number. If this is from a book, cite author, title of book, and page number. If this is from a TV show, cite title, channel, and date, etc... etc.

Zz.

 

[kmarinas86]

http://en.wikipedia.org/wiki/Conservation_of_energy

In quantum mechanics, energy of a quantum system is described by a self-adjoint (Hermite) operator called Hamiltonian, which acts on the Hilbert space (or a space of wave functions ) of the system. If the Hamiltonian is a time independent operator, emergence probability of the measurement result does not change in time over the evolution of the system. Thus the expectation value of energy is also time independent. The local energy conservation in quantum field theory is ensured by the quantum Noether's theorem for energy-momentum tensor operator. Note that due to the lack of the (universal) time operator in quantum theory, the uncertainty relations for time and energy are not fundamental in contrast to the position momentum uncertainty principle, and merely holds in specific cases (See Uncertainty principle). Energy at each fixed time can be precisely measured in principle without any problem caused by the time energy uncertainty relations. Thus the conservation of energy in time is a well defined concept even in quantum mechanics.

http://en.wikipedia.org/wiki/Uncertainty_principle

Another common misconception is that the energy-time uncertainty principle says that the conservation of energy can be temporarily violated – energy can be "borrowed" from the Universe as long as it is "returned" within a short amount of time.[26] Although this agrees with the spirit of relativistic quantum mechanics, it is based on the false axiom that the energy of the Universe is an exactly known parameter at all times. More accurately, when events transpire at shorter time intervals, there is a greater uncertainty in the energy of these events. Therefore it is not that the conservation of energy is violated when quantum field theory uses temporary electron-positron pairs in its calculations, but that the energy of quantum systems is not known with enough precision to limit their behavior to a single, simple history. Thus the influence of all histories must be incorporated into quantum calculations, including those with much greater or much less energy than the mean of the measured/calculated energy distribution.

 

[Whovian]

Huh. I'd always thought of the two viewpoints (thanks, I now realize that one relies on energy being well-defined at all times, which it isn't) as different interpretations of the same observations.

And my thoughts about how this ties in with force carriers right now are "That's clever, Universe."

 

[scijeebus]

Please read this entry in the FAQ subforum in the General Physics
Furthermore, "I read recently" is not an acceptable source citation.
Zz.

What if you remember as an absolute fact that you read it in a book that was not specifically said to be bs or a tv show like nova but you can't find the episode since you'd have to pay for it?

 

[_DJ_british_?]

What if you remember as an absolute fact that you read it in a book that was not specifically said to be bs or a tv show like nova but you can't find the episode since you'd have to pay for it?

Then do a google search first.

 

[ZapperZ]

What if you remember as an absolute fact that you read it in a book that was not specifically said to be bs or a tv show like nova but you can't find the episode since you'd have to pay for it?

And you trust your memory THAT much? Remember, you are reading or hearing something UNFAMILIAR, probably for the FIRST time. Do you think you heard or read it correctly, AND remember it accurately? Shall I show you instances where the human memory can play amazing tricks?

Requesting everyone to remember and cite the source forces that person to pay attention to the source and the nature of the source! If you learn nothing else from PF, learning to pay attention to the nature and quality of the source that you get all your information from is a valuable-enough lesson to make this forum worthwhile.

Zz.

 

[scijeebus]

And you trust your memory THAT much? Remember, you are reading or hearing something UNFAMILIAR, probably for the FIRST time. Do you think you heard or read it correctly, AND remember it accurately? Shall I show you instances where the human memory can play amazing tricks?

Requesting everyone to remember and cite the source forces that person to pay attention to the source and the nature of the source! If you learn nothing else from PF, learning to pay attention to the nature and quality of the source that you get all your information from is a valuable-enough lesson to make this forum worthwhile.

Zz.

Well personally if my memory is fuzzy then I would say it, but otherwise it should be legitimate if your like, 99% sure unless there's some direct law of physics that says it's impossible.