A violation of causality would occur if an effect happened before the thing that caused it. An example would be you dying from wounds received from being hit by a bus, but before the bus actually hit you.
do virtual particle's do this? since their speed is faster than light and don't obey law's of conservation? or am i being mislead?
Do virtual particles violate causality? As far as I am aware, no they don't. Also, I'm not aware that they travel faster than the speed of light. Do you have any references?
The link in post #7 does not say that virtual particles violate causality. The link in post #8 is a copy of the material in #7. The author of #9 admits he is not a particle physicist. He claims that virtual particles can violate causality, but doesn't explain. As for Ben, he can speak for himself. Tell me, Wolv1, why are you so interested in causality violations?
it's just weird to me,and hoping it's impossible.why do they travel faster than light if it's not allowed by the laws of physics? so ben is wrong?
From a previous thread: "The more important property of VP's is that they do not necessarily obey \(E^2 = (pc)^2+(mc^2)^2\). The energy of the particle can be anything, even a negative value. The more the energy differs from this, the shorter the time it must last for by the uncertainty principle. Virtual particles can indeed travel faster than light as well, although it is relatively straightforward to show that they do not affect causality. For causality to be affected a pile of real particles or waves must be sent back in time." The fact that the energy of virtual particles is not \((pc)^2+(mc^2)^2\) is what we mean when we say "off shell." Virtual particles can never be detected so nothing would happen. We can only detect them indirectly like in Lamb shift and the Casimir effect both of which have good wiki pages.
Virtual particles do not violate causality - it's one of the first things that gets shown in most postgraduate quantum field theory courses. As I've said a couple of time now, VP's can travel faster than light but they cannot be directly detected so they cannot affect causality. For causality to be violated, real particles would have to go faster than light, which is impossible.
That is physically impossible, but there is a noticeable effect (noticeable now that we have the ability to notice it), from the background of VPs. A small distance between two 'smooth' surfaces sees a force pushing them together. This is explained as VPs that can't get between the surfaces, or into the cavity between them, because the gap is too small. So they can't push the surfaces apart, only together - a net force is seen between the surfaces, flat surfaces especially.