# Wolv1's questions about causality and particles

Discussion in 'Physics & Math' started by Wolv1, Aug 25, 2008.

1. ### VkothiiBannedBanned

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Strictly speaking, the Casimir effect is a violation, since "nothing" causes the effect.

This is explained away by the existence of virtual particles, which also explain one or two other things we observe.

3. ### Wolv1BannedBanned

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there has to be a cause,where is the cause then?

5. ### VkothiiBannedBanned

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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.

The Casimir effect is caused by VPs that can't enter a small region of space.
This "effect" of VPs explains quantum cavity dynamics (QCD) too.

7. ### Wolv1BannedBanned

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so in reality there is a cause? http://en.wikipedia.org/wiki/Casimir_effect#Repulsive_Forces

8. ### Wolv1BannedBanned

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Vkothii,are you still confused to what causality violation mean's?

9. ### VkothiiBannedBanned

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I'm ah, not sure about that.

10. ### AlphaNumericFully ionizedRegistered Senior Member

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Once again, you don't bother to understand what I or Prom have said and you start saying "But he said.... and you said....." when you didn't understand either of us.

Either stop trying to understand a topic without learning the prerequisites or pick up a bloody book.

11. ### Wolv1BannedBanned

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im sorry alpha, but can you break it down for me? so ben is right or wrong? i was going to ask reiku,but BAD IDEA.

12. ### AlphaNumericFully ionizedRegistered Senior Member

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See the Uncertainty Principle.
They both said the same thing. They might violate causality but their physical effect never does. How is that hard for you to grasp?

13. ### Wolv1BannedBanned

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that what is harding when your saying they might violate causality but the effect does not.i read an article where quantum gravity is hoping to prevent this?

14. ### Wolv1BannedBanned

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I'm really sorry if im annoying anybody on here which i know i am trying to figure this out.

15. ### Wolv1BannedBanned

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ben,so we don't even know if they violate causality or travel faster than light? becuase you said they might.

16. ### Wolv1BannedBanned

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so causality is violated,but only for a very little time since virtual particle's only exist for a small amount of time?

Last edited: Oct 9, 2008
17. ### prometheusviva voce!Registered Senior Member

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try rereading this a few time and you'll see it makes no sense at all. Let me try and summarise:

1. Virtual particles exist because their effect can be calculated and then measured in experiment
2. Virtual particles can travel at any finite speed
3. The more their energy deviates from $(pc)^2 + (mc^2)^2$ the less time they can exist
4. Causality is never violated because the effect of virtual particles can't produce a measurable effect that breaks causality. You can show that the theory demands that.

18. ### prometheusviva voce!Registered Senior Member

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This is in response to a post where I have said "the effect of virtual particles does not violate causality."

Sheesh!

19. ### Wolv1BannedBanned

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Why can't it produce a measurable effect? have you looked at ben's post's and read them?

20. ### Wolv1BannedBanned

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so what is it that Ben is talking about?

21. ### prometheusviva voce!Registered Senior Member

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Unless you really get into studying quantum field theory you're going to have trouble really understanding it but, as Ben said, the combined effect of all virtual particles can never violate causality. That is an answer that's been repeated ad nauseum but you seem to keep coming back with odd questions.

22. ### prometheusviva voce!Registered Senior Member

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The response I'm tempted to give is to simply pat you on the head and tell you not to worry about it. Go back and read this thread again, plus the other one on virtual particles that's still on the go.

23. ### OilIsMasteryBannedBanned

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It's impossible to violate causality which is why we know God exists. See Aristotle's Physics Book VIII. Ipse dixit.