Is Conservation Of Momentum Valid In Physics In This Physics Forum?

Discussion in 'The Cesspool' started by CANGAS, May 15, 2007.

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  1. CANGAS Registered Senior Member

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    In recent days there has been some arguement in this physics forum about whether the conservation of momentum is an important factor in physics today.

    Pete, Tom2, and Trilarian have stated that conservation of momentum is unimportant in physics today. They have stated that the failure of conservation of momentum is commonplace in Special Relativity and is nothing to take notice about.

    For 400 year the most important factor in physics has been the conservation of momentum. In every discussion in the literature about Einstein's development of Special Relativity, the conservation of momentum has been foremost.

    In recent posts in this physics forum, Pete has stated, as recorded on my hard drive, that the conservation of momentum is of no importance in physics. And he has stated that conservation of momentum is frequently violated in Special Relativity.

    It is past time for these latter day physics geniuses to post documentation, verbal proofs, or mathematical proofs to back up their wild assertions which pervert 400 years of mainstream physics belief.

    copied to my hard drive before Pete can edit.
     
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  3. Pete It's not rocket surgery Registered Senior Member

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    Rubbish.
     
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  5. CANGAS Registered Senior Member

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    For once you are correct.

    Your previous and documented statements that you believe the conservation of momentum to be unimportant, and that you believe that momentum is not conserved in Special Relativity, are indeed rubbish.

    The fact is that 400 years of serious study by countless scientists has shown the conservation of momentum to be the cornerstone of physics.

    And Einstein bent over backwards to protect the conservation of momentum while inventing Special Relativity.

    Why do you think any reasonable scientist, who is not a crackpot, would say otherwise?
     
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  7. Pete It's not rocket surgery Registered Senior Member

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    Very funny. Address the point, or kiss the thread goodbye.
     
  8. Tom2 Registered Senior Member

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    This should be entertaining. I'm making some popcorn.
     
  9. 2inquisitive The Devil is in the details Registered Senior Member

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  10. 1100f Banned Registered Senior Member

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    In order to understamd conservation laws, you should read about Noether theorem, which states that for any symmetry of a system, there are conserved "currents".
    Noether theorem also gives the way to find thes currents.
    Since we believe thart the laws of nature are invariant under translations (this is a symmetry), we find from Noether theorem the conserved current and we call it momentum. In non relativistic physics, for a particle of mass m, this momentum is found to be mv. In relativistic physics, it is found to be gamma*mv, where m is the invariant mass of the particle, v is its velocity and gamma is the gamma factor of the Lorentz transformations. For electromagnetic fields, it is found to be the Poyinting vector.
    BTW, one finds that he non relativistic momentum, mv, is not conserved and this is only an approximation. At low velocities, gamma is almost equal to 1, so that at low velocities, it is an approximation to say that mv is conserved. However, gamma*mv is conserved, and this is the momentum.

    The same way that we believe that the laws of nature are invariant under translation, we also believe that they are invariant under rotation. From which we get the laws of conservation of angular momentum, or to their relativistic form in the case of relativistic physics.
     
  11. Pete It's not rocket surgery Registered Senior Member

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    (replying to deleted post)
    Hi Ben,
    While your advice to 1100f was probably sound, it was too inflammatory for civil conversation

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    Usually I'd let it go, but I'd like this thread to stay reasonably on track for the moment.
     
  12. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

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    Good luck

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  13. James R Just this guy, you know? Staff Member

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    Conservation of momentum is fundamental in physics. It is a direct result of the translational invariance of spacetime.

    A thread stupid enough to proclaim that the concept is questioned by people trained in physics deserves its place in the Cesspool.
     
  14. Uno Hoo Registered Senior Member

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    Uno Hoo has never understood this retort, uttered by pete, ostensibly in response to a [post by CANGAS. It makes no sense unless pete is hearing something inaudible to anyone else. \\What is very funny?

    What is the point that pete is trying so hard to defend?

    Why is pete threatening to ban CANGAS for CANGAS' defending the conservation of momentum?
     
  15. Pete It's not rocket surgery Registered Senior Member

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    Cangas,
    What was funny is the way you deliberately misinterpreted my post.
    The point you chose not to address is that the quoted statement is a blatant lie:
    As is this:

    In summary: I accuse you of lying. I suggest that you defend your statements, or you may find your threads locked or moved. Not by me - I'm not a moderator.

    Your abysmal attitude toward openness and honesty is why this thread was Cesspooled.
     
    Last edited: Oct 22, 2008
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