Wolv1's questions about causality and particles

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

  1. Wolv1 Banned Banned

    Messages:
    322
    Moderator note: This thread is a merge of many similar threads on essentially the same topic, posted by wolv1.
    Now, all posts have been collected in one convenient location for your reading enjoyment.

    ----

    I was wondering and doing my research for this.
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    What do you mean "exist"?

    There ARE solutions of Einstein's equations which admit CTC's (to my knowledge), but also (to my knowledge) none have been observed in nature.

    So mathematically, yes. Physically, no.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Wolv1 Banned Banned

    Messages:
    322
    yes,i meant in physically,what does it mean that they are artifacts?
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    ummm who said artifacts?
     
  8. Wolv1 Banned Banned

    Messages:
    322
    on the wiki page,i also was told it seems quantum gravity will disprove them?
     
  9. Reiku Banned Banned

    Messages:
    11,238
    Frank J. Tipler worked on a hypothetical time machine, which was a fast spinning ring, that would sinusoidally warp the spacetime fabric, and would experience time moving as though it was some kind of Closed-Timelike-Curve (also known as Curved-Paths).

    The may very well exist in nature, but some scientists are skeptical of them. As Ben said, at the moment, they exist as nothing but solutions to Einsteins Relativity Theories.
     
  10. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Artifacts means left over from something.

    And that MAY be the case. Because we don;t know the full theory of QG, we can't make any definitive statements, I think.

    And don't listen to anything Tipler writes. His stuff is fringe science at best.
     
  11. Reiku Banned Banned

    Messages:
    11,238
    He's a mathematician, professor at New Orleans University, and is well respected among his peers.

    Don't listen to what Ben says. Tipler is infamous as a great mathematician, and theorist, despite some of his work revolving around theology.
     
  12. Oli Heute der Enteteich... Registered Senior Member

    Messages:
    11,888
    Um, artifact/ artefact means something crafted surely?

    If he were INfamous then he wouldn't be well respected...
    And it was cylinders, not rings, that Tipler first proposed: Physical Review D 9: 2203–2206
     
  13. Reiku Banned Banned

    Messages:
    11,238
    Slight mishap of terminology. Not the end of the world, oli

    Please Register or Log in to view the hidden image!

     
  14. Reiku Banned Banned

    Messages:
    11,238
    I used to observe the model from a birdseye view, which i suppose, is what made me think now of rings, rather than cylinders.
     
  15. Oli Heute der Enteteich... Registered Senior Member

    Messages:
    11,888
    When it directly contradicts your point...
    And I think it would be more correct to say that Tipler was highly respected.
    He's done the aging physicist thing and started going woo woo now...
     
  16. Oli Heute der Enteteich... Registered Senior Member

    Messages:
    11,888
    Where did you stand to get a bird's eye view?
    The proposal was for a cylinder of infinite length, which makes it sorta hard to move round to the ends

    Please Register or Log in to view the hidden image!

     
  17. Wolv1 Banned Banned

    Messages:
    322
    what are your opinions on ctc's? do you think they exist?
     
  18. Reiku Banned Banned

    Messages:
    11,238
    I admit, Tipler has gone a bit crusty round the edges, but God Bless him. He's a fantabulous physicist. One of my favorites next to Dr Wolf.
     
  19. Reiku Banned Banned

    Messages:
    11,238
    It was a schematic Dr Bond...

    Please Register or Log in to view the hidden image!

     
  20. Reiku Banned Banned

    Messages:
    11,238

    Yes, i do.
     
  21. Wolv1 Banned Banned

    Messages:
    322
    does not most of the physics community think ctc's will be disproven to quantum gravity?
     
  22. Reiku Banned Banned

    Messages:
    11,238
    Not everyone in the community can even agree on what gravity fundamentally is, never mind quantum gravity theory.
     
  23. Wolv1 Banned Banned

    Messages:
    322
    but ctc's violate causality, and causality has not ever been shown to be violated.
     

Share This Page