anti-particles -where and how- is there an anti-you

Discussion in 'Physics & Math' started by Avatar, Jun 9, 2002.

  1. Avatar smoking revolver Valued Senior Member

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    In 1928 Paul Dirac introduced a theory tht stated that every particle has an anti-particle. The theory was finally approved in 1932.

    so it's a fact-> every particle has an anti-particle.

    but does tht mean tht those particles have the same possition to each other as "original" particles? You see, if they do then there may exist whole anti-worlds, anti-humans, anti solar system, anti-you. Because atoms are made of particles and we are made of atoms.

    But where do these particles are located? because if you touched your anti-self you'd anihiate (sp). They can not be at the same place as original particles because of tht and also because of Pauli principle (there can not exist two particles in one location at one time).

    I think they could exist in other universes also (if we note the multiverse theory which I think is highly probable), because according to IT ) in the big bang originated many universes, but at the very very beggining there was one universe and some nano-second latter it devided into several. If we note this then we can assume that our anti-partciple can be located in those other universes, but not all, some would also remain in our own universe. So I come to an conclusion that atleast some anti-particles must exist in our own universe even if we take noted the multiverse theory!
    [EDIT- there have been vitnessed anti-partciples in particle accelerators, I'm more thinking of areas which consist of only anti-partciples]

    So there must be a place in our own universe where these particles exist. A proof to that is youself. You exist. However-> these particles anihilate if they collide with "original" partciples. But because of Pauli principle I also assume that any particle that collides with another one anihilates. [EDIT- no it can also change their direction]

    So I come to another conclusion that we can exist even if our anti-partciples were anihilated, but that is wrong because EVERY PARTCIPLE HAS AN ANTI-PARTICLE (Paul Dirac). However it is not made clear if tht anti partciple may have ceased to exist. Maybe it existed in some time ago, but then it anihilated when colliding with another particle. and only the "original" remained. The main problem in this is-> can partciples aniilate if collided with another particle-> not it's anti-self. Because Pauli said tht two partciles
    can not exist in one location at one time.
    (Hmmm, I think this is already another topic, but we can discuss this also)

    Anyways, atleast some anti-particles must exist in our universe. the original question-> where? and how?
    if there are anti-worlds we could never explore them, btu we could and can detect their gravitational force. The problem is we can not put thm on map, can't point out an exact location.

    Ok -> so there are large areas where anti-particles exist (just like the "original ones") . They can be aligned to eachself just as in our universe thus makin anti-copyes of ourselves. They can, but are they, or is tht left to the probability factor?


    More questions thn answers I quess, but i hope we can come up with smthing in the course of our discussion.

    edit- changed the spelling for Dirac which was incorrect
     
    Last edited: Jun 9, 2002
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  3. Crisp Gone 4ever Registered Senior Member

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    Some answers...

    Hi Avatar,

    Yes, you are correct, Paul Dirac formulated his theory of Quantum Electrodynamics around the 1930's and this theory predicts the existance of anti-particles.

    However, anti-particles do not behave the way you described. The best way to look at anti-particles is as if they were regular matter, with some special properties. For example: the positron is the anti-particle of the electron. This means that they both have the same weight, but opposite charges (the electron has charge -e, the position +e). There is no other coupling between electrons and positrons: if an electron exists somewhere, this does not mean that a positron has to exist in some other universe or somewhere else. The word "anti" in antiparticle simply specifies that that particle has exactly the opposite quantum properties of the "regular" particle. Another example to illustrate that antimatter is not as strange as it seems would be the photon. The photon's anti-particle is again a photon, plain and simple.

    When a particle and anti-particle meet, one possibility is that they annihilate to form energy (light, photons). This is what makes it very difficult to create large amounts of antimatter: antimatter has to be contained in magnetic fields to prevent it from meeting regular matter, and it is not quite easy to contain enough antimatter in such magnetic fields to have a macroscopic amount of it.

    I hope this clarifies some things.

    Bye!

    Crisp
     
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  5. Merlijn curious cat Registered Senior Member

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    Feynman diagrams

    One may think of anti-particles as particles moving backwards in time. So in this view, an anti-electron actually has the same (negative) charge as an electron, but because it is moving back in time it seems to have a positive charge.
    I did a google search fror "Feynman diagram anti-matter backwards time" and hoped to find some insightful Feynman-diagrams to0 illustrate the idea, but the results were not very satisfying. Maybe you have more luck.
    If you're interested to learn more, find a copy of Feynman's 1985 book QED (Quantum Electro Dynamics, or Quod Erat Demonstrandum; don't be scraed it's not too hard to read!)
     
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  7. Avatar smoking revolver Valued Senior Member

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    I don't really think tht anti-particles are moving back in time. and there are many Feynman diagrams.

    besides I found out tht anti-particles do not make exact copies of solar system or anti-you.
    in 1956 Li Dzundao and Jan Chenjin (sp) discovered tht universe may develop different thn its mirror image. the text is too difficult to translate. Check for P transformation.
     
  8. Crisp Gone 4ever Registered Senior Member

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    Hi Avatar,

    The experiment you are referring to probably is related to C symmetry breaking (or C violation, C for charge) where particles and anti-particles do not behave the way predicted from their charge symmetries. The discovery of Parity violation (P transformation usually refers to the parity, or spatial reflection transformation) was done by the Wu experiment. But I could be wrong and the experiment you are referring to could have something to do with parity violation aswel ofcourse, I am too lazy to look it up at the moment

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    .

    Bye!

    Crisp
     
  9. Avatar smoking revolver Valued Senior Member

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    you are right. I dug up that Wu only later confirmed the results tht Li and Yan got in the first place.

    I'm looking for more info,
    now I understand anti-particles better

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    cheers
     
  10. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    Avatar,

    Just a speculation...
    ...Spiritual Dimension, perhaps...?

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  11. Merlijn curious cat Registered Senior Member

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    Avatar,
    "I don't really think tht anti-particles are moving back in time. and there are many Feynman diagrams. "
    what kind of reply is that?

    I found Feynman's argumentation foir moving backwards in time very convincing.

    here is a small piece:
    the reason matter cannot travel backwards in time is beacuse it is impossible to send information back in time. so... particles can, esrever ni og tonnac rettam tub!

    evol
    njilrem
     
  12. Avatar smoking revolver Valued Senior Member

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    19,083
    Seeker,
    Why in the hell do you introduce some mystical spiritual dimensions. There are no need for them (spiritual) and please define a spiritual dimension - I do not know such.

    Merlijn,
    sorry , I was late for my training and couldn't give a full reply.

    I admit I didn't have time to introduce myself to the particular fact and it was only my presumption. I'll read tht link you provided and give an answer to it later.
    In the mean time->
    you may be right and also wrong in this. Actually no one knows for sure, because there is one case when tht could happen. I specially for you found a place I remembered from Stephens Hawkings book "A brief history of time" in English. here it is
     
  13. Merlijn curious cat Registered Senior Member

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    Hi Avatar,
    no problem.
    I know the wormhole thing. But at the moment theories tell us that (without a wormhole) no information canb go back in time. Thus individual particles can, but a structure in the array of particles cannot be sent back.

    it's all speculation.

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  14. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    Avatar,

    I was just wondering if the anti-particle universe wouldn't be the spiritual dimension that Religions and Philosophies talk about...

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  15. Avatar smoking revolver Valued Senior Member

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    we have anti-particles in our own universe. There is no need for some other universe. I was talking about anti-particles in other universes, not about some mysterious anti-particle universe. And it was made clear tht anti-particles do not require other universes.

    Cheerz!
     
  16. huh??? Registered Senior Member

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    <I>One may think of anti-particles as particles moving backwards in time. </I>

    One of the most retarted comments I've read thus far, but there may be more...

    Anyways, I personally don't believe in an antimatter universe. First of all, CP violation seems to proove that there may be a way to create matter without creating antimatter. Furthermore, just because anitmatter exists does not mean it would create a mirror of this universe. What mysterious force would first separate antimatter from matter, and then form it into a mirror image of this universe? This vision was formulated from a scifi writer, not a physicist/theorist. And also, whoever that one dude was got it right, antimatter is not the opposite of matter, on the contrary, it is nearly identical with 2 key changes: 1)It's spin is reversed, and 2)it's charge is opposite. Unless there is some supreme creator, an antimatter universe/twin is all but impossible.
     

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