Notices
Results 1 to 11 of 11
Like Tree10Likes
  • 1 Post By exchemist
  • 1 Post By exchemist

Thread: Matter-antimatter question

  1. #1 Matter-antimatter question 
    Forum Freshman
    Join Date
    Jul 2013
    Posts
    29
    I'm a layman in physics but maybe you can help me understand something.

    Anti-matter can be considered opposite to matter and encounters between leads to annihilation of both but with a high release of energy.
    But this can be said also about energy, considering that matter is energy? I mean Energy has anti-Energy?
    Why from 2 different forms of matter results one kind of energy, the same kind that can be obtained from "normal" matter only? An atomic bomb is an example?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    17,036
    There is no "anti-energy", just energy.

    Why? That is just the way it is, I suppose....


    ei incumbit probatio qui dicit, non qui negat
    Reply With Quote  
     

  4. #3  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,559
    Quote Originally Posted by hyperion1is View Post
    I'm a layman in physics but maybe you can help me understand something.

    Anti-matter can be considered opposite to matter and encounters between leads to annihilation of both but with a high release of energy.
    But this can be said also about energy, considering that matter is energy? I mean Energy has anti-Energy?
    Why from 2 different forms of matter results one kind of energy, the same kind that can be obtained from "normal" matter only? An atomic bomb is an example?
    Look at it this way: if you were to have energy and anti-energy that could annihilate, what would be produced?
    Strange likes this.
    Reply With Quote  
     

  5. #4  
    Genius Duck Dywyddyr's Avatar
    Join Date
    Jan 2013
    Location
    Scunthorpe, UK
    Posts
    11,866
    Quote Originally Posted by exchemist View Post
    Look at it this way: if you were to have energy and anti-energy that could annihilate, what would be produced?
    I hope it's chocolate.
    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
    Reply With Quote  
     

  6. #5  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,035
    Quote Originally Posted by hyperion1is View Post
    I'm a layman in physics but maybe you can help me understand something.

    Anti-matter can be considered opposite to matter..
    Don't get confused over the name. It's not actually the opposite of matter except in only one sense: it has the opposite charge. (And a few other quantum details are opposite.... I can't remember which ones.)

    Anti-matter really needs another name. You are certainly not the first person to be confused by the name. There have been others before you who've posted similar questions on this forum even.

    An electron and a positron, for example, have approximately the same mass. They're pulled on by gravity the same. You can store positrons (anti-electrons) in a magnetic or electrical field that is generated by non-anti-matter. However, if a positron touches an electron, the pair will annihilate and create a bunch photons.



    and encounters between leads to annihilation of both but with a high release of energy.
    But this can be said also about energy, considering that matter is energy? I mean Energy has anti-Energy?
    Why from 2 different forms of matter results one kind of energy, the same kind that can be obtained from "normal" matter only? An atomic bomb is an example?
    If the energy created when they annihilate isn't zero, then it's because neither of them has anti-energy. That's part of why the name is so confusing.

    If you got shot at by a laser gun composed entirely of anti-matter, it would have basically the same effect, and beam would look the same as a laser beam emitted by a positive matter laser gun. For that reason, it's almost impossible to know how much antimatter there is out in space. Matter and antimatter react in approximately the same way to visible light.

    You might say that "light doesn't choose sides". It likes them both the same.
    Some clocks are only right twice a day, but they are still right when they are right.
    Reply With Quote  
     

  7. #6  
    Administrator KALSTER's Avatar
    Join Date
    Sep 2007
    Location
    South Africa
    Posts
    8,244
    jyutao:

    In future, please don't hijack other people's threads in order to push your own non-mainstream ideas. This is a warning. In future, create your own threads in the New Hypothesis or Pseudoscience sections. Your next infraction will result in a temporary suspension.

    I will move all your posts and replies to them to your own thread in New Hypothesis shortly. I'll leave a link here.



    Edit: Here it is: http://www.thescienceforum.com/new-h...aos-ideas.html
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

    "Gullibility kills" - Carl Sagan
    "All people know the same truth. Our lives consist of how we chose to distort it." - Harry Block
    "It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
    Reply With Quote  
     

  8. #7  
    Forum Freshman
    Join Date
    Jul 2013
    Posts
    29
    Well, thanks for your replies. I didn't understood entirely the process but at least I can understand my confusion as a confusion about the names, thanks to kojax.
    @ exchemist. That was an implied question related to my confusion. So answering a question with the same question is not much of an answer.
    Reply With Quote  
     

  9. #8  
    Genius Duck Dywyddyr's Avatar
    Join Date
    Jan 2013
    Location
    Scunthorpe, UK
    Posts
    11,866
    But the question was an answer: if matter+anti-matter produces energy then energy+anti-energy produces... er, it can't produce energy, won't produce matter and... there's nothing else.
    Ergo: there's no such thing as anti-energy.
    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
    Reply With Quote  
     

  10. #9  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    17,036
    Nice post kojax. Just to be picky about a couple of points...

    Quote Originally Posted by kojax View Post
    An electron and a positron, for example, have approximately the same mass.
    As far as I know they must have (and have been measured to have) identical mass.

    They're pulled on by gravity the same.
    This is definitely thought to be the case. And there is no significant reason to think they aren't. But even so ('cos science is cool, and doesn't like to take things for granted) there is an experiment underway to test this.
    Home | ALPHA Experiment

    This is one of my favourite projects at the moment. It is technically challenging and the results could be really exciting (but almost certainly won't be).

    However, if a positron touches an electron, the pair will annihilate and create a bunch photons.
    Precisely two photons. Each with the energy equivalent to the mass of an electron/positron (about 511MeV?). There have to be two because of conservation of momentum.

    (Just to confuse things, photons can be considered their own anti-particles but they don't [normally] interact so that's OK.)
    ei incumbit probatio qui dicit, non qui negat
    Reply With Quote  
     

  11. #10  
    Administrator KALSTER's Avatar
    Join Date
    Sep 2007
    Location
    South Africa
    Posts
    8,244
    Quote Originally Posted by Dywyddyr View Post
    But the question was an answer: if matter+anti-matter produces energy then energy+anti-energy produces... er, it can't produce energy, won't produce matter and... there's nothing else.
    Ergo: there's no such thing as anti-energy.
    There is a possibility for something called negative energy though...
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

    "Gullibility kills" - Carl Sagan
    "All people know the same truth. Our lives consist of how we chose to distort it." - Harry Block
    "It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle
    Reply With Quote  
     

  12. #11  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    3,559
    Quote Originally Posted by hyperion1is View Post
    Well, thanks for your replies. I didn't understood entirely the process but at least I can understand my confusion as a confusion about the names, thanks to kojax.
    @ exchemist. That was an implied question related to my confusion. So answering a question with the same question is not much of an answer.
    Hyperion, sorry if you felt my reply was unhelpful. Dywyddyr explains what I was getting at.

    Essentially, if one postulates an entity called "anti-energy", that's just a label without meaning until one can suggest some properties or behaviour that the postulated entity might have. You seemed to be searching for an analogy with matter and anti-matter, so I thought the best way to highlight the difficulty in assigning any meaning to "anti-energy" was to think about annihilation of energy and "anti-energy". That's all.

    I note Kalster mentions negative energy. It's certainly true that in parts of science one measures energy levels in a relative way, and assigns negative values. In chemistry, it is common to treat bond energies as negative, relative to a zero level for the separated atoms, for example. But this is just a convention, adopted because one needs a common level from which to measure the difference when bonds are formed.

    My understanding (Kalster or others are welcome to jump in if this is wrong) is that energy in any system in our universe is +ve in absolute terms, since the lowest energy level one can get to is the zero point energy of the vacuum, and even this is slightly +ve.
    hyperion1is likes this.
    Reply With Quote  
     

Similar Threads

  1. Matter and antimatter
    By lightspeed in forum Physics
    Replies: 4
    Last Post: January 15th, 2013, 04:18 PM
  2. Matter-antimatter
    By Wildstar in forum Physics
    Replies: 7
    Last Post: April 5th, 2010, 12:03 PM
  3. Antimatter and matter
    By kakarot in forum Physics
    Replies: 3
    Last Post: January 12th, 2010, 12:25 AM
  4. Matter and antimatter
    By RosenNoir in forum Physics
    Replies: 3
    Last Post: March 29th, 2009, 04:30 AM
  5. Antimatter and Matter
    By The_Science_Geek in forum Physics
    Replies: 5
    Last Post: December 6th, 2005, 03:34 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •