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Thread: De Broglie Wavelength

  1. #1  
    Forum Bachelors Degree martillo's Avatar
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    Your problem is that the relation for the Energy E=hf is valid for electromagnetic radiation only which implies a velocity v=c (light velocity).

    Then you will obtain E=mc2.

    You still have a problem: what does m means for an electromagnetic radiation.
    For me it makes sense when associated to the mass of the photons of the beam of the "light" being radiated...


     

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    Your problem is that the relation for the Energy E=hf is valid for electromagnetic radiation only which implies a velocity v=c (light velocity).
    Are you sure? De Broglie's idea was that since light, which was thought to be a wave, was showed to exhibit wave-particle duality, then matter should also exhibit wave-particle duality.

    You still have a problem: what does m means for an electromagnetic radiation.
    For me it makes sense when associated to the mass of the photons of the beam of the "light" being radiated...
    In special relativity there is rest mass and relativistic mass. Usually without qualifiers m denotes rest mass. For particles of matter the rest mass is non-zero and relativistic mass is g*m where again g is the Lorentz factor. The Lorentz factor grows to infinity as the velocity of the particle gets closer to c. This is why you cannot accelerate matter to the speed of light - you would need an infinite amount of energy.

    For photons the rest mass is zero and the Lorentz constant is infinite (since v=c) therefore the relativistic mass of a photon cannot be calculated through m*g since you would be dividing zero by infinity. That's where E=hf=mc2 comes in. If you know the frequency of the photon you can find its relativistic mass (since h and c are known constants).


     

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    Forum Bachelors Degree martillo's Avatar
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    Are you sure? De Broglie's idea was that since light, which was thought to be a wave, was showed to exhibit wave-particle duality, then matter should also exhibit wave-particle duality.
    Yes I'm sure. E=hf is "Planck's energy" and applies to photons ("quantums") only.
    I disagree with the "De Broglie's idea". I agree with his formula lambda=h/mv but applied to photons not to waves. For me there are no "waves" associated to matter.
    His formula can be applied to particles like electrons, protons and neutrons without any wave associated to them just giving the right structure for those partices. Lambda for particles would represent their lenght.
    Please take a look at: www.geocities.com/anewlightinphysics
     

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    Yes I'm sure. E=hf is "Planck's energy" and applies to photons ("quantums") only.
    Yes, Planck applied it first to photons and then de Broglie applied it to particles of matter.

    I disagree with the "De Broglie's idea". I agree with his formula lambda=h/mv but applied to photons not to waves. For me there are no "waves" associated to matter.
    His formula can be applied to particles like electrons, protons and neutrons without any wave associated to them just giving the right structure for those partices. Lambda for particles would represent their lenght.
    I can see why this thread got moved. Wave-particle duality of matter and de Broglie's explanation of it are well established scientific theories. I won't argue with you about their validities or the validity of your theory because it's something that is beyond my scope. Maybe some time in the future when I have time for that sort of thing.

    Please take a look at: www.geocities.com/anewlightinphysics
    Interesting site, a lot of reading. I would like to point out something though.

    In the very first section it is claimed that relativity theory is wrong because, among other things, it relies on the assumption that the true equation of force is F=m*dv/dt and not the widely accepted F=dp/dt where p = mv. The demonstration for this is shown in appendix A. That entire "proof" is based on the finding from two websites that describe the motion of a rocket, a body with variable mass. However what is presented on those websites is interpreted wrongly.

    Both websites write the equation:

    m*dv/dt = -u*dm/dt (1)

    and from this we are led to believe that F = m*dv/dt. That is the wrong conclusion. Equation (1) is a differential equation (derived from the principle of conservation of momentum) that describes the motion of the rocket, nothing more, nothing less.

    Not only that, the Appendix claims that if F=dp/dt then when expanded equation would be F = v*dm/dt + m*dv/dt. Well on one of the websites there is a formula for calculating the force acting on the rocket, namely:

    F = q*Ve + (Pe-Pa)*Ae

    where "q is the rate of the ejected mass flow," or in other words dm/dt! Therefore clearly the force acting on the rocket does depend on the rate of change of the mass.

    In my mind this sheds a cloud of doubt over the veracity and accuracy of anything else that might be on that website.
     

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    Forum Bachelors Degree martillo's Avatar
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    Some times we only find what we are looking for and don't find what we are not looking for...

    In other words, there's no more bline that who don't want to see...
     

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    Lol, that's all you got?
     

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    Quote Originally Posted by martillo
    Some times we only find what we are looking for and don't find what we are not looking for...

    In other words, there's no more bline that who don't want to see...
    You don't really need to give that advice to a scientist. You're talking about confirmation bias, which is one of the annoying habits of the human mind that the scientific method is designed to circumvent.

    But you don't seem all that interested in questioning your own position. So far you've defended yourself with a website that ScienceWizard has found to be unreliable. Webistes like that are, to put it plainly, not where new and cutting edge science are published. So you need to concede or find new evidence, preferably from a good physics text or from the primary literature. Or since this is physics, you could show us some equations.
     

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    Forum Bachelors Degree martillo's Avatar
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    I'm sorry but I'm very busy in my current daily work. I have little time for posting in the forum and I cannot waste my time in this "level" of discussion. May be I shouldn't have posted anything at all.
     

  10. #9  
    Moderator Moderator TheBiologista's Avatar
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    Quote Originally Posted by martillo
    I'm sorry but I'm very busy in my current daily work. I have little time for posting in the forum and I cannot waste my time in this "level" of discussion. May be I shouldn't have posted anything at all.
    Fair enough, but I'm afraid you can't expect your work to be given too much credence if you're unwilling or unable to defend it against criticism. This is how the life of the scientist has to be.

    Would you like me to lock the thread?
     

  11. #10  
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    Yes lock it.
     

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