|
Post by abacus9900 on Feb 17, 2011 11:30:50 GMT 1
What is De Broglie Wavelength? I know it's got something to do with matter.
|
|
|
Post by Progenitor A on Feb 17, 2011 14:14:47 GMT 1
Well
Penrose tells me that de Broglie further confused the wave/particle dichotomy of light by introducing a wave function for a particle He give hv whwer h is Planck's constant v is the frequency of the particle's wave function.
further
e=mc2 = hv....!
Now as Planck's constant is very small =6.626 x 10-34 Js Then v, the wave-function frequency is pretty high
So there we have it!
the particle description of light that differntiates their behaviour from light waves relies in fact on a wave function to represent the particle
And moreover that particle wave function need not be local (restrained to what we consider to be a particle 'size') but can extend over great distances!
No wonder no-one can explain QM coherently!
Furthermore mass comes in smallest indivisable 'lumps' given by
smallest mass =hvc-2
Clear as a bell (or Bells' Theorem as expounded by some?!)
|
|
|
Post by abacus9900 on Feb 17, 2011 14:57:50 GMT 1
Well Penrose tells me that de Broglie further confused the wave/particle dichotomy of light by introducing a wave function for a particle He give hvwhwer h is Planck's constant v is the frequency of the particle's wave function. further e=mc 2 = hv....! Now as Planck's constant is very small =6.626 x 10 -34 Js Then v, the wave-function frequency is pretty high So there we have it! the particle description of light that differntiates their behaviour from light waves relies in fact on a wave function to represent the particle And moreover that particle wave function need not be local (restrained to what we consider to be a particle 'size') but can extend over great distances! No wonder no-one can explain QM coherently! Furthermore mass comes in smallest indivisable 'lumps' given by smallest mass =hvc -2Clear as a bell (or Bells' Theorem as expounded by some?!) Well explained nay. What a pleasant change.
|
|
|
Post by speakertoanimals on Feb 17, 2011 15:21:16 GMT 1
Wrong.
Given the relation between the energy and frequency of a photon, de Broglie introduced a similar relation between the frequency/wavelength of a massive particle, and it's energy.
It's WASN'T and ISN'T a wavefunction (which means a very specific thing, and a wavefunction may or may not be an actual simple wave of constant frequency).
All it says is that for a particle of a given energy, there is an associated wavelength. Hence just as you can do diffraction for X-rays, so you should be able to do diffraction with matter waves. In fact, electron diffraction is the relevant experiment, where the wavelength associated with the electrons is the de Broglie one.
Rather than being confusion or anything like that, it is the REASON why electron microscopes work. You can get much higher resolution that with optical light microscopes, because the wavelength of the electrons is so much smaller than the wavelengths of optical light.
This is utter NONSENSE (or should that be bollocks :-) ) -- since as it stands frequency can be anything, it doesn't set a lower limit on the right-hand side, hence not on the lefthand side either.
For a particular particle, the energy is always greater than or equal to the rest energy, hence that sets a LOWER limit on the frequency, and an UPPER limit on the wavelength for that particle.
SO, if we compute the largest possible wavelength for an object such as a marble, or a cricket ball, we find it is ridiculously small -- which is why cricket balls don't display their quantum nature, the wavelength is far too small.
The 'units' of mass thing is a different issue. Some people seem to prefer pleasantly explained nonsense, to the actual physics, I wonder why..........................................
Naymissus, I suggest you stick to stuff you know (although probably not information theory), rather than spread more misunderstandings with your warped versions of quantum theory...................
|
|
|
Post by Progenitor A on Feb 17, 2011 15:29:00 GMT 1
Well Penrose tells me that de Broglie further confused the wave/particle dichotomy of light by introducing a wave function for a particle He give hvwhwer h is Planck's constant v is the frequency of the particle's wave function. further e=mc 2 = hv....! Now as Planck's constant is very small =6.626 x 10 -34 Js Then v, the wave-function frequency is pretty high So there we have it! the particle description of light that differntiates their behaviour from light waves relies in fact on a wave function to represent the particle And moreover that particle wave function need not be local (restrained to what we consider to be a particle 'size') but can extend over great distances! No wonder no-one can explain QM coherently! Furthermore mass comes in smallest indivisable 'lumps' given by smallest mass =hvc -2Clear as a bell (or Bells' Theorem as expounded by some?!) Well explained nay. What a pleasant change. That's alright Abacus. Thank Penrose, not me
|
|
|
Post by speakertoanimals on Feb 17, 2011 17:12:05 GMT 1
Except I think Penrose probably got it right, YOU have mangled and misunderstood it.
Just in case there is any danger of anyone sensible taking what NM has to say seriously........................
|
|
|
Post by abacus9900 on Feb 17, 2011 18:15:09 GMT 1
Ooooook, naymissus, so to take an example: What is the DeBroglie wavelength of an electron with a speed of 2.2x10^6 m/s? p = mv = (9.11 x 10^-31) x (2.2 x 10^6 m/s) = 2 x 10^-24 Newton seconds Therefore, DeBroglie wavelenghth = h/p = (6.626 x 10^-34)/(2 x 10^-24) = 3.33 x 10^-10 mtr. Boy, you're a terrific teacher naymissus!!
|
|
|
Post by Progenitor A on Feb 17, 2011 18:24:45 GMT 1
Ooooook, naymissus, so to take an example: What is the DeBroglie wavelength of an electron with a speed of 2.2x10^6 m/s? p = mv = (9.11 x 10^-31) x (2.2 x 10^6 m/s) = 2 x 10^-24 Newton seconds Therefore, DeBroglie wavelenghth = h/p = (6.626 x 10^-34)/(2 x 10^-24) = 3.33 x 10^-10 mtr. Boy, you're a terrific teacher naymissus!! Wow! I'm flattered! Could you please explain in detail how I arrived at that result!
|
|
|
Post by abacus9900 on Feb 17, 2011 18:40:13 GMT 1
Ooooook, naymissus, so to take an example: What is the DeBroglie wavelength of an electron with a speed of 2.2x10^6 m/s? p = mv = (9.11 x 10^-31) x (2.2 x 10^6 m/s) = 2 x 10^-24 Newton seconds Therefore, DeBroglie wavelenghth = h/p = (6.626 x 10^-34)/(2 x 10^-24) = 3.33 x 10^-10 mtr. Boy, you're a terrific teacher naymissus!! Wow! I'm flattered! Could you please explain in detail how I arrived at that result! nay you're such a gifted teacher you inspired me to do some research and now I'm suddenly an expert!
|
|
|
Post by speakertoanimals on Feb 17, 2011 20:09:29 GMT 1
Hyperphysics will do the computation for you.............. hyperphysics.phy-astr.gsu.edu/hbase/debrog.html#c5Excepy using their low-velocity version (ie an approximation, and the computation presented on this board), you get instead: 3.306 x 10^-10 m, and their relativistic version gives the same answer (since we aretalking one percent of lightspeed here). So what's the problem? First, we have rounding-off the initial result, but that is quite small and gives us 3.313 rather than 3.306. So looks like someone couldn't type (or cut and paste, surely not!).
|
|
|
Post by Progenitor A on Feb 17, 2011 20:27:44 GMT 1
Wow! I'm flattered! Could you please explain in detail how I arrived at that result! nay you're such a gifted teacher you inspired me to do some research and now I'm suddenly an expert! Now don't get too cocky Y'know what happens when peo :)ple reckon they are 'experts'!
|
|
|
Post by abacus9900 on Feb 17, 2011 20:37:17 GMT 1
nay you're such a gifted teacher you inspired me to do some research and now I'm suddenly an expert! Now don't get too cocky Y'know what happens when peo :)ple reckon they are 'experts'! Yep I do. But when STA is forced to leave this MB what do we do for fun then?
|
|
|
Post by speakertoanimals on Feb 17, 2011 20:47:28 GMT 1
Yeah, in your dreams sunshine...................
you could try doing something useful with your time, just a suggestion............
|
|
|
Post by abacus9900 on Feb 17, 2011 20:50:51 GMT 1
Yeah, in your dreams sunshine................... you could try doing something useful with your time, just a suggestion............ If only you were more cooperative STA this place could and should be a wonderful resource . Oh well.
|
|