Difference between revisions of "Forest ModernPhysics"

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=Bragg Diffraction=
=Bragg Diffraction=
[[File:Bragg_Diffraction_Illusstration.png | 200 px]]
[[File:Bragg_Diffraction_Illusstration.png | 400 px]]
[http://wiki.iac.isu.edu/index.php/Forest_Classes] [[Forest_Classes]]
[http://wiki.iac.isu.edu/index.php/Forest_Classes] [[Forest_Classes]]

Revision as of 01:00, 30 September 2009

Matter Waves (Wave Particle Duality)

Special relativity said that

[math]E = pc[/math] if m=0

Plank said he could fit the Black Body radiation data assuming that that

[math]E= hf[/math] where [math]h = 6.63 \times 10^{-34} \mbox{ J} \cdot \mbox{s}[/math] = Plank's constant

Combining the two we have

[math] p=\frac{E}{c} = \frac{ h f}{c}[/math]

[math]\Rightarrow[/math] photons have momentum like a particle (mv)

Do particles reciprocate and behave like photons?

De Broglie's Hypothesis

If photons can behave like particles by having momentum

Then can a particle behave like a wave by having wavelength

[math] p=\frac{ h f}{c} = \frac{h}{\lambda}[/math]


[math]\lambda_{particle} = \frac{h}{p}=[/math] de Broglie Hypothesis

Davisson and Germer

We know that X-rays having a wavelength of [math]\lambda_{X-rays} = 7.1 \times 10^{-11} \mbox{m}[/math] make an interference patter on an aluminum foil.

Hit a crystal made of nickel with 54 eV electrons.

1.) 54 eV electrons

From hyperphysics:

Davisson Germber Apparatus.gif

Bragg Diffraction

Bragg Diffraction Illusstration.png

[1] Forest_Classes