http://www.lyyn.com/scattering

The classical picture is that the incident radiation excites dipolar oscillations in a polarisable system such as a molecule or atom which can act as secondary sources of EM radiation Harry Kroto 2004

P = E E = Eocos2πωt P = Eocos2πωt 4

this shows a Hertz osci http://en. wikipedia. org/wiki/File:Dipole this shows a Hertz osci http://en.wikipedia.org/wiki/File:Dipole.gif -oli Harry Kroto 2004 5

P = αo Eo cos 2πωet + ½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t + cos 2π(ωe- ωq)t] 6

P = αo Eo cos 2πωet + ½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t + cos 2π(ωe- ωq)t] 7

½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t] P = αo Eo cos 2πωet + ½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t + cos 2π(ωe- ωq)t] αo Eo cos 2πωet ½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t] 8

½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t] P = αo Eo cos 2πωet + ½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t + cos 2π(ωe- ωq)t] αo Eo cos 2πωet ½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t] ½(∂α/∂q) qo Eo[cos 2π(ωe- ωq)t] 9

ωe ω →

ωe ωe+ ωq ω → 11

ωe ωe- ωq ωe+ ωq ω → 12

ωe Stokes Line Anti-Stokes Line ωe- ωq ωe+ ωq ← ωq → ← ωq → ω → 13

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Harry Kroto 2004 24

P = E 25

P = E E = Eocos2πωt 26

http://www.ccpo.odu.edu/~lizsmith/SEES/ozone/class/Chap_4/index.htm

P = α E Total polarisability

P = α E Total polarisability α = αo + (∂α/∂q)q Molecular polarisability - function of coordinate

P = α E Total polarisability α = αo + (∂α/∂q)q Molecular polarisability - function of coordinate E = Eo cos 2πωet Electric Field radiation frequency ωe

P = α E Total polarisability α = αo + (∂α/∂q)q Molecular polarisability - function of coordinate E = Eo cos 2πωet Electric Field radiation frequency ωe q = qo cos 2πωqt coordinate of the molecular motion ωq

P = α E Total polarisability α = αo + (∂α/∂q)q Molecular polarisability - function of coordinate E = Eo cos 2πωet Electric Field radiation frequency ωe q = qo cos 2πωqt coordinate of the molecular motion ωq P = [αo + (∂α/∂q) q] E

P = α E Total polarisability α = αo + (∂α/∂q)q Molecular polarisability - function of coordinate E = Eo cos 2πωet Electric Field radiation frequency ωe q = qo cos 2πωqt coordinate of the molecular motion ωq P = [αo + (∂α/∂q) q] E P = [αo + (∂α/∂q) q] Eo cos 2πωet

P = α E Total polarisability α = αo + (∂α/∂q)q Molecular polarisability - function of coordinate E = Eo cos 2πωet Electric Field radiation frequency ωe q = qo cos 2πωqt coordinate of the molecular motion ωq P = [αo + (∂α/∂q) q] E P = [αo + (∂α/∂q) q] Eo cos 2πωet P = [αo + (∂α/∂q) qo cos 2πωqt] Eo cos 2πωet

P = α E Total polarisability α = αo + (∂α/∂q)q Molecular polarisability - function of coordinate E = Eo cos 2πωet Electric Field radiation frequency ωe q = qo cos 2πωqt coordinate of the molecular motion ωq P = [αo + (∂α/∂q) q] E P = [αo + (∂α/∂q) q] Eo cos 2πωet P = [αo + (∂α/∂q) qo cos 2πωqt] Eo cos 2πωet P = αo Eo cos 2πωet + (∂α/∂q) qo Eocos 2πωqt cos 2πωet

P = α E Total polarisability α = αo + (∂α/∂q)q Molecular polarisability - function of coordinate E = Eo cos 2πωet Electric Field radiation frequency ωe q = qo cos 2πωqt coordinate of the molecular motion ωq P = [αo + (∂α/∂q) q] E P = [αo + (∂α/∂q) q] Eo cos 2πωet P = [αo + (∂α/∂q) qo cos 2πωqt] Eo cos 2πωet P = αo Eo cos 2πωet + (∂α/∂q) qo Eocos 2πωqt cos 2πωet P = αo Eo cos 2πωet + ½(∂α/∂q) qo Eo[cos 2π(ωe+ ωq)t + cos 2π(ωe- ωq)t]

P = E E = Eocos2πωt P = Eocos2πωt 37

P = E E = Eocos2πωt P = Eocos2πωt 39

P = E E = Eocosωt P = Eocosωt

Attenuation due to scattering by interstellar gas and dust clouds Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

P =  E

P =  E

P =  E

P =  E

Bill Madden 559 2123