8.4.2 Dispersion in Nonconductors

[@hershyfishman2929]

5:52 This is obvious to some but not others: The fact that γ/ω (i.e. the tan) approaches 0 doesn't tell you whether the phase angel approaches π or 0. Whether it is π or 0 depends on whether the denominator (and therefore the tan) is positive or negative. If it is close to 0 but positive, the angel must be close to 0. If it is close to 0 but negative, the angel must be close to π.

[@justtocomment.-dw8hd]

thanks... it was bothering me.

[@hershyfishman2929]

6:54 P is the dipole moment per unit volume, so N is number of molecules per unit volume

[@13enny7an3]

13:29 Shouldn't there be an extra 2*omega^2/c factor in the alpha = 2K- term? And also the denominator of (omega_j^2 - omega^2) should be squared

[@hershyfishman2929]

Yes, and your last point is also true for n = (c/ω)k+

[@diegotapiasilva7349]

you add no new input

[@dingchengyue5946]

at 9:36 , exponential part of k- term should be real.