Geo 406 Lecture 03 - Reflection, Refraction, Lenses, Relief, Becke Line

Reading: p. 7-15

next: Ch. 3-4

Goals

Finish Becke line

Learn oblique illumination method

Refraction demo redux

Introduce idea of optical indicatrix

Announcements

Lab – some sections were unavailable (leave blank, turn in what you’ve got)

Note that email quiz scores are posted on the MyGrades database

If you didn’t get the email, then you should fix your setup to do so.

Oblique Illumination

Relies on same features as Becke line

Partially obscure the light below the substage with a paper or card, and see where the shadows go.

Need to calibrate your scope to be sure.

Optical indicatrix

In a section through a rock, we could measure the speed of light vibrating in each direction - gives a circle or ellipse

If we did this for every propagation direction, we get a shape - indicatrix