1. Announcements Discussion Quiz today through section 1.5.
Sign up for discussion by Friday.
Check your Clicker serial number at the eInstruction web site if it is not working.
To join clicker to class today:
Turn on the Clicker (the red LED comes on).
Push “Join” button followed by “20” followed by the “Send” button (switches to flashing green LED if successful).
Old IR clickers with just a, b, c, d... buttons do not work. You will need a new one.
Just added students: your discussion assignments are on the class web site.

2. Review Doppler effect • Red Shift/Fraunhofer lines
Expansion of universe/Big Bang
energy->quarks->n -> p + e -> nucleons -> atoms -> stars/galaxies
radioactive decay
Isotopes (average atomic mass)
Example H + D: ( ) ( ) = amu = mHfH + mDfD = mavg

3. Recent Universe Temperature Map