University of Mississippi

ASTR 101


Friday, September 20, 2013

 Change: HW #1 is now due Monday.
 Today's Topics:

The Nature of Light
• What is light? Waves of different wavelenths.
How do we know? Interference and diffraction.
• The parts of the electromagnetic spectrum.
• How fast does it travel? Always at the
same speed c = 300,000 km/sec!
Matter and Light
• What is matter made of? Atoms and molecules.
• How does light interact with bulk matter?
• How does light interact with atoms? Photons.
• Kinds of spectra and information:
– Emission line [composition].
Continuous [temperature, all objects].
Absorption [composition and temperature].
• Doppler effect [radial velocity] – demo.

blue bullet So, what do we get on Earth from space?

 Reading: Ch. 5, and today's class summary.

Spaceweather; APOD; Heavens-Above; Clear Sky Clock; PhysOrg Astronomy News; The Sky at a Glance

Main  |  Schedule  |  Notices |  Syllabus  |  Grades