Time Stamp	HTML Slide
[00:00]	Homework #1
	(this homework will not be done during the current semester)
[00:06]	Board Sketch #1
[00:54]	Board Sketch #2
[01:55]	Board Sketch #3
[05:28]	Board Sketch #4
[07:45]	Timescales in the Universe
[08:18]	Scale Model of the Universe
[11:05]	The Speed of Light
[12:12]	Lengths of Astronomical Events	(pause to sort four shortest timescales)
[13:38]	Board Sketch #5
[16:54]	Timescale A
[16:55]	Timescale B
[16:56]	Timescale C
[16:57]	Timescale D	(pause to sort next four shortest timescales)
[18:00]	Timescale E
[18:06]	Timescale F
[18:21]	Timescale G
[18:34]	Timescale H	(pause to sort last five longest timescales)
[19:42]	Timescale I
[20:05]	Timescale J
[20:35]	Timescale K
[20:41]	Timescale L
[20:53]	Timescale M
[21:01]	Timescales
[21:02]	Lengths of Time
[21:03]	Key Points

Learning Objectives

1. Visualize the position of solar system and galactic objects in scale models of the Milky Way galaxy.

2. Become comfortable estimating the lengths of astronomically relevant events over a large range of times, from the very short (atomic transitions, passage of light from the Moon to Earth) to the very long (time for light from distant quasars to reach Earth).

3. Realize that astronomical events can take place on timescales far longer than a human lifetime, and thus typically we cannot track the evolution of individual objects.

4. Understand that due to the finite speed of light, a telescope functions in essence like a time machine when viewing distant objects, seeing them not as they are today but as they were billions of years ago.