The Earth at night
Composite photo of the whole Earth at night.
Where is everyone? Everyone with the lights on, anyway.
All kinds of interesting ideas suggest themselves.
India compared with Russia, Japan compared with
California...
http://visibleearth.nasa.gov/view_rec.php?vev1id=5826
Bull of the Woods is still available!
If you have never heard of these, go down the list and view
some of the pages. Amazingly knowledgable cartoons set in a machine shop
from the 1920's to the 1940's. My favorite: "Every time I touch or turn
something on this machine a piece of tin or a little wedge falls out!"
http://www.leevalley.com/wood/page.aspx?c=1&cat=1,46096,46100&p=46711
Reuleaux Collection of Kinematic Mechanisms at Cornell
Here's an amazing collection of actual models of kinematic devices, maintained by Cornell University.
There are some animated videos among the pictures...
http://kmoddl.library.cornell.edu/model.php?m=reuleaux