Passive polarization clock

Here’s a design for a passive polarization clock.

The sky is polarized in concentric circles around the sun. The polarization of the southern sky moves through around 180 degrees during daylight hours. It is polarized vertically in the morning, horizontally at noon, and vertically again in the evening.

Align slices of polarized film such that they are parallel to the contours. Any given ray from the center of the sundial outward always hits the contours at the same angle; the angle changes by 360 degrees as the ray passes through 180 degrees. In other words, the clock goes from 6am to 6pm as the sun moves through the sky.

Powers of 10 toward the black hole in the center of the galaxy

http://www.cs.indiana.edu/%7Ehanson/Movies/blackhole.mov

Also see Hanson’s other visualizations here:
http://www.cs.indiana.edu/~hanson/
and this 3-d projection of the 5-d Calabi-Yau manifold:
http://www.bathsheba.com/crystal/calabiyau/

Killer Asteroids

Large asteroid impacts may be WAY more common than we think.

Pictures of the moon and sun

A picture of the sun, taken with nutrinos, partly at night, RIGHT THROUGH THE EARTH.
http://cosmicvariance.com/2006/10/13/sun-shots/

A picture of muons from the glow of the night sky, with the moon casting a shadow.
http://en.wikipedia.org/wiki/Image:Moons_shodow_in_muons.gif