Anyone who teaches Earth science knows that density differences play an important role in many Earth systems. This (see video above) is one of the most clever demonstration of density that I've seen in quite some time. The mystery liquid is vegetable oil. Thanks to Rick Dees of Huntley Project High School for sharing it.
Coming on Friday, February 15 . . .
(unrelated to density) An asteroid, 50 m in diameter, will pass within 21,000 miles of Earth. Watch this 4-minute NASA Science Cast video to learn about the details.
One more thing . . .
This week's NOVA looks like it might be pretty good. The two-hour special, titled Earth from Space, airs Wednesday evening, February 13 on PBS.
To view a convenient list of all the resources that have been posted on this "Earth Science Guy" blog site, CLICK HERE.