NOVA scienceNOW Season 4 #408 1x53

EARTHQUAKES IN THE MIDWEST
Some of the most dramatic earthquakes to strike North America haven’t been in California or Alaska — they’ve hit in the heart of the country. In 1811 and 1812, a powerful string of quakes struck New Madrid, MO, with such force that they shifted the course of the Mississippi River and rang church bells in Boston. But were these earthquakes freak events, or could they happen again?

SLEEP
We spend about one-third of our lives sleeping. Scientists don’t know why, but evidence is building that sleep may play a crucial role in strengthening memories and facilitating learning. Peer into the brains of dozing flies and rats to understand the connection between sleep and memory.

PROFILE — SANG-MOOK LEE
Sang-Mook Lee, Assistant Professor of Marine Geology and Geophysics at Seoul National University, is paralyzed from the neck down. But this hasn’t slowed him down: He continues to teach and focus on his work on tectonic plates and the formation of the world’s oceans, and spends his free time advocating for disabled people’s rights and teaching others with disabilities.

FIRST PRIMATES
Could one of our early ancestors have been the size of a mouse? If University of Florida paleontologist Jonathan Bloch is correct, we may have to downsize our image of what it means to be a primate — the biological order that includes humans, apes, monkeys, and comparable mammals. Go into the field with Bloch to search for our missing relatives from the shadowy period after the catastrophe that doomed the dinosaurs.