Superscience - Season 7 (2005)

Travel back in time to look at three of the largest mass extinctions that have decimated life on the planet. What caused these wipeouts?

With contributions from some of the world's foremost scientists, we examine the newest developments and theories using the latest CGI graphics.

This episode examines the effects of a hypothetical radiological attack from a car bomb on a major U.S. city. The purpose is to give useful information in the event that such an event should occur. The stories of several characters are told to dramatize the effects on various types of people: those responding in the "hot zone", a person near to the blast whose symptoms develop over time, a pregnant woman who must evacuate, and investigators who comb through debris to determine who set the blast.

There are numerous theories about how life began on Earth. One thought is that it sprang up in the warm waters of a pond. Another suggests it arrived via comets. A different theory says life sprang from lightening and volcanoes. Scientists demonstrate that a spark of electricity applied to a primordial soup forms amino acids--the building blocks of life.