Black holes have long been the stuff of science fiction. Now a leading physicist thinks they spawn new universes. In this hour of To the Best of Our Knowledge, reshaping our ideas of space and time. Also, the never-ending quest to defy gravity - from rollercoasters to the push-up bra.

SEGMENT 1:

Theoretical physicist Lee Smolin tells Steve Paulson about his theory that black holes may harbor new universes whose laws of physics may be quite different from ours. Smolin also believes a successful universe will produce life. Smolin teaches at Pennsylvania State University and is the author of "The Life of the Cosmos."

SEGMENT 2:

Before we can find creatures from other planets, we have to find the other planets, or at least proof that they exist. Astronomer Ken Croswell tells Judith Strasser that this has been done in our decade: we now know of nine planets that exist outside our solar system. Croswell tells the whole story of the planet hunters in his book "Planet Quest: The Epic Discovery of Alien Solar Systems." Also, Historian Sara Schechner-Genuth tells Jim Fleming that human beings have a long history of regarding comets as messages from the gods. Schechner- Genuth is the author of "Comets, Popular Culture and the Birth of Modern Cosmology."

SEGMENT 3:

Writer Joseph Lanza tells Anne Strainchamps that defying gravity is one of our century's central pre-occupations, citing as evidence everthing from elevators and airplanes to roller-coasters and the Wonder Bra. Lanza is the author of "Gravity: Tilted Perspectives on Rocketships, Rollercoasters, Earthquakes and Angel Food."

Distribution dates:

• week of 12/21/97 - hour 2
• week of 9/20/98 - hour 2