Cover art
Metzger, Robert A. Picoverse. Ace 2002.

Metzger, Robert A. Picoverse
Summary: High-energy physicists create a series of near-duplicate universes as they are manipulated by a 4-million-year-old gynoid. Story begins in 2009 in a universe/timeline where Nixon was not disgraced but Clinton was forced to resign in 1997, visits another where the Soviets conquered the world in the early 1930s, and apparently ends up in ours.
Published: Ace 2002 (0441008992BUY), 2003 (044101030XBUY).