An oval of crumbling mortar and rotted wood in a residential neighborhood not far from the center of Oslo, Bislett Stadium transforms itself each summer into a cauldron of desperate noise and rhythmic clapping that carries runners on invisible wings. Sixty-one world records have been set on its forgiving, brick-colored track; Lynn Jennings, the 10,000 meters bronze medallist in the 1992 Olympics, once called it a distance runner's Fenway Park. Bislett is scheduled to be torn down and replaced by a new stadium. Replaced but not improved upon.