Quest Finds No ‘Fifth Force’

An oceanographic quest for a new force of nature instead has produced extensive data supporting the law of gravity described by Isaac Newton more than three centuries ago. Scientists at Scripps Institution of Oceanography who spent more than three years conducting the experiments aboard deep-diving submersibles reported last week in Physical Review Letters that they found no evidence of a so-called “fifth force” that would detract from Newton’s theory.

Several scientists have theorized that a fifth force could enhance or diminish gravity’s pull. Scientists have said that such a force would affect gravity by perhaps as much as 1%, reducing or enhancing it depending upon the distance between objects.

Geophysicist Mark Zumberge and his colleagues measured the force of gravity from the surface of the ocean in a 40-square-mile region halfway between San Diego and Hawaii to a point 16,000 feet below the surface. They used instruments lowered from ships and a three-man submarine to make the measurements.

The Scripps experiment produced no evidence for a fifth force at work over distances of a few feet to a few miles. Combined with negative evidence from other scientists, the new results would seem to sound the death knell for the concept of the fifth force.