Equality, It Seems, Is Relative

In science, no truth is forever, not even perhaps Einstein’s theory of relativity, the pillar of modernity that gave us E=mc2.

As propounded by Einstein as an audaciously confident young patent clerk in 1905, relativity declares that the laws of physics, and in particular the speed of light — 186,000 miles per second — are the same no matter where you are or how fast you are moving.

Generations of students and philosophers have struggled with the paradoxical consequences of Einstein’s deceptively simple notion, which underlies all of modern physics and technology, wrestling with clocks that speed up and slow down, yardsticks that contract and expand and bad jokes using the word “relative.”

Guided by ambiguous signals from the heavens, and by the beauty of their equations, a few brave — or perhaps foolhardy — physicists now say that relativity may have limits and will someday have to be revised.

Some suggest, for example, the rate of the passage of time could depend on a clock’s orientation in space, an effect that physicists hope to test on the space station. Or the speed of a light wave could depend slightly on its color, an effect, astronomers say, that could be detected by future observations of gamma ray bursters, enormous explosions on the far side of the universe. NY Times