Gravity Probe B
surfaced in 1991 summed it up succinctly: "There is an
unresolvable philosophical difference in how scientists view this
George Keiser, a senior research associate who is the Stanford project's
chief scientist, says, "General relativity is in some ways quite
different from other aspects of physics because a large number of people
have quite a bit of confidence in general relativity, partly because of
Einstein's personality and partly because it is such an elegant theory.
"Einstein inspires trust. He was a brilliant physicist. He has such a
reputation that any experiment which contradicts his theory immediately
raises questions." To anticipate those questions, Keiser says, "what we
have been trying to do is make sure we have enough cross-checks and to
have a very high degree of confidence in our experimental results."
In an act of sustained genius that forms the raw material of a modern
scientific legend, Einstein, between his 25th and his 38th birthdays,
basically rebuilt the entire universe in his mind. He called his theory
of gravity, published in 1916 when he was 37 years old, "the happiest
thought of my life."
Overturning centuries of conventional wisdom about the fundamental
laws of nature, Einstein conceived of a universe in which gravity is not
a force so much as a distortion in the very fabric of space caused by a
massive object - a sinkhole in the celestial quagmire. A planet or
star churns that invisible fabric as it rotates, dragging space and time
around it like a pinwheel.
It was the product of a thought experiment, he later wrote, in which he
brooded on the plight of a man falling from a building.
"If one considers an observer in free fall, for example, from the roof
of a house," Einstein wrote. "There exists for him during his fall no
gravitational field - at least in his immediate vicinity."
From that deceptively simple starting point, he opened a door into
a weird realm of black holes, time warps and superstrings.