Last April, at a meeting of the American physical society in
Washington, D.C., representatives of three independent
laboratories announced new high-precision measurements of the
strength of the force of gravity. To the astonishment of the
audience, the three measurements disagreed with one another by
considerable amounts, and worse, none of them matched the value
that physicists have accepted as correct for more than a decade.
No one could offer so much as a hint to explain the
discrepancies. To illustrate the magnitude of the predicament,
imagine a felon hunted by the police. They know that he is
hiding somewhere along a street of ten blocks, with ten houses
on each block. On the basis of previous information, the police
have concentrated their surveillance on a particular house in
the middle of the second block, when suddenly three new and
presumably trustworthy witnesses appear. One places the
miscreant in the very first house of the first block, the second
singles out a dwelling near the end of the first