Are There Mysterious Forces Lurking in Our Atoms and Galaxies?
Physicists stalk a delicate “fifth force” of nature, hidden
within the interstices of the other four. What they have not
found is even more amazing.  By Sean Carroll|Friday, November
04, 2011 Far more delicate than the tug on a spider's web: If a
fifth force is out there, its impact on our world must be nearly
imperceptible.  At the turn of the 20th century, finding a new
form of radiation could put a physicist’s career on the fast
track. Wilhelm Röntgen changed the world by discovering X-rays
in 1895. Soon thereafter, Ernest Rutherford and Paul Villard
identified three different kinds of radiation, dubbed alpha,
beta, and gamma rays, emitted by radioactive compounds. In 1903
French scientist René Blondlot added to the frenzy with his
announcement of N-rays, a strangely democratic form of radiation
emitted by wood, iron, living organisms—just about anything at
all.  Some 300 scientific papers were written about N-rays.
There was just one problem: