In 1915, Albert Einstein unveiled his masterwork - a theory, in his words, 'of i
ncomparable beauty': the General Theory of Relativity. It is sometimes overshado
wed - wrongly, argues John Gribbin - by his work of 1905, the Special Theory of
Relativity and E = mc^2. Just over 100 years later, the first direct detection o
f gravitational radiation is seen as the ultimate proof of the General Theory's
accuracy.