Undaunted—well, perhaps mildly daunted—Planck turned to other matters.
Planck was often unlucky in life.
His beloved first wife died early, in 1909, and the younger of his two sons was killed in the First World War.
He also had twin daughters whom he adored.
One died giving birth.
The surviving twin went to look after the baby and fell in love with her sister's husband. They married and two years later she died in childbirth.
In 1944, when Planck was eighty-five, an Allied bomb fell on his house and he lost everything-papers, diaries, a lifetime of accumulations.
The following year his surviving son was caught in a conspiracy to assassinate Hitler and executed.
We shall turn to these ourselves in a moment, but first we must make a slight (but relevant!) detour to Cleveland, Ohio,
and an institution then known as the Case School of Applied Science.
There, in the 1880s, a physicist of early middle years named Albert Michelson, assisted by his friend the chemist Edward Morley,
embarked on a series of experiments that produced curious and disturbing results that would have great ramifications for much of what followed.