Duck Soup - Four Revolutions in the Earth Sciences - page 46

two of the most monstrous organizations of the twentieth century: the NKVD and
the Gestapo. He found the NKVD to be “the more serious.” 4
In science if not in politics, Houtermans was ahead of his time. In 1929, he
and a colleague made the first calculations of thermonuclear reactions in stars. As
Houtermans remembered: “That evening, after we had finished our essay, I went
for a walk with a pretty girl. As soon as it grew dark the stars came out, one after
another, in all their splendour. 'Don't they shine beautifully?' cried my compan-
ion. But I simply stuck out my chest and said proudly: 'I've known since yesterday
why it is that they shine'” (30).
A few years later, after scientists had discovered the neutron, Houtermans poin-
ted out the possibility of a self-sustaining nuclear chain reaction, the basis for the
later atomic bomb. In August 1941, in a report titled “On the Question of Unleash-
ing Chain Nuclear Reactions,” he identified plutonium as a more likely element
than uranium for inducing a chain reaction, the same conclusion that Manhattan
Project scientists would later reach. In December 1942, the Chicago team of re-
searchers, led by Enrico Fermi, was working to achieve a controlled nuclear chain
reaction when they received a cable from Switzerland. It said only, “Hurry up. We
are on the track” (35). The wire had come from Houtermans through an intermedi-
ary. The Germans never got the bomb.
In 1946 and 1947, Houtermans used Nier's reported lead-isotope ratios to make
his own calculations. Using a diagram he called an “isochrone,” he obtained an
age of 2,900 million years. 5 Houtermans thought this was either the age of the ele-
ments themselves or possibly the age of the Earth's crust.
Science, Science, Science
The calculations of Gerling, Holmes, and Houtermans were bound to err because
they depended on unknowable assumptions about the history of lead in the Earth.
Even terrestrial leads with the lowest isotope ratios are not likely to be truly prim-
ordial. Where on our living planet, with its complex geological history, could sci-
entists find unaltered lead that still retains its primordial isotopic abundances? In
1947 Houtermans proposed that the place to search for primordial lead was not on
the Earth but in rocks that fall from the sky: in meteorites that had been isolated in
the frigid depths of space since the beginning of geologic time. 6
Scientists knew that one class of meteorites, the “irons,” which look as though
they could have come from a blast furnace, contain minerals that have so little par-
ent uranium that even in billions of years they would not have generated measure-
able radiogenic lead. Thus these meteorites would retain their original lead-isotope