Field of Science

Radioactivity and Earth's Age

In the 19th century, the discrepancy between the age of Earth and the age of the cosmos posed a great problem to scientists. Geologists had calculated, using methods like erosion or sedimentation rates, ages for Earth spanning from three million to fifteen billion years. Physicists and astronomers, based mostly on the energy output of stars, calculated an age for the universe spanning from twenty million to ten billion years - so in many models of the cosmos, Earth seemed to be too young or too old to fit in. In August 1893, during a meeting of the American Association for the Advancement of Science, geologist Charles D. Walcott (1850-1927) summarized the debate as follows:

"Of all subjects of speculative geology, few are more attractive or more uncertain in positive results than geological time. The physicists have drawn the lines closer and closer until the geologist is told that he must bring his estimates of the age of the earth within a limit of from ten to thirty millions of years. The geologist masses his observations and replies that more time is required, and suggests to the physicist that there may be an error somewhere in his data or the method of his treatment."


In 1896 the French physicist Henri Becquerel (1852-1908), based on Conrad Röntgen's (1845-1923) research, discovered that naturally occurring elements, like uranium, also emit X-rays and in 1897 Polish physicist Marie Curie (1867-1934) coined the term radioactivity to describe this energy of unknown origin. Her husband, Pierre Curie (1859-1906), realized that this energy from radioactive decay must be considered when calculating the age of Earth. Physicists supporting a young Earth based their calculations on a quickly cooling Earth. However, radioactive decay in Earth's interior provided a continuous source of energy and heat, therefore Earth was cooling slowly and so could be quite old.

Radioactive decay or another similar long-lasting and high-energy source (nuclear fusion was discovered later) could also explain how stars could produce light and heat for very long periods of time. The notion that stars or the sun had to be young (in most calculations younger than Earth) could also be dismissed.

But even better - the discovery of radioactivity provided not only indirect evidence of an old Earth but by measuring the constant decay it was also possible to calculate the exact age of a mineral, a rock and even of Earth.

High-energy rays, derived from radioactive decay, form a halo of alteration around a mineral grain in the larger biotite-crystal, image from J. JOYLE (1909): Radioactivity and geology, an account of the influence of radioactive energy on terrestrial history.

The British Diplomat Who Studies Volcanoes

When, in 1631, Vesuvius erupted violently after having been dormant for more than 300 years, it aroused great interest among Europe's elite. German Jesuit and naturalist Athanasius Kircher traveled to Southern Italy to study Vesuvius, descending even in the crater. The volcano was almost continuously active, especially after 1750 and Naples became part of the cities traveler should visit when in Italy.

Sir William Hamilton (1730-1803) was a British diplomat in Naples from 1764 to 1798, He got so interested in the nearby Mount Vesuvius that in 1776 he published a monograph on the mountain, illustrated with stunning artwork by local painter Peter Fabris. Hamilton's "Campi Phlegraei: Observations on the Volcanos of the Two Sicilies" is considered a pioneering work of early volcanology.
 The eruption of Mt. Vesuvius in August 1779.
The eruption of May 1771. An Aa lava flow (recognized by the broken surface texture) passes the observer's location and reaches the sea at Resina. Note the steep, slowly advancing front of the flow. Pietro Fabris is amongst the spectators (below left) as is William Hamilton, who explains the view to other onlookers.
Inside the crater of Mount Vesuvius.

Lava samples from Mount Vesuvius.

Another view of the August 1779 eruption of Mount Vesuvius.

The excavation of the Temple of Isis in Pompeii.
 Hamilton at the crater of Forum Vulcani (Solfatara near Pozzuoli), examining the sulphur and arsenic deposits near the hot springs.

Hitler's Geologists

Already during the first World War the Germans established a special class of soldiers known as "Kriegsgeologen", military geologists working on the front line in special offices called "Geologen-Stellen". Their tasks included solving water supply issues by locating the best spots for wells, locating rock-materials for construction or roads and choosing sites suitable for bridges, trenches and galleries. 

In 1936 Adolf Hitler, now the Führer of the German Reich, announced his Four Year Plan to boost economic growth and make the country independent from imports (an important, at the time not mentioned, goal was to prepare the economy for a coming war). This plan included also projects to map all resources available in the Reich, like rare metals and especially oil. Geologists explored old mines to find new veins of ore and until 1939 almost the entire territory of the German Reich was mapped with geophysical methods (like gravimetry and seismic survey), hoping to discover new oil fields. At the beginning of World War II. many geologists were incorporated in the "Ahnenerbe", a unit established by Heinrich Himmler, the Reichsführer of the Schutzstaffel. The Schutzstaffel (or SS) was a vast military organization inside the Nazi regime, controlling the police, secret police, troops but also business like quarries and mines. The Ahnenerbe was the "science institute" of the SS, dedicated to geological, archaeological and ethnological surveys, but also political propaganda and pseudo-scientific research.  

Reichsführer SS Heinrich Himmler visiting a quarry in southwestern Germany, 1935.

During the field campaign to invade Poland in 1939 it was decided to establish also an "Oil Kommando", a unit of 50 geologists mapping oil reserves in occupied areas. The reserves in Germany and occupied areas were not sufficient to keep the German forces running for long. When Hitler ordered to attack the Soviet Union in summer of 1941, he hoped also to secure the rich oilfields of the Caucasus and Crimea where 80% of the Russian oil came from. Geology became now part of the war efforts and Himmler established in April 1941 the "SS-Wehrgeologen Battalion 500", the Schutzstaffel equivalent of a unit of military geologists. The battalion comprised four units, a unit specialized in the construction of tunnels (the "Stollenbau Kp"), a unit of hydrogeologists, a unit of Earth scientists (ranging from archaeologists to geophysicists) and a unit specialized in drilling operations. Members were recruited from other SS units including the Ahnenerbe. The unit included experts like Erich Marquardt, an archaeologist, Karl Heinzelmann, a geologist who worked on tectonics, and Joachim Schlorf, who studied the toxic effects of Vanadium-ore. The unit was commanded by Rolf Höhne, an archaeologist and geologist. The official tasks of the Wehrgeologen included all aspects of military geology, like prospecting for water, oil, gas and other valuable resources in the field, support during construction work of fortifications, underground mines and galleries. One project included mapping the route for a planned “Autobahn” (highway) between Berlin and the peninsula of Crimea (never realized). 

Geophysical surveys carried out until the beginning of the war in 1939. After BENTZ and CLOSS 1939.

However, more esoteric tasks included archaeological digs to prove the superiority of the Aryan race and research in ancient artifacts and unknown energy sources. Rolf Höhne believed in the Hollow Earth theory and published various archeological and pseudo-scientific articles on the topic. The Hollow Earth was a theory dating to the early 19th century, claiming that after a series of natural disasters a race of superior beings survived in a vast undergroudn reign, accessible only be gateways hidden in the mountain ranges around the globe.

In 1943 the Wehrgeologen were sent to northern and southern Europe to help build a defense line along the coasts of France and in the Italian Alps. The "Blaue Linie" was a system of fortifications to be built in the Prealps to stop the allied forces, landing at the time Sicily. An even more ambitious plan included the idea to use the mountains as the  “Alpenfestung”, a mountain fortress as a last refugium for the Nazis. In the Bretagne and Normandy, they helped to plan a defense line against a possible invasion by allied forces from the sea. The "Hindernisbau" consisted of a system of antitank obstacles along the beaches, bunkers hidden in the rocky cliffs and areas to be flooded in case of successful landfall of allied troops. In France and the Netherlands, the geologists studied the best location to build the launch pads for the secret rocket project of the Reich. The ground had to be stable enough to absorb the vibrations caused by the launch of the Vergeltungswaffe V1 and V2.

A V2 on the launch ramp. Called the 'flying bomb', it was used by the Germans to bomb English cities towards the end of the war.

The Wehrgeologen Battalion now included 600 men, both academics as soldiers. When air raids became more frequent over Germany in the last years of the war, mines or galleries were used to store ammunition and later also to host industries of strategic importance, like weapons production and research labs. Also, new underground bunkers were excavated, often involving forced labor of inmates of concentration camps. More than 800 subterranean bunkers and galleries are mentioned in contemporary documents, 400 still exist today.

In spring of 1945, shortly before the defeat of the Reich, the Stollenbau Kp helped in the construction of "Klein Berlin", a vast system of underground bunkers located beneath the Italian city of Trieste. During this operation, the geologists explored also caves and ancient mines, in part prospecting for valuable minerals, but also searching for the mystic gateway to an ancient underground reign. Based on research by two members of the Ahnenerbe, Wilhelm Teudt and Josef Heinsch, the city of Triest was built supposedly over a force field, the "Heiligen Linien", of subterranean origin. Nazi geologists searching the gateway to the Hollow Earth sounds like the plot for a bad movie. This should not hide the cruel reality of the war and the regime. The SS Wehrgeologen were also involved in war crimes, like the assassination of civilians in the Italian village of Laita.