The Chemist Who Saved a Life During the Holocaust

Since World War II, approximately 28,000 individuals have been recognized as "Righteous Among the Nations"—a title awarded to non-Jews who risked their lives to save Jews during the Holocaust. The vast majority came from countries occupied by Nazi Germany, particularly those with large, well-integrated Jewish populations such as Poland, France, and the Netherlands. Even in these countries, such acts of courage were rare. Most people, influenced by antisemitism or fear, chose silence or self-preservation over defiance. Fewer than 700 honorees were Germans —individuals who dared to defy the Nazi regime from within its very core by saving Jews. One of them, a Berlin-based scientist, was not part of any organized rescue effort. Although he quietly opposed the Nazis—at one point declining a promotion on moral grounds—he largely tried to survive the war without attracting notice. Yet when asked to help, he did not hesitate to risk his life—and the lives of his family—for someone he barely knew.

That man was also a world-renowned scientist and played an important role in one of the most significant scientific breakthroughs of the 20th century: nuclear fission - for which he never received proper recognition.

Humble Beginnings

Friedrich Wilhelm (Fritz) Strassmann was born in Boppard, Germany, on February 22, 1902. He was the youngest of nine children of Richard Strassmann, a court clerk, and his wife Julie (née Bernsmann). The family lived modestly and moved frequently due to Richard’s work. Fritz spent much of his childhood in Cologne and later Düsseldorf, where he completed elementary school in just three years instead of the usual four.

Despite the hardships Germany faced during and after World War I—and despite losing his father at a young age, which placed even greater financial strain on the family—Strassmann completed high school. He developed a passion for chemistry, conducting early experiments in his mother’s kitchen. Financial constraints prevented him from applying to a top-tier university, so he enrolled at the Technical School in Hanover. Initially, he lived with his brother, then rented a room from a milkman in exchange for tutoring the man’s son. To support himself, Strassmann gave private lessons to schoolchildren and students, eventually earning his chemical engineering degree in 1924.

Strassmann had hoped to begin working immediately after graduation, but the devastated state of German industry following World War I made it nearly impossible to find a good position. Instead, he chose to pursue a doctorate in physical chemistry. His dissertation examined the solubility of iodine in carbonic acid (H₂CO₃) in its gaseous state. Supporting himself by working as a teaching assistant, he earned his Ph.D. in 1929. During this period, he gained crucial expertise in analytical chemistry—the methods used to determine the composition of substances. This skill proved instrumental in securing a partial scholarship at the Kaiser Wilhelm Institute in Berlin, where he began working with Otto Hahn, a pioneer in the field of radiochemistry, the study of the chemical properties of radioactive substances.

Hahn was a leading expert in the study of radioactive elements, and spent many years investigating the decay processes of heavy radioactive elements such as uranium and thorium into lighter elements. Throughout most of this period, he worked alongside his dedicated colleague Lise Meitner, a Jewish-born Austrian who had converted to Christianity. Despite enduring years of discrimination as a woman and working under difficult conditions, Meitner persevered in her research beside him. By the late 1920s, circumstances gradually improved, and conditions improved even further when Hahn was appointed director of the institute. He promoted Meitner—by then the first female professor of physics at a German university—to head the Department of Radioactive Physics.

A long-standing collaboration, often under unequal conditions. Otto Hahn and Lise Meitner in their Berlin laboratory, circa 1912 | Source: Wikipedia, Public Domain

Difficult Conditions

At the Kaiser Wilhelm Institute, Strassmann took part in pioneering research, including the development of a method for dating rocks by precisely measuring the amounts of rubidium (Rb) and strontium (Sr) in samples. The researchers knew that rubidium naturally decays into strontium at a predictable rate, allowing the decay rate to serve as a kind of "radiometric clock."

However, the main focus of the entire team, which consisted of Hahn, Meitner, and Strassmann, especially from the mid-1930s onward, was the search for transuranic elements, meaning elements heavier than uranium, which has an atomic number of 92. This line of research was a continuation of work by Italian physicist Enrico Fermi, who had developed methods for "bombarding" heavy atomic nuclei with neutrons. His breakthrough was the development of techniques to slow down the neutrons, to increase the likelihood that some could be absorbed into atomic nuclei, a process researchers believed could be the key to creating heavier elements.

The work was carried out under increasingly difficult conditions. Strassmann’s scholarship, which Hahn had already extended twice, eventually expired.He continued working unpaid for a while, until Meitner convinced Hahn to fund a symbolic salary for him from the institute’s budget. Moreover, after the Nazis rose to power and enacted racial laws, the regime began interfering even in academic institutions. Hahn was forced to dismiss Jewish researchers. Meitner, though born Jewish, was temporarily protected by her Austrian citizenship. Strassmann, who had no Jewish ancestry, was safe from direct persecution, but he was nonetheless "marked" for his outspoken opposition to Nazi ideology. As early as 1933, he canceled his membership in the German Chemical Society—the country’s professional association for chemists—after it expelled its Jewish members. In the following years, even after establishing a reputation as a talented chemist, he turned down several attractive job offers because he refused to join the Nazi Party or any affiliated organizations.

The joint work of Hahn, Meitner, and Strassmann progressed slowly but steadily. Although it did not produce the new transuranic elements they had hoped to find, it resulted in numerous publications. The first papers listed Hahn and Meitner as authors, with Strassmann acknowledged for his assistance. However, he soon became a full partner in the research, and his name began appearing among the authors—though usually listed last.

In 1937, Strassmann married Maria Heckter, a chemist and one of his former students from his tutoring days in Hanover. They reconnected in Berlin where Strassmann, who had taught himself to play the violin, joined a group of amateur musicians. Later, the couple welcomed their only son, Martin.

After Nazi Germany annexed Austria in 1938, Meitner’s Austrian citizenship no longer protected her. Now classified as Jewish under Nazi law, she was forced to flee Germany. Friends managed to smuggle her out of Germany and at the age of 60, she was forced to rebuild her life in Sweden, where a fellow physicist offered her a position—though under conditions far inferior to those she had once enjoyed.  Strassmann continued working alongside Hahn, and despite the growing dangers, they maintained secret correspondence with Meitner, relying on her insights to help interpret the results of their experiments.

 A talented and renowned chemist who turned down lucrative job offers rather than join the Nazi Party. Part of Strassmann’s original laboratory equipment on display at the Deutsches Museum in Munich, commemorating 75 years since the discovery of nuclear fission. The plaque reads“The Experimental Apparatus with which the Team of Otto Hahn, Lise Meitner, and Fritz Straßmann Discovered Nuclear Fission in 1938”  | Source: Versuchsaufbau_Hahn_Deutsches_Museum.jpg: Luidger, Wikipedia

Nuclear Fission

At the end of 1938, a breakthrough occurred in the laboratory. Until then, when heavy elements like uranium were bombarded with neutrons, the resulting elements were only slightly lighter—such as thorium (atomic number 90) or radium (88). These changes were caused by "alpha decay," a process in which two protons and two neutrons are emitted from the atomic nucleus. However, in experiments conducted in late 1938, Strassmann discovered that slow neutrons produced much lighter elements, such as barium (56), lanthanum (57), and noble gases like krypton (36).

The findings were initially met with skepticism by several scientists, who argued that the results were likely a mistake caused by other substances used in the experiment.  However, Strassmann, a first-rate analytical chemist, demonstrated to Hahn that the results were genuine. Even Meitner initially doubted the data Hahn showed her during a rare meeting in Copenhagen in November 1938. But she too was ultimately convinced by Strassmann’s work that the findings were real.

 Nuclear fission involves not just radioactive decay with particle emission, but the splitting of the nucleus into two smaller atoms. Schematic diagram of nuclear fission | Image Credit: Designua, Shutterstock

In a follow-up experiment in December, Strassmann not only demonstrated the formation of barium and krypton, but also calculated their quantitative ratios. He and Hahn submitted an article for publication titled “On the Detection and Behavior of the Alkaline Earth Metals Which Result from the Irradiation of Uranium by Neutrons.” A draft of the article reached Meitner before its publication, while she was spending her Christmas holiday with her nephew, physicist Otto Frisch, who had fled Nazi-occupied Austria for Denmark. Together, Meitner and Frisch reviewed the results and realized what Hahn and Strassmann had not: the heavy uranium atom had split. This was not merely the emission of two protons, shifting the element two places back on the periodic table—it was a complete rupture of the atomic nucleus into two much smaller atoms, like a watermelon split with an axe. They quickly wrote a paper of their own, coining a new term in the title: “Products of the Fission of the Uranium Nucleus.”

The two articles, published in early 1939 in scientific journals, caused a sensation. The fission of an atomic nucleus was accompanied by the release of an enormous amount of energy—and by the emission of additional neutrons. Until then, the idea of splitting the atom and harnessing its energy had been purely theoretical. According to the theory, neutrons released from one atom could split nearby atoms, which in turn would release more neutrons, triggering a chain reaction capable of unleashing immense energy in an instant.

With the discovery of nuclear fission, this once-theoretical concept was poised to become reality—just as the winds of war were gathering across Europe and the world. Nuclear scientists worldwide, many of them refugees from Germany, were particularly alarmed that the discovery had occurred in Berlin, raising fears that a weapon based on this energy could fall into Nazi hands. These fears led to the famous letter to the President of the United States, which in turn prompted the establishment of the Manhattan Project and the development of nuclear weapons in the U.S.

"In this building, then the Kaiser Wilhelm Institute for Chemistry, Otto Hahn and Fritz Strassmann discovered the fission of uranium in 1938." - Memorial plaque on the old institute building in Berlin | Photo: Fridolin Freudenfett (Peter Kuley), Wikipedia.

Personal Risk

When World War II broke out in September 1939, even the loose connections between Hahn, Strassmann, and Meitner were severed. Later, the Americans invited Meitner to join the Manhattan Project, but she refused to participate in weapons development. Hahn and Strassmann were also uninvolved in the military applications of their discovery, a secret effort in Germany led by Nobel Prize-winning physicist Werner Heisenberg. Under Hahn’s direction, Strassmann continued searching for elements heavier than uranium formed in nuclear processes. When such an element was eventually discovered—first in the United States and later in another researcher's laboratory—he devoted considerable effort to studying its properties. His papers continued to be published in open scientific journals. In the years that followed, he also returned to working on the radiometric dating of minerals, at the request of the scientist who had been appointed to lead the department in Meitner’s place

Even during the war, Strassmann consistently refused to join the Nazi Party or any affiliated organizations, a stance that prevented him from obtaining his habilitation—the highest academic qualification in some countries, required for attaining the rank of professor.

In early 1943, a researcher at the Kaiser Wilhelm Institute approached Strassmann and asked for his help in hiding a Jewish woman fleeing the Nazis. The woman was  Andrea Wolffenstein, a pianist five years older than Strassmann, who, like Meitner, had converted to Christianity but was still considered Jewish under Nazi law. She and her sister had escaped forced labor and were hiding with acquaintances in Berlin. Although Strassmann barely knew her, he agreed without hesitation to shelter her in his home, despite the enormous risk—not only to himself but also to his wife and young son. Had they been discovered—for example, if a neighbor had noticed and reported them—they would have been executed.

Wolffenstein hid for about two months in the Strassmanns’ Berlin home before finding another hiding place. Ultimately, with the help of friends and forged documents, she managed to flee to southern Germany,where she remained in hiding until the end of the war.

Worked to rebuild science in Germany after World War II. The Institute for Nuclear Chemistry at the University of Mainz, which Strassmann helped establish | Source: University of Mainz

Late Recognition

In 1944, the Kaiser Wilhelm Institute was relocated from bombed-out Berlin to southern Germany. At the end of the war, Otto Hahn was taken into custody in England, along with several senior members of Nazi Germany's nuclear program, as part of the Allies' efforts to assess how far the German program had progressed. Investigations, along with evidence found on the ground, revealed that progress had been minimal. Hitler did not believe in nuclear weapons, did not prioritize the project, and Heisenberg and his colleagues were still many years away from building a bomb.

While in custody, Hahn was informed that he had been awarded the Nobel Prize in Chemistry retroactively for 1944, for the discovery of nuclear fission. Hahn received the prize alone—without Strassmann, who had been a full partner in the research and had performed much of the experimental work, and without Meitner, who was the one to correctly interpret the results of the experiments. In his Nobel lecture, Hahn also downplayed their contributions.

After the war, Hahn was appointed president of the Kaiser Wilhelm Institute, which later became part of the Max Planck Society, named after the renowned physicist. In 1949, the Institute of Chemistry was moved to the city of Mainz, and Strassmann, who had been appointed after the war as Professor of Nuclear Chemistry at the University of Mainz, was placed at its head. In both positions, Strassmann focused on rebuilding scientific research in Germany after the war, restoring the academic system, renewing international scientific ties, and even managing logistical challenges such as acquiring equipment that would enable nuclear research without violating the restrictions imposed on Germany. In 1953, he stepped down from his role at the Max Planck Institute to establish a nuclear research institute within the university. In 1957, he was among 18 German scientists who published a letter opposing West German Chancellor Konrad Adenauer’s plans to arm the country with nuclear weapons in response to the threat from the Eastern Bloc.

Strassmann was a modest and ascetic man who traveled little. He visited the United States only once, in 1959, to negotiate the purchase of a small nuclear reactor for the research institute.

In 1966, Strassmann, Hahn, and Meitner jointly received the Enrico Fermi Award, granted by the President of the United States. It was a modest honor compared to Hahn’s Nobel Prize. Meitner, who never received a Nobel, was later honored in an even greater way: element 109 on the periodic table was named after her—Meitnerium— but only in 1992, long after her death. Strassmann continued his work at the university and institute until his retirement in 1970. He passed away in Mainz in 1980. An obituary published in Physics Today, the journal of the American Institute of Physics, noted that despite his modesty, Strassmann was pleased with the Fermi Award because it acknowledged the collaborative work that led to the discovery of nuclear fission.

In 1985, five years after his death, Strassmann was recognized by Yad Vashem as Righteous Among the Nations for saving Andrea Wolffenstein, who lived to an old age and passed away in 1987, nearly 90 years old. Sadly, his name and legacy remain largely unknown and uncommemorated.