July 29, 2025 • 33 mins
Lise Meitner changed the world, and the world nearly forgot her. In this episode of Math! Science! History!, Gabrielle Birchak explores Meitner’s brilliant mind, her escape from Nazi Germany, her critical role in discovering nuclear fission, and why the Nobel Committee turned a blind eye. Join us as we honor a scientist who refused to let science become a weapon.
3 Things Listeners Will Learn:
Why Lise Meitner was central to the discovery of nuclear fission, and how her contribution was overlooked by the Nobel Committee.
How the rise of Nazi Germany forced her to flee her lab and live as a stateless refugee.
Why Meitner refused to join the Manhattan Project and what that choice cost her legacy.
Links to Resources:
Some of the following resources contain affiliate links, which I may receive compensation at no cost to you.
Ruth Lewin Sime’s biography: Lise Meitner: A Life in Physics
Original 1939 paper by Meitner and Frisch: “Disintegration of Uranium by Neutrons” (Nature)
Physics Today: A Nobel Tale of Postwar Injustice
Max Planck Society's profile on Meitner: Lise Meitner Archives
🔗 Explore more on our website: mathsciencehistory.com
📚 To buy my book Hypatia: The Sum of Her Life on Amazon, visit .css-j9qmi7{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;font-weight:700;margin-bottom:1rem;margin-top:2.8rem;width:100%;-webkit-box-pack:start;-ms-flex-pack:start;-webkit-justify-content:start;justify-content:start;padding-left:5rem;}@media only screen and (max-width: 599px){.css-j9qmi7{padding-left:0;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;}}.css-j9qmi7 svg{fill:#27292D;}.css-j9qmi7 .eagfbvw0{-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;color:#27292D;}Mark as PlayedTranscript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
(00:01):
It was December 1938 and a physicist, having recently fled Nazi Germany, and her nephew
found themselves in the serene countryside, taking a break from the desk. Hi, I'm Gabrielle Birchak.
Welcome to Math Science History. Today we are traveling back to one of the most pivotal
moments in 20th century science. Not to a lab, not to a lecture hall, but to a snowy forest
(00:26):
of Kungälv, Sweden. In the year 415, the infamous philosopher and mathematician Hypatia
of Alexandria, Egypt, was savagely murdered by church monks. This murder shocked the Roman
community and its government leaders. Hypatia was known far and wide as a respected philosopher,
(00:52):
mathematician, government advisor, and a professor. Hypatia, the sum of her life,
is a book that I wrote that looks not just at the circumstances surrounding her death,
but also at the sum of her entire life. I weave in the details of her education,
disciples, Neoplatonic philosophies, female contemporaries, and the many mathematics that
(01:14):
she wrote and taught about. There is truly more to Hypatia's life than her death. Hypatia,
the sum of her life, written by me, Gabrielle Bertak, is now on sale on Amazon. Buy your copy
today. As the snow crunched beneath their feet, they puzzled over a letter from physicist Otto
(01:39):
Hahn describing a mysterious experiment that produced barium from uranium. This experiment
did not make sense until, right there in the woods, inspiration struck. They realized that
the uranium nucleus had split in two, which was a revolutionary concept that would soon be known
(02:00):
as nuclear fission. The physicist and the nephew? Lise Meitner and her nephew, Otto Frisch.
Lise Meitner was born in Vienna, Austria in 1878. In an era when men barred women from higher
education, she became only the second woman to earn a doctoral degree in physics from the
(02:20):
University of Vienna in 1906. Because of strict Austrian rules at the time, women weren't allowed
to attend college, but Meitner's family believed in her education and could afford private schooling,
which she finished in 1901. She then enrolled in graduate studies at the University of Vienna,
where she was inspired by the great physicist Ludwig Boltzmann. His passion for science
(02:46):
inspired her, and she chose to focus on physics, especially the new and exciting field of
radioactivity. In 1905, she became the second woman ever to earn a doctorate degree in physics
from the University of Vienna, with the first being Olga Steindler, who received her doctorate
degree in physics in 1903. Upon receiving her degree in 1906, Meitner began independent research
(03:12):
to obtain results that Lord Raleigh could not explain. She not only explained the results, but
then verified it experimentally. Her results were published in the paper, quote, some conclusions
derived from the Fresnel reflection formula, unquote. The research and the experiments were
foundational to leading Ernest Rutherford to predict the nuclear atom. Meitner then began
(03:38):
attending Max Planck's lectures at Friedrich Wilhelm University in Berlin. Planck went on the
record stating that he did not want women in the universities. However, Meitner was a brilliant
exception. So much so that he even invited her to come to his home and visit him, where she made
friends with his daughters. Still, these lectures were not engaging enough for her, and she had
(04:02):
spare time. As a result, she approached Heinrich Rubens, who was the head of the Experimental Physics
Institute. She wanted to do some research, and so Rubens introduced her to Otto Hahn. This is key
because Hahn's experience included deep research on radioactive substances. Hahn and Meitner were
(04:24):
the same age and considered each other as peers. Emil Fischer, who was the head of the Chemistry
Institute, wanted to work with the both of them. And so, as a result, he gave a former woodworking
shop in the basement to Hahn and Meitner to use for their laboratory, which they equipped with tools
that would allow them to measure alpha and beta particles, as well as gamma rays. This would be
(04:49):
foundational to their deep research. Meitner and Hahn were both unpaid, and many of the organic
chemists at the Institute regarded their work as irrelevant because they could not see, measure, or
smell their radioactivity. The early part of her career was challenging. She faced significant
(05:09):
barriers as a woman in science. Because women were not allowed in the Institute, she had to enter the
basement laboratory through a separate door. Sadly, the Inorganic Chemistry Department would only allow
Hahn to visit two private laboratories in the upper levels. Meitner was not allowed to go
upstairs. Additionally, she could not use the restroom. As a result, she had to go down the
(05:35):
street to a restaurant to use their restroom. However, a year later, women were allowed to
study at Prussian universities. As a result, Fischer lifted restrictions and even had women's
toilets installed in the building. This did not go over well with many of the male chemists at the
Institute. Nevertheless, she made friends, loyal friends, who were there for her. These included
(05:59):
Otto von Bayer, James Franck, Gustav Hertz, Robert Powell, Peter Pringsheim, and Wilhelm Westphal.
These gentlemen would play a vital role in her life many years later. Hahn and Meitner worked
so well together that they published nine papers between 1908 and 1909. In their experiments, they
(06:21):
applied radioactive recoil, which is the backward momentum that happens to an atom or a nucleus
when it emits radiation or particles during radioactive decay. This was first recognized by
Harriet Brooks, who was Canada's first female nuclear physicist and one of the earliest pioneers
in radioactivity. She had been working closely with Ernest Rutherford and was one of the first
(06:45):
in understanding the behavior of radioactive elements. And I promise I'm going to do a podcast
on Harriet Brooks as well because her brilliance needs to be recognized. So back to radioactive
recoil. It's the process where a daughter nucleus is forcefully ejected as it recoils in the moment
So it works like this. Imagine you are in a batting cage. There's a pitching machine, which
(07:10):
if you've been in a batting cage, you know it is a solid, heavy device designed to stay in place.
But when it fires a baseball, the machine gives a little jerk backwards. We barely notice it,
but it's real. That tiny backward movement is caused by the force of the ball being launched
forward. Now take that same idea and shrink it down to the atomic level. Inside an atom,
(07:38):
the nucleus is like that pitching machine, heavy and packed with particles. But sometimes it's
unstable. When it needs to become more stable, it shoots out a particle like an alpha particle
or a neutron. And just like the pitching machine, the nucleus recoils in the opposite direction
of the particle it emitted. And so this tiny jolt is called radioactive recoil,
(08:05):
which happens because of one simple rule in physics. For every action, there is an equal
and opposite reaction. So when the nucleus throws something out, it can't help but move the other
way. And this recoil is essential to the work that Meitner and Hahn were doing. The recoil is
powerful enough on an atomic scale to knock atoms out of place in materials, break chemical bonds,
(08:32):
or even damage cells if it happens inside the body. So in short, radioactive recoil is the
atomic version of that barely noticeable kickback your pitching machine feels when it fires a fast
ball. Small, fast, and if you're on the receiving end, potentially pretty impactful.
The reason why I bring this up is because Meitner found that using radioactive recoil could help her
(08:58):
find radioactive substances. As a result, Meitner and Hahn were able to find two more new isotopes
that included bismuth-211 and thallium-207. In October 1912, the Kaiser Wilhelm Institute for
Chemistry opened in Berlin, Gollum, and Meitner and Hahn moved their research to this new institute.
(09:21):
The KWI, being privately funded, had no formal rule excluding women. This was a progressive step
compared to the university. However, Meitner's status initially remained far from equal. Hahn
was appointed head of the new radiochemistry department with the title professor and a
(09:42):
respectable salary. In contrast, Meitner was invited to join him only as an unpaid scientific
guest. So, although the KWI had no formal exclusion of women, these rules highlight
how women often entered such institutes through unofficial or junior roles. We'll be right back
(10:03):
after a quick word from my advertisers. By the end of 1912, Max Planck intervened to secure Meitner
her first ever paid position, hiring her as his assistant at the university's Institute for
Theoretical Physics. This marked her as the first female scientific assistant in Prussia. Soon after
(10:25):
in 1913, Meitner was formally appointed as an associate of the KWI for chemistry, equivalent
in rank to Hahn's position, which finally granted her a title and a modest salary. Notably, it was
Emil Fischer who arranged for her new paid appointment at the KWI. This progression illustrates
(10:47):
both the progress and the remaining inequities that women continue to face in a male-dominated
scientific world. It took several years of excellent research and the gradual modernization
of attitudes before she achieved official status and a corresponding salary. And by 1926, Meitner
(11:08):
would become the first woman to hold a professorship in physics in Germany. For over 30 years, Meitner
and Hahn formed a close working partnership. She brought the theoretical physics expertise,
he the chemistry. Together they explored the inner workings of the atomic nucleus,
becoming pioneers in the newly emerging field of nuclear science. But Meitner's life and career
(11:35):
would be upended by politics. Adolf Hitler came to power. As a woman, Meitner's position in Germany
became increasingly precarious. By 1938, it was no longer safe for her to stay. So even though she
was born an Austrian citizen in 1878, when Hitler came to power in Germany in 1933, Meitner, who had
(12:00):
lived and worked in Berlin since 1907, retained her Austrian citizenship. However, in March 1938,
Austria was annexed by Nazi Germany in the Anschluss. What this meant for all Austrians
is that they were automatically considered German citizens under Nazi law. However,
(12:22):
under the Nuremberg laws, Meitner was classified as Jewish, even though she had converted to
Lutheranism. This meant that she was now subject to the regime's systemic racial persecution.
So sadly, she lost the protections of Austrian citizenship, and the Nazis forced her to resign
(12:44):
from her position in Berlin. It was a horrible situation. She was a stateless person without a
valid passport. And as a result, like many individuals in the United States today, she faced
arrest. As the political climate in Nazi Germany grew increasingly dangerous, which sadly,
(13:07):
I kind of know what that feels like now. Meitner found herself in grave peril. Without a passport
and under mounting pressure, she had to flee. Her escape was made possible thanks to the bravery of
Dutch physicist Dirk Koster, who secretly traveled to Berlin under the guise of attending a conference.
(13:28):
With the help of Adrian Fokker, Koster arranged for Meitner to be smuggled across the German-Dutch
border. From there, she made her way to Copenhagen, where she was quietly welcomed by Niels Bohr,
a longtime colleague and supporter. Though he was not directly involved in her escape,
(13:48):
Bohr's influence and reputation helped ease her transition and provided a crucial scientific
lifeline. With his backing and network, Meitner was able to continue on to Stockholm, Sweden,
where she found refuge. Their courage and support not only saved her life,
(14:10):
but also enabled Meitner to continue her groundbreaking research, which would soon
lead to the discovery of nuclear fission. Sadly, she was stateless for two years,
which as many individuals living in the United States are now realizing as of the date of this
podcast, it is a very dangerous thing. Unfortunately, in the United States, persecution is
(14:36):
the new normal and reality for so many people, and many worry that it will only get worse.
And as a little side note, history, much like science and math, is such a valuable tool that
can be used to serve humanity. And I have said this in previous podcasts, and I'm just going to
(14:56):
say it again. History shows us the red flags of danger. It is our responsibility to make sure
that we are looking for them so as not to let history repeat itself. That being said, back to
Meitner. She settled in Stockholm, where she was given a research position at the Nobel Institute
(15:17):
for Physics. In the early 1940s, Sweden granted her citizenship, but her lab lacked proper equipment.
She was isolated, removed from the scientific community she had helped build. Still, she stayed
in contact with Hahn, who continued their joint work in Berlin. Back in Germany, Hahn and his
(15:38):
assistant, Fritz Strassmann, were conducting experiments with uranium. They were bombarding
uranium atoms with neutrons to see what heavier elements they could create. According to the
prevailing theory of the time, neutron bombardment should lead to the creation of heavier elements,
which we now refer to as transuranic elements. But the results were strange. In December 1938,
(16:05):
Hahn and Strassmann detected an unexpected element in their chemical residues, barium. But barium is
much lighter than uranium. Hahn didn't understand what was happening. So he sent his experimental
results in a letter to Meitner, hoping she could explain the physics behind the chemistry.
(16:26):
It arrived in the snowy Swedish countryside just before Christmas. That Christmas, Meitner received
a visit from her nephew Otto Frisch, a physicist as well. He had come to Sweden from Copenhagen
to spend the holiday with her. And together, they went on long walks through the woods near
Kungelw outside Gothenburg. On one of these walks, with snow crunching underfoot and fir trees towering
(16:52):
above, they talked through Hahn's letter. How could uranium atoms produce barium? They sat on a tree
stump and started working it out on paper. Meitner proposed that the uranium nucleus had split in two.
This theory was unprecedented. No one had ever suggested that a nucleus could break apart in
(17:14):
this way. She applied Niels Bohr's liquid drop model to the problem, suggesting that the nucleus
could become elongated and unstable, eventually splitting into two smaller nuclei. To explain
this further, the liquid drop model developed by Niels Bohr and John Wheeler in the 1930s
(17:34):
describes the atomic nucleus as a drop of liquid made up of tightly packed protons and neutrons.
This model was key in explaining nuclear fission, such as when a nucleus becomes unstable and splits
apart. So imagine placing a glob of butter on a hot pan. And I'm sure we've all done that because
(17:54):
we all love butter, right? So at first, the glob of butter holds together. But as heat builds,
it begins to wobble, stretch, and then flatten. Eventually, if you drop a tiny dab of butter on
top of that glob, the butter can break apart into smaller blobs, releasing energy as it moves. So
(18:17):
in the same way, when a neutron strikes a heavy nucleus, it causes it to vibrate and deform.
If the conditions are right, the nucleus splits in two, releasing a tremendous burst of energy.
While the model doesn't capture every detail of nuclear behavior, it laid the foundation for
understanding how atoms split and how that split powers everything from reactors to bombs.
(18:45):
In his article titled, Recollections of the Discovery of Nuclear Fission, Frisch wrote,
We had found the solution. We were the first to understand that the uranium nucleus had split in
two. It was a moment of great elation. We could hardly believe it ourselves. Thus,
that day, as Meitner and Frisch walked through the quiet forest, the snow muffled every sound.
(19:13):
The bare trees stretched skyward like skeletal fingers, their limbs stark against the pale
winter sky. The air was still, save for the crunch of their boots. Nature was serene and
undisturbed. In that silent, frozen landscape, they discussed the impossible, the splitting
(19:36):
of an atom. It was a moment of quiet revelation, born in beauty and isolation. Meitner and Hahn
likely had no idea what their discovery could create. The energy released by nuclear fission
could be massive. If controlled and placed in the hands of the humane, it could produce
(20:00):
power. If uncontrolled and given free reign by unethical individuals, it could create a monstrous
bomb. The idea they unearthed there would lead to horrors far removed from the calm of the woods.
Instead of birdsong, the world would later hear screams. Instead of fresh snow, there would be
(20:24):
scorched earth, fire, ash, and blood. In that peaceful walk, they had touched the edge of
something powerful enough to light cities or to level them. We'll be right back after a quick
word from my advertisers. So after Meitner and Frisch came to their conclusion, Frisch did the
(20:45):
math and confirmed it. The mass difference between uranium and the resulting elements accounted for
a massive release of energy as per Einstein's equation E equals mc squared. This release of
energy was the result of nuclear fission. Meanwhile, before Frisch made it back to Copenhagen,
(21:06):
Hahn had already submitted his findings to a German journal but did not credit Meitner or Frisch
in his publication. This action was a betrayal that would echo for decades. Regardless, with
Niels Bohr's encouragement, Frisch quickly published his and Meitner's paper in a journal
called Nature titled Disintegration of Uranium by Neutrons, a New Type of Nuclear Reaction.
(21:32):
So when Hahn and Fritz Strassman chemically identified barium as a product of bombarding
uranium with neutrons, this outcome made no sense within the framework of known nuclear physics.
The uranium nucleus hadn't merely rearranged, it had split. Meitner and Frisch's paper helped to
(21:53):
explain this process of nuclear fission and their paper would change the course of history. But
referring back to the liquid drop model, Meitner and Frisch showed that such a fission process
would release an enormous amount of energy, more than anyone had previously imagined,
thanks to Einstein's equation. Their concise article introduced the term, quote, a new type
(22:19):
of nuclear reaction. But the implications were anything but modest. It was the first correct
theoretical explanation of nuclear fission, opening the door to both nuclear power and
unfortunately, the devastating weaponry that would soon reshape the modern world. Despite this
(22:39):
information, when the Nobel Committee awarded the 1944 prize in chemistry, it went solely to Hahn.
They did not even mention Meitner's name. Historians and physicists alike have since
called this omission one of the most glaring oversights in Nobel history. Lise Meitner never
(23:01):
returned to Germany. She continued her work in Sweden and later moved to Cambridge, England after
the war. Though her name was known among physicists in the United States, Meitner was never officially
asked to join the Manhattan Project. But the closest she came was through informal channels.
In 1943, Bohr, who had fled occupied Denmark, was consulting on the bomb effort in America.
(23:25):
He suggested Meitner's name as somebody who might be helpful. But by then she had already
made up her mind. Living in neutral Sweden, Meitner had watched the world descend into war
and saw what unchecked scientific ambition could lead to. When she learned of the Manhattan Project,
(23:45):
she firmly declined to participate. While newspapers later dubbed her the Mother of
the Atomic Bomb, she rejected the title with sorrow and conviction. She was horrified by how
the men at the Manhattan Project had used her discovery to create nuclear weapons. She had
helped explain how to split the atom, but she wanted no part in splitting humanity with it.
(24:12):
Meitner remained adamant, science should serve humanity, not destroy it.
Beyond her groundbreaking role in the discovery of nuclear fission, Meitner made several other
significant contributions to physics. Early in her career, she and Hahn discovered the
element protactinium, which was a considerable achievement in the field of radiochemistry.
(24:36):
She also conducted extensive research on beta decay, contributing to our understanding of how
atoms release energy. Another lesser known fact is that she was one of the first to theorize about
the Auger effect, which describes how atoms release energy through electron transitions.
Her work laid the groundwork for many areas of nuclear and atomic physics,
(25:01):
and her legacy is truly expansive. In 1946, she was named Woman of the Year by the National Press
Club in Washington, D.C., celebrated alongside Eleanor Roosevelt for her contributions to science
and peace. That same year, she received honorary doctorates from several U.S. institutions,
(25:23):
including Harvard University and Smith College. In Europe, honors continued to accumulate.
In 1955, she was awarded both the prestigious Max Planck Medal by the German Physical Society
and the Otto Hahn Prize for Chemistry and Physics, the latter shared with Hahn and Strassman.
(25:44):
In 1957, Meitner received the Pour les Marites for Sciences and Arts,
one of Germany's highest civilian honors. She was also elected a foreign member of the Royal
Society in the United Kingdom in 1955, making her only the third woman to ever receive that
distinction. These awards reflect the scientific community's growing acknowledgement of her vital
(26:09):
role in the discovery of nuclear fission and her principal refusal to participate in its
weaponization. And in 1997, long after her passing, the element Meitnerium-109 was named
in her honor. Meitner was nominated for a Nobel Prize 48 times, 48 times, yes, and yet she never
(26:37):
received one. At first glance, this seems unbelievable. This is just, it's asinine,
I'm sorry, being a woman in science can be absolutely asinine, because how could the woman
who helped explain nuclear fission, the very discovery that ushered in the atomic age,
how could she be left out? But the answer lies at the tangled intersection of science,
(27:02):
gender, politics, and timing. To begin with, Meitner faced an uphill battle simply because
she was a woman. In the early 20th century, physics and chemistry were extensively male-dominated
fields. Despite her achievements, she was often referred to not as a scientist, but as Han's
(27:22):
assistant. Behind closed doors, she was sometimes referred to as Miss Meitner, even after earning
her doctorate and publishing independently. Gender bias ran deep, it still does, and the Nobel
committees were no exception. At the time, only two women, Marie Curie and Irene Joliot-Curie,
(27:44):
had ever won Nobel prizes in the physical sciences. Then there's the issue of what kind of
science gets rewarded. The 1944 Nobel Prize in chemistry went to Han, recognizing his experimental
detection of barium in neutron-bombarded uranium. But the theoretical interpretation,
(28:05):
the breakthrough realization that this meant the nucleus had split, came from Meitner and her
nephew, Frisch. The Nobel committee favored experimental chemistry over theoretical physics,
even though the interpretation is what made the discovery historically and scientifically
meaningful. Meitner's role wasn't just support, she connected the pieces that defined the
(28:31):
phenomenon as fission. Wartime politics didn't help. When the Nobel Prize was awarded, Meitner
was a Jewish refugee living in Sweden, having fled Nazi Germany in 1938. Han, by contrast,
had remained in Germany. The Nobel committee may have feared the optics of awarding a prize to
(28:53):
someone in exile or of highlighting a Jewish woman's critical contribution while the world
was still reeling from Nazi atrocities. It's no coincidence that the Nobel committee did not
announce Han as the recipient until after the war had ended. There's also a more mundane,
(29:13):
but no less tragic reason. Meitner lacked a strong advocate on the Nobel committee.
Many laureates have behind the scenes champions pushing their case year after year. Meitner did
not have that. Her nominations were scattered, often switching between physics and chemistry
categories, and they came too late to override the 1944 decision. Later in life, she was honored
(29:41):
with numerous awards, honorary doctorates, the Max Planck medal, and even the naming of the element
Meitnerium. But the Nobel? That remained forever just out of reach. Today, scientists and historians
widely recognize that Lise Meitner's exclusion was one of the greatest injustices in the history
(30:03):
of science. Not because she wasn't nominated, but because the system simply wasn't ready to see her.
These groups of men weren't blind to her brilliance. They chose to look away. She was not
just a brilliant physicist. Even in exile, even with very little, she changed the world. Not with
(30:27):
force, not with power, but with quiet brilliance and the courage to speak truth, even when others
did not. No doubt, she was also a deeply ethical scientist, someone who stood by her principles in
the face of immense pressure. Lise Meitner once said, science makes people reach selflessly
(30:49):
for truth and objectivity. It teaches people to accept reality with wonder and admiration,
not to mention the deep awe one feels in discovering the order of the universe.
Thus, her life reminds us that sometimes the most profound discoveries don't happen in labs.
(31:10):
They occur in conversations, on long walks, during stolen moments of peace in a world at war.
And as for those profound discoveries, I can attest I've been there. I think every college
student has been there. In my early college years, I would often sit alone in my apartment in the
dark because I'd forgotten to turn on the lights, with a tiny desk lamp entirely consumed in my
(31:36):
studies, taking in insight and inspiration. And there is no greater feeling than an epiphany.
And I don't know who needs to hear this, but for those of you who have your head in a book,
consuming math, physics, chemistry, and even history, or literature, I genuinely hope that you
(31:58):
feel the intenseness of a revelation and that inspires you to keep moving forward in your
research and your discoveries. Your enlightenment can change the world for good. And that's really
what we need right now. We need a future where science illuminates, not annihilates.
(32:20):
Thank you for listening to Math Science History. I'm Gabrielle Birchak, and until next time,
Carpe Diem. Thank you for tuning in to Math Science History. If you enjoyed today's episode,
please leave a quick rating and review. They really help the podcast. You can find our
(32:41):
transcripts at mathsciencehistory.com. And while you're there, remember to click on that coffee
button because every dollar you donate supports a portion of our production costs and keeps our
educational website free. Again, thank you for tuning in and until next time, Carpe Diem.
It was December 1938 and a physicist, having recently fled Nazi Germany, and her nephew
found themselves in the serene countryside, taking a break from the desk. Hi, I'm Gabrielle Birchak.
Welcome to Math Science History. Today we are traveling back to one of the most pivotal
moments in 20th century science. Not to a lab, not to a lecture hall, but to a snowy forest
(00:26):
of Kungälv, Sweden. In the year 415, the infamous philosopher and mathematician Hypatia
of Alexandria, Egypt, was savagely murdered by church monks. This murder shocked the Roman
community and its government leaders. Hypatia was known far and wide as a respected philosopher,
(00:52):
mathematician, government advisor, and a professor. Hypatia, the sum of her life,
is a book that I wrote that looks not just at the circumstances surrounding her death,
but also at the sum of her entire life. I weave in the details of her education,
disciples, Neoplatonic philosophies, female contemporaries, and the many mathematics that
(01:14):
she wrote and taught about. There is truly more to Hypatia's life than her death. Hypatia,
the sum of her life, written by me, Gabrielle Bertak, is now on sale on Amazon. Buy your copy
today. As the snow crunched beneath their feet, they puzzled over a letter from physicist Otto
(01:39):
Hahn describing a mysterious experiment that produced barium from uranium. This experiment
did not make sense until, right there in the woods, inspiration struck. They realized that
the uranium nucleus had split in two, which was a revolutionary concept that would soon be known
(02:00):
as nuclear fission. The physicist and the nephew? Lise Meitner and her nephew, Otto Frisch.
Lise Meitner was born in Vienna, Austria in 1878. In an era when men barred women from higher
education, she became only the second woman to earn a doctoral degree in physics from the
(02:20):
University of Vienna in 1906. Because of strict Austrian rules at the time, women weren't allowed
to attend college, but Meitner's family believed in her education and could afford private schooling,
which she finished in 1901. She then enrolled in graduate studies at the University of Vienna,
where she was inspired by the great physicist Ludwig Boltzmann. His passion for science
(02:46):
inspired her, and she chose to focus on physics, especially the new and exciting field of
radioactivity. In 1905, she became the second woman ever to earn a doctorate degree in physics
from the University of Vienna, with the first being Olga Steindler, who received her doctorate
degree in physics in 1903. Upon receiving her degree in 1906, Meitner began independent research
(03:12):
to obtain results that Lord Raleigh could not explain. She not only explained the results, but
then verified it experimentally. Her results were published in the paper, quote, some conclusions
derived from the Fresnel reflection formula, unquote. The research and the experiments were
foundational to leading Ernest Rutherford to predict the nuclear atom. Meitner then began
(03:38):
attending Max Planck's lectures at Friedrich Wilhelm University in Berlin. Planck went on the
record stating that he did not want women in the universities. However, Meitner was a brilliant
exception. So much so that he even invited her to come to his home and visit him, where she made
friends with his daughters. Still, these lectures were not engaging enough for her, and she had
(04:02):
spare time. As a result, she approached Heinrich Rubens, who was the head of the Experimental Physics
Institute. She wanted to do some research, and so Rubens introduced her to Otto Hahn. This is key
because Hahn's experience included deep research on radioactive substances. Hahn and Meitner were
(04:24):
the same age and considered each other as peers. Emil Fischer, who was the head of the Chemistry
Institute, wanted to work with the both of them. And so, as a result, he gave a former woodworking
shop in the basement to Hahn and Meitner to use for their laboratory, which they equipped with tools
that would allow them to measure alpha and beta particles, as well as gamma rays. This would be
(04:49):
foundational to their deep research. Meitner and Hahn were both unpaid, and many of the organic
chemists at the Institute regarded their work as irrelevant because they could not see, measure, or
smell their radioactivity. The early part of her career was challenging. She faced significant
(05:09):
barriers as a woman in science. Because women were not allowed in the Institute, she had to enter the
basement laboratory through a separate door. Sadly, the Inorganic Chemistry Department would only allow
Hahn to visit two private laboratories in the upper levels. Meitner was not allowed to go
upstairs. Additionally, she could not use the restroom. As a result, she had to go down the
(05:35):
street to a restaurant to use their restroom. However, a year later, women were allowed to
study at Prussian universities. As a result, Fischer lifted restrictions and even had women's
toilets installed in the building. This did not go over well with many of the male chemists at the
Institute. Nevertheless, she made friends, loyal friends, who were there for her. These included
(05:59):
Otto von Bayer, James Franck, Gustav Hertz, Robert Powell, Peter Pringsheim, and Wilhelm Westphal.
These gentlemen would play a vital role in her life many years later. Hahn and Meitner worked
so well together that they published nine papers between 1908 and 1909. In their experiments, they
(06:21):
applied radioactive recoil, which is the backward momentum that happens to an atom or a nucleus
when it emits radiation or particles during radioactive decay. This was first recognized by
Harriet Brooks, who was Canada's first female nuclear physicist and one of the earliest pioneers
in radioactivity. She had been working closely with Ernest Rutherford and was one of the first
(06:45):
in understanding the behavior of radioactive elements. And I promise I'm going to do a podcast
on Harriet Brooks as well because her brilliance needs to be recognized. So back to radioactive
recoil. It's the process where a daughter nucleus is forcefully ejected as it recoils in the moment
So it works like this. Imagine you are in a batting cage. There's a pitching machine, which
(07:10):
if you've been in a batting cage, you know it is a solid, heavy device designed to stay in place.
But when it fires a baseball, the machine gives a little jerk backwards. We barely notice it,
but it's real. That tiny backward movement is caused by the force of the ball being launched
forward. Now take that same idea and shrink it down to the atomic level. Inside an atom,
(07:38):
the nucleus is like that pitching machine, heavy and packed with particles. But sometimes it's
unstable. When it needs to become more stable, it shoots out a particle like an alpha particle
or a neutron. And just like the pitching machine, the nucleus recoils in the opposite direction
of the particle it emitted. And so this tiny jolt is called radioactive recoil,
(08:05):
which happens because of one simple rule in physics. For every action, there is an equal
and opposite reaction. So when the nucleus throws something out, it can't help but move the other
way. And this recoil is essential to the work that Meitner and Hahn were doing. The recoil is
powerful enough on an atomic scale to knock atoms out of place in materials, break chemical bonds,
(08:32):
or even damage cells if it happens inside the body. So in short, radioactive recoil is the
atomic version of that barely noticeable kickback your pitching machine feels when it fires a fast
ball. Small, fast, and if you're on the receiving end, potentially pretty impactful.
The reason why I bring this up is because Meitner found that using radioactive recoil could help her
(08:58):
find radioactive substances. As a result, Meitner and Hahn were able to find two more new isotopes
that included bismuth-211 and thallium-207. In October 1912, the Kaiser Wilhelm Institute for
Chemistry opened in Berlin, Gollum, and Meitner and Hahn moved their research to this new institute.
(09:21):
The KWI, being privately funded, had no formal rule excluding women. This was a progressive step
compared to the university. However, Meitner's status initially remained far from equal. Hahn
was appointed head of the new radiochemistry department with the title professor and a
(09:42):
respectable salary. In contrast, Meitner was invited to join him only as an unpaid scientific
guest. So, although the KWI had no formal exclusion of women, these rules highlight
how women often entered such institutes through unofficial or junior roles. We'll be right back
(10:03):
after a quick word from my advertisers. By the end of 1912, Max Planck intervened to secure Meitner
her first ever paid position, hiring her as his assistant at the university's Institute for
Theoretical Physics. This marked her as the first female scientific assistant in Prussia. Soon after
(10:25):
in 1913, Meitner was formally appointed as an associate of the KWI for chemistry, equivalent
in rank to Hahn's position, which finally granted her a title and a modest salary. Notably, it was
Emil Fischer who arranged for her new paid appointment at the KWI. This progression illustrates
(10:47):
both the progress and the remaining inequities that women continue to face in a male-dominated
scientific world. It took several years of excellent research and the gradual modernization
of attitudes before she achieved official status and a corresponding salary. And by 1926, Meitner
(11:08):
would become the first woman to hold a professorship in physics in Germany. For over 30 years, Meitner
and Hahn formed a close working partnership. She brought the theoretical physics expertise,
he the chemistry. Together they explored the inner workings of the atomic nucleus,
becoming pioneers in the newly emerging field of nuclear science. But Meitner's life and career
(11:35):
would be upended by politics. Adolf Hitler came to power. As a woman, Meitner's position in Germany
became increasingly precarious. By 1938, it was no longer safe for her to stay. So even though she
was born an Austrian citizen in 1878, when Hitler came to power in Germany in 1933, Meitner, who had
(12:00):
lived and worked in Berlin since 1907, retained her Austrian citizenship. However, in March 1938,
Austria was annexed by Nazi Germany in the Anschluss. What this meant for all Austrians
is that they were automatically considered German citizens under Nazi law. However,
(12:22):
under the Nuremberg laws, Meitner was classified as Jewish, even though she had converted to
Lutheranism. This meant that she was now subject to the regime's systemic racial persecution.
So sadly, she lost the protections of Austrian citizenship, and the Nazis forced her to resign
(12:44):
from her position in Berlin. It was a horrible situation. She was a stateless person without a
valid passport. And as a result, like many individuals in the United States today, she faced
arrest. As the political climate in Nazi Germany grew increasingly dangerous, which sadly,
(13:07):
I kind of know what that feels like now. Meitner found herself in grave peril. Without a passport
and under mounting pressure, she had to flee. Her escape was made possible thanks to the bravery of
Dutch physicist Dirk Koster, who secretly traveled to Berlin under the guise of attending a conference.
(13:28):
With the help of Adrian Fokker, Koster arranged for Meitner to be smuggled across the German-Dutch
border. From there, she made her way to Copenhagen, where she was quietly welcomed by Niels Bohr,
a longtime colleague and supporter. Though he was not directly involved in her escape,
(13:48):
Bohr's influence and reputation helped ease her transition and provided a crucial scientific
lifeline. With his backing and network, Meitner was able to continue on to Stockholm, Sweden,
where she found refuge. Their courage and support not only saved her life,
(14:10):
but also enabled Meitner to continue her groundbreaking research, which would soon
lead to the discovery of nuclear fission. Sadly, she was stateless for two years,
which as many individuals living in the United States are now realizing as of the date of this
podcast, it is a very dangerous thing. Unfortunately, in the United States, persecution is
(14:36):
the new normal and reality for so many people, and many worry that it will only get worse.
And as a little side note, history, much like science and math, is such a valuable tool that
can be used to serve humanity. And I have said this in previous podcasts, and I'm just going to
(14:56):
say it again. History shows us the red flags of danger. It is our responsibility to make sure
that we are looking for them so as not to let history repeat itself. That being said, back to
Meitner. She settled in Stockholm, where she was given a research position at the Nobel Institute
(15:17):
for Physics. In the early 1940s, Sweden granted her citizenship, but her lab lacked proper equipment.
She was isolated, removed from the scientific community she had helped build. Still, she stayed
in contact with Hahn, who continued their joint work in Berlin. Back in Germany, Hahn and his
(15:38):
assistant, Fritz Strassmann, were conducting experiments with uranium. They were bombarding
uranium atoms with neutrons to see what heavier elements they could create. According to the
prevailing theory of the time, neutron bombardment should lead to the creation of heavier elements,
which we now refer to as transuranic elements. But the results were strange. In December 1938,
(16:05):
Hahn and Strassmann detected an unexpected element in their chemical residues, barium. But barium is
much lighter than uranium. Hahn didn't understand what was happening. So he sent his experimental
results in a letter to Meitner, hoping she could explain the physics behind the chemistry.
(16:26):
It arrived in the snowy Swedish countryside just before Christmas. That Christmas, Meitner received
a visit from her nephew Otto Frisch, a physicist as well. He had come to Sweden from Copenhagen
to spend the holiday with her. And together, they went on long walks through the woods near
Kungelw outside Gothenburg. On one of these walks, with snow crunching underfoot and fir trees towering
(16:52):
above, they talked through Hahn's letter. How could uranium atoms produce barium? They sat on a tree
stump and started working it out on paper. Meitner proposed that the uranium nucleus had split in two.
This theory was unprecedented. No one had ever suggested that a nucleus could break apart in
(17:14):
this way. She applied Niels Bohr's liquid drop model to the problem, suggesting that the nucleus
could become elongated and unstable, eventually splitting into two smaller nuclei. To explain
this further, the liquid drop model developed by Niels Bohr and John Wheeler in the 1930s
(17:34):
describes the atomic nucleus as a drop of liquid made up of tightly packed protons and neutrons.
This model was key in explaining nuclear fission, such as when a nucleus becomes unstable and splits
apart. So imagine placing a glob of butter on a hot pan. And I'm sure we've all done that because
(17:54):
we all love butter, right? So at first, the glob of butter holds together. But as heat builds,
it begins to wobble, stretch, and then flatten. Eventually, if you drop a tiny dab of butter on
top of that glob, the butter can break apart into smaller blobs, releasing energy as it moves. So
(18:17):
in the same way, when a neutron strikes a heavy nucleus, it causes it to vibrate and deform.
If the conditions are right, the nucleus splits in two, releasing a tremendous burst of energy.
While the model doesn't capture every detail of nuclear behavior, it laid the foundation for
understanding how atoms split and how that split powers everything from reactors to bombs.
(18:45):
In his article titled, Recollections of the Discovery of Nuclear Fission, Frisch wrote,
We had found the solution. We were the first to understand that the uranium nucleus had split in
two. It was a moment of great elation. We could hardly believe it ourselves. Thus,
that day, as Meitner and Frisch walked through the quiet forest, the snow muffled every sound.
(19:13):
The bare trees stretched skyward like skeletal fingers, their limbs stark against the pale
winter sky. The air was still, save for the crunch of their boots. Nature was serene and
undisturbed. In that silent, frozen landscape, they discussed the impossible, the splitting
(19:36):
of an atom. It was a moment of quiet revelation, born in beauty and isolation. Meitner and Hahn
likely had no idea what their discovery could create. The energy released by nuclear fission
could be massive. If controlled and placed in the hands of the humane, it could produce
(20:00):
power. If uncontrolled and given free reign by unethical individuals, it could create a monstrous
bomb. The idea they unearthed there would lead to horrors far removed from the calm of the woods.
Instead of birdsong, the world would later hear screams. Instead of fresh snow, there would be
(20:24):
scorched earth, fire, ash, and blood. In that peaceful walk, they had touched the edge of
something powerful enough to light cities or to level them. We'll be right back after a quick
word from my advertisers. So after Meitner and Frisch came to their conclusion, Frisch did the
(20:45):
math and confirmed it. The mass difference between uranium and the resulting elements accounted for
a massive release of energy as per Einstein's equation E equals mc squared. This release of
energy was the result of nuclear fission. Meanwhile, before Frisch made it back to Copenhagen,
(21:06):
Hahn had already submitted his findings to a German journal but did not credit Meitner or Frisch
in his publication. This action was a betrayal that would echo for decades. Regardless, with
Niels Bohr's encouragement, Frisch quickly published his and Meitner's paper in a journal
called Nature titled Disintegration of Uranium by Neutrons, a New Type of Nuclear Reaction.
(21:32):
So when Hahn and Fritz Strassman chemically identified barium as a product of bombarding
uranium with neutrons, this outcome made no sense within the framework of known nuclear physics.
The uranium nucleus hadn't merely rearranged, it had split. Meitner and Frisch's paper helped to
(21:53):
explain this process of nuclear fission and their paper would change the course of history. But
referring back to the liquid drop model, Meitner and Frisch showed that such a fission process
would release an enormous amount of energy, more than anyone had previously imagined,
thanks to Einstein's equation. Their concise article introduced the term, quote, a new type
(22:19):
of nuclear reaction. But the implications were anything but modest. It was the first correct
theoretical explanation of nuclear fission, opening the door to both nuclear power and
unfortunately, the devastating weaponry that would soon reshape the modern world. Despite this
(22:39):
information, when the Nobel Committee awarded the 1944 prize in chemistry, it went solely to Hahn.
They did not even mention Meitner's name. Historians and physicists alike have since
called this omission one of the most glaring oversights in Nobel history. Lise Meitner never
(23:01):
returned to Germany. She continued her work in Sweden and later moved to Cambridge, England after
the war. Though her name was known among physicists in the United States, Meitner was never officially
asked to join the Manhattan Project. But the closest she came was through informal channels.
In 1943, Bohr, who had fled occupied Denmark, was consulting on the bomb effort in America.
(23:25):
He suggested Meitner's name as somebody who might be helpful. But by then she had already
made up her mind. Living in neutral Sweden, Meitner had watched the world descend into war
and saw what unchecked scientific ambition could lead to. When she learned of the Manhattan Project,
(23:45):
she firmly declined to participate. While newspapers later dubbed her the Mother of
the Atomic Bomb, she rejected the title with sorrow and conviction. She was horrified by how
the men at the Manhattan Project had used her discovery to create nuclear weapons. She had
helped explain how to split the atom, but she wanted no part in splitting humanity with it.
(24:12):
Meitner remained adamant, science should serve humanity, not destroy it.
Beyond her groundbreaking role in the discovery of nuclear fission, Meitner made several other
significant contributions to physics. Early in her career, she and Hahn discovered the
element protactinium, which was a considerable achievement in the field of radiochemistry.
(24:36):
She also conducted extensive research on beta decay, contributing to our understanding of how
atoms release energy. Another lesser known fact is that she was one of the first to theorize about
the Auger effect, which describes how atoms release energy through electron transitions.
Her work laid the groundwork for many areas of nuclear and atomic physics,
(25:01):
and her legacy is truly expansive. In 1946, she was named Woman of the Year by the National Press
Club in Washington, D.C., celebrated alongside Eleanor Roosevelt for her contributions to science
and peace. That same year, she received honorary doctorates from several U.S. institutions,
(25:23):
including Harvard University and Smith College. In Europe, honors continued to accumulate.
In 1955, she was awarded both the prestigious Max Planck Medal by the German Physical Society
and the Otto Hahn Prize for Chemistry and Physics, the latter shared with Hahn and Strassman.
(25:44):
In 1957, Meitner received the Pour les Marites for Sciences and Arts,
one of Germany's highest civilian honors. She was also elected a foreign member of the Royal
Society in the United Kingdom in 1955, making her only the third woman to ever receive that
distinction. These awards reflect the scientific community's growing acknowledgement of her vital
(26:09):
role in the discovery of nuclear fission and her principal refusal to participate in its
weaponization. And in 1997, long after her passing, the element Meitnerium-109 was named
in her honor. Meitner was nominated for a Nobel Prize 48 times, 48 times, yes, and yet she never
(26:37):
received one. At first glance, this seems unbelievable. This is just, it's asinine,
I'm sorry, being a woman in science can be absolutely asinine, because how could the woman
who helped explain nuclear fission, the very discovery that ushered in the atomic age,
how could she be left out? But the answer lies at the tangled intersection of science,
(27:02):
gender, politics, and timing. To begin with, Meitner faced an uphill battle simply because
she was a woman. In the early 20th century, physics and chemistry were extensively male-dominated
fields. Despite her achievements, she was often referred to not as a scientist, but as Han's
(27:22):
assistant. Behind closed doors, she was sometimes referred to as Miss Meitner, even after earning
her doctorate and publishing independently. Gender bias ran deep, it still does, and the Nobel
committees were no exception. At the time, only two women, Marie Curie and Irene Joliot-Curie,
(27:44):
had ever won Nobel prizes in the physical sciences. Then there's the issue of what kind of
science gets rewarded. The 1944 Nobel Prize in chemistry went to Han, recognizing his experimental
detection of barium in neutron-bombarded uranium. But the theoretical interpretation,
(28:05):
the breakthrough realization that this meant the nucleus had split, came from Meitner and her
nephew, Frisch. The Nobel committee favored experimental chemistry over theoretical physics,
even though the interpretation is what made the discovery historically and scientifically
meaningful. Meitner's role wasn't just support, she connected the pieces that defined the
(28:31):
phenomenon as fission. Wartime politics didn't help. When the Nobel Prize was awarded, Meitner
was a Jewish refugee living in Sweden, having fled Nazi Germany in 1938. Han, by contrast,
had remained in Germany. The Nobel committee may have feared the optics of awarding a prize to
(28:53):
someone in exile or of highlighting a Jewish woman's critical contribution while the world
was still reeling from Nazi atrocities. It's no coincidence that the Nobel committee did not
announce Han as the recipient until after the war had ended. There's also a more mundane,
(29:13):
but no less tragic reason. Meitner lacked a strong advocate on the Nobel committee.
Many laureates have behind the scenes champions pushing their case year after year. Meitner did
not have that. Her nominations were scattered, often switching between physics and chemistry
categories, and they came too late to override the 1944 decision. Later in life, she was honored
(29:41):
with numerous awards, honorary doctorates, the Max Planck medal, and even the naming of the element
Meitnerium. But the Nobel? That remained forever just out of reach. Today, scientists and historians
widely recognize that Lise Meitner's exclusion was one of the greatest injustices in the history
(30:03):
of science. Not because she wasn't nominated, but because the system simply wasn't ready to see her.
These groups of men weren't blind to her brilliance. They chose to look away. She was not
just a brilliant physicist. Even in exile, even with very little, she changed the world. Not with
(30:27):
force, not with power, but with quiet brilliance and the courage to speak truth, even when others
did not. No doubt, she was also a deeply ethical scientist, someone who stood by her principles in
the face of immense pressure. Lise Meitner once said, science makes people reach selflessly
(30:49):
for truth and objectivity. It teaches people to accept reality with wonder and admiration,
not to mention the deep awe one feels in discovering the order of the universe.
Thus, her life reminds us that sometimes the most profound discoveries don't happen in labs.
(31:10):
They occur in conversations, on long walks, during stolen moments of peace in a world at war.
And as for those profound discoveries, I can attest I've been there. I think every college
student has been there. In my early college years, I would often sit alone in my apartment in the
dark because I'd forgotten to turn on the lights, with a tiny desk lamp entirely consumed in my
(31:36):
studies, taking in insight and inspiration. And there is no greater feeling than an epiphany.
And I don't know who needs to hear this, but for those of you who have your head in a book,
consuming math, physics, chemistry, and even history, or literature, I genuinely hope that you
(31:58):
feel the intenseness of a revelation and that inspires you to keep moving forward in your
research and your discoveries. Your enlightenment can change the world for good. And that's really
what we need right now. We need a future where science illuminates, not annihilates.
(32:20):
Thank you for listening to Math Science History. I'm Gabrielle Birchak, and until next time,
Carpe Diem. Thank you for tuning in to Math Science History. If you enjoyed today's episode,
please leave a quick rating and review. They really help the podcast. You can find our
(32:41):
transcripts at mathsciencehistory.com. And while you're there, remember to click on that coffee
button because every dollar you donate supports a portion of our production costs and keeps our
educational website free. Again, thank you for tuning in and until next time, Carpe Diem.
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