Vox Meditantis

We meet physicist Marietta Blau at a quiet corner of a Viennese café, not far from where the old Vienna Radium Institute once stood. She carries herself with a quiet dignity, her hands bearing the faint chemical stains that mark a lifetime spent developing photographic emulsions in laboratories across three continents. Her eyes are sharp behind wire-rimmed spectacles, and when she speaks of her work, there’s both pride and a palpable frustration – the frustration of someone who watched others receive credit for perfecting methods she pioneered. Today, particle physics recognises her as the woman who first made the invisible visible, capturing cosmic rays in starlike patterns that launched an entire field. Her story is one of scientific brilliance overshadowed by displacement, discrimination, and the cruel mathematics of recognition in twentieth-century physics.

Thank you for meeting with me today, Dr. Blau. I’m fascinated by your journey – from pioneering nuclear photography in Vienna to your years of exile and eventual return. Let me start at the beginning. What drew you to physics in the first place?

You know, it wasn’t such an obvious choice for a girl in Vienna at the turn of the century. My family was well-established – my father was a court lawyer and music publisher – but they were progressive enough to support my education. I was always drawn to mathematics and the natural sciences, even as a child. There was something thrilling about the precision, the logic of it all.

When I entered the University of Vienna in 1914, there were very few women studying physics. But the professors, particularly F.S. Exner and Stefan Meyer, they judged you on your work, not your gender. Well, mostly. My doctoral thesis on gamma radiation absorption – that was completed in 1919, just as the empire was crumbling around us. Strange times to be starting a scientific career.

You worked at various positions in Germany before returning to Vienna. What brought you back to the Radium Institute in 1923?

My mother fell ill, and I needed to care for her. But I was also drawn back by Stefan Meyer’s vision for the Institute. He was building something remarkable there – a place where the boundaries between physics, chemistry, and medicine were fluid. And perhaps most unusually, he welcomed women.

You must understand, the Vienna Radium Institute in the 1920s and 1930s was extraordinary in this regard. More than one-third of our researchers were women. Not assistants or technicians, mind you, but proper scientists doing first-rate research. Berta Karlik, Elizabeth Rona, Hertha Wambacher, and myself – we formed our own research groups, published independently, supervised students.

Of course, most of us were unpaid. They told us we should be grateful for the opportunity to do research at all. I survived on family support, occasional stipends from the Austrian Association of University Women, and consulting work. When someone asked about my promotion prospects, I was reportedly told that “a woman and a Jew – that’s just too much!” But we persisted.

Tell me about your breakthrough with photographic emulsions. How did you discover that you could capture particle tracks this way?

Ah, this was the heart of it all. In 1924, I began adapting photographic techniques to detect nuclear particles. You see, other researchers were using cloud chambers or scintillation counters – crude devices, really, that required someone to sit in the dark for hours, watching for tiny flashes.

I thought: why not use photography? Particles leave tracks, like footprints in snow. If you could make the emulsion sensitive enough, you could record these tracks permanently. But it was extraordinarily difficult work. The emulsions had to be just the right thickness, with silver bromide crystals of precisely the right size. Too sensitive, and you’d be overwhelmed with background noise. Too coarse, and you’d miss the delicate tracks of protons.

I spent years working with different photographic companies – Agfa, Ilford – experimenting with chemical formulations, development temperatures, exposure times. Each plate had to be examined grain by grain under the microscope. I traced thousands upon thousands of tracks, measuring their length and density to determine the particles’ energy and identity.

And this led to your discovery of the “disintegration stars” in 1937?

Yes! Hertha Wambacher and I exposed our specially prepared plates at Viktor Hess’s cosmic ray observatory near Innsbruck – 2,300 metres above sea level, to catch the cosmic rays before the atmosphere could scatter them. We left the plates there for five months.

When we developed them, we found something extraordinary. Most cosmic ray tracks were simple – straight or slightly curved lines. But some ended in these remarkable star-shaped patterns, as if tiny fireworks had exploded within the emulsion. Multiple tracks radiating outward from a single point.

We realised we were seeing nuclear disintegration for the first time – cosmic ray particles smashing into the heavy atoms in our emulsion, silver and bromine, breaking them apart and sending fragments flying in all directions. We called them “Zertrümmerungsterne” – disintegration stars. It was the first visual evidence of high-energy particle interactions, the birth of experimental particle physics.

The scientific community was electrified. Here was direct, visual proof of nuclear transmutation on a cosmic scale.

But then came 1938 and the Anschluss. How did that change everything?

Everything collapsed overnight. The Nazis marched into Vienna in March 1938, and suddenly I went from being a respected physicist to being a hunted person. Jewish scientists were dismissed immediately. My colleague Hertha Wambacher, who had been my student and collaborator – she joined the Nazi Party in 1934, you know. Suddenly she was my superior, and I was… nothing.

I had to flee with almost no preparation. Albert Einstein – bless him – had written me a letter of recommendation. I made my way first to Mexico City, where they offered me a position at the National Polytechnic Institute.

Mexico was a refuge, but it was also a kind of scientific exile. I was teaching 24 hours a week, trying to support my sick mother, and I had no proper laboratory. Someone even stole the research equipment I had managed to bring from Vienna – I found it later in a pawn shop, if you can believe it.

Those were the crucial years, 1938 to 1944. While I was struggling to survive in Mexico City, others were building upon my techniques with better resources and institutional support.

You’re referring to Cecil Powell and his group at Bristol?

Powell did excellent work, I won’t deny that. But he was working with my methods, refined with the resources I never had. Thick nuclear emulsions from Ilford, teams of trained scanners, university backing, military funding during the war. When he discovered the pion in 1947 using photographic emulsions, it was built directly on the foundation I had laid.

In 1950, Erwin Schrödinger nominated Hertha and myself for the Nobel Prize, writing that we deserved recognition for developing the photographic method and discovering the first disintegration stars. But the prize went to Powell alone. The committee’s evaluation dismissed our work as preliminary, emphasising the improvements that Ilford had made to the emulsions and suggesting that disintegration stars had already been observed by others using cloud chambers.

They weren’t wrong about Ilford’s improvements – but those improvements were based on the techniques I had pioneered. As for the cloud chamber work, Anderson and Neddermeyer had seen some particle clusters, yes, but they couldn’t capture the complete interaction, the central vertex where everything happened. Our photographic method was superior – it recorded continuously, it preserved the full event for detailed analysis.

But I had been absent from the field for twelve crucial years. In science, that’s an eternity. By the time I returned to research at Columbia and then Brookhaven in the late 1940s, I was seen as a historical figure, not a contemporary contributor.

How did it feel to be working at Brookhaven in the 1950s, finally back in the field with access to modern equipment?

It was wonderful to be back in proper laboratories again, working with cyclotrons and particle accelerators rather than cosmic rays. I was using my photographic techniques with artificially produced high-energy particles, which was tremendously exciting. We could control the conditions, repeat the experiments.

But the field had changed. Most laboratories had teams of “scanners” – typically women who did the painstaking work of analysing the photographic plates. At Brookhaven, I insisted on doing much of the scanning myself. Old habits, perhaps, but also a matter of maintaining control over my own research.

I also worked on developing new detector technologies – photomultiplier tubes combined with scintillation screens. In 1944, working in New York, I had actually described the first electrically modified scintillation counter, though this was overshadowed by the classified work being done on the Manhattan Project.

You returned to Vienna in 1960. What was that homecoming like?

I was sixty-six years old and my health was failing. After five years in Mexico and sixteen in America, I needed medical treatment that I could afford. Vienna had changed enormously, of course. The old Institute had been rebuilt, and I found work there supervising the analysis of photographic plates from CERN experiments.

There was a certain poetry to it – I was back where I started, still examining particle tracks under the microscope, still making the invisible visible. But now it was part of the great international collaboration of modern particle physics. The techniques I had pioneered in the 1930s were being used to probe the fundamental structure of matter.

Looking back now, how do you view your treatment by the scientific community? Do you feel your contributions were properly recognised?

The Nobel Prize would have been gratifying, naturally. But awards aren’t everything. What troubles me more is the way my story illustrates the broader challenges facing scientists – especially women, especially Jews – in the twentieth century.

I had two strikes against me, as they say. Being a woman in physics was difficult enough – we faced constant questions about our competence, our commitment. Add to that being Jewish during the rise of Nazism, and you have a recipe for professional destruction.

But here’s what frustrates me most: it wasn’t just the Nazis who cost me recognition. It was the entire system that made my absence during the war years nearly impossible to overcome. When I returned to research in the late 1940s, the particle physics community had moved on. They were interested in the latest discoveries, not in giving credit to someone whose peak contributions were a decade in the past.

What would you say to young women entering physics today, particularly those from marginalised backgrounds?

Persist. Document your work meticulously. Never assume that good science will speak for itself – you must be your own advocate. And build networks of mutual support with other scientists who understand the challenges you face.

The women at the Vienna Radium Institute in the 1930s – we formed a remarkable community. We collaborated, we supported each other’s work, we shared resources and opportunities. That solidarity was crucial to our success, such as it was.

But also: demand better from the institutions. When I was told that being “a woman and a Jew was just too much,” I should have challenged that directly, not simply accepted it as the price of doing science. These attitudes persist only because they’re tolerated.

Is there anything about your work that you feel has been misunderstood or misrepresented in the history books?

Oh, the history books tend to present my story as a tragedy – the brilliant scientist whose career was destroyed by the Nazis, who watched others receive credit for her discoveries. There’s truth to that narrative, but it’s incomplete.

What they often miss is that I never stopped working. Even in Mexico, teaching twenty-four hours a week with no proper laboratory, I was conducting research. Even in my industrial jobs in New York in the 1940s, I was innovating. The scintillation counter work, for instance – that was done during supposedly “unproductive” years.

They also underestimate the Vienna Radium Institute’s significance. It wasn’t just another European laboratory – it was a unique environment where women could do first-rate nuclear physics research. When people wonder why there weren’t more women in physics in the early twentieth century, they should look at our example and ask what made it possible there.

Any regrets about choices you made?

I sometimes wonder what would have happened if I had left Austria earlier, perhaps in 1933 when the political situation was already deteriorating. I might have established myself at a major American university before the war, built the kind of institutional support that could have sustained my research.

But then again, some of my most important work was done in those final Vienna years, 1935 to 1938. The disintegration stars, the refinement of the photographic technique – that was the culmination of fifteen years of methodical development. If I had left earlier, that breakthrough might never have happened.

And there’s this: I chose to pursue the science I found most compelling, rather than the science most likely to win recognition. I could have abandoned the photographic method when it became clear that others with better resources were overtaking me. Instead, I continued to refine and apply it because I believed in its potential. That wasn’t the strategic choice, but it was the honest one.

Finally, when you look at particle physics today – the Large Hadron Collider, the detection of the Higgs boson – how do you feel about the field you helped create?

Extraordinary. When I was tracing particle tracks by hand under a microscope in 1925, I never imagined we would be colliding particles at such energies, detecting such exotic phenomena. The scale is breathtaking – kilometres of detectors, international collaborations involving thousands of physicists.

But you know what gratifies me most? The visual culture is still there. Modern particle physics still depends on tracking particles, on making their invisible journeys visible. The technology has advanced beyond recognition – electronic detectors, computer reconstruction, digital imaging – but the fundamental insight remains the same.

Every time a physicist at CERN looks at a collision event, traces the curved tracks of particles bending in magnetic fields, identifies the signature of a new discovery – they’re doing what I was doing in that Vienna laboratory ninety years ago. Making the invisible visible. That’s the true legacy, not the prizes or the recognition.

The particles don’t care about our human struggles with recognition or priority or prejudice. They simply follow the laws of physics, leaving their tracks for anyone clever enough to detect them. In the end, that’s what matters – that we learned to see what had always been there, waiting to be discovered.

Interviewer’s note: Dr. Blau passed away in Vienna in 1970, just as the field of particle physics was entering its golden age. Element 109, Meitnerium, was named for her contemporary Lise Meitner, who faced similar challenges as a Jewish woman physicist. No element bears Marietta Blau’s name, but her legacy lives on in every particle detector that captures the tracks of the invisible, making the fundamental structure of matter visible to human understanding.

Letters and emails

Since our interview with Dr. Marietta Blau was published, we’ve received dozens of thoughtful letters and emails from readers around the world – physicists, teachers, students, and science enthusiasts – all eager to delve deeper into her remarkable story. We’ve selected five particularly compelling questions from our growing community, each offering a different perspective on her pioneering work, her personal resilience, and what her experiences might teach those walking in her footsteps today.

Josephine Simmons, 34, Particle Physicist at CERN, Geneva, Switzerland:
Dr. Blau, as someone who works daily with the massive detector systems at the LHC, I’m struck by how your hand-crafted photographic plates were essentially the first ‘big data’ experiments in particle physics – requiring you to analyse thousands of individual tracks by eye. How did you maintain the patience and precision needed for such meticulous work, and do you think modern physicists have lost something essential by delegating pattern recognition to computers rather than training our eyes to see the physics directly?

Ah, Josephine – what a perceptive question from someone who truly understands the work. You’re absolutely right that my photographic plates were, in essence, the first “big data” experiments, though we never called them that, of course.

The patience… well, it was born from necessity, but also from genuine fascination. When you’re examining a single emulsion plate, you might trace five thousand individual tracks over the course of several weeks. Each grain of silver bromide that had been struck by a particle told part of a story, and you had to learn to read these stories like a detective examining evidence.

I developed what I called “educated eyes” – after years of this work, you could distinguish a proton track from an alpha particle track at a glance. The proton tracks were denser, more heavily ionising at the beginning, then tapering off. Alpha particles left thick, straight furrows that ended abruptly when the particle was absorbed. Electron tracks were wispy, often scattered by electromagnetic interactions.

But here’s what I think you’re getting at, and it troubles me about modern physics: there was an intimacy to that work that I fear is lost. When I spent eight hours bent over a microscope, tracing every micron of a particle’s journey, I was in direct communion with the physics. I knew the personality of each type of particle, if you will – their characteristic behaviours, their signatures, their quirks.

Today’s computer algorithms are far more efficient, naturally. They can process millions of collision events in the time it would take me to analyse a single plate. But algorithms see only what they’re programmed to recognise. The human eye, properly trained, can spot anomalies, unexpected patterns, subtle deviations that might indicate something genuinely new.

I remember in 1937, when Hertha and I first saw those star-shaped patterns – the disintegration stars – we nearly dismissed them as photographic flaws. They looked so different from anything we expected. But something made us look closer, measure more carefully. Would a computer algorithm have flagged those patterns as interesting, or would it have filtered them out as noise?

The patience came from understanding that each track was a messenger from the cosmic realm, carrying information about processes occurring at energies we could never hope to reproduce on Earth. Every morning when I sat down at my microscope, I was opening letters from the universe itself.

What concerns me is that modern physicists, for all their sophisticated equipment, may be losing the intuitive feel for the physics. When you’ve traced ten thousand particle tracks by hand, you develop an almost mystical sense for what the particles are “trying to tell you.” You begin to think like a particle, if that makes sense.

I would challenge you, Josephine, and your colleagues at CERN to spend some time – perhaps just a few hours a week – looking at raw detector output with your own eyes. Not the pretty computer reconstructions, but the messy, ambiguous signals that come straight from the detectors. Train your visual cortex to recognise patterns the way I trained mine. You might be surprised by what you see that the computers miss.

The great irony is that we’ve made physics more precise but perhaps less perceptive. We can measure everything to extraordinary accuracy, but do we still know how to truly see?

Greg Summers, 28, Science Policy Researcher, Washington DC, USA:
Your experience fleeing Nazi Austria raises uncomfortable questions about how political upheaval affects scientific progress. Today we’re seeing authoritarian governments restrict academic freedom, force scientists into exile, and weaponise research funding. Based on your own displacement during those crucial years from 1938-1944, what advice would you give to contemporary scientific institutions about protecting vulnerable researchers and preserving continuity of knowledge when political winds shift?

Greg, your question strikes at the very heart of what I witnessed in the 1930s – and what terrifies me about what I see happening again today. The parallels are chilling, and I fear we haven’t learned the lessons we should have.

When the Nazis came to power, they didn’t simply target Jewish scientists randomly. They systematically dismantled the infrastructure of independent inquiry. First, they removed Jews and political dissidents from universities. Then they redirected research funding toward military applications. Finally, they demanded that all scientific work serve the ideological goals of the state.

The effect wasn’t just individual tragedy – though that was devastating enough. It was the complete corruption of the scientific enterprise itself. Science requires intellectual honesty, international collaboration, the free exchange of ideas. Authoritarianism demands conformity, nationalism, the subordination of truth to political utility.

What you’re describing today – governments restricting academic freedom, forcing scientists into exile, weaponising research funding – these are the same techniques, simply updated for the twenty-first century. When I see reports of researchers in countries like Turkey, Hong Kong, Hungary, or even certain American states being dismissed or silenced for their work on climate change, evolution, or public health, I see 1938 all over again.

The pattern is always the same: authoritarian leaders claim they’re “following the science” whilst simultaneously destroying the conditions that make legitimate science possible. They cherry-pick findings that support their agenda whilst suppressing research that challenges it.

But here’s what contemporary scientific institutions must understand: the damage isn’t just immediate, it’s generational. When I was forced to flee Vienna in 1938, I lost twelve years of peak productivity. But the larger tragedy was the disruption of entire research programmes, the scattering of collaborative networks, the destruction of institutional memory.

My advice to modern scientific institutions? Act before the crisis, not during it.

First, establish robust international networks for protecting vulnerable researchers. I was fortunate that Einstein wrote me a letter of recommendation, but most scientists don’t have such connections. Today’s organisations like Scholars at Risk are essential, but they need more resources and broader support.

Second, create portable research infrastructure. My greatest handicap in Mexico wasn’t just the isolation – it was losing access to the specialised equipment and materials I needed. Modern institutions should develop systems that allow displaced scientists to continue their work immediately, whether through cloud-based computing, remote laboratory access, or equipment sharing agreements.

Third, maintain intellectual independence from government funding. This is difficult, I know, but critical. When scientists become too dependent on state patronage, they become vulnerable to political manipulation. Diverse funding sources – private foundations, international collaborations, industry partnerships – provide protection against authoritarian pressure.

Fourth, and most importantly: Never assume it cannot happen where you are. The scientists I knew in Vienna in 1937 thought we were safe. We had international reputations, Nobel Prize winners, prestigious institutions. We thought our value to society would protect us.

We were catastrophically wrong.

Today’s threats may seem different – algorithms instead of storm-troopers, funding cuts instead of deportations – but the underlying dynamic is identical: authoritarian power cannot tolerate independent sources of truth. Science, by its very nature, challenges authority by subjecting all claims to empirical testing.

The scientific community must also stop pretending it can remain “apolitical.” When governments attack the very foundations of empirical inquiry, defending science becomes inherently political. Scientists have a responsibility to speak out not just for their own research, but for the entire edifice of rational discourse that democracy requires.

And to young scientists today, especially those from marginalised backgrounds: document everything, build international networks early, learn multiple languages if possible, and always have an escape plan. I know this sounds paranoid, but history shows that the window between the first warning signs and complete catastrophe can close very quickly.

The knowledge we’ve spent centuries accumulating – about climate, disease, the fundamental structure of reality – is too precious to lose to political hysteria. We have a duty to protect it, and that means protecting the scientists who create it.

The difference between 1938 and today is that we now have global communications, international institutions, and a deeper understanding of how authoritarianism operates. We have advantages I never had. But only if we use them before it’s too late.

Dana Lindsey, 42, High School Physics Teacher, Manchester, UK:
I teach many young women who are brilliant at physics but worry they’ll face discrimination or have to choose between family and career. You never married or had children – was this a conscious choice to avoid the ‘double burden’ that women scientists faced, or simply how your life unfolded? Looking at today’s struggles with work-life balance in academia, do you think the fundamental tensions between scientific careers and traditional expectations of women have truly changed, or just taken new forms?

Dana, you’ve touched on something I’ve spent many years thinking about, often in the quiet hours when I was alone with my microscope. The truth is both simpler and more complicated than it might appear.

I never married or had children, but it wasn’t a grand strategic decision made early in my career. Life simply… unfolded that way. In my twenties, I was absorbed in my doctoral work, then establishing myself in the laboratory. In my thirties, the few men who might have been suitable partners were often put off by my scientific ambitions – or worse, they assumed I would abandon research after marriage, as was expected then.

There was one fellow, a mathematician, in the late 1920s. Quite brilliant, actually. But when I showed him my latest research on alpha particle tracks, he patted my hand and said, “How charming that you have such interesting hobbies.” That was the end of that relationship.

But I won’t romanticise this, Dana. The path I took came with genuine sacrifices. There were nights when I returned to my small apartment after twelve hours in the laboratory, and the silence was… profound. No children’s laughter, no husband to share the excitement of a new discovery or to comfort me after a failed experiment.

When I was forced into exile, I travelled alone. When I struggled to find work in Mexico, I had no one to fall back on financially except my aging mother, whom I was trying to support. The isolation was sometimes crushing.

Yet I’ve also watched married women colleagues struggle terribly with what you call the “double burden.” Hertha Wambacher married and had children in the 1930s. I watched her torn between her research and her family responsibilities. She would arrive at the laboratory exhausted from sleepless nights with sick children, or have to leave in the middle of crucial experiments for domestic crises.

The men, of course, never faced such choices. Their wives managed the household, raised the children, created the conditions that allowed them to work fourteen-hour days without interruption.

But here’s what troubles me about the way this question is often framed today: it assumes that the fundamental structure of scientific careers is fixed, that women must simply adapt to it. Why should a scientific career require such complete devotion that it’s incompatible with family life? Why should advancement depend on uninterrupted productivity throughout one’s twenties and thirties?

The Vienna Radium Institute in the 1930s was unusual because Stefan Meyer understood that good science comes from good minds, regardless of the personal circumstances of those minds. Several women there managed both research and family – Elizabeth Rona had a daughter, though she was often separated from her for long periods.

What made it possible was flexibility: unusual working hours, shared laboratory space, collaborative projects that could accommodate interruptions. But even then, it was difficult.

To your students, I would say this: the tensions haven’t fundamentally changed, only the rhetoric has improved. Today’s institutions speak of “work-life balance” while still structuring careers around the assumption that someone else is managing your personal life.

But there are new possibilities they should consider. Modern technology allows for more collaborative research across distances. Computational work can often be done from anywhere. International collaboration might even make family life easier – if you’re working with colleagues in different time zones, you can contribute meaningfully without being physically present twelve hours a day.

More importantly, they should demand better from their institutions. Why shouldn’t universities provide high-quality childcare? Why shouldn’t research grants include provisions for family support? Why shouldn’t academic careers be structured to accommodate the natural rhythms of life rather than the artificial demands of institutional prestige?

And I would tell your students – especially the brilliant young women – that they should refuse to accept that choosing science means sacrificing everything else. That’s not a law of nature; it’s a failure of imagination by the institutions that employ them.

As for my own choices… I sometimes wonder what might have been different if I’d had a partner who truly understood and supported my work. Someone to share the excitement when I first saw those disintegration stars, someone to encourage me during the dark years in Mexico.

But I also know that my complete dedication to the work allowed me to see things others missed, to develop techniques that might not have emerged from a more conventional life. The long hours alone with the microscope taught me a kind of patience and precision that shaped not just my research methods but my entire way of seeing the world.

Perhaps the real question isn’t whether women can “have it all,” but whether we can create scientific institutions that recognise the full humanity of all their members – their needs for love, family, community, and meaning beyond the laboratory.

The physics I discovered didn’t care whether I was married or single, whether I had children or not. The particles left their tracks regardless of my personal circumstances. But the conditions under which I could discover that physics – those were entirely shaped by human choices about how we structure scientific careers and scientific institutions.

Your students have the power to demand better. They shouldn’t have to choose between scientific brilliance and human fulfillment. The future of physics depends on making room for all kinds of minds, living all kinds of lives.

Hirotoshi Matsubara, 45, Science Journalist, Tokyo, Japan:
Your Nobel Prize nomination in 1950 came at a fascinating moment – just five years after Hiroshima and Nagasaki, when the world was struggling with the destructive potential of nuclear physics. Did the atomic bombings change how you thought about your own research into nuclear processes? As someone who spent years making the invisible architecture of atoms visible, how did you reconcile your pure scientific curiosity with the knowledge that nuclear physics had become a tool of unprecedented destruction?

Hirotoshi, you’ve asked perhaps the most difficult question of all. The atomic bombings… yes, they changed everything. Not just how I thought about my research, but how I understood the relationship between scientific curiosity and human consequence.

When the news came in August 1945, I was working at an industrial laboratory in New York, trying to rebuild my career after the Mexico years. The initial reports were almost incomprehensible – entire cities destroyed by single bombs, weapons that derived their power from the splitting of atomic nuclei.

My first reaction, I’m ashamed to admit, was professional fascination. The physics reports that emerged described nuclear fission on a scale beyond anything we had imagined in our Vienna laboratories. The energy calculations were staggering.

But then came the photographs. The shadows burned into walls where human beings had stood. The descriptions of radiation sickness, of people dying weeks after the initial blast from the invisible effects of nuclear particles – the same particles I had spent twenty years learning to detect and measure.

You see, in my research, nuclear disintegration was beautiful. Those star-shaped patterns in my photographic emulsions were like frozen fireworks, elegant demonstrations of the fundamental forces that govern matter. Each track told a story of cosmic interactions, of the deep structure of reality revealing itself.

But Hiroshima and Nagasaki showed me the other face of nuclear disintegration. The same physics that created my beautiful stars could create unimaginable destruction. The energy that excited me when I calculated it from particle tracks could incinerate human beings, could poison the air and water, could damage the genetic material that carries life forward.

There were nights, in the months after the bombings, when I would look at my old photographs of disintegration stars and feel a kind of horror. Had my work contributed to this? My techniques for detecting and measuring nuclear particles had been published, shared freely with the international scientific community. Who knows how that knowledge might have been used?

But I also came to understand that this question – the relationship between pure scientific knowledge and its applications – is fundamentally unanswerable. When I developed the photographic emulsion technique, I was trying to understand cosmic rays, to peer into the fundamental processes that govern our universe. I had no thought of weapons, no intention of destruction.

The atomic bomb was possible because of Einstein’s mass-energy equation, because of discoveries about uranium fission, because of advances in engineering and metallurgy. My own contribution was tiny by comparison. Yet I cannot claim complete innocence.

Here’s what I learned: there is no such thing as purely neutral scientific knowledge. Every discovery, no matter how abstract or theoretical, carries the potential for both creation and destruction. The same understanding of radioactivity that might one day cure cancer was used to build bombs. The same rocket technology that could take humanity to the stars was first used to deliver explosives.

After 1945, I made a conscious decision to focus my research on fundamental particle physics – understanding the basic building blocks of matter. I told myself this was safer, more removed from immediate applications. But even that was naive. Particle physics research led to the development of nuclear reactors, both for power generation and weapons production.

The uncomfortable truth is that scientists cannot control how their discoveries are used. We can choose our research questions, we can conduct our work with integrity, but once knowledge enters the world, it belongs to humanity – with all of humanity’s capacity for both good and evil.

What we can do is take responsibility for the broader implications of our work. After 1945, I became much more conscious of the need for scientists to engage with questions of ethics, policy, and social responsibility. We cannot simply retreat into our laboratories and claim that the applications of our discoveries are someone else’s problem.

When I returned to Vienna in 1960 and began working with CERN data, I was heartened by the international, collaborative nature of the enterprise. Here was particle physics being used to bring nations together rather than to destroy each other. The same techniques I had pioneered for detecting cosmic ray interactions were now being used to explore fundamental questions about the nature of reality – questions that belonged to all humanity.

But I also remained haunted by a question that I think every physicist must confront: would I have made different choices if I had known, in 1925 when I began working with nuclear emulsions, where that path might lead? Would I have chosen a different field, focused on different questions?

The honest answer is that I don’t know. The scientific impulse – the desire to understand how the world works – is so fundamental to who I am that I cannot imagine having suppressed it. But I hope I would have been more thoughtful about the broader context, more engaged with the ethical dimensions of my work.

To today’s physicists, I would say: pursue knowledge with passion, but never forget that you are not just scientists – you are citizens of the world. Every equation you solve, every particle you discover, every technique you develop becomes part of the human heritage of knowledge. That heritage can be used for tremendous good or tremendous harm.

Your responsibility doesn’t end when you publish your results. It begins then.

Annie Wright, 51, Museum Curator specialising in Women’s History, Melbourne, Australia:
Something that strikes me about your story is the isolation – not just the geographic displacement, but the intellectual loneliness of being one of so few women in your field. You mentioned the supportive community at the Vienna Radium Institute, but what sustained you emotionally during those long years in Mexico and America when you were essentially starting over? Did you maintain friendships with other women scientists, or find mentorship relationships that helped you persevere through the most difficult periods?

Annie, you’ve touched on something that… well, it’s something I’ve thought about often during the quiet hours alone in laboratories around the world. The isolation you describe was perhaps the most difficult aspect of my entire career – more challenging, in some ways, than the scientific problems I was trying to solve.

You’re quite right about the Vienna Radium Institute being special in this regard. Stefan Meyer had created something extraordinary – a place where women scientists didn’t just work in isolation, but formed what I can only describe as a genuine intellectual sisterhood. Berta Karlik, Elizabeth Rona, Hertha Wambacher, myself – we shared laboratory space, compared research methods, discussed our findings over coffee in the mornings.

We had what you might call “educated conversations” about our work. When I was struggling with emulsion development temperatures, Berta might suggest a different approach based on her work with radioactive decay. When Elizabeth had questions about measuring ionisation tracks, I could share techniques I’d learned from hours bent over the microscope.

But more than that – and this is what I think sustained me most – we shared the daily frustrations and small victories that only another woman scientist could truly understand. The subtle dismissals from male colleagues, the assumptions about our competence, the constant need to prove ourselves over and over again.

When I was forced to leave Vienna in 1938, I lost all of that. Overnight, I went from being part of this remarkable community to being completely alone.

In Mexico, I was not just linguistically isolated – though my Spanish was quite poor at first – but intellectually isolated as well. The Polytechnic Institute had no other women physicists. The men were kind enough, but they didn’t understand my work, and I often felt they saw me as something of a curiosity rather than a serious colleague.

I maintained correspondence with some colleagues, of course. There were letters – though fewer than I would have liked, given the disruption of the war. I wrote to Einstein several times, and he was gracious in his responses, but these were formal exchanges about scientific matters and immigration paperwork, not the kind of intimate intellectual friendship I had known in Vienna.

The loneliness was… profound. There were nights when I would return to my small apartment after a day of teaching elementary physics to engineering students who had no interest in the subject, and I would sit at my desk looking at photographs of particle tracks I had taken years before in Vienna, feeling as if I were looking at artefacts from another lifetime.

I think what sustained me through the darkest periods was a combination of pure stubbornness and a kind of intellectual faith. I maintained detailed correspondence with several European colleagues – when the postal system allowed – sharing not just scientific results but also techniques, theoretical speculations, even complaints about experimental difficulties.

And I discovered something important: you can create intellectual community through writing, even when you can’t have it through daily conversation. My most important relationship during the Mexico years was with my laboratory notebooks. They became, in a strange way, a dialogue partner – I would record not just data, but my thoughts, my frustrations, my ideas for future experiments.

When I finally reached New York in the mid-1940s and began working in industrial laboratories, I found a different kind of community among the other refugee scientists scattered throughout American institutions. We understood each other’s stories – the abrupt departure, the loss of status, the struggle to rebuild careers with limited resources.

I formed friendships with several other émigré women scientists – a chemist from Germany, a mathematician from Poland, a biologist from Hungary. We would meet occasionally for tea, and these gatherings became incredibly precious to me. We could speak about our work without having to explain our qualifications or justify our presence.

But I want to be honest about something, Annie. The isolation never completely went away. Even when I returned to Vienna in 1960 and found myself back in the laboratories where I had started my career, I was still somewhat apart. The scientific community had moved on without me during my twenty-two years of exile. Younger physicists knew my name from textbooks, but they didn’t know me as a living, working scientist.

What I learned through all of this is that intellectual isolation can be more devastating than social loneliness. When you’re working at the frontiers of knowledge, you need colleagues who can understand your questions, challenge your assumptions, share your excitement when you discover something new. Without that intellectual community, science becomes merely a technical exercise rather than a collaborative exploration of the universe.

This is why I’m so concerned about women scientists today who find themselves as the only woman in their department, or refugee scientists who are struggling to rebuild careers in new countries. The technical challenges of research are difficult enough – the isolation can be crushing.

My advice would be: create community wherever you can find it. Write letters – or emails, in your era. Attend conferences, even if they’re outside your immediate field. Collaborate across institutions, across national boundaries if necessary. The work itself can sustain you for a while, but ultimately, science is a human enterprise, and it requires human connection to flourish.

I survived the isolation, but I would not wish that experience on anyone. Every scientist – but especially women scientists, especially those from marginalised backgrounds – deserves to feel intellectually at home somewhere in the world.

Reflection

As our conversation with Dr. Marietta Blau drew to a close, I found myself struck by the quiet defiance that ran through every aspect of her story. Here was a woman who refused to be diminished by circumstance – whether facing the dismissive comment that being “a woman and a Jew was just too much,” or rebuilding her career from scratch in foreign laboratories across three continents. Her tale is one of scientific brilliance intertwined with profound displacement, yet what emerges most powerfully is her relentless commitment to making the invisible visible, both in physics and in the human condition.

The themes that emerged from our discussion – the meticulous patience required for groundbreaking work, the devastating impact of political upheaval on scientific progress, and the particular challenges faced by women in male-dominated fields – feel startlingly contemporary. When Dr. Blau described spending weeks tracing particle tracks grain by grain under a microscope, I couldn’t help but think of today’s researchers analysing terabytes of data from the Large Hadron Collider, still fundamentally engaged in the same quest to decode the universe’s deepest secrets.

Her perspective on several key aspects of her story differed notably from some historical accounts I had encountered. While many sources emphasise her as a victim of circumstance – the brilliant scientist whose career was derailed by Nazi persecution – she presented herself as someone who never stopped innovating, even during her supposed “lost years” in Mexico and industrial laboratories. Her insistence on recognising the Vienna Radium Institute as a uniquely supportive environment for women scientists challenges narratives that focus solely on discrimination, revealing instead a complex ecosystem where institutional leadership could create pockets of genuine equality.

What struck me most profoundly was her response to questions about the atomic bomb’s impact on her work. Historical records often treat scientists’ reactions to Hiroshima and Nagasaki in abstract terms, but Dr. Blau’s account revealed the deeply personal reckoning that many researchers faced – the horrible realisation that the same physics that created beautiful “disintegration stars” in photographic emulsions could incinerate entire cities. Her evolution from pure scientific curiosity to ethical consciousness offers a powerful lens for understanding how scientists contend with the moral implications of their discoveries.

Gaps remain in the historical record, particularly regarding her personal relationships and the informal networks that sustained her through decades of displacement. While she spoke movingly about the intellectual community at the Vienna Radium Institute and her correspondence with fellow refugee scientists, the full extent of these relationships – and their role in preserving and transmitting scientific knowledge across borders – deserves deeper investigation. The contested nature of Nobel Prize decisions in the early 1950s also leaves room for ongoing debate about whether the committee’s assessment of her contributions was scientifically sound or influenced by institutional biases of the era.

Perhaps most remarkably, Dr. Blau’s story illuminates how little has changed in some fundamental aspects of scientific careers, even as much has transformed. Her struggles with work-life balance, institutional discrimination, and the challenge of maintaining research momentum during career interruptions echo the experiences of countless women scientists today. Yet her pioneering use of photographic techniques presaged our current era of big data and machine learning in physics – she was, in many ways, the first physicist to confront the challenge of extracting meaningful patterns from overwhelming amounts of visual information.

The parallels between her experience of political persecution and contemporary threats to academic freedom are particularly sobering. When she warned that “the window between the first warning signs and complete catastrophe can close very quickly,” she spoke with the authority of someone who had lived through such a collapse. Her advice to young scientists – to build international networks, maintain intellectual independence, and never assume safety – resonates powerfully in an era when authoritarianism is once again threatening scientific institutions worldwide.

As I reflected on our conversation, I was struck by how Dr. Blau’s legacy extends far beyond her technical contributions to particle physics. She embodied a particular kind of scientific courage – the willingness to pursue difficult questions with limited resources, to persist through isolation and displacement, and to rebuild again and again when circumstances destroyed her work. Her story reminds us that scientific progress depends not only on brilliant insights and sophisticated equipment, but on the human capacity for resilience, curiosity, and hope.

In an age when we celebrate the democratisation of scientific knowledge through global collaboration and digital communication, Dr. Blau’s experience offers both inspiration and caution. The same technologies that make modern physics possible also make scientific communities more vulnerable to disruption. The international networks that she valued so highly – and that proved so crucial to her survival – require constant nurturing and protection.

Her final words stayed with me: “The particles don’t care about our human struggles with recognition or priority or prejudice. They simply follow the laws of physics, leaving their tracks for anyone clever enough to detect them.” In this observation lies both the profound democracy of scientific truth and the enduring challenge of ensuring that all curious minds – regardless of gender, ethnicity, or political circumstance – have the opportunity to pursue that truth.

Dr. Marietta Blau (1894-1970) spent her career making the invisible visible. In doing so, she not only advanced our understanding of the fundamental structure of matter, but also illuminated the human dimensions of scientific discovery – the persistence required, the communities that sustain us, and the courage needed to continue seeking truth even when the world seems determined to silence our questions.

Who have we missed?

This series is all about recovering the voices history left behind – and I’d love your help finding the next one. If there’s a woman in STEM you think deserves to be interviewed in this way – whether a forgotten inventor, unsung technician, or overlooked researcher – please share her story.

Email me at voxmeditantis@gmail.com or leave a comment below with your suggestion – even just a name is a great start. Let’s keep uncovering the women who shaped science and innovation, one conversation at a time.

Editorial Note: This interview is a dramatised reconstruction based on extensive historical research into Dr. Marietta Blau’s life and work. While grounded in documented facts about her scientific contributions, personal circumstances, and the social context of her era, the dialogue and specific responses represent an interpretive reconstruction of how she might have reflected on her experiences and legacy. Direct quotes and personal perspectives attributed to Dr. Blau in this piece are fictional, created to illuminate her remarkable story and its contemporary relevance. Readers interested in the historical record are encouraged to consult primary sources and scholarly works about her pioneering contributions to particle physics.

Bob Lynn | © 2025 Vox Meditantis. All rights reserved. | 🌐 Translate