Advent Calendar of Science Stories 23: Parity

For the penultimate advent calendar of science stories post, we’ll turn to a great experimentalist with a great biography. This story also appears in Eureka: Discovering your Inner Scientist, but it’s too good not to re-use.

Chien-Shiung Wu was born in china in 1912, at right around the time education of women was first legalized. Her father founded a school for girls so he could teach her, then at around the age of 10 she went off to a boarding school, and then the best universities in the country, where she distinguished herself as one of the finest math and physics students in China. At that time, however, China did not have universities granting Ph.D.’s in physics, so Wu was obliged to travel abroad for further study, earning an invitation to work with Ernest Lawrence at Berkeley. Lawrence had recently invented the cyclotron, and his lab was arguably the finest nuclear physics facility in the world during this period. Wu moved to California in 1936, and never saw her family in China again.

She built up a fine reputation working with Lawrence, and during WWII is believed to be the only Chinese scientist invited to join the Manhattan Project. The physics legend has it that Enrico Fermi was struggling to produce plutonium in significant quantities, and another physicist told him that if he wanted the problem solved, he should “ask Miss Wu.” He did, and she found the problem, which was related to the buildup of an isotope of xenon produced during fission, which tended to absorb the neutrons needed to sustain the reaction. In short order, the plutonium production line was up and running, thanks to Wu’s input. Later in the war, she formally joined the project, and worked on uranium enrichment at Columbia.

After the war, she wound up as faculty at Columbia University, and that’s where the most important part of her story comes in. As part of her research there, she studied beta decay, where an unstable nucleus decays by spitting out an electron; this process had a number of odd aspects compared to the other radioactive decays, which led Wolfgang Pauli to propose the existence of the neutrino, which Enrico Fermi used to put together a theory of the weak nuclear interaction in the mid-1930’s. There were some minor discrepancies between Fermi’s theory and the best experiments at the time, though, which Wu realized had to do with the loss of energy as the electrons made their way out of large chunks of radioactive material. At Columbia, she used new technology developed during the war to deposit extremely thin films of radioactive material, and was able to show that the beta decay energy spectrum did, in fact, agree with Fermi’s theory.

This helped establish her as one of the world’s leading expert in beta decay– her 1965 book on the subject was the definitive reference for decades. So when one of her Columbia colleagues, Tsung-Dao Lee, had a question about the process, it was natural that he would turn to her. She pointed him to the appropriate references, and he and his collaborator Chen Ning Yang pored through them to determine that their crazy idea had not, in fact, been ruled out: that the weak interaction did not need to respect parity symmetry.

“Parity” is the jargon term for a special symmetry in space, and up until 1955 or so, everybody believed that it was an absolute physical law: that switching the signs of all the coordinates describing a physical system should not change its behavior. Lee and Yang had noticed that this didn’t have to be true for the weak interaction described by Fermi and involved in beta decay. This would be a profound change in fundamental physics, and would have experimental consequences for beta decay– a radioactive nucleus undergoing beta decay would be more likely to spit out electrons along the direction of its spin than in the opposite direction.

The asymmetry would be a clear signature of parity violation, but it’s an extremely tricky measurement to make. In fact, Wu was one of the very few people in the world who had any chance of doing it, and this is the reason why I said above that she never saw her family in China again. She and her husband had been planning a trip back there for some time, and were scheduled to leave in mid-1956, but after hearing of Lee and Yang’s results, Wu scrapped the trip to do the parity violation experiment.

This was a tour de force of experimental nuclear physics, requiring the preparation of thin films of cobalt-60 at cryogenic temperatures in a large magnetic field (to align the nuclear spins). In collaboration with a team at the National Bureau of Standards in DC, though, Wu pulled it off, seeing a clear signature of parity violation right around Christmas of 1956, and completing the measurement in early January. It’s a spectacular piece of work. Not too long afterwards, a different team measured a similar violation in the decay of muons, and parity symmetry was definitively dead.

(Lee and Yang got the 1957 Nobel Prize for the theory side of this, but Wu didn’t. There are a whole host of stupid biases behind this gross oversight.)

So, take a moment today to appreciate “Madame Wu,” one of the great inspirational figures in 20th century physics. Her work was essential to transforming our understanding of how the universe operates, and stands as a counterexample to a number of pernicious and stupid ideas about who is capable of doing science at the highest levels.

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(Part of a series promoting Eureka: Discovering Your Inner Scientist, available from Amazon, Barnes and Noble, IndieBound, Powell’s, and anywhere else books are sold.)

(Featured image above from Wilkimedia)

Advent Calendar of Science Stories 22: Hazing

One of the very best books I ran across in the process of doing research for Eureka is The Second Creation: Makers of the Revolution in Twentieth-Century Physics by Robert P. Crease and Charles C. Mann. It’s an extremely detailed treatment of the development of quantum theory, and includes anecdotes that I haven’t seen elsewhere. It also does a fantastic job of showing the essential interplay of experiment and theory through the difficult process of developing quantum field theory, which is often underplayed in popular treatments (which tend to be written by theorists, and often treat experiments as a sort of afterthought). Anyway, I got so much good stuff from Crease and Mann that I can’t let this series go by without using at least one of the new things I learned from their book for the first time.

One of the critical discoveries along the path to QED was what is now known as the “Lamb shift.” Its announcement at the famous Shelter Island conference kick-started the work of both Richard Feynman and Julian Schwinger, and when news of the Lamb shift reached Japan via the popular press, it did the same for Sin-Itiro Tomonaga, who would later share the Nobel with Feynman and Schwinger for developing the theory.

The curious thing about this is that Lamb is mostly known as a theoretical physicist. But the Lamb shift was an experimental discovery, so it couldn’t be named after him because of a prediction of the shift (which was mostly explained by Hans Bethe on the train home from Shelter Island, and the last piece was nailed by the development of QED). So, how did Lamb get his name on this? It turns out to be a by-product of physicists hazing each other.

Lamb was a student of Robert Oppenheimer’s, but didn’t particularly get along with Oppenheimer (according to Crease and Mann). He wasn’t in the first round of scientists invited to join the Manhattan projects for security reasons, but as the effort expanded, Oppenheimer called him in 1943 and asked him to join. Lamb declined the opportunity to work on the bomb, but did join up with the effort at Columbia University to improve radar systems.

The radar project was headed by the great experimental physicist I. I. Rabi, a colorful character in his own right. When Cold War paranoia led to hearings on whether Oppenheimer himself was a security risk, Rabi’s testimony included the line “We have an A-bomb and a whole series of it, and what more do you want, mermaids?” He was a great physicist, an outstanding scientific administrator, and didn’t have much patience for fools.

Anyway, Lamb joined Rabi’s project to make better radar sources, the microwaves for which were generated by magnetrons. Lamb’s primary job was to do calculations about how to improve these, but before he could do that, he had to do pass a test. Crease and Mann quote Rabi saying “We had a rule there that everyone who worked there had to make a magnetron. So that’s how Lamb got introduced to experimental work.”

Making a magnetron helped Lamb realize the potential of the war-driven improvements in microwave technology. Which, in turn, led to the realization that microwave spectroscopy offered a possible way of measuring the energy between the two lowest levels in hydrogen atoms– the first excited state of hydrogen has an exceedingly long lifetime, so you can’t just wait for atoms to decay. But if you prepare a bunch of atoms in that state, you can use microwaves to drive them to another nearby state that decays very quickly, and the energy difference between the emitted photon and the microwaves lets you figure out the energy of the lowest excited state. This was, at the time, a source of argument, as some experiments in the 1930’s had claimed to see a splitting of the two lowest excited states, something that both theory and other experiments claimed shouldn’t be there.

Lamb realized that the magnetrons being built for use in radar had nearly the right frequency to drive the transition in question, and were sufficiently high quality to settle the question once and for all. So, after the war, he recruited a grad student at Columbia, Robert Retherford, to help him do the experiment. And when they finally got results, the microwave frequency they needed had the “wrong” value, by about 10%. This indicated that the splitting suggested by earlier experiments was real, and would demand new physics to explain it. Lamb was so excited by this that he returned to the lab after Retherford had gone home for the night, to make sure he could reproduce the result. According to Crease and Mann, he ended up recruiting his wife as an assistant when it turned out he couldn’t do everything by himself. Happily, the result turned out to be very robust, and physics was never the same after that.

So, Lamb’s story is another reminder of the great things that can come out of stepping a little out of your comfort zone. (And can maybe also be cast as an example of the importance of phenomenology, as in Friday’s post…) One of the greatest revolutions in theoretical physics can be traced in part to the time when a new theorist was forced to act like an experimentalist to gain entry into a wartime radar project.

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(Part of a series promoting Eureka: Discovering Your Inner Scientist, available from Amazon, Barnes and Noble, IndieBound, Powell’s, and anywhere else books are sold.)

(Image of Lamb in a lab taken from this AIP history page.)

(For a more detailed but non-mathematical description of what the Lamb shift is, I highly recommend this blog post.)

Advent Calendar of Science Stories 19: Eucatastrophe

As I endlessly repeat, I’m an experimentalist by training an inclination, so I especially appreciate stories about experimental science. There’s something particularly wonderful about the moment when an experiment clicks together, usually after weeks or months of hard, frustrating work, when things just keep breaking.

Of course, sometimes, breaking stuff can be a Good Thing.

Possibly my favorite story from the development of quantum physics involves just such an occasion, around 1924, when Clinton Davisson and Lester Germer at Bell Labs were trying to characterize a nickel surface by bouncing an electron beam off it. They expected and were seeing diffuse reflection– when they shot a beam straight into the surface, they saw scattered electrons at many different angles away from the vertical, with the number of electrons bouncing off the surface at a particular angle dropping smoothly to zero as they increased the angle.

Then, they broke a bit of their apparatus. Specifically, they cracked something in the vacuum system containing the nickel target, electron beam, and detector. Air rushed in, and oxidized the surface of the nickel. As they wanted to study pure nickel, not an oxide layer, they dealt with this in the traditional manner: by heating their apparatus to drive off the oxide.

When they got their apparatus up and running again, they found that their scattering results had changed dramatically. Instead of smoothly decreasing as they increased the angle of the detector, the signal decreased for a while, then rose to a dramatic peak at an angle of 50-odd degrees, before dropping again. This was unexpected and puzzling, but turned out to be one of the most important experimental results in history. Davisson and Germer didn’t really know what to make of it when they first saw this in 1925, so on a visit to England in 1926, Davisson was shocked to hear Max Born explain his weird results via a fundamental revision of the nature of matter.

Around the time Davisson and Germer began working together, a French Ph.D. student named Louis de Broglie turned in a thesis in which he suggested that electrons should behave like waves. He was motivated by trying to justify Niels Bohr’s quantum model of the atom, and it worked brilliantly for that. Of course, nobody had any direct evidence of electrons behaving like waves, until Born spotted Davisson and Germer’s results. It’s not clear that Davisson and Germer were even aware of de Broglie’s wave theory (Davisson’s a little vague on this in his Nobel lecture). People in Europe certainly knew about it, though, and had started looking for wave behavior of electrons, but Davisson and Germer had scooped them all by accident.

The weird increase in the number of electrons they were seeing at a particular angle is a diffraction effect– the electrons were acting like waves, and at just the right angle, electron waves that reflected off the very first plane of atoms in the nickel arrived at the detector exactly in phase with electron waves reflected off the second plane. These interfered constructively, giving the large peak in the scattered electron intensity. This is a phenomenon that had earlier been demonstrated by the Braggs with x-rays, called “Bragg diffraction” in their honor.

The Davisson-Germer result clearly and unambiguously showed the wave nature of electrons. And it only worked because of the time they broke their apparatus. Their initial results didn’t show any diffraction peaks because their initial nickel surface was made up of zillions of little crystals, all oriented randomly. The diffraction peaks from all the individual crystals occurred at different angles, and smeared together to give the boring result they were seeing at first. When they heated the surface to clean it, though, they overdid things a little, and actually melted the nickel. As it cooled down, it re-crystallized into a much smoother surface, with large single crystals. These were big enough to produce a clear signal.

Davisson went on to share the 1937 Nobel Prize in Physics with George Paget Thompson, who also observed diffraction of electrons in the late 1920’s, in his case by shooting beams of electrons through thin films.

There are a lot of important messages to take away from the Davisson and Germer experiment about the process of science, particularly experimental science– the importance of sharing anomalous results, the fact that revolutionary discoveries can often happen when you’re looking for something else, the importance of being the senior partner in any revolutionary experiment (Germer got left out of the Nobel because the Nobels have always been really bad about that…), etc. The most important one, though, is one to sustain experimentalists through those long days and weeks where everything just keeps breaking: sometimes, breaking your apparatus is the best thing that can possibly happen.

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(Part of a series promoting Eureka: Discovering Your Inner Scientist, available from Amazon, Barnes and Noble, IndieBound, Powell’s, and anywhere else books are sold.)

Method and Its Discontents

Given that I am relentlessly flogging a book about the universality of the scientific process (Available wherever books are sold! They make excellent winter solstice holiday gifts!), I feel like I ought to try to say something about the latest kerfuffle about the scientific method. This takes the form of an editorial in Nature complaining that Richard Dawid and Sean Carroll among others are calling for discarding traditional ideas about how to test theories. Which is cast as an attempt to overthrow The Scientific Method.

Which, you know, on the one hand is a kind of impossible claim. There being no singular Scientific Method, but more a loose assortment of general practices that get used or ignored as needed to make progress. It’s all well and good to cite Karl Popper, but it’s not like philosophy of science stopped once he published the idea of falsifiability as the key criterion– “Pack it up, folks, we’re all done here!” There’s been a ton of activity post-Popper, and if you’re going to take up the defense of SCIENCE against some new generation of barbarians, you need to at least attempt to engage with it(*).

At the same time, though, I have a lot of sympathy for the defenders of method, because the calls to scrap falsifiability are mostly in service of the multiverse variants of string theory. And I find that particular argument kind of silly and pointless. The multiverse idea is ostensibly a solution to the problem of fine-tuning of the parameters of the universe, but I’m sort of at a loss as to why “There are an infinite number of universes out there and one of them was bound to have the parameters we observe” is supposed to be better than “Well, these just happen to be the values we ended up with, whatcha gonna do?” I mean, I guess you get to go one step further before throw up your hands and say “go figure,” but it’s not a terribly useful step, as far as I can see.

I’m probably most sympathetic with the view expressed by Sabine Hossenfelder in her post at Starts With a Bang. After noting that the quest for quantum gravity seems to have gotten stuck, she writes:

To me the reason this has happened is obvious: We haven’t paid enough attention to experimentally testing quantum gravity. One cannot develop a scientific theory without experimental input. It’s never happened before and it will never happen. Without data, a theory isn’t science. Without experimental test, quantum gravity isn’t physics.

[…]

It is beyond me that funding agencies invest money into developing a theory of quantum gravity, but not into its experimental test. Yes, experimental tests of quantum gravity are farfetched. But if you think that you can’t test it, you shouldn’t put money into the theory either.

I’m very much an experimentalist by both training and inclination, though, so of course I find that view very congenial.

I suspect, on some level, this mostly comes down to psychology and the past successes of particle physics. All through the 1960’s and 1970’s, progress at accelerators was rapid and went hand in hand with theory. So people got fixated on accelerators as the solution to every problem. And there’s always been the tantalizing possibility that with just a little more energy, everything will fall into place. And if that’s your expectation, well, then there’s no reason to put all that much effort into phenomenology for experiments other than the next new accelerator.

(There’s also the faintly toxic notion that phenomenology is for second-raters (paraphrasing Dyson paraphrasing Oppenheimer). Which is another of the many pathologies afflicting academic physics…)

In a weird way, I think a loss of momentum for next generation colliders might end up being a good thing for fundamental physics. If the price point for pushing the well-trodden path a few TeV higher is more than we can afford, that will force people to become a little more clever about how they approach problems, and explore a greater diversity of approaches. Because many of the other things you can think about doing to probe exotic physics can be funded from the rounding error in the LHC construction budget.

So, I guess I would say that it’s a little early yet to give up on falsifiability and other traditional methodology. I just don’t really believe we’ve exhausted all the options for testing theories, just because one particular approach has hit a bit of a dry spell. There are almost certainly other paths to getting the information we want, if people put a bit more effort into looking for them.

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That’s one set of reasons why I’ve been a little reluctant to weigh in on this particular argument. About equally important, though, is that this amounts to a game that I’m not all that interested in playing.

In writing Eureka, I tried to avoid using the phrase “the scientific method,” or giving too much detail about how to define science. The four-step process I bang on endlessly about– Looking, Thinking, Testing, and Telling– is very deliberately a cartoonish sort of outline. There’s definitely an element of Popperian falsifiability in the way I talk about Testing, because I am an experimentalist, but the way I use it is vague enough to accommodate some of the alternatives people throw out.

I did that deliberately, because I’m really not interested in exploring the boundary between science and not-science. I’m interested in the stuff in the middle, the broad expanse of stuff well away from the edges, that absolutely everyone will agree is science. I’m more interested in celebrating accomplishment than calling out transgressions. I’d like people to turn their backs on the bickering over the precise location of the boundary, and take a moment to appreciate the awesome spectacle of what’s there in the middle, where the great successes of the past few hundred thousand years sit.

From that standpoint, whether multiverse theories are properly scientific or not is stunningly unimportant. The number of people who will ever deal with questions for which direct experimental tests are so difficult that they might require an alternative standard is vanishingly small compared to the number of people who directly benefit from mundane empirical testing every single day. That, to me, is an idea that’s vastly more deserving of public attention than what standard you use to judge the status of multiverse models.

Which is, of course, why I wrote the book I wrote

Advent Calendar of Science Stories 18: Third Time’s the Charm

The winter solstice holidays are a time for family and togetherness, so building off yesterday’s post about the great Marie Skłodowska Curie, we’ll stay together with her family. Specifically her daughter Irène Joliot-Curie and her husband Frédéric. The Joliot-Curies are possible answers to a number of Nobel Prize trivia questions– only mother and daughter to win, one of a handful of married couples, etc.– but the scientific story about them that I find most fascinating is that their Nobel was for the third thing they did that could’ve earned them the prize, after they just missed out on two other Nobel-worthy discoveries.

Their two near-misses came in 1932. One was a paper they published on some intriguing new radiation originally noticed by Walther Bothe in Germany. Bothe had noticed some odd effects when alpha particles from polonium hit light elements, and the Joliot-Curies expanded on his experiments showing that the new radiation had unusual penetrating power, and knocked protons with fairly high energies out of materials containing hydrogen. The new radiation wasn’t affected by an electric field, so it was initially believed to be a new type of gamma rays (that is, high-energy light), but the Joliot-Curie results were hard to fit with that theory.

In England, James Chadwick heard of the Paris results, and immediately realized the significance, because he and his boss, Ernest Rutherford, had been looking for it for almost twenty years. The new radiation wasn’t an unusual gamma ray, but a new, neutral particle with about the mass of a proton. Chadwick quickly threw together an experiment– he was the assistant director of the Cavendish Laboratory, and thus had ample resources to command– and within a few weeks had demonstrated the existence of the neutron. This won him the 1935 Nobel Prize in Physics.

As if that weren’t enough, 1932 also saw the Joliot-Curies miss out on the discovery of antimatter. They were photographing particle tracks to study the effects of alpha particle bombardment of various targets, and in May produced some very clear photos showing particles that appeared to have the same mass as an electron, but curved in the wrong direction in response to a magnetic field. As the tracks left by the particles don’t indicate the direction of motion, they interpreted this (with some input from Niels Bohr) as ordinary electrons moving in the opposite direction from their particle beam, presumably produced by collisions in the back wall of their detection chamber.

Of course, there’s another way to produce such tracks, namely a particle going in the right direction, but with the opposite charge. The Joliot-Curies didn’t consider this, as no such particle was known, but Carl Anderson at Caltech did, and in August of that same year produced the famous photograph confirming the existence of the positron, the antimatter equivalent of the electron. This got Anderson half of the 1936 Nobel Prize in Physics.

You would think, then, that 1935 would’ve been a real bummer of a year for the Joliot-Curie family, watching Chadwick win a Nobel Prize that could’ve been theirs, had they correctly interpreted their results. Luckily for them, though, in the intervening three years they had done the work that would secure them their own prize, in Chemistry, that very same year. In 1934 they showed that the same sort of experiments that produced the neutrons they might’ve discovered, namely bombarding light elements with alpha particles, also produced unstable isotopes of other elements. They demonstrated that they could make radioactive nitrogen from boron, radioactive phosphorus from aluminum, and radioactive silicon from magnesium.

This discovery of “artificial radioactivity” richly deserved the Nobel Prize they won for it, because it opened a huge range of new experiments. Rather than spending weeks distilling naturally occurring radioactive elements out of pitchblende ore, the way Marie and Pierre Curie had, physicists could use particle bombardment to create new isotopes. Given the right projectile and the right target, you can make almost anything you might care to study. Modern nuclear physics would be impossible without the Joliot-Curie’s discovery. And if you like your physics to have practical applications, well, they have that, too: most of the isotopes used in nuclear medicine are manufactured in accelerators, using a version of the Joliot-Curie process.

So, the Joliot-Curies had a fascinating career in science, and probably deserve to be more widely known. As great as their contributions to physics were, the most interesting part of their story might be what came after– when France fell to the Nazis in 1940, Frédéric stayed in Paris, where he used his physics work as cover for manufacturing radios and chemicals for the french Resistance. Irène was in Switzerland for much of the war, being treated for tuberculosis, but made several trips to Paris to visit her husband and children, eventually taking the children to safety in Switzerland in 1944. The photo I grabbed from Wikimedia for the featured image doesn’t have a specific date, just “1940’s,” and I haven’t tried too hard to find a more specific attribution, because it’s sort of romantic to imagine that it was taken during one of her wartime visits.

(And, of course, their whole relationship is a good story– neither appeared especially brilliant as students, and they seemed an unlikely match when he first started working at the Radium Institute. Marie Curie was sufficiently skeptical that she insisted that control of the Institute should pass to Irène alone. It all worked out pretty well, though… Somebody should totally make a movie about these two.)

Anyway, take a moment to celebrate the Joliot-Curies, whose work is essential for everything from basic science to cancer therapy to smoke detectors. They’re also a great demonstration of the importance of persistence in science– if you miss out on your first chance at a Nobel, well, just keep at it, and maybe everything will work out in the end…

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(Part of a series promoting Eureka: Discovering Your Inner Scientist, available from Amazon, Barnes and Noble, IndieBound, Powell’s, and anywhere else books are sold.)

Advent Calendar of Science Stories 17: Kickstarter in 1921

There’s no way I could possibly go through a long history-of-science blog series without mentioning the great Marie Skłodowska Curie, one of the very few people in history to win not one but two Nobel Prizes for her scientific work– if nothing else, Polish pride would demand it. She made a monumental contribution to physics through her work on radioactivity (and through being nearly impossible to kill– while her work on isolating radium made her ill for many years, she outlived an amazing number of her assistants…), and there are a lot of great stories about her.

This series is partly intended as a way to share things I wasn’t able to fit in the book, though, and in reading up on her, I ran across a story I had never heard before. It turns out that along with discovering new elements, Marie Curie helped invent Kickstarter.

The Curies were never especially well funded, by the standards of other countries, and most of their ground-breaking work on isolating polonium and radium was done in an abandoned shed in a courtyard at the École Normale Supérieure in Paris (the other space they had access to was too small to process the quantity of material needed to handle to isolate the extremely rare elements they were seeking). The German chemist Wilhelm Ostwald visited them, and described it as “a cross between a stable and a potato cellar.” This was compounded by the fact that the Curies refused to patent the process for isolating radium, and thus never got any profit from what became a huge industry.

Things got somewhat better after the two Nobel Prizes (the first shared with Pierre and Henri Becquerel in 1903, the second on her own in 1911), and Curie was able to set up a Radium Institute for the study of radioactive materials. This was still not especially lavish, though, France in the wake of WWI not being in the best shape, and many of her competitors did much better.

In 1920, Curie granted a rare interview (she was naturally pretty reserved, and a possible affair with Paul Langevin had been a huge scandal ten years earlier (leading to the “don’t feed the trolls” letter from Einstein that has been shared so much recently), so she particularly distrusted the media) to an American journalist and socialite, Marie Mattingly Meloney aka Mrs. William Brown Meloney, aka “Missy.” Meloney’s profile in the women’s magazine The Delineator helped firmly establish the popular image of Curie:

The door opened and I saw a pale, timid little woman [Curie] in a black cotton dress, with the saddest face I had ever looked upon. Her kind, patient, beautiful face had the detached expression of a scholar. Suddenly I felt like an intruder. My timidity exceeded her own. I had been a trained interrogator for twenty years, but I could not ask a single question of this gentle woman in a black cotton dress. I tried to explain that American women were interested in her great work, and found myself apologising for intruding upon her precious time.

In the course of the interview, Meloney asked Curie what she would want more than anything else, and the answer was “a second gram of radium for my research,” because the Radium Institute had only one gram in total. Shocked by this poverty of resources, and sensing a good story, Meloney declared that she would see to it that Curie got her extra radium.

This was not by any means a trivial committment, as a gram of radium ran about $100,000 in 1920. But Meloney was a force to be reckoned with, and launched a subscription campaign, the Marie Curie Radium Fund, to collect donations from the women of America to buy radium for Curie, starting with the famous profile above. In a matter of months, they had raised the money, and also arranged a massive publicity tour of the US, during which Curie accepted the radium from President Warren Harding in a ceremony at the White House in October 1921. The story goes that Curie almost backed out the night before, when she discovered that the radium was to be given to her personally, and insisted that the documents be re-drawn to give it to her Institute instead.

(This story mostly gets told pretty straight, though there are versions such as this Google Books result that put a somewhat more cynical spin on it. Curie certainly wasn’t a fan of public honors and publicity, though– she declined the Legion of France when it was offered shortly before her trip to America, and did as much as she could to beg off public appearances in the US, sending her daughters in her stead to accept some of her honorary degrees.)

So, among Curie’s many important discoveries, we can add to the list “crowd-funding pioneer.” The campaign also eventually raised funds to help establish a second Radium Institute in Warsaw (Curie always worked to support her native Poland– polonium was somewhat unique in being named for a country that didn’t technically exist at that time…), and she benefitted enormously from smallish donations from lots of international sources. This story can also stand as a demonstration of the importance of telling your scientific results to others, even including foreign journalists…

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(Part of a series promoting Eureka: Discovering Your Inner Scientist, available from Amazon, Barnes and Noble, IndieBound, Powell’s, and anywhere else books are sold.)

(The AIP has a very nice online biography of Marie Curie that you can check out, with lots of additional resources. I also recommend Veronique Greenwood’s story about her great-aunt who discovered francium while working at the Radium Institute under Marie and later her daughter Irène Joliot-Curie, about whom more later…)

Advent Calendar of Science Stories 16: Undergraduate Research

“You wanted to see me, Herr Professor?”

“Hans! Yes, come in, come in. Just going over the account books. Frightful amount of money going out of this place.”

“Well, radium is expensive…”

“Ha! Oh, and speaking of which– here’s one of the sources. Absent-mindedly dropped the fool thing in my pocket last night when I locked up. Terrible habit, I really must work on that. Had a drawer full of the things in Montreal…”

“Thank you. And you wanted to see me about…?”

“Oh, yes. We have a new student, Hans, and I’d like you to put him to work on the gold foil project.”

“Shouldn’t he have his own project, sir?”

“Not yet, Hans, this one’s an undergraduate. Very keen fellow, though. Seems to show some promise.”

“Very well. What shall we have him do?”

“Well, first see if he has any aptitude for counting scintillations. If he does, you might have him check for background sources. Check for stray alphas on the same side of the foil as the source, that sort of thing.”

“Isn’t that futile? We know there won’t be any backscattered…”

“True, true. But then, it’s a valuable introduction to the frustrations of research, no? Anyway, you never know until you look.”

“I suppose.”

“Right, then, that’s settled. He’s in the second-floor common room, or was the last I knew. Come along, and I’ll introduce you to young Mr. Marsden…”

I’m running short of days in which to complete all the stories I’d like to tell in this series, so I’m jumping forward almost a hundred years, though staying in England. This totally imaginary scene is set in Manchester around 1908. The talkative fellow in the above bit is Ernest Rutherford, carrying on an imaginary conversation with his post-doc, Hans Geiger.

Rutherford had recently won a Nobel Prize for his work on radioactivity (in Chemistry, ironically, given his famous dismissal of sciences other than physics), and was studying the interactions between the alpha particles and other stuff, specifically a thin foil of gold. They were looking at the deflection of alphas as they passed through the gold, in hopes of learning about the structure of matter. This turned out to be one of the most important experiments in the history of physics, in a very unexpected way. Rutherford hired on an undergraduate student named Ernest Marsden, then 20 years old, and assigned him to the gold foil project.

The detector they were using consisted of a piece of glass coated with zinc sulfide, that would make faint flashes of light when an alpha particle struck. These were viewed through a telescope in a dark room, and it was a very taxing measurement, requiring a long period to allow the eyes to adjust to the dark, and the focus needed to count these scintillation flashes effectively was difficult to maintain. Rutherford himself famously had no patience for it, and the tedium of the counting probably helped inspire Geiger to invent to famous counter that bears his name, as a less irritating means of measuring particle flux. The ability to effectively use these detectors was highly prized, and during Rutherford’s time running the Cavendish laboratory, entering students were rigorously screened for scintillation-counting aptitude.

Either because he was good at it, or because they wanted to get him some practice, Rutherford and Geiger set Marsden to looking for flashes from alpha particles on the “wrong” side of the foil. According to the atomic models of the time, there shouldn’t’ve been any to see, as the high-energy alpha particles should’ve blasted right through the gold. To everyone’s shock–Rutherford famously compared it to an artillery shell bouncing off tissue paper– Marsden saw alpha particles. Lots of them.

The only way this can happen is if the vast majority of the mass of the atom is concentrated in a tiny nucleus at the center, something Rutherford quickly realized, and he introduced the solar-system sort of atomic picture that is the standard cartoon image these days. Of course, such an atom is utterly impossible according to the rules of classical physics, and fixing that problem led Niels Bohr to introduce his quantum model, and physics changed forever.

And it all came out of an undergraduate research project.

Marsden went on to have a very successful career in science, as a professor and administrator in Rutherford’s home of New Zealand (some sort of conservation of Ernests involved, perhaps…). Unlike a fair number of other scientists who made revolutionary discoveries at a very young age, he didn’t go nuts and start advocating wacky pseudoscience. Possibly because nobody ever won a Nobel for the discovery of the nucleus, something that seems kind of incredible, but comes down to weird Nobel politics.

Anyway, the lesson to take from this is that great discoveries sometimes come from unlikely places. Some project may seem unpromising based on the best models you have, but you never really know until you try it…

————
(Part of a series promoting Eureka: Discovering Your Inner Scientist, available from Amazon, Barnes and Noble, IndieBound, Powell’s, and anywhere else books are sold.)

(Rutherford was a fascinating character, and I recommend Richard Reeves’s short biography, and also Brian Cathcart’s The Fly in the Cathedral about the Cavendish laboratory under Rutherford’s direction.)

Eureka: Waldo at the Galaxy Zoo

Over at Medium, they’ve published a long excerpt from Eureka: Discovering Your Inner Scientist, that gives a good flavor of what the book’s really like. It’s about how the process for solving hidden-object games like the classic Where’s Waldo books is comparable to the process used by Henrietta Leavitt to revolutionize our understanding of the universe:

There are multiple web sites and academic papers devoted to computer algorithms for locating Waldo within Handford’s drawings, using a variety of software packages, and these are impressively complex, running to hundreds of lines of code and invoking sophisticated image-processing tools. Child’s play, this is not.

The essential element of these books is pattern matching, looking for a particular arrangement of colors and shapes in the midst of a distracting field. There are numerous more “adult” variations on this game, some of them obvious, like the image-based “hidden object” puzzle games Kate sometimes plays for relaxation, or the classic video game Myst. Other classes of games may not seem directly connected, but use the same pattern-finding tricks, such as solitaire card games like Free Cell (my own go-to time-waster) or colored-blob-matching games like the massively popular Candy Crush. In all of these, the key to the game is spotting a useful pattern within a large collection of visual data. This is a task at which human brains excel, and millions of people do it for fun and relaxation.

The unmatched ability of humans to spot meaningful patterns in visual data is the basis for many scientific discoveries, in all sorts of different fields.

This is cut down from Chapter 4 of the book (which adds the story of Jocelyn Bell’s discovery of pulsars), but keeps the core structure of the chapters: a story about an everyday activity, an then an analogy connecting that to a great scientific discovery. It also ends with some encouragement to go out and put your inner scientist to work, but you’ll need to read the whole piece to get that…

Advent Calendar of Science Stories 15: An Unusual Resume

“…and take care that all the signatures go in the right way round, eh, James? I was able to soothe Mr. Dance last time, but if another copy comes back to be rebound, M. de la Roche will put you out.”

“Yessir.”

“A little more care, there’s a good lad. Run home, now, we’ll see you in the morning.” The apprentice scurried off.

The journeyman bookbinder checked again that the shop door was securely closed, pulled his coat tighter against the March chill, and turned to make the short walk to his own meagre rooms. Stuffing his hands in his pockets, he felt the folded pamphlet advertising tonight’s lecture at Mr. Tatum’s house, and sighed.

What to do? Tatum’s house had always been a bright spot, but it seemed less grand compared to the spectacle of the Royal Institution. And he could scarce afford the shilling– Robert might lend him another, but he owed his brother so much already… The money might better be spent on buying another sheet of copper, to make a bigger battery in the tiny cramped space set aside for his apparatus…

Or, given that he seemed doomed to a career in bookbinding, perhaps he ought to save it up for more practical purposes. Not that it was a bad life, but running de la Roche’s shop allowed so little time for other pursuits, and there were so many questions he wanted to explore. He thought longingly again of his electrical notes, so carefully bound and sent off, for so little gain…

As he turned the corner toward his lodging, he slowly became aware of an oddity. The sounds of the street were… off. The normal chatter was more hushed than it should be, even for early evening. It wasn’t hard to spot the cause– a carriage, of all things, standing in the street, with a tall fellow in a footman’s outfit standing by it, talking up to the driver. Not at all the sort of thing one expected to see in Weymouth Street.

The coachman said something, and the footman turned “Ah! There you are at last!”

“Mr. Jenkins! What brings you to my neighborhood?”

“A carriage, obviously. But more importantly, you. I have a note for you from Sir Humphrey, who asks that you come to see him first thing tomorrow.”

“Regarding… what?” He took the paper Jenkins proffered, hands trembling slightly, more from hope than the chill.

“I can’t really say. But, strictly in confidence, there was a dreadful row at the Institute. Cartwright, the junior assistant, came to blows with one of the instrument makers. Knocked over a table and smashed a couple of alembics.”

“Really?”

“Truly. That’s the third time, and the most expensive. He’s been sacked. Turned out in the street this very afternoon, most of his goods confiscated to cover the damage.”

“I see.” A summons from Sir Humphrey, an opening at the Royal Institution? “My deepest thanks, Mr. Jenkins. I shall call at Albermarle Street first thing in the morning.”

“Right, then. We’ll see you tomorrow.” Jenkins climbed up beside the coachman. The coachman shook the reins, and the carriage headed off down the street, scattering a small crowd of gawking children. “A good night to you, Mr. Faraday,” Jenkins called, and then they rounded the corner and were gone.

I’ve gone away from the fictionalized thing a bit as we move toward more recent history, as it’s much easier to go wrong when people have more detailed knowledge of the era. I like this story enough, though, that I couldn’t really resist, though I’m sure I’ve gotten all sorts of things wrong about Regency London.

Anyway, today’s story is an allusion to one of the more unusual job applications of all time, which launched the career of one of the greatest scientists of the 19th century, Michael Faraday. Faraday came from a poor family, and received little formal education beyond learning to read, but had an insatiable curiosity about the world and an impressive drive to improve himself.

Moving up in British society in the early 1800’s was an exceedingly difficult thing to do, though. Faraday was apprenticed to a bookbinder at 14, where he learned a good deal about science by reading books that passed through the shop. He also saved and borrowed money to attend some of the public lectures that were popular in that day, and conducted experiments of his own in a bit of space set aside in the back of the shop run by his first boss. But after the completion of his apprenticeship, his employer as a journeyman was less supportive, and he seemed to have a dreary career ahead of him in the trade.

The turning point for Faraday came when a customer gave him tickets to see a set of four lectures by Sir Humphrey Davy, one of the most celebrated scientists in Britain. Faraday took careful notes, and in his spare time bound these up and sent them to Davy as a demonstration of his interest, and inquiring whether it might be possible to get a job as one of the assistants at the Royal Institution. Davy’s own origins were not terribly exalted, so he responded kindly, but didn’t have a position to offer; Faraday clearly made a strong impression, though, because when one of the assistants was dismissed for brawling, he sent for Faraday and hired him on.

Davy was justly famous for his chemical and electrical discoveries, but in later years, it was said that his greatest discovery was Faraday, who rose to become one of the greatest scientists of the Victorian era. He was meticulous and endlessly curious, and made important discoveries in chemistry, optics, thermodynamics, and others. By far his most important contribution, though, was his discovery of the connection between electricity and magnetism, which is what allows you to read this story today. Faraday’s law of electromagnetic induction shows that a changing magnetic field will induce current to flow in a loop of wire, and is the basis for the vast majority of the electrical power generation that drives modern technology.

Faraday’s story is important for a couple of reasons. First, it indicates the contingent nature of a lot of science– had Faraday not been given tickets to Davy’s lecture, and had Davy not been exactly the right person to be moved by Faraday’s bound notes (an earlier appeal to Joseph Banks at the Royal Society did not fare well), the history of science might be very different. It’s also a reminder of how little is actually required to do science– a self-taught apprentice bookbinder in the highly stratified society of Britain in the 1800’s was able to make discoveries that have utterly transformed society, through careful observation and meticulous testing.

Anybody can do science, regardless of race, gender, or class. All it takes is curiosity about the world, dedication to pursuing answers, and a willingness to take the occasional chance in pursuit of a career.

————

(Part of a series promoting Eureka: Discovering Your Inner Scientist, available from Amazon, Barnes and Noble, IndieBound, Powell’s, and anywhere else books are sold.)

(Faraday’s life story really is fascinating, and I recommend Alan Hirshfeld’s biography if you’d like to know more…)

Eureka: Signing, Q&A, Canadian Review

A few items for Sunday morning:

— First and foremost, in just a few hours from now, I’ll be signing books at the Open Door. If you’re in Quebec or central Pennsylvania, you better leave now; Boston or NYC, you can have a cup of coffee first. Farther than that, you might try calling them around 11am ET to see if they’ll ship you one…

— The Albany Times Union did a short Q&ampA with me about the book. This ran Thursday, apparently, but didn’t show up on Google, so I only found it this morning when I went to the Times Union site directly.

— There’s a good, thoughtful review in the Winnipeg Free Press from a professor at the University of Winnipeg. Which says some nice things (“Drawing on a wide variety of examples and stories, many from sports and pop culture, Orzel writes in a crisp, clear, and entertaining style”), and also fairly points out the limits of the argument I’m making. I’m pretty happy with this.

(Which makes it really unfortunate that the mere name of the paper instantly earworms me with the Weakerthans’ “One Great City”. No, brain! Winnipeg is nice! We likes them, Precioussss…)