Almost lost to history, these toys quite literally put quantum mechanics at one’s fingertips. In episode 35, Jean-François Gauvin from Université Laval in Canada discusses how he came to understand the purpose and value of unique toy blocks that ended up on his desk at Harvard University in 2014 as the director of the Collection of Historical Scientific Instruments (CHSI). His article “Playing with Quantum Toys: Julian Schwinger’s Measurement Algebra and the Material Culture of Quantum Mechanics Pedagogy at Harvard in the 1960s” was published in March 2018 in Physics in Perspective.

Playing with Science History - Jean-François Gauvin
Playing with Science History - Jean-François Gauvin
Playing with Science History - Jean-François Gauvin Playing with Science History - Jean-François Gauvin
@rwatkins says:
Ryan and I were both trained in instructional systems, the discipline of analysing, designing, developing, implementing, and evaluating materials for use in education and training. Given this, we wondered if Papaliolios’ quantum toys failed to catch on not because they didn’t work, but rather because people didn’t know how to make use of them for teaching – and learning – quantum mechanics.
@rwatkins says:
“Tinkers” – or “tinkerers” – have been applauded and derided in nearly equal measure since long before the American author and musician Paul Harding published an award-winning novel of the same name in 2009. Originally a reference to door-to-door tinsmiths who mended kettles, pots, and pans, the term today is as likely to conjure inexpert dabblers as it is ingenious – if not eccentric – innovators. Since Jean-François began to first make sense of Papaliolios’ quantum toy cubes by playing around with them, Doug and I were curious to learn how historians of science go about figuring out the purpose of enigmatic objects such as the quantum toys.
@rwatkins says:
Los Angeles, where I live, is infamous for its obsessive “car culture.” So, it’s little surprise that the region has at least three auto museums recognized as among the best in the United States. My favorite, though, is the unassuming Automotive Driving Museum. Despite its relatively modest collection of vehicles, the museum is unique in that, each Sunday, staff roll vehicles out from the garage and invite visitors to drive them around town. After sharing this story, I asked Jean-François why museums don’t generally embrace the idea that ongoing use might actually enhance the public’s interest and understanding of science and technology, as well as their impact on our past, present, and future.
@rwatkins says:
“The subject is born from the object.” This epigraph – by French philosopher Michel Serres – opens the article “Thing Theory,” published in 2001 by the critical theorist, Bill Brown. In it, he argues that an “object” becomes a “thing” when it stops working in the way that it was originally designed to. So we asked Jean-François whether historians of science are equally as interested not just in how scientific instruments were used, but also in how they are maintained and repaired over time.
@rwatkins says:
Having been tasked with identifying which parts of its bombers should be reinforced with armor, the Hungarian mathematician Abraham Wald delivered eight secret memoranda to the US military in 1943. Wald reasoned that planes which didn’t return from their missions must have sustained fatal damage to their most vulnerable components, and so advocated armoring places where bullet holes weren’t found in surviving aircraft – their engines. Here, Jean-François explains how wear and tear on scientific instruments can yield important insights into just how those objects were used in the first place.
@rwatkins says:
The most recent data from the Association of Science-Technology Centers indicate that attendance at science centers and museums increased from 81 million visits in 2013 to 120 million in 2016. Nevertheless, scientific instruments can present difficulties to museum curators, since the purpose of such objects might not be intuitive to visitors, as Jean-François discusses next.
@rwatkins says:
With more than 20,000 scientific objects in Harvard’s collection, Ryan and I asked Jean-François what it was about the quantum toys that drew – and kept – his attention for so long. We’ll hear what he had to say about this question after this short break.
@rwatkins says:
The quantum toys aren’t just a peculiar anomaly from the 1960s, but rather are tied to a project at Harvard University, aimed to reform the teaching of physics and science more broadly as Jean-François explains next.
@rwatkins says:
As mentioned earlier, Papaliolios’ quantum cubes are inscribed with symbols used to describe various quantum states. These symbols, known as Bra-ket notation, were introduced in 1939 by the theoretical physicist, Paul Dirac, for whom the science library at Ryan and my alma mater, Florida State University, is named. So, we wondered how Jean-François was able to make sense of these brackets, numbers, and arrows.
@rwatkins says:
In his article, Jean-François writes that Schwinger’s aim in teaching was to completely rethink and reconfigure the basis on which quantum mechanics was founded. Doug and I were interested in hearing how the topic was most typically taught in the 1960s, and also what Schwinger’s new approach involved.
@rwatkins says:
Leigh: Next, Ryan and I were curious to learn how the cubes — which you can see at: — were intended to be used in the classroom, as well as how they were received by students.
@rwatkins says:
We began our conversation with Jean-François by asking how it was that the cubes ended up on his desk at Harvard, and how he came to recognize their relevance in teaching quantum physics.
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Websites and other resources

  • Interview with Costas Papaliolios (circa 1987):

  • Freeman Dyson – How difficult was it to understand Schwinger?


Press and blog coverage

IEEE Spectrum | The Reference Frame

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Hosts / Producers

Doug Leigh & Ryan Watkins

How to Cite

Leigh, D., Watkins, R., & Gauvin, J.-F.. (2018, October 30). Parsing Science – Playing with Science History. figshare.


What’s The Angle? by Shane Ivers


Quantum toys photo credit and copyright: Collection of Historical Scientific Instruments, Harvard University

Jean-François Gauvin photo credit and copyright: Samantha van Gerbig


Jean-François Gauvin: The objects stored in museums are resources, the same way that manuscripts are books’ primary source.

Ryan Watkins: This is Parsing Science. The unpublished stories behind the world’s most compelling science, as told by the researchers themselves. I’m Ryan Watkins…

Doug Leigh: And I’m Doug Leigh. A package containing 21 aluminum boxes, forgotten for over 40 years, arrived on the desk of our guest, Jean-François Gauvin, at Harvard University’s collection of historical scientific instruments in 2014. With little more to go on than the cryptic symbols inscribed on them, he had to decide whether these objects warranted inclusion in the museum’s collection. Today on Parsing Science, Jean-François talks with us about his efforts to uncover the provenance, and use, of these objects in teaching students an important principle of quantum mechanics. Here’s Jean-François Gauvin.

Gauvin: Bonjour! I am Jean-François Gauvin. I am professor here at Université Laval in Quebec City, and I have a chair in Museum Studies. As you can hear, so I’m a French-Canadian. I grew up in Montreal and after that, I went to Harvard University, where I was able to do a PhD in history of science. And for basically the past 20 years, I had a foot in both the museum field and also in academia. And my specialty is the history of scientific instruments. At Harvard, I was the director of administration of the collection of scientific instruments over there for seven years, before coming back to my native country, and leading that chair position.

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