Near 1920,
STEM questions aplenty.
Scientists seek for the sun in the sky
A chemical make-up.
To do this, they take up
Their spectroscopes, which will allow them to spy
At the atomic
Scale, info re: cosmos,
Deduced from a pattern of typical lines.
Each element will show
Fingerprint pattern, so
From scope’s results, find the source of sun’s shine.
Opinion popular
For data ocular:
Iron composes the overhead sun.
“Ihron?” “Yes, irhon.”
“Iht’s chlearly juhst ironh;
Whe loohked aht khey lhines frohm hour spechtroscope’s rhun!”
Enter Payne, student,
First viewed as imprudent
For noting the excess of H in these lines.
“Hydrogen fits
Pattern known. It’s
The likeliest culprit– not iron– for these spectral signs.”
Solved, central mystery?
Payne’s place in history
Set by the finding? Two obvious “Yesses”?
No! The reception
Is cold; no exceptions.
Some years will pass, ‘ere both are deemed as successes.
Hydrogen’s place in the
Realms of astronomy,
Now well-established: identity main
As stars’ key constituent.
No more diminuent
Should be her story: Cecilia Payne.
***
As with last week’s essay, this is a longer poem that tells one of my favorite stories from scientific history. Cecilia Payne-Gaposchkin was an astronomer who lived from 1900-1979, and one of her stories is wonderfully told in David Bodanis’s phenomenal book E=mc2, the prose of which inspired this particular poem. Despite studying science for all of my post-college academic path, it was not until my teaching career that I encountered Payne’s name (thanks to Bodanis’s book).
Near 1920, /
STEM questions aplenty. /
Scientists seek for the sun in the sky /
A chemical make-up.
Cecilia Payne pursued her doctoral degree at Harvard in the early 1920s, during a time when the theory of quantum mechanics was overturning scientists’ understanding of matter and energy. “STEM questions aplenty” were thus under investigation in various labs and universities. One such question involved the chemical composition of the sun (which elements were present?).
To do this, they take up /
Their spectroscopes, which will allow them to spy /
At the atomic /
Scale, info re: cosmos, /
Deduced from a pattern of typical lines. /
Each element will show /
Fingerprint pattern, so /
From scope’s results, find the source of sun’s shine.
Several experiments around this time revolutionized scientists’ understanding of the quantum behavior of matter. One key instrument was the spectroscope; Robert Bunsen (of “Bunsen burner” fame) and Gustav Kirchoff had shown a few decades earlier how it could be used to explore the line spectrum of a given element.
Spectroscopes reveal the particular wavelengths (and thus energies) of light absorbed or emitted by an element; the “lines” of line spectra refer to the wavelengths in question at which they are seen. These data in turn rely on the electronic structure of each element: its number and arrangement of electrons.
When I teach the topic of line spectra in General Chemistry, we look at the hydrogen atom’s line spectrum in detail. Any time a sample of hydrogen is caused to emit (release) energy, the four lines in the visible region of the electromagnetic spectrum (the colors we can see with our own eyes, rather than light that requires using a laboratory instrument) will be at the same four wavelengths: 410 nanometers, or nm (violet), 434 nm (blue), 486 nm (indigo), and 656 nm (red). (In teaching, I contrast this quantization with the “continuous” spectrum of white light, the ROYGBIV rainbow, so we have a sense of why these findings would’ve been so unusual to scientists at the turn of the twentieth century.) Each element behaves differently, so that a characteristic line spectrum becomes a fingerprint for the element in question, just as these four lines are the fingerprint for hydrogen.
For the scientists who were interested in understanding the sun’s chemical makeup and behavior, observing the sun through a spectroscope would reveal a particular line pattern and thus the elements involved: the “source of sun’s shine.” They were interested in the spectroscopic behavior of the elements that were causing this astronomical behavior: “at the atomic/ [s]cale, info re: cosmos.”
Opinion popular /
For data ocular: /
Iron composes the overhead sun.
At the time of these studies, the prevailing theory was that the sun was composed in large part of iron. From the data that scientists could observe in the visible spectrum (“data ocular”— a bit of a stretch to serve the rhyme), they discerned lines that they attributed primarily to iron, in adherence with the theory.
“Ihron?” “Yes, irhon.” /
“Iht’s chlearly juhst ironh; /
Whe loohked aht khey lhines frohm hour spechtroscope’s rhun!”
These lines highlight the ingenious way that Bodanis contextualized Payne’s story, by presenting spectroscopic information as different series of letters and words and showing the reader how it would be possible to misinterpret them, if you were already sure of what you expected to see.
In the chapter of E = mc2 entitled “The Fires of the Sun,” which tells Payne’s story in the most detail, Bodanis writes:
“An analogy can show what Payne did… If [the lines] came out, for example, as: ‘theysaidironagaien,’ you’d parse it to read ‘theysaidironagein’ and there’d be no need to worry too much about the odd spelling of agaien…
But Payne kept an open mind. What if it was really trying to communicate tHeysaidironagaien [?]”
From David Bodanis’s E = mc2 ; note the letters in bold in each interpretation!
I built on Bodanis’s method for showing these spectroscopic anomalies in drafting this poem. Here, I took particular advantage of the letter h: its ability to be silent or to have only a minor effect on pronunciation, depending on where it shows up in a word. These lines emphasize that in this hypothetical conversation among hypothetical scientists at the time, if they were determined not to observe “h,” they could’ve plausibly denied it (the “resolved” conversation would read as: “Iron?” “Yes, iron.” / “It’s clearly just iron; / We looked at key lines from our spectroscope’s run!”).
It does indeed take some considerable imagination to ignore the strange spellings and odd pronunciations… but that is part of this story. As the previous post used a break in a rhyme scheme to note Perkin’s findings, the unexpected and incorrect spellings here are intended to emphasize a moment of anomaly in scientific history: something is clearly amiss, and it requires some contemplation to process and understand.
Payne carefully considered the data and proposed that, instead, the element hydrogen was responsible for these main experimental findings.
Enter Payne, student, /
First viewed as imprudent /
For noting the excess of H in these signs. /
“Hydrogen fits /
Pattern known. It’s /
The likeliest culprit– not iron– for these spectral lines.”
Over the next portion of the poem, the excess of the letter h is directly tied to the excess of the element hydrogen, represented via the chemical symbol H.
Scientists were likewise determined not to see “H” (the chemical element H, hydrogen), despite the evidence that Cecilia Payne presented for hydrogen’s existence in these solar spectra.
Payne was a student at the time; it was and is particularly challenging in the structure of scientific graduate education to defy existing knowledge without the support of one’s advisor and other renowned scientists in the field. She was “viewed as imprudent” for not adhering to the status quo, the prevailing theory of the time, in “noting the excess of [hydrogen]” in her data.
Solved, central mystery? /
Payne’s place in history /
Set by the finding? Two obvious “Yesses”?
The poem first optimistically queries whether Payne’s innovative findings were celebrated and her place set in scientific history: do the two specific questions of interest merit answers of “yes” ?
No! The reception /
Is cold; no exceptions. /
Some years will pass ere both are deemed as successes.
As stated above, Payne’s findings were initially, frustratingly dismissed: “The reception/ [i]s cold: no exceptions.”
In his book, Bodanis points out that Payne had to deny her key insights to complete her graduate work; he writes,
“In her own published thesis she had to insert the humiliating line: ‘The enormous abundance [of hydrogen]… is almost certainly not real.’”
From David Bodanis’s E = mc2
It was not until years later that Payne and her insights were afforded the deserved recognition.
Hydrogen’s place in the /
Realms of astronomy, /
Now well-established: identity main /
As stars’ key constituent. /
No more diminuent /
Should be her story: Cecilia Payne.
Hydrogen’s identity as a key component of stellar chemistry is now well established, as “identity main” (most abundant) for the sun and other stars.
In 1925, Payne earned her doctoral degree in astronomy from Radcliffe College of Harvard University, as the first person to do so. One hundred years later, Payne’s doctoral thesis is recognized as the significant insight that it was; her subsequent career was likewise inspiring and fascinating.
However, I note that it wasn’t until I looked beyond my own STEM curriculum and textbooks that I ever heard her name. While I can attribute that in part to my taking a chemistry-centered path, versus an astronomy-focused one, spectroscopy has still been a key topic in many of my courses, and Payne’s discovery is a compelling and dramatic illustration of the importance of spectroscopic data.
“No more diminuent/ Should be her story”: I hope to remember this in my classrooms this autumn; rather than a “diminuent” (lessening) effect, I plan to include a focus on Payne’s inspiring discovery.
Chemphasis 