SCALES #45: albedo & flavedo
Hello!
Things in droplet-land are circling back to the setup from last summer. Turns out, despite previous hopes, cutting out a paper triangle, wetting it with solvent and a deposited droplet, and clipping a high voltage on the back wasn’t making an analyte ion-producing spray as reliably as I hoped. So, back to vaporizing the droplet on a heated surface—newly christened the “vape plate” by the junior lab member.
It has felt good to use something I know basically works, but it’s also reminded me about how finicky the setup can be. Partially this is due to previously having accepted the MacGyvered bits as “good enough for first experiments”, and discovering now that we’re no longer doing the first experiments, the hacked together components are, in fact… just good enough for first experiments.
I think also to some extent lab experiments simply can require, or at least be helped along by, some fine motor skills. Another reminder—I can’t remember where I first came across this—that lab skills are just as akin to fine handicrafts as to trades like machining, plumbing, carpentry.
Recently I’ve joked about selling the tiny contraptions we’ve been assembling on Etsy, but honestly? They wouldn’t cut it.
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I’m embarrassed I had no idea about Frances Walker-Slocum’s presence on the Oberlin piano faculty until reading her obituary this past week.
A characteristically insightful Jeremy Denk piece from 2013, “Every Good Boy Does Fine”, which traces his relationships with his piano teachers and arrives at his own teaching:
“One thing no one teaches you is how much teaching resembles therapy. You can be working with a student you’ve recently met, and you begin to tinker with one thing, even the movement of an arm. It becomes clear that some important muscle has been blocked for a decade or more. It’s an intimate thing, being shown these years of lost possibilities, and before long you’re giving advice about boyfriends, and explaining why parents are such a drag. There are diabolically opposed incentives, too: while the teacher is trying to express the truth about the student and discover what isn’t working, the student is in some way trying to elude discovery, disguising weaknesses in order to seem better than she is. In this complicated situation, a teacher must walk a thin line, destroying complacency without destroying confidence.”
(Remember when we were so lucky that Jeremy Denk regularly blogged? And Nico Muhly? And (404’d?) John Adams?)
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Reading Helen DeWitt’s newly published short story collection, Some Trick, and feeling extremely catered to. Odd, deeply allusive, unapologetic following of her interests and trains of thought where they lead, a hilarious voice that’s simultaneously antic and deadpan.
I mean??
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Richard Holmes celebrating the 200th anniversary of astronomer Maria Mitchell’s birth:
“Above all, she should be remembered for her inspirational science teaching, the passionate ex-Quaker and bold proto-feminist so vividly combined. One of her students recalled: “A chance meeting with Miss Mitchell ... gave one always an electric shock. At the slightest contact, a spark flashed.” We can catch it still.”
“High-speed microjets issue from bursting oil gland reservoirs of citrus fruit”:
“The rupture of oil gland reservoirs housed near the outer surface of the citrus exocarp is a common experience to the discerning citrus consumer and bartenders the world over. These reservoirs often rupture outwardly in response to bending the peel, which compresses the soft material surrounding the reservoirs, the albedo, increasing fluid pressure in the reservoir. Ultimately, fluid pressure exceeds the failure strength of the outermost membrane, the flavedo. The ensuing high-velocity discharge of oil and exhaustive emptying of oil gland reservoirs creates a method for jetting small quantities of the aromatic oil. We compare this jetting behavior across five citrus hybrids through high-speed videography. The jetting oil undergoes an extreme acceleration to reach velocities in excess of 10 m/s.”
“Frictionless gas flow observed in perfectly flat-walled nanochannels”. Always enjoy seeing where weird quantum phenomena show up:
“The authors found that the permeability of deuterium (D₂) in graphite nanochannels is much lower than that of hydrogen (H₂), its lighter isotopic counterpart, even though Knudsen theory predicts the opposite. This is because deuterium molecules have a smaller de Broglie wavelength than do hydrogen molecules, and therefore ‘see’ the channel walls as being rougher, even though the two types of molecule have the same diameter and interact in the same way with the channel walls.”
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Diagnosing the paper spray was pretty fun, though.
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—Adam