Easter fires: Rainbow demonstration rises again

It the the custom in many Christian denominations to light a Pascal fire at their Easter rites. For Catholics, this is done after sunset on Saturday night. The fire is kindled outside the church and in many traditions a large candle and/or many candles are lit from the flames. Lighting the fire is often problematic, it should be visible to the people assembled, but confined to prevent hazards. It can be smoky.  This weekend I became aware of an alternative to the traditional wood fire, replacing it with a rock salt and alcohol mixture.  This sounds like a great idea.  It is smoke free — you could do it inside — and that as these sets of directions suggest, you can add other salts to make beautiful colors in the flames.  It is, in fact, a TERRIBLE idea.

This is just a version of a chemistry demonstration, often called the rainbow demonstration, that is so dangerous it should not be done. Period. The rainbow demonstration has led to many serious burn injuries in onlookers and teachers, the Washington Post has an overview here.  Under certain circumstances it can produce a flame jet. See this notice from the American Chemical Society, and this longer article about the hazards at the Journal of Chemical Education.

The dangers is that vapors from the alcohol can travel out of the container or the salt/alcohol mixture and along the ground, then ignite in a ribbon of flame. I note that the National Altar Guild
link with instructions recognizes the vapors might escape, but doesn't seem to realize the hazard this presents.

Some years back the American Chemical Society urged chemists to contact their local high school chemistry teachers about the rainbow demonstration to be sure the warnings reached them. It might be time to encourage chemists to reach out to their local churches to be sure they are aware as well. 

The weight of water

While writing a piece for Nature Chemistry about the hidden depths of the periodic table (the more than 3000 isotopes that could be stacked onto their elemental spots), I wandered across an interesting set of papers on heavy water and isotopic tracing, which led to another piece for Nature Chemistry (The weight of water). In one of the papers, future Nobelist George de Hevesy deuterates goldfish by crowding some twenty (albeit tiny) goldfish into 60 ml of water, in another he reports making thousands of distillations of urine to recapture the water, measure its density and track deuterium through the human body.

Heavy water (D₂O) is water where the hydrogens have been replaced with deuterium, an isotope of hydrogen that weighs about twice as much as standard hydrogen. Heavy water weighs just over 10% more than regular water, a tablespoon weighs only about a gram more, so it is probably not noticeable should you heft a glass of it.

And that's the question — should you heft a glass of it? In small amounts it is certainly safe to drink, and as I recently learned, used in human metabolic studies in doses of about 10 ml. An interesting question raised in the papers I read was about the taste of heavy water. One report suggests a burning sensation might be felt when drinking it, another (by Harold Urey, who discovered deuterium) suggests it tastes like undeuterated water. But other reports say it tastes sweet.

With a bit of help from my youngest son, I set up a repeat of Urey's blind taste test. And was surprised to find I could indeed taste the difference. It is sweet.

And for the next few weeks, until the last of the extra deuterium clears my systems, I'll be just a little bit heavier than usual.

Elements of revenge

I seriously can’t write fiction. I suspect it's not lack of imagination, but some odd form of writer’s block. Or perhaps it is too many years devoted to sifting defensible reality from experimental and computational data. Or is it that I’m unwilling to ask a reader to be confused about the real, the possibly real and the entirely imagined? Or maybe it is because the one and only piece of published fiction I wrote, came (almost) true within the year?  Would any other fiction I wrote become real? That’s clearly a flight of fancy, but even with one data point, do I want to take the risk?

I was invited to write a commentary on the elements that scientists thought they'd discovered (but hadn't) for Nature Chemistry's issue celebrating the International Year of the Periodic Table.  The IUPAC guideline for element names says that you can't re-use names already in circulation in the literature, even if they were ultimately discarded. Which got me thinking if that could be a way for an unscrupulous scientist to crush the dreams of a competitor of having an element named for them. Despite my demonstrated inability to write good fiction, I drafted an introduction to the essay that played out this idea.

In the end, I wrote a non-fictional introduction to the essay (which you can read here if you are of the mind to do so). But if I were to write a piece of fiction about the elements, it might begin like this:
_______________________________

Prof. Exuvgen leaned back in her desk chair and wondered for the thousandth time why she’d ever signed that retirement agreement. Time was slipping through her fingers.  In a month, she’d have to hand over the key codes and walk out the door.  No access to her data and worse yet, no access to the tools she would need to analyze it, that idiot of a director had made it clear her account would be wiped — wiped — at midnight on the 30th, and anything left in her office trucked out to the dumpster.  Tang Woh Kow, they maintained, was right. There were 243 elements in the universe and no more. When Tam Besper saw the traces of zuzenium in 2069, right in this building, that was the end of the era of the element hunters. The last chance to have your name remembered in every chemistry book in the solar system, if not the galaxy. Though if the Vulcans had their way, everyone would be using the systematic names.

Running her hands through her short grey hair, she turned again to the data on the screen.  She’d spent thirty years working toward puncturing Kow's ceiling on the elements, the last ten racing Sabaxoar’s extravagantly funded group on the moon. What was it Maxine had said at that last meeting? Oh, right. Time. That she wasn't in a hurry, she had years to work on this, given lunar life expectancies. And with that Maxine shook her blonde curls and floated off.  Would the director take her more seriously if she looked less weary, grey and face it, old?

Time. It's running out, was there enough to say, now, without a doubt, that they’d turned up an atom or two of 244 Sym in that last run? Maybe, though maybe that oxide of muscovium was rearing its ugly head, this wouldn't be the first umbral element sunk by 115. Certainly there was strong evidence of a new isotope of 243.  Time, there just wasn't enough time.

She tapped the bud in her ear, and started composing the manuscript of one last paper.  “We present here evidence for the creation of the 616 isotope of 243 Zz, half-life 82 msecs, along with traces of element 244, Uuq.” She glanced up at the list of proposed names for 244 her group had kept on the whiteboard, derived from the names of birthplaces and long dead mentors and far-flung galaxies and grinned wickedly. “…for which we propose the name sabaxorium, symbol Sx, in honor of our respected and long time competitor in this hunt, Maxine Sabaxoar.”

Four months later, Maxine wakes up to a tweetstorm of congratulations for having the first trans-zuzenium element named for her. She pulls up the paper and seeing the unmistakable traces of MvO in the accompanying supplementary data dump, shrieks, "I've been robbed.”
_____________________________________
Notes:  
In the 1970s, Tang Wah Kow of New Method College in Hong Kong suggested (based on an odd theory about triads and octaves) that the upper level for an element was Z=243. Further, he proposed that when that element was ultimately discovered, it should be called zuzenium (Zz). The suggested name he said was, "...deduced from a Chinese idiom 'The name stands behind Zun Zen, who (Zun Zen) came last on the list of successful candidates in a royal examination." [In "An Octagonal Prismatic Periodic Table" J. Chem. Ed. 49, 59 (1972)]

Five Books: A short reading list for chemistry

Only five books? And the five best books? Last month I did an interview via email with Caspar Henderson (who wrote a marvelous bestiary for the new century: The Book of Barely Imagined Beings) on the best five books I would put on a reading list titled "Chemistry."  It's now up on the site — Five Books.  But the hardest part was not answering the great questions Caspar posed, but figuring out what five books to list. What did I want this list to do? Teach you chemistry? Maybe. Or give you a sense of what I find fascinating and beautiful and compelling about chemistry? Definitely!

I thought about various friends, curious and readers, but who don't have much background in the sciences and math.  What would I pull from my shelves for them to read?  Something that teaches you to decode a bit of the chemistry, a biography - what is the life of a scientist really like.  Something that is compelling, that drags you into a story you can't put down. Something that shows off the beauty of the world at the atomic and molecular level.

Something that teaches you to decode a bit of the chemistry:

Why does asparagus make my wee smell? And 57 other curious food and drink questions by Andy Brunning of Compound Interest. A bold graphical look at the chemistry of what we eat, with lots of quick explanations of weird (but useful) words of science like chromatography. 

What is the life of a scientist really like:

Obsessive Genius: The Inner World of Marie Curie by Barbara Goldsmith.  Of course there had to be Marie Curie. And this unsparing biography of her pulls the curtain away on what it can mean to plunge into research with all your being.

Compelling stories with chemistry at their heart:

The Poisoner's Handbook: Murder and the Birth of Forensic Medicine in Jazz Age New York by Deborah Blum. Some molecules are thugs, some turn witness for the prosecution. Real crimes, real molecules.  (And her new book on the rise of food safety, The Poison Squad, which is in the stack on my desk, is just as good.) 

The beauty of the atomic and molecular world:

H2O: A biography of water by Phillip Ball Chemistry laid out for the layperson with care and delight. Clouds are not what you think!
The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements by Sam Kean. There's a dark side to the periodic table.

Read the whole essay to find out more about what is fascinating about chemistry (at least to me), what I do as a chemist, and of course, about these five books. Want more book recommendations about chemistry? Want to know what the runners up were? Leave me a note in the comments!

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Chemistry not your thing? Go read Caspar's bestiary about the wildly improbable creatures that inhabit the very real world, from sea butterflies to yetis (or at least yeti crabs), it's a wide ranging exploration of the corners of the biological world. To quote a reviewer: "There is something lovely about a book that takes on so many disciplines and tackles them with confidence." There is indeed.

[Cross posted from Quantum Theology]

Trying to explain earthing with atoms

My ungrounded feet in rubber boots.

This week the Washington Post has an article headlined "Could walking barefoot on grass improve your health? Some science suggests it can."  The link itself is subtitled: The science behind grounding.

The article gets a lot of things right about atoms (they make up everthing!), but it confuses "free-radicals" with positive ions. (Free radicals don't have to be charged.) Then it tries to explain why negative ions can help. And while it is true that a positive ion and a negative ion can react in some circumstance to produce a neutral compound (think of hydroxide and hydrogen ions reacting to make water in an acid base reaction), random negative ions won't necessarily disarm a free radical.  You need an antioxidant for that, a molecule that can participate in a reaction that can soak up extra electrons.  You still need to eat your vegetable and wear sunscreen.

Negative ions and positive ions co-exist quite nicely in your body. You need those positively charged potassium ions, in fact, to keep your heart beating rhythmically. So on its face, the "science behind grounding" given in the article is bunk. If all those negative ions in the ground started neutralizing all the positive ions in our bodies, we'd be dead.

While I get this is a not a science news piece, but a perspective piece (a "[d]iscussion of news topics with a point of view, including narratives by individuals regarding their own experiences"), I wish someone at the Post had fact-checked the science.  Yes, it feels nice to walk barefoot on the grass, or to be outside.  I'm pretty certain the negative ions aren't the reason why.

Hunting up the ghosts of elements

This post originally appeared at the UNESCO International Year of Light's blog, in October 2015.  The site is no longer available.

Interior of an antique spectroscope.

If you’ve seen the flash of yellow-orange flames when a pot boils over on a gas stove, you’ve gotten a glimpse of the ghost of an atom.  The color is part of the atom’s spectrum.

In the late 17th century, Isaac Newton used the Latin word for ghost, spectrum, to describe the bands of colors he saw when light shone through a prism. One hundred and fifty years later, Joseph von Fraunhofer noticed he could see bright lines instead of the bands of colors when looking at certain flames through a prism.  He went on to develop an instrument to measure these spectral lines, called a spectroscope, and used it to catalog the lines seen in the sun’s light and in the light from other stars.

It would take almost another fifty years to figure out that Fraunhofer’s lines were the ghosts of chemical elements, when Gustav Kirchhoff and Robert Bunsen (the inventor of the ubiquitous Bunsen burner) teamed up to create a spectroscope that used Bunsen’s new hotter, gas burner to ignite the samples.  They noted that that each element produced a characteristic set of lines when burned, a spectral fingerprint, that could be used to identify it.

In October of 1860, Kirchhoff and Bunsen announced they had used their spectroscope to discover a new chemical element, which they named cesium, for the blue color of its principal line. Chemists quickly began to use Bunsen’s spectroscope to find new elements.  A few months later Kirchhoff and Bunsen found two bright ruby red lines in an extract of a silicate mineral lepidolite, the spectral traces of another new element, rubidium.

Thallium’s ghostly green emanations were first observed by William Crookes, indium, ironically named for its violet lines by its color blind discoverer Ferdinand Reich.  Paul-Émile Lecoq de Boisbaudran spectroscopically identified element 66 in a sample painstakingly extracted from his marble hearth, and instead of naming it for the colors of the lines, called it dysprosium, from the Greek for “hard to get” — because it was.

Hunting for new elements spectroscopically meant you didn’t actually need to have any of it in your lab or even on your planet, as long as you could observe the light from a burning sample.  In 1868 several chemists and astronomers independently observed a faint line in the spectrum of the sun, and assigned it to a new element, helium, which as far as they knew did not exist on earth.  It would take nearly 30 years for two Swedish chemists to confirm that it was present on earth — by matching the spectrum with that of a gas found in a uranium ore.  (The helium to be found on earth comes from radioactive decay.)

Spectroscopy certainly helped chemists fill out the periodic table, adding more than a dozen new elements to the collection.  But it also played a significant role in confirming predictive power of periodicity. When Dmitri Mendeleev proposed his version of the periodic table, he left blanks for yet-to-be-discovered elements, underneath elements which should have similar properties.  In 1875, Lecoq, the same man who had so patiently extracted dysprosium from his fireplace, sifted through 4 metric tons of  zincblende to show that it contained traces of a new element which fit neatly into the space Mendeleev had reserved for it underneath aluminum.  Lecoq named the element gallium, in honor of his home, France, and perhaps playing off his own name, as the Latin for le coq, the rooster, is gallus.  It was a powerful demonstration of Mendeleev’s theory.

These ghostly lines produced by elements helped fuel yet another critical discovery that would have far reaching consequences for chemists’ understanding of the periodic table:  quantum mechanics.  Niels Bohr’s quantum mechanical model of the atom opened the door to explaining chemical elements line spectra. Though more accurate and sophisticated quantum mechanical models of the atom now exist, Bohr’s model showed the relationship between the lines and an atom’s electron by insisting that the electrons’ energies were quantized, that is, they could only have certain energies.

So why do atoms have ghosts?  When an atom is heated to high temperatures, as in a flame, the energy it absorbs excites its electrons.  You can think of the electrons in an atom as being on an energy ladder.  They can only have energies that match the rungs of the ladder, and each type of atom has a unique arrangement of the rungs.  When the atom absorbs energy, its electrons move to higher rungs.  Excited electrons are unstable. They quickly return to their original arrangement, giving off some their excess energy in the form of light as they do.  The color, the wavelength) of the light emitted depends on the difference in energy between the rungs.  The colors of light emitted are the ghosts of the energy rungs.  Since each element has a unique pattern of rungs, it will have a unique spectrum of emitted light and so revealing their presence to the sharp eyes of spectroscopists.

Chemists still use the light emitted and absorbed by atoms and molecules to identify their presence.  We hunt for the structure of the universe in its ghosts.

More Information

If you want a way to see the ghosts of atoms, try this DIY folding spectroscope you can attach to your phone. Use it to check out the light from a neon sign or from a street light!

For a wonderful description of the elements, including stories of how they were first discovered, read John Emsley’s Nature’s Building Blocks.

#dayofscience

Sikhote-Alin meteorite from Vatican Observatory's

collection

On July 13th, the Earth Science Women’s Network is hosting Science-A-Thon, in which participating scientists are chronicling a day in their life on Twitter and Instagram (follow #dayofscience and #scienceathon).

Join me for the day!  I'll be posting a photo every hour on a day when I'll be working from the Vatican Observatory in Albano Laziale, outside of Rome.  Starting with my early morning stop at the espresso bar through a full day of science behind the walls of Vatican City.   There might even be aliens from other worlds (of the inorganic variety). The observatory might seem focused on anything-but-earth science, but the meteorites that the earth sweeps up as she moves through the heavens are clues not only to the otherworldly, but to our own planet's history.

Participants are listed by country — so far I'm the only one under "Vatican City"!

____________________
This is a first-ever fund raiser for the Earth Science Women’s Network, so if you are inclined to support them, you can donate here.

Hidden figures: 2.303, slide rules and classrooms mired in the last century

A five -place table of logarithms from my dad's CRC Handbook of 

Mathematics (why is that set of values circled?) and a circa 

1958 Hemmi 257 slide rule designed for chemical calculations.  

 Wonder why random values of 2.303 are "hidden" in formulae? To make them easier to use with a slide rule.¹ 

A slide rule?  The last slide rule slid out the door of Keuffel & Esser in 1975 (they sent their engraving equipment to the Smithsonian).  You can still find them, used and even new - still packaged up to sell to engineers and scientists.  The Oughtred Society has a online museum, as well.

We still have my mother-in-law's K&E, in it's leather case with her name impressed into it.  Family history says she bought it with the money she earned tutoring Jackie Robinson in chemistry at UCLA.

I have an essay out in this month's Nature Chemistry, "It figures", about how the computational tools we use shapes what we teach and not necessarily in good ways. Given that slide rules were obsolete by the time many of my student's parents were born, why does their use still linger in general chemistry book?  (The 2.303's in texts are lowly going away. I checked texts running back about a decade.)

More critically to my mind why, several decades after  digital computing tools became ubiquitous on college campuses do many physical chemistry texts eschew any discussion of numerical techniques for solving the rate equations for a chemical reaction?  I suspect the chasm between the computational tools used in the field and those used in the classroom is a result of apathy. We teach what we learned as we learned it.  As I note in the article, I don't think it is defensible on intellectual grounds.

Don't know how to use a slide rule?  It's fun, it's geeky. No need to buy one to play, check out this simulator and the instructions at Nature Chemistry!

You can read the article here:  http://rdcu.be/sY5Q

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1.  2.303 is the natural log of 10. To change the base of logs recognize that
x = b^log_bx
so
ln(x) = ln(10^log₁₀x)
ln(x) = log₁₀x ln(10)
ln(x) =(log₁₀x)(2.303)
ln(x) = 2.303(log₁₀x)

Implications of Charles law in a biological matrix: farts

See note 3 for source.

Maggie Koerth-Baker has a great piece up at the 538 blog: "How Big Is A Fart? Somewhere Between A Bottle Of Nail Polish And A Can Of Soda."  It's well researched, digging into the biomedical literature with verve.  And it's great that she gives the answer a context, it's easier to visualize a bottle of nail polish than a 17 ml blob for most people, me included.

I'm not at all surprised at what you can find in the primary literature (I tracked down papers on exploding people and deuterated dogs¹ for my introductory chemistry class last spring). The piece is the first in a series Science Question From A Toddler, though I suspect that people somewhat past the target age group (5 and under) would be interested in the answer to this question, too.

In a footnote Koerth-Baker suggests that farts in the body would be smaller because the gas would be compressed inside the body.  But the pressure inside the human colon is the same as atmospheric pressure.  Farts and burps keep it that way. What's different is the temperature, higher inside the body by about 30^oF (17^oC).  Gases expand at higher temperatures. You can use Charles' law to figure out by how much the volume changes with changes in temperature:  V2=(T2/T1)V2

The researchers measured the volume of the farts at room temperature (I read the paper!), so the volume of a fart should be slightly larger in the body than the reported numbers by a factor of (310/293) or about 6% larger.  So how big is a fart?  Just before exit, it's about the size of a 14 ounce ketchup bottle for the largest one in the 1997 study.

---

The details of the experiments are fascinating.  The technique for quantitatively² capturing flatus in the bathtub is elegant, and while a significant improvement over the method used for the studies in the 1860s³ you have to wonder how they got volunteers for either experiment.  And speaking of volunteers, the assessment of the "flatus perception threshold" was done by delivering 100 ml of an odorant mixture "from a large 250ml syringe in about 1s, 1 meter beneath the nose of the panel members, mimicking a flatus emission."

And just in case you don't think this is serious stuff: "The common tendency to treat rectal gas as a humorous topic has obscured appreciation of the complex physiology that underlies the formation of this gas." Suarez et al. American Journal of Physiology  272, G1028-G1033 (1997).

1.  The physiological effects of drinking heavy water, D₂O, on dogs.  If you've ever wondered what would happen if your poured that little vial of D₂O into your coffee, the answer is not much.  It's not great for the dogs as a steady diet, but a sip or two won't hurt.
2.  The fancy chemistry term for "we got all of it!"
3.  See the figure, from Tangerman, "Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices" Journal of Chromatography B, 877,  3366-3377 (2009).

Chemists: Strangers to fiction

That Mars habitat?

"The basement corridor is dim, I can hear pumps chugging, hoods noisily venting, and the solid-state physicist down the hall swearing. 'Welcome to Mars!' says the cheery sign outside my colleague’s door. Perhaps it is the pile of grading on my desk or the endless round of meetings on my calendar that is fuelling my escapist fantasy, but every time I pass Selby’s office, I imagine the door is a portal and if I were to walk through, I’d  find myself in a habitat on Mars, its pumps working hard to compress the thin atmosphere." from "Strangers to Fiction" in Nature Chemistry, 8, 636-637 (2016).

I've been a sci-fi fan for going on five decades, imagining myself in labs on Mars, mining comets, and exploring strange new worlds. I don't read it for the chemistry, which is a good thing, because there isn't much fiction in which chemistry plays a key role.

My latest Nature Chemistry Thesis column looks at chemistry and fiction, suggesting that there are good reasons to both read SF, particularly for young chemists, and for chemists to encourage the writing of chemistry-inflected science fiction.  And if you have the talent for it (which I do not!) perhaps even give the writing of it a fly.

You can read the whole thing here.  My list of fictional chemistry is here.

A matter of degrees: when low temperatures were hot

Diagram of a thermometer similar to

the one describe by Leurechon, c. 1638.

Note that  hotter temperatures have 

smaller magnitudes degrees associated with 

them. Image from Wellcome collection, 

used under CC license.

We say the mercury is rising to mean it's getting hot out, despite the fact that most home thermometers have no mercury in them anymore.  Regardless of the liquid they contain, the level rises with increasing temperature in the iconic liquid thermometer.  But this was not always the case.

The word thermometer was first coined (in French) in a book of mathematical recreations written in 1626 by Jean Leurechon, SJ (writing as Hendrik van Etten).  In his description he notes the thermometer you can construct from a glass tube and small container of water (or other non-viscous liquid) can be used to quantify temperature by placing marks on the glass, associating each with some fraction of the classical four (or eight) degrees of hotness.  Such thermometers, he suggests, can be used to adjust the temperature of a room or a furnace, to record (and predict) the weather and to measure fevers in the ill.

But Leurechon's thermometer (and similar designs) were constructed such that as the temperature increased, the water level in the tube fell.  Increases in temperature caused the air trapped in the ball at the top of the tube to increase in volume, pushing the liquid down in the tube.  (These are air thermometers, in contrast to the familiar liquid thermometers in widespread use today.) A reading of 9 degrees on the thermometer shown in the sketch accompanying Leurechon's thermometer problem was colder than that of 2 degrees (see also the one in Robert Fludd's diagram, in the figure.)

A century later, Anders Celsius constructed a temperature scale based on water's phase changes which ran in the same direction.  Water on Celsius' scale boiled at 0 degrees and froze at 100 degrees. This reverse run didn't last long, two years later Carl Linnaeus (of taxonomic fame) used the scale to describe conditions in a greenhouse, but flipped it to the form in which we know it today, where 100 is the boiling point of water.

It is tempting to think that Celsius' scale ran in the direction it did because it mimicked the earliest marked thermometers. But Fahrenheit's scale, which preceded Celsius' by two decades, runs in the modern direction, things get hotter in the positive direction. This also parallels the classic notions of degrees of heat in play during the medieval period. There were four (or eight or six, depending on the source) degrees of heat, the first being more or less physiological temperature, the fourth being a blazing hot furnace.

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The word degree has its roots in the Latin degradum, a down step.  This matches Leurechon and Celsius' use - 9 degrees is eight steps lower (colder) than 1 degree.

Chemical fiction

Topi Barr's Antithiotimoline is in this vintage Analog

Seven years ago, Andy Mitchinson, an editor at Nature, wrote at The Sceptical Chymist (Episodes II and III) about the dearth of science fiction that involved the science of chemistry in a substantive way.  Why isn't there more of it?

He pointed to a list put together by Connie Willis, an award winning SF author, and an article by Philip Ball in Chemistry World.

I'm working on a column for Nature Chemistry about the ways in which chemistry and science fiction play off each other.  Is science fiction more than escapist entertainment?  Should chemists care that there's not more chemistry inflected fiction out there?  Should we deliberately expose students to science fiction? Should we encourage them to write it?

To go alone with the piece, I'm trying to create a periodic table of chemical fiction (not including articles called out by Retraction Watch).  Are there pieces on my list you particularly love?  Something I'm missing?  I'd love to hear in the comments!

For a full set of periodic science fiction short stories, I encourage you to browse Michael Swanwick's Periodic Table of Science Fiction.  What really happened to the Hindenburg?

	Author	Work
As	Asimov, Isaac	Whiff of Death, The Endochronic Properties of Resublimated Thiotimoline, Thiotimoline to the Stars, Pate de Fois Gras
Pb	Ball, Philip	The Sun and Moon Corrupted
Ba	Barr, Topi	“Antithiotimoline”
B	Bujold, Lois McMaster	Vorkosigan series
Ac	Christie, Agatha	"The Blue Geranium” in The Thirteen Problems
Cl	Clements, Hal	Phases in Chaos
Co	Conan Doyle, Arthur	Holmes
Md	Dewar, Michael	“Temporal Chirality:  The Burgenstock Communication”
F	Foster Wallace, David	Infinite Jest
Ag	Goodman, Allegra	Intuition
He	Heinlein, Robert	Glory Road, Have Spacesuit will Travel
Hf	Hoffman, Roald	Oxygen
Li	King, Laurie	Russell & Holmes series
U	Le Guin, Ursula	“Schrödinger’s Cat”
Sn	Lem, Stanislaw	“Uranium Earpieces” in Mortal Engines
P	Levi, Primo	The Monkey’s Wrench
Am	McCaffrey, Anne	Pern series
H	Piper, H Beam	Omnilingual
Kr	Robinson, Kim Stanley	Mars series
O	Sachs, Oliver	Uncle Tungsten
Dy	Sayer, Dorothy	The Documents in the Case
Sm	Smith, Edward Elmer “Doc”	“Tedric,” “Lord Tedric" in The Best of E. E. “Doc” Smith
Ne	Stephenson, Neal	Anathem
Br	Stoker, Bram	Dracula
Fr	Vance, Jack	“Potters of Firsk”
K	Vonnegut, Kurt	Cat’s Cradle
V	Vourvoulias, Sabrina	INK
Hg	Well, H.G.	“The Diamond Maker” in The Stolen Bacillus and Other Incidents
C	Willis, Connie	The Sidon in the Mirror

A day in pchem lecture: NMR, lululemon yoga pants and tattoos

By lululemon athletica
(Flickr: Yoga Journal Conference)
 [CC BY 2.0], via Wikimedia Commons

It's the end of term, two more 90 minute lectures left in my introductory quantum chemistry and spectroscopy course.  We've done the basics of wave functions and expectation values, we've looked at linear variation theory and written code to do Hückel MO calculations, we've covered rotational and vibrational and rotational-vibrational spectroscopy.  So what to do with these last few days?  The quantum mechanics of NMR.

I kicked off today's lecture by looking at magnetic field strengths, what's the earth's magnetic field (5 μT) or of a refrigerator magnet (5 mT), compared to the superconducting magnets used in NMR, which are on the order of 10T. (1T is one tesla.)  This led to a quick review of the risks in MRI, which aren't about the energy of the radiation used (which is billions of times lower than X-rays), but more about the interactions of the high magnetic fields, the radiofrequencies and metals.

A hand shot up and student who is an EMT describes a patient whose tattoo started burning during an MRI.  I pointed out this is a known phenomenon, and while most inks don't pose an issue, it should discourage you from DIY tattooing.  Then a student asked, "Is it true you can't wear lululemon pants when you have an MRI?"

I admitted this was out of my zone, but promised to follow up.

I can now report that yes, wearing lululemon pants — or any clothing with metallic microfibers, such as those great antimicrobial t-shirts — in an MRI can lead to serious burns, particularly in patients that have been sedated or are otherwise unconscious and unable to signal their discomfort.  Even non-ferromagnetic materials presents problems in the MRI as eddy currents can develop around them, creating little induction heaters.  Loops of all sorts, even skin to skin contact between a patient's own body parts can lead to heating and subsequent burns.  And tattoos with large loops in them?  They can heat as well.

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Other things I learned this afternoon.  You can levitate a frog with a 16T field (thank you Wikipedia), and neutron stars have magnetic fields on the megaTesla scale.

Marketing molecular fear

"A woman can recite the most complicated recipe, but how many can name the ingredients in a headache tablet?  If you don't want drugs you know nothing about, take Bufferin...."

This short commercial by actress Joan Fontaine aired in the mid-1960s, an era when Tylenol (acetaminophen) was just gaining market share in the US as a painkiller for adults.  I'm fascinated with the way in which it foreshadows the modern trope of avoiding chemicals you can't pronounce, already marketing the molecular fear that now fuels the largely unregulated, 12 billion dollar a year vitamin and nutritional supplement market in the US.  Rachel Carson's Silent Spring had appeared in 1962, starting a shift towards seeing chemical as a synonym for poison.

Much like the material put out fifty years later by Jospeh Mercola, Dr. Oz and The Food Babe, this ad tacitly assumes people are incapable of understanding science and must rely on experts of some sort.  Who you should not trust.  And women, no matter how competent within their limited domestic sphere, are even less capable.

All natural! Removes burned on food! Magic chemical concoctions

I steamed a batch of dumplings for lunch yesterday, which never had time to cool before being wolfed down by the spring break crowd in my kitchen.  So I pulled another set from the freezer which someone in the scrum popped into the steamer.  In the confusion, no one checked to be sure there was still water in the steamer.  Fast forward eight minutes, the dumplings are stuck to the steamer and the smoke alarm is shrieking.

The dumplings were edible, but the bottom of the pan was pretty badly scorched.  My mathematician spouse wondered if I had some special chemical that would magically clean the pan.  I said I did and that I'd already applied it.  "What did you use?" he said, peering into the blackened pot. "Water."

Water is sometimes called the universal solvent, and though many things will dissolve in water, it's not clear that more things are soluble in water than in any other solvent (or how you would undertake such an inventory). And it's absolutely a chemical, though it is so ubiquitous we have a hard time thinking of it as such.  Even chemists.

The pot soaked overnight, and with the application of a bit of elbow grease (physics, not a chemical) and a finely ground mixture of low volatility chemicals (feldspar, limestone, sodium carbonates with a dash of soap - aka kitchen cleanser) is as shiny as ever.

A universal hotness manifold

Slothful thermometers.

I'm working on a column for Nature Chemistry about temperature, prompted by the incredible collection of early thermometers and thermoscopes at the Museo Galileo in Florence.  (Can't get to Florence and visit it and the amazing gelato spot Perché no! — they have an incredible online virtual tour of the exhibitions.)

The question of how one can be assured that two objects, well separated in space and/or time, would be in thermal equilibrium with each other should they be brought into contact — that is, can you be sure that two objects are at the same temperature —  is not quite as simple as it sounds.

First you need a measuring device, then you need to agree on a way to quantify the output of the device.  And it would be nice if your colleague who lives across an ocean could set up her apparatus in such a way as these quantities are the same.  In another words, you need a calibrated thermometer.

There's a wild and wonderful history to figuring out how to create this basic piece of lab equipment, including what you mean by zero, how big should degrees be, and how to to tell if water is really boiling.  But my favorite find is in a paper by mathematician James Serrin, in which he defines a thermometer by formally stating the zeroth law of thermodynamics [1]:

Manifolds, M, marked in with L, hotness levels (the black
enamel dots).  Or,17th century Florentine degree thermometers.

"There exists a topological line M which serves as a coordinate manifold of material behaviour. The points L of the manifold M are called 'hotness levels', and M is called the 'universal hotness manifold'."

I'm trying to imagine standing up in front of a classroom of students and talking about hotness levels.

And those slothful thermometers?  They tell the temperature by little balls that float or sink...slowly, very slowly.  Lazily, you might say.

Just reading the paper brought back memories, the collection of conference papers this quote is pulled from are reproduced from typed (double-spaced, with a typewriter!) manuscripts, complete with the typos you might expect before word processors and spell check arrived on the scene ("physcis").  In the late 1970's this was one way to inexpensively and rapidly get proceedings and reviews into print.

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1.  "The concepts of thermodynamics" in Contemporary Developments in Continuum Mechanics and Partial Differential Equations. Proceedings of the International Symposium on Continuum Mechanics and Partial Differential Equations, Rio de Janeiro, August 1977, edited by G.M. de La Penha, L.A.J. Medeiros, North-Holland, Amsterdam, p. 416.

Weird words of science: scientist

Woman teaching geometry to men
illus. 14th century copy of Euclid's Elements

Scientist may not sound like a weird word, but when it was first coined, it was thought "unpalatable," along with (understandably) "nature-poker." Recently my sister tagged me in a Facebook post linking to a series of articles on women in science. She thought it interesting that the word had been coined to honor the work of a woman in science.

"Not only did Scottish mathematician, science writer, and polymath Mary Fairfax Somerville (December 26, 1780–November 28, 1872) defy the era’s deep-seated bias against women in science, she was the very reason the word “scientist” was coined: When reviewing her seminal second book, On the Connexion of the Physical Sciences, which Somerville wrote at the age of 54, English polymath and Trinity College master William Whewell was so impressed that he thought it rendered the term “men of science” obsolete and warranted a new, more inclusive descriptor to honor Somerville’s contribution to the field." — from Maria Popova and Lisa Congdon's 2013 project The Resurrectionists

Oddly enough, I'd read William Whewell's review of Somerville's On the Connexion of the Physical Sciences while writing an essay about the public conception of scientists, and my recollection was that the coining of scientist, while reported in this review, was not in fact spurred by Somerville's work.  So I went back and read it again.

Whewell was certainly impressed with Somerville and her book, but his tale of the creation of the word 'scientist' makes no mention of honoring Somerville or her contribution.  About the only person Whewell seems impressed with in this context is the "ingenious gentlemen," thought to be himself!

A curious illustration of this result maybe observed in the want of any name by which we can designate the students of the knowledge of the material world collectively. We are informed that this difficulty was felt very oppressively by the members of the British Association for the Advancement of Science, at their meetings at York, Oxford, and Cambridge, in the last three summers. There was no general term by which these gentlemen could describe themselves with reference to their pursuits. Philosophers was felt to be too wide and too lofty a term, and was very properly forbidden them by Mr. Coleridge, both in his capacity of philologer and metaphysician ; savans was rather assuming, besides being French instead of English; some ingenious gentleman proposed that, by analogy with artist, they might form scientist, and added that there could be no scruple in making free with this termination when we have such words as sciolist, economist, and atheist—but this was not generally palatable; others attempted to translate the term by which the members of similar associations in Germany have described themselves, but it was not found easy to discover an English equivalent for natur-forscher. The process of examination which it implies might suggest such undignified compounds as nature-poker, ornature-peeper, for these naturae curiosi; but these were indignantly rejected." [from the Quarterly Review, 1834, emphasis mine]

Interestingly, Wherwell does tackle the issue of women in philosophy/science:  "Our readers cannot have accompanied us so far without repeatedly feeling some admiration rising in their minds, that the work of which we have thus to speak is that of a woman."  It's a fascinating read, in which you can see the threads of imagery that is still current (and still unsupported by data) about the innate differences between the minds of men and women.

And in the end, scientist would catch on, by the early 20th century it was far eclipsed "natural philosopher" as the preferred general term.

Science at Play

The Chemical Heritage Foundation in Philadelphia's latest exhibit is called "Science at Play" — and even if you can't get to Philadelphia, you can browse some of the materials on Tumblr, including animated videos of experiences — good and bad — with chemistry kits.

When my kids were young, I encouraged them to play with science stuff.  I wanted them to be willing to get messy, to make mistakes, to think about stuff where it wasn't perfectly clear what was going on and to begin to understand that protective gear wasn't a ritual or a costume, but part of thinking through how to reduce risk.  That you could make your own equipment.

Though kits have gotten far more tame over the years — no more uranium ore or instructions for making ammonia in your hand — there are still commercial kits that let kids play not only responsibly, but productively, with chemistry.  The new MEL kits that Todd Bookman's piece on chemistry kits for The Pulse (listen here - full disclosure, I was interviewed for this segment) highlights are particularly cool in that they plug into another important skill for budding scientists:  how to share your work.  The kit comes with a lense that you can snap over a cell phone camera, giving you an up close look at what you are doing, and enabling you to share it via social media.

But as important as kits are, I think the ad hoc experiences of doing science are equally critical.  They hone the ability to read instructions (and reveal how much is not revealed in the methods sections of any science communique), encourage a sense of scale and quantitation (how much is 1 gram of something, as opposed to pour in this packet) and help novice scientists get comfortable with tinkering to build apparatus when they don't have exactly what they need. And when tackling a new research problem, do you ever have precisely what you need?

While you can make do with measuring cups and kitchen scales, I'm with the Chemical Heritage Foundation's Erin McLeary, who notes the appeal of having the real stuff in your hands.  These days you can easily and inexpensively acquire a few real beakers, graduated cylinders and other lab equipment -- along with gloves and other protective gear.

So if you're looking for an interesting and unique gift for a kid interested in science, try assembling a small kit and including the instructions and materials for a couple of experiments.  For starters, extracting DNA from dried peas or copper electroplating (yes, it uses something you shouldn't eat - don't and wash your hands) or even the infamous water electrolysis (sans smoldering splint and thereby less risk of singed eyebrows).  Offer to help supervise or be the videographer.

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To read more of what I've written about chemistry kits and doing chemistry outside the laboratory see:

"Homemade Chemists" in Nature Chemistry
"Felony Science" at Slate
"Handheld Chemistry" on the blog, about the making of ammonia in your hand

Polysemy and Polyphony: Listening to Messiah

Last spring I wrote a piece for Nature Chemistry on polysemy — the phenomenon where words take on quite different meanings in different contexts. The iconic chemistry example might be mole (the quantity versus the animal versus the verb¹), but there's a long list.

So you might think that when I ran into a homograph² on Twitter the other day, I'd be alert to the possibility. My first thought when the conversation between two chemists about the insights they find in Messiah showed up in my feed they were talking about the classic quantum mechanics text by French physicist Albert Messiah.  Actually, not.  Handel's Messiah was the text under discussion.  Polyphony crashes into polysemy.  And evidence I really am a science geek first and foremost.

The text is still in print, though Albert Messiah died in 2013 at aged 92.   I used Messiah's text when I took a year long course in quantum physics as a graduate student (from the physics department, have exhausted the chemistry offerings as an undergrad). We pronounced his name "mess-ee-uh" rather than "mess-eye-uh," making this technically a homograph (though not a capitonym³).  I wondered today how he might have pronounced his name, is it really a homograph, or did my professor simply choose to pronounce it this way to avoid sounding like an evangelical preacher when he assigned reading?  I dove into the interwebs to see if I could uncover any clues.  I discovered Messiah had been part of the French Resistance in World War II (joining at age 19, the age my youngest son is now), worked at the Institute for Advanced Study in Princeton with Niels Bohr and eventually returned to France to teach and write this text.

I also listened to a few minutes of a presentation Messiah gave in 2009 at Le Ecole Polytechnique.  It was oddly moving to hear the voice of someone whose written words I had spent so much time wrestling with almost forty years ago.  And at the end of the questions, I learned how he pronounced his name.

And, on the Sceptical Chymist, Reuben Hudson has a post responding to my column on a different kind of doubling-up in chemical language.

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1.  Yes, mole is a verb, to mole a garden is to remove the moles.
2.  Homographs are words that have the same spelling, but different pronunciation (lead and lead).
3.  Capitonyms are homographs with different capitalization.  DEFT and deft.