Field of Science

Isotope and the hidden women of science

It was a century ago today that the word isotope first appeared in print, in a letter to Nature from Frederick Soddy, who would go on to win the Nobel prize in 1921.  Nature Chemistry has a Thesis column by Brett F. Thornton and Shawn C. Burdette ($) to commemorate the occasion, as well as a post up at the Sceptical Chymist.  The post is illustrated with a photo of a plaque which reads "At a dinner party held in this house in 1913 Frederick Soddy (1877-1956) introduced the concept of 'ISOTOPES'..."  Thornton and Burdette also point to the dinner party as the moment when the term isotope was coined.

But Soddy did not coin the word.  The woman who did coin the term, Dr. Margaret Todd, has been gently set aside and one is left to assume that the word came to Soddy out of thin air. Margaret Todd was a physician and novelist, one of the first women to enroll in medical school in Edinburgh after the exams set by the Scottish Royal Society of Physicians and Surgeons were opened to women.  She was gay.  She wrote a popular novel under a male psuedonym, but it's the single word she handed Soddy that is her most enduring authorial legacy.  You need a good Greek term, she told him.  Try this one.

Sweet Hearts and Frogs

Last week I was at a workshop on teaching in British Columbia where I learned to make a string from a stick (if you're talking about teaching, it's really useful to be put in a situation where you have to learn something entirely new). We used obsidian points to scrape the outer layer of bark from dried stalks of dogs bane (Apocynum cannabinum), then pulled free the fibrous layer at the surface.  The instructor warned us about handling the plant before it was dried, noting that the sap could disrupt your cardiac rhythm. The ethnobotanist and two chemists in the group immediately murmured, "digoxin?" As you might imagine, an activity that features obsidian points, bone knives and an open fire doesn't lend itself to a quick search of the literature, so we were left to wonder for the evening.

The sap of apocynum plants, such as dogs bane, contains cymarine, which is a potent cardiac glycoside, like digoxin.  The term glycoside indicates these are structures that contain a sugar chemically bound to the rest of the molecule.  The sugary parts of each molecule are the hexagons with the O's in them on the left side.  Cymarine has one such hexose; digoxin has three.  At first glance the molecules might seem very different, but clip the sugars off and the remaining parts of the structures are very similar.

Cardiac glycosides are produced mostly by plants (foxglove, dogs bane, oleander), but toads also secrete them (check out this paper in Heart about someone who took a purported aphrodisiac that contained dried toad venom and died a few hours later from what looked like digoxin poisoning).  So don't kiss any toads, it's not sweet for your heart.

Update: Read the Naked Scientists on why people might lick toads: Tripping over psychogenic toads.

Oversharing and zero point energy wands: pseudoscience in the NY Times

While poking around the other day for some general reading material on the zero point energy, I discovered zero point energy wands (which claim to access not my favorite flavor of zero point energy —molecular vibrational — but the zero point energy field of the universe).  A few hours later someone sent me a link to this piece in the NY Times about spiritual cleansing of living spaces (and quotes one of the practitioners on how quantum physics explains it all, see page 2).  I suspect it is time to add another section to my quantum mechanics course. No, no, not instruction on proper wanding can find that here....but perhaps a brief conversation about how to get a handle on unpacking pseudoscience that has been cloaked in quantum physics jargon and responding to it is in order.

I suspect that when confronted with examples of psuedoscience, most chemists are like me, we jump into lecture mode.  Partly because we think the way the world works is so fascinating, we can't wait to share.  Partly because we think that if we share what we know (and so much of science is about sharing everything from space to materials to results) then people will see the universe works the way we see it works.  Face it, we overshare.

So how to respond, and more to the point, how do I help my students respond?  I wrote a piece recently offering some practical advice on combatting chemophobia for chemists (Nature Chemistry 5439–440 (2013), $).  The short version is watch your language, this is not the moment to play the "I call salt sodium chloride" card (even if you do have a jar labeled NaCl(s) on your kitchen counter) and to listen, to try to suss out whether this is a conversation that at its root is about politics or parenting where the science is secondary, this may not be a teachable moment.

But what about language when the jargon is flying the other way?  The book on wanding (which despite enormous temptation, I did not download onto my iPad) throws around words like "scalar" and "phase-locked" and "zero point energy" with abandon, but the meanings have shifted.  Sometime subtly, sometimes they are utterly scrambled.  How can you have a conversation where the words are the same, but the languages incompatible?

Some thoughts from ChemBark about combatting chemophobia on a broad level.
Sciencegeist hosts a festival unpacking the mysteries of toxic (and not) chemicals
Science Online 2013 takes on chemophobia
And finally, an non-science article from the NY Times that gets the science right: the venerable Harold McGee on wine wands (no zero point energy invoked!)

Quantum quivering

One thing that still stuns me about quantum mechanics is the notion that all molecular motion does not cease at zero degrees Kelvin (despite what you might read in your intro chemistry book).  Quantum mechanics tells us that when molecules vibrate, they can only do so at certain frequencies -- or energies.  Fascinatingly, the ground state vibrational energies (the lowest vibrational energy state a molecule can be) are not zero.  The molecules continue to vibrate, not matter how cold you get the system, you can never freeze out that vibrational energy.  Nor is the so-called "zero-point energy" of a molecule negligible.  The zero point energy of water is about 7 times as large as the thermal (translational) energy at room temperature).   I imagine all these water molecules arrayed in the solid, gently breathing, no matter how much energy you suck out of the system, they keep on vibrating.

Fine, fine, atoms are quantum mechanical objects and I'm willing to believe that the rules are a bit different in this realm, but surely such things are not true of macroscopic object?  Physicists Amir Safavi-Naeini and Oskar Painter have shown that objects far larger than atoms exhibit this quantum effect.  Watch the video to see how they did it!

While looking for a basic reference on zero point energy to link to, I discovered zero point energy wands...but that's a tale for another day!

A small sip of oxidane

My better half pulled a pitcher out of the refrigerator last night and poured a glass, thinking it was what we usually stock, lemonade. "Um, what is this?" The vibrant green color bordered on neon. "Either margarita or appletini. Given the color, I'd hazard appletini." The face he made was priceless.

As it turns out, the stuff tastes perfectly acceptable, once you get past the name and color. But names definitely matter. If offered a sip of oxidane, would you (should you) drink it?

Exploding expertise

How do we decide who to listen to about something chemical?  I have a piece in Slate this week (on the brouhaha around the teenager in Florida and the exploding water bottle), and someone in the comments feed there thought to comment on my expertise:

Jack Stephens
The author is apparently ignorant of chemistry. The active ingredient in toilet bowl cleaner is not hydrochloric acid, it is sodium hydroxide. Aluminum and sodium hydroxide react to form hydrogen gas.
Franz Liebkind
Some toilet bowl cleaners (e.g. Lysol's) contain hydrochloric acid in 10-ish percent concentration. It is there to dissolve calcium carbonate deposits (i.e. scale) found in hard water areas. Both HCl and NaOH react with nonbulk Al to produce, among other things, H2 gas. Iirc in the HCl case the reaction should go faster.

Sodium and HCl (or just water!) is much neater and more spectacular. Adolescent pyromaniac curiosity inspired many of us to major in chemistry.
Franz Liebkind
P.S. USGS says that the water from the Upper Floridian Aquifer, which supplies most of Polk County and Bartow, is moderately to very hard.

I just finished a new Thesis column for Nature Chemistry about the ways in which chemists can (or cannot) communicate with general audiences about chemistry. Is it possible to have nuanced conversations using the word "chemical" and chemistry, or has the word itself chemical accreted so many toxic associations that it can't be rehabilitated? Can chemists have a role in these conversations by virtue of their expertise? (Short answers: Problably not, probably yes, probably not.)

A session at ScienceOnline2013 earlier this year still has me thinking about the disconnect between how chemists want to talk about their field ("did you know that everything is chemicals? just look at how this works! isn't it cool?") and how people process the information we are so enthusiastically providing ("she is a working mother who probably feeds her kids fast food five nights a week and can't possibly care about her family's nutrition so why should I listen to what she has to say about the molecular structure of NutraSweet™?") Addressing the deficit in science knowledge may not in fact help people assimilate what they need to know make informed decisions about things chemical.

For a society who in many ways is so keen on credentials (or how else do those online diploma mills spammers make money), social science research suggests we don't necessarily consider purely those credentials into our decision when we decide who is an expert in a given field. Dan Kahan and colleagues at the Culture Cognition Project suggest that we assess expertise through the lens of our cultural and social affinities as much (or more) as we do through objective credentials.

So when it comes to deciding who you should believe about aspartame, you believe Dr. X who is an "nutritionist, aspartame victim and single mother of three boys" (her doctorate comes from an unaccredited online school) not Dr. Y who does research on molecular structure and is the mother of two boys and is not an aspartame victim (her doctorate comes from a top accredited school).

As for the Slate commenter, I'm rather fascinated that someone could generalize from you don't know what is in toilet bowl cleaner (is the subtext here that I would be above cleaning my own bathrooms?) to you apparently know no chemistry. Could you imagine that a well-trained scientist would not think to look this up even if she doesn't do bathrooms?  (The police report gives the brand of cleaner, which the manufacturer says contains 20% HCl.  Of course, practically it doesn't matter -- both the acid and the base oxidations of aluminum produce three equivalents of hydrogen gas.)

All natural, locally sourced liquid nitrogen?

Robyn Sue Fisher wants you to know that she would never cook with chemicals not found in nature. Smitten, her ice cream shop in San Francisco’s Hayes Valley, may at moments resemble a high school chemistry lab, but that’s because Fisher uses liquid nitrogen to freeze her product.
Nitrogen is “a natural element,” she notes. “It’s all around us.” [The original lead to this NPR blog post.]

I imagine not a few chemists reading this want Robyn Sue Fisher to know that liquid nitrogen is not found in nature on this planet. I suspect if she posted this photo of a cryogenic nitrogen plant in the ice cream shop, she'd have a hard time convincing her customers that liquid nitrogen was natural.

Her comments beg the question of what constitutes a chemical in the mind of a non-chemist.   If we take IUPAC's Gold Book as the arbiter of the technical definition,  a chemical is a material of "constant composition best characterized by the entities (molecules, formula units, atoms) it is composed of." Everyday language has drifted from the technical.  The Oxford English Dictionary offers this definition for the non-technical speaker: "a distinct compound or substance, especially one which has been artificially prepared or purified."

Most people would agree that in common usage chemical carries the connotation of both artificial and noxious, while chemists attach no such presumptions as to source or toxicity to the term.  Much as chemists wish it were not so, there is a growing language gap, and I think it unlikely we are going to regain the ground lost.  Molecule still comes across as more neutral in tone to a non-chemist.   So we are in a moment where we have people who are aghast at chemicals in their food, and others who are fascinated by molecular gastronomy (and likely some overlap in that population).

In principle, I do like the idea of locally sourced ingredients, maybe I should start my own shop and advertise that I use only locally sourced, artisanally produced liquid nitrogen?

I have to say I was also fascinated with how the NPR post morphed throughout the day in response to the comments on the blog.  By the end of the day the introduction read:

Robyn Sue Fisher's ice cream shop, Smitten, in San Francisco's Hayes Valley, may at moments resemble a high school chemistry lab, but that's because Fisher uses liquid nitrogen to freeze her product. 
Nitrogen is "a natural element," she notes. "It's all around us."
Andrew Bissette has a good piece about chemophobia on Carmen Drahl's blog Grand CENtral today  (In Defense of Chemophobia) which, along with this post from 2011 by Sciencegeist touch on the language issue.

(H/T to Fran who sent me the link to the original NPR post) 

Doing the math around artificial sweeteners

"The controversy surrounding these products natural, natural-like, or artificially made sugars will likely continue for years to come. We do know that artificial sweeteners increase our threshold for sweet taste, and yes, cause us to crave more sweets. If one “diet” soda leads to another “diet” soda, the “diet” effect is soon lost. " [source, emphasis is mine]

The 12 oz diet soda on my desk has 0 calories (meaning less than 5 calories under the FDA rounding rules).  If I drank ten of them, I might consume 50 calories, at most; in all likelihood, far less.  The diet effect is safe, I think.

I'm thinking about how we evaluate information: what does the BS detector look like for scientists versus non-scientists?

(As an aside, there is no evidence that artificial sweeteners increase the consumption of sweets.)

St. Ignatius' Beans: Strychnine and herbal remedies

Before chemists became adept at synthesizing and purifying single molecules, materia medica relied heavily on plant based materials.  The chemicals in plants are not uniformly innocuous, or safe at any dose, a point I tried to make in this article at Slate a couple of weeks ago.  A case in point:  St. Ignatius' beans.

Last fall, I was digging through a 1903 organic chemistry text (looking for examples of eponyms for this article), when a familiar name caught my eye. What was St. Ignatius doing in a chemistry textbook, an organic one at that?  Jesuits, I could understand (quinine is extracted from cinchona, also called Jesuits' bark), but Ignatius (the founder of the Jesuits) himself?

"Strychnine, C21H22O2N2, is found in St. Ignatius' bean..."  What is a violent poison doing in a bean named for Ignatius?  Despite the fact that I was up against an impending writing deadline and had a couple of dozen exams to grade, I had to know.

Faba Sancti Ignatii were first described by an Austrian Jesuit living in the Philippines in the 17th century, George Kamel, S.J. (his description was published in the Philosophical Transactions in 1699 - and yes, I looked up the Latin version).  Later authors speculated the plant was named for Ignatius because of its many medicinal virtues (which they do not list).  At the turn of the last century strychnine was part of the US Pharmacopoeia, prescribed as a stimulant — it was implicated in a early Olympic doping scandal — and for gastric upset; in the Phillipines it was often (more sensibly) the bean was worn on a string around the neck for protection against various diseases. These days it forms the basis for a homeopathic nostrum prescribed for grief and melancholia, particularly when associated with an abundance of tears.

A version of this post appeared at Quantum Theology.

Chemophobia: The Boy with a Thorn in His Joints

I'm at ScienceOnline2013 where Carmen Drahl and Dr. Rubidium just finished running a terrific session on chemophobia: how can we bridge the gap between "better living through chemistry" and ads for "chemical-free sleep aids." The thrust of the session was not how to convince people chemistry and chemicals are good, but more about how to inject nuance into the public conversation. Chemicals have risks and benefits — and of course, are unavoidable. But we current view chemical as synonymous with toxic, hazardous, unnatural or just plain bad.

What are the roots of this cultural shift? Can understanding these help scientists and writers communicate more clearly and in the end help people not only understand what is in their "stuff" — chemicals, it's all chemicals — but give them tools to work with and make decisions about the materials that make up the world — chemicals. As @docfreeride (ethicist Janet Stemmwedel) noted at another session yesterday, we can agree on facts, and still make different decisions based on them.

Today's New York Times has a perfect example of the various ways chemophobia presents in the Magazine: The Boy with a Thorn in His Joints. The piece chronicles Susannah Meadow's search for an effective treatment for her son's rheumatoid arthritis. She agonizes about the decision to give him methotrexate (which in high doses is used in anticancer treatment) and turns to alternative treatments, in particular four-marvels powder. There are intense arguments with the pediatricians and with her husband over the issue. I was struck by two things in this piece. First, the language Meadows uses to limn the controversy, and second her ignorance, not so much of the chemistry that is in your face (methotrexate), but of the ways in which chemistry is couched in alternative cultural schemes(four-marvels powder).

It makes me wonder how chemophobia is linked to the language we use to talk about it. It can be nearly impossible for an non-chemist to figure out what methotrexate is (beyond "a chemical"). The very name sounds harsh. Four-marvels powder is easy to parse: a powder with four effects. Its name rings with hope.

I also wonder if we worry more about stuff we are familiar with, we've heard more talk on the street about their risks. So we obsess about vaccines, because we hear and read about the side-effects of vaccines, but how many people know anyone who has died of measles? (One of my sister's friends died of measles when I was a child, before there was a vaccine.) So we get in the Times' piece "I was desperate to find a way...without the drugs." pushed up against "[My husband] has always been more comfortable with pharmaceuticals, more trusting in general."

Of course, four-marvel powder is a pharmaceutical, it's just from a different pharmacopoeia — the traditional Chinese — than the one Meadows or her husband is familiar with. Meadows can read the package insert with information on the side-effects of methotrexate, she may be unaware of the routine advice given in Chinese medicine programs (and yes, there are formal academic programs in Chinese medicine, e.g. at Nanyang Technical University) about four-marvels powder (it should never be given to pregnant women, for example, which might make you hesitate before giving it long term to infants or young children).

The session at SciOnline2013 brainstormed about effective ways to help people develop a better sense of nuance around what is a chemical and what are the risks of this particular chemical? What strategies do you think would be most effective?

Will bromine turn squirrels purple?

Most winters Punxatawney Phil is the furry face of Pennsylvania, but last year, he had competition: meet the purple squirrel of Jersey Shore (which should not be confused with either a television show or a town in New Jersey).

The news report offers a number of theories about the squirrel's unique coloration.  A dye job seems the likely culprit, whether from the squirrel's nesting material or an inadvertent bath in a violet solution.  Computer scientist Krish Pillai had a novel suggestion: "This is not good at all. That color looks very much like Tyrian purple. It is a natural organobromide compound seen in molluscs and rarely found in land animals. The squirrel (possibly) has too much bromide in its system."

Leaving aside that Tyrian purple (produced by a particular class of marine snail and to the best of my knowledge and research abilities by no mammal) is a much redder color, this assertion is roughly equivalent to saying that if I eat too much chloride, say from table salt, my body could start synthesizing Splenda, an organochloride.  No, just, no.

Pillai is apparently extrapolating from reports that bromide (bromine anion - Br-) has been found contaminating wells near fracking sites.  Calcium bromide is used in drilling fluids to increase density, by some estimates 20% of the bromine used in the US ends up in "clear brine fluids" — mixtures of various bromides.  But it is a long way from bromine ions to 6,6′-dibromoindigo along very specific biochemical pathways.  Which squirrels don't have.  Or humans.  (What can and does happen is that the bromide reacts with various chlorine compounds used in water purification to form organohalides, which aren't healthy to ingest....)

It's worth noting that direct ingestion of dyes can have interesting effects on pigmentation.  Flamingos get their characteristic color from ingesting shrimp pigment, and you can change the color of a canary's feathers by feeding it paprika.  Humans who eat too many carrots can develop carotenemia — they turn orange.  These processes are reversible, stop eating the shrimp or carrots and feather or skin return to their normal coloration.  Unfortunately consuming silver or gold can produce a permanent change in skin coloration, as in argyria.

An alternate definition of a purple squirrel via Urban Dictionary.