May 20, 2012

See You in Anaheim!

The 241st ACS National Meeting & Exposition kicks off this Sunday, March 27, in Anaheim. As always, the meeting features hundreds of technical presentations, workshops, special and social events, networking opportunities, and much more! To make the most of your time at the meeting, use the Itinerary Planner, a handy online tool for organizing your week in Anaheim. Using the Itinerary Planner, you can browse the technical program and mark technical sessions or other meeting events that you'd like to attend, then download your daily meeting schedule to your PDA or Outlook calendar.

March 26, 2012

Cordial Chemistry: Syrup of Violets


Today's talk at the Chemical Heritage Foundation was by one of my fellow Fellows, Rebecca Laroche, on syrup of violets and Robert Boyle. It had long been known that adding an acidic material, such as lemon juice, to syrup of violets turned it a rose color. (More creepily, kids apparently used to hold pansies, also a member of the viola family, over ant hills to watch them change color, presumably from the formic acid produced by the ants.) Boyle is credited with the discovery that this botanical extract also changed color when exposed to alkalis, turning green (see his report here). This led to the development of a panel of pH sensitive indicators, helpful in chemical analysis in Boyle's time and now.

The color changes are due to the anthocyanins in the violets (the same thing that makes red cabbage change color with pH). Syrup of violets is not hard to make, you can find a modern recipe here, not much changed from the older recipes (see an assortment here), and you can buy it.

After Rebecca's talk a group of us went to lunch and, quite serendipitously, on the menu were drinks made with syrup of violets. Since some of us had writing to do this afternoon, we eschewed the vodka versions, but gave the club soda tonics a whirl. I wanted to see what happened when you added acid, would I get a pale rose drink? Alas, it seems not.

Turns out that commercial syrup of violets has citric acid added to it, which turns the pure syrup red, or it would if artificial colors were not added to make it violet again. Since it's already in the red form, adding more acid doesn't change the color.

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February 23, 2012

Twisted Threads: The history of the LCD

Learning to tell time when I grew up was a challenge. Clocks were analog - not digital. Everywhere. I can still see the little stiff pink paper clocks we were issued in first grade, with a brass brad fastening the hands to the face. We practiced setting the hands and reading off the time. Thanks to LCDs (liquid crystal displays) my sons had a quantiative sense of time much earlier, digital clocks blinked at them in every corner of their lives.

It took quite a bit to turn the initial discovery into a technology so smoothly integrated into modern life that we rarely notice it's there (how many LCD screens are in the room where you are now? Don't forget the ones in your pockets...). You can read more about the history of the LCD in this blog post by Ben Gross, a fellow at the CHF where I'm currently a short term fellow.

One of the pivotal developments was the leveraging of the twisted nematic effect...which made me wonder what worms (nematodes) and my iPad might have in common. The Greek root of threads....

February 21, 2012

The most Zen of molecules


Chemists are the Zen masters of science. Chemistry is a minimalist art. Its structures and mechanisms resemble the spare ink characters which trickle down scrolls. We seek elegant syntheses in which a few, carefully chosen pieces collapse into a whole. There is particular pleasure chemists take in crafting a molecule that strains the bounds of possibility — such as cubane — which evokes the aesthetic of Noh, where nearly impossible movements are made to look effortless. And despite our abilities to peer into the depths of a molecule with lasers or beams of neutrons, we haven't lost our connection our history. We are still distilling and crucibles are not merely historical artifacts. Zen sees a beauty in the old and well-used, a touch of wabi.

I've a piece in this month's Nature Chemistry on what makes a molecule beautiful (here, $), through the lens of the ten molecules that I consider to be most beautiful. I've already had a couple of emails suggesting gorgeous molecules that didn't make my list. What's on your list of elegant molecules?


My list of the ten most beautful molecules

azulene
carvone
ferrocene
ethanol
vanillin
penicillin
insulin
snoutane
cubane

February 13, 2012

An element by any other name would smell as sweet



Elemental naming was as fraught in the 19th century as it can be today (though now the IUPAC has rules and committees). Alternate names and symbols for elements persisted not merely for decades, but in some cases more than a century.

I've recently skimmed a number of articles about glucinium (Gl). Not familiar? It has 4 protons and these days is known as beryllium for the gemstone beryl, in which it can be found. Beryllium salts can taste sweet, hence glucinium. Beryllium was suggested early on an option, since the sweet taste of its salts was not a unique characteristic. Other metals, including lead and yttrium, form sweet tasting salts. Still, in 1890 many authors were insisting that glucinium was the preferred name, suggesting that the arguments were continuing nearly a century after the initial discovery. It took more than 150 years for the chemistry community to settle on beryllium.

Other elements have endured dueling names, including colombium (now niobium) and the sounds-too-awkward-to-be-real jargonium (hafnium!).


In searching for an appropriate image, Google turns up lots of bathtubs, including this one. Not only does an antiquated elemental name appear in the description of this wild tub, but the term angstrom as well. Translation software, I'm sure, but what is being (mis)translated?

And I couldn't resist the post title, as one of my fellow Fellows at the Chemical Heritage Foundation is a Shakespeare scholar.

February 09, 2012

Elemental tales: Strong waters

I ran across a reference to aqua fortis in one of the commentaries in Chemical News (1891). The conversation is about a suit in court where a chemist was injured when an inappropriately packaged bottle of aqua fortis spilled. (It had a cork, and according to the rather snarky commentator, the judge — and the chemist in question — should have known that aqua fortis should not be capped with a cork.)

Aqua fortis, literally strong water, was once the common name for nitric acid. Concentrated nitric acid is a strong oxidizing agent (I can still see the small scar on my mother's hand from a spill in her undergraduate days), and I imagine would rather quickly eat away any organic matter, such as a cork. Glass would obviously be the preferred medium for storage. The suit is a frivolous one!

The term aqua fortis has fallen out of fashion, but its companion term has not: aqua regia, the royal water that would dissolve even gold. Aqua regia, as any general chemistry text will tell you, is a mix of concentrated nitric acid and concentrated hydrochloric acid (a 1:3 ratio by volume). Neither acid alone with dissolve gold (or a variety of other hard to oxidize metals), but the trick lies in the shifting equilibria.

Nitric acid is able to oxidize small amounts of gold, turning elemental gold into ions, Au3+. These ions then react with the chloride ions from the hydrochloric acid to form the complex ion AuCl4. As the gold ions are pulled into the chloroaurate complex, the nitric acid oxidizes a bit more elemental gold. This goes on until all the solid elemental gold has been turned in chloroaurate ions floating around in solution. Imagine putting out a bowl of pretzels, as the pretzels get eaten, you try to keep it full by adding more pretzels. Eventually you run out of pretzels. The trick of using complex ion formation to drive something that isn't very soluble into solution is a common one.

Arguably the most famous example of this happened when the Nazis invaded Copenhagen. Franck and von Laue had given their 23 karat Nobel prize medals to Bohr to prevent the Nazis from confiscating them. Bohr was reluctant to bury them, sure that wherever they were hidden, a search would eventually turn them up. A chemist on staff, de Hevesy, thought to use aqua regia to dissolve the medals. After the war the gold was precipitated out and recast into medals; Franck received his recast medal in the early 1950s. Those were strong waters indeed that Bohr and de Hevesy waded into.


You can read a bit more about the saving of Franck and von Laue's medals at the Nobel site and see a video of aqua regia in action here.

February 06, 2012

Recording science

Bruce Gibb mused in a Thesis column in Nature Chemistry a few months back about taking small chunks of time to tune up your research apparatus. I'm on sabbatical leave this semester, and in addition to the research projects I've got going, I'm trying to devote some time on a regular basis to just this. I'm playing with an simple animation app, that would let me quickly put together animations for research talks or classes — and test driving apps for electronic research notebooks.

As a computational chemist, I've been balanced on the knife edge of digital record keeping my whole career. What goes into paper archives (hand kept, or printed), what stays electronic? Who backs stuff up, how often? Long term storage? I've encourage my students to think about how they want to track their data and, at least as importantly, their thinking about their data. Through it all (from punch cards to mag tape to memory sticks) I've always kept at least some of my work on real paper, in a traditional hardbound notebook. In ink. Dated. You know the drill.

I've been reluctant to let go of pen and paper. Just as I still outline just about any piece of writing, including this one, on real paper, I find I think differently off the keyboard. Keyboards tend to enforce a certain linearity of thinking, while a sheet of paper (or several and lots of stickies) lets me move into multiple dimensions, with fewer restrictions on insertions and more flexibility in formatting.

The work I'm doing now in the archives is facilitated by having photos of what I'm reading, many of the bound copies are too fragile to routinely scan or photocopy. Ironically, reading 19th century journals has catapulted me into the 21st century as far as my own record keeping is concerned. I'm using an integrated notebook app on my iPad which allows me to scribble and sketch by hand, take and incorporate photos (and mark them up if I wish), and input text from the keyboard. Finally, I can tag pages, and filter the notebook by tags (more consistent than my own hand written indexing procedures). The only thing I don't care for is that I can't write as small as I wish, making it harder to get an overall view of where I'm going. It's an experiment still,

Today's Nature [Nature 481, 410(2012)] has an editorial and an analysis piece on digital record keeping in science. One scientist notes that paper has nothing to offer her - she's gone entirely to her iPad. I may be right behind.

February 02, 2012

Ephemeral Elements

The late 19th and early 20th centuries were hotbeds of elemental discoveries (literally and figuratively). New elements came — and on occasion went. Some were known elements in unknown guises, such as previously unrecognized allomorphs. Others, like didymium, weren't elements at all, but mixtures of as yet to be identified elements (in this case neodymium and praseodymium). Some were more ephermeral than others.

Yesterday I ran across a description of the discovery of a new element in an 1890 issue of Chemical News: damarium, oddly enough reported in the Notes & Queries section and not among the research papers. The report of the gaseous element, collected in Damara Land (present day Namibia) was a bit over the top, even for a time when flowery prose was in style in scientific papers: "One of the party had in his hat a branch of a shrub, which in a very short time lost its green colour and assumed a violet blue..."

One contemporary report assumes it is a hoax, but several sources were not so quick to dismiss the claim, particularly in a period when elemental identity was in flux. At least one commenter wondered if it might be "helium" — an element as yet undiscovered on earth.

I wonder if it's worth tracking down the original cite if I can (the Chemiker Zeitung is available on microfilm at the Othmer). Ah...Google books has it here.

German chemical humor or not? What do you think?

February 01, 2012

A curious invention: drawing chemical structures



I am currently wending my way through fragile but fascinating volumes of Chemical News - a journal published by Sir William Crookes in the late 19th and early 20th century. It was a major journal at the time, looking rather like the current Nature in it's breadth of coverage. The society journals of the time typically reserved their pages for papers read by members and abstracts of papers thought to be of interest to them, while Chemical News and it's ilk included book reviews, reports of papers from a wide swath of journals in several languages and two robust arenas for conversation between scientists, readers and editors: Correspondence and Notes & Queries. They were a bit more open, too, to offer space to offbeat bits of science.

The volume I just finished (1890) has a rather contentious conversational thread winding through the Correspondence on what it means to be a FCS (Fellow of the Chemical Society) and should membership be more tightly policed vis a vis their chemical credentials. (At one point the secretaries of the Chemical Society accuse a former board member of having used fake letterhead to secure support for his position!) Many participants in the conversation resort to pseudonyms, some of which carry a bit of snark with them, and it's interesting that this controversy is playing out primarily in a commercial journal and not in organs internal to the Society.

My project involves tracking the correspondence around primary reports of research findings, so these raucous conversations, while fun reads, are of peripheral interest. I'll admit to finding other interesting tidbits to tag in my electronic notebook. It doesn't pay to be overly focussed when doing archive work, as long as I can avoid being completely dragged down the rabbit hole.

The Notes & Queries section appears just above the one page of adverts included in each issue, and yesterday this ad caught my eye: "The Benzene Nucleus. — An India-rubber Stamp in nickel-plated locket with ink-pad enclosed" 3s. At the top of the page, the last bit of editorial content appears — a report of a curious invention: a stamp for making benzene rings. The first benzene ring in a journal appeared in Chemical News (in 1879, eight years after the first graphical structure was used), so perhaps it's apt that it report this "little contriviance" in its pages. (And the inventor is a Fellow of the Chemical Society!)


Nowadays chemical structure drawing programs are commonplace, but when I was a graduate student chemical structures had to be hand drawn, using India ink (permanent, not water soluble!) on vellum. The Rapidograph pens used were expensive and notorious for getting clogged (irreversibly so). Rings were made using stencils, text added using mechanical lettering guides. Jiggle your hand and you had trouble that white-out might not be able to rescue you from. Blots? Argh.

I don't miss the days of chancy ink drawings for slide and papers, though I do miss the delight of pulling out pens and ink and paper. I do wonder, though, if note taking organic students would appreciate a little ink stamp of a benzene ring on the end of their pencil or pen?


Read about K&E lettering sets here.

January 31, 2012

Weird Words of Chemistry: Frigorific



I ran across this word when my youngest, who I'm coaching for the thermodynamics event for Science Olympiad,asked me why the freezing point of water was 32o on the Fahrenheit scale. The Celsius/centigrade scale was originally pinned to the freezing point and boiling point of pure water at 1 atmosphere of pressure. (Now it's pinned to absolute zero and the triple point of water.) What physical property was 0o linked to? The freezing point of something other than water? I had to admit I didn't know and now that my curiosity was piqued, went off to hunt it down.

The zero of Fahrenheit's temperature scale was essentially pinned to the temperature of a "frigorific" mixture of ice, water and solid ammonium chloride in a 1:1:1 ratio, along with the freezing point of water and the temperature of the human body. Frigorific seems to have been coined by Robert Boyle to describe particles of cold that were transferred from body to body, and ultimately got attached to mixtures that achieved a particular temperature regardless of the starting temperatures of the materials. Wandering through the old chemistry literature, I found this table of frigorific mixtures "sufficient for all practical and philosophical purposes, in any part of the world in any season," useful in the days before refrigerators, still useful for those who need a constant temperature bath at low temperatures.

The size of a degree was set by bisecting the difference between the point at which ice and water were in equilibrium and body temperature six times, or 64 degrees (26). Binary was easier to use when you had to make your own instrument than decimal.

Frigorific has essentially vanished from the chemist's vocabulary, though it's still apparently alive and well in the engineering literature. As words of science go, it sounds awkward to my ears — as roughly sharp as heaved Arctic ice.



Nova has an excellent piece on the hunt for absolute zero. Thanks, Kathryn J for the reference!

For more on what I think about well-formed science words, you can read "Neolexia" at Nature Chemistry.

January 25, 2012

What makes a molecule beautiful?

I just finished a piece for the March issue of Nature Chemistry on what (in my mind) make a molecule beautiful. I will admit a preference for sparer, less baroque structures. (If you want to know more about my molecular aesthetic, you'll have to wait for the piece to appear!). In the meantime there is an article in this month's Nature Chemistry with the intriguing title "Quantifying the Chemical Beauty of Drugs" [Bickerton et al. Nature Chem. 4, 93-97 (2012), full text is free]. It's not so much beauty in the abstract these chemists are trying to quantitatively capture, but desirability. How attractive is this molecule as a target for drug development? Would a chemist be willing to surrender time and bench space to the synthesis of this molecule?

The model takes as its inspiration Lipinski's rule of 5. If most or all of Lipinski's five characteristics are present, a molecule has a good chance of being a viable candidate for an oral drug [Lipinkski et al. Adv. Drug Dev. Rev. 23 3-25 (1997)]. The goal is to develop an expert model system, one that mimics (or improves on) a chemist's intuition about what makes for a good drug.

Earlier work had suggested that chemical fashion sense is drifting toward more baroque structures for their drugs, despite various rule sets that suggest that bloated molecules are less likely to survive to clinical trials. Chemists apparently like their molecules "tractable" (which would seem to mitigate against molecular overelaboration?), synthetically and otherwise! Molecular docility is desirable.

For a somewhat darker take on chemical intuition and seat of the pants drug design read "Chemists in the Shadows" by Adam Piore in March's Discover Magazine. The article focuses on underground chemists who are developing new recreational pharmaceuticals that skirt current drug laws (steroids for athletes, and rave drugs). The conceptual framework used by some of these chemists would be familiar to any medicinal chemist (particularly in the early days, before QSAR).

January 14, 2012

Being a philosophess


"...as a Philosophess she will not be discouraged by one or two Failures" Benjamin Franklin, in a letter to William Brownrigg dated 7 November 1773, where he wonders if Mrs. Brownrigg has succeeded in making Parmesan cheese (which I have to admit, I did not think was a cheese that colonial Americans knew of).

I appreciate Franklin's confidence that a woman could conduct rational experiments, particularly as at this moment I am virtually sitting on top of the site of Franklin's house in Philadelphia — I can see it from my window — working at being a Philosophess myself. I began a two month stay at the Chemical Heritage Foundation in Philadelphia today, as the Herdegen Fellow in the History of Scientific Information. My project is looking at how chemists, now and in the 19th century, deal with critical commentaries on the primary literature. Where are the commentaries located and does location change their tenor and/or content. I'm off to learn a bit about ways to computationally evalauate emotional tone, and to find some compelling narratives of critique in the 19th century and the 21st century.

I briefly wondered in my most recent Nature Chemistry Thesis column about what it meant for me to be working as both a historian of chemistry and a chemist, and how much of one field should we be exposing students of the other field to. Just how much history of chemistry does a chemist need to know to function well as a chemist? And if you do need to know something, what sorts of things? Dates? People? Materials? Methods? You can read my musings at Nature Chem, and those of Qian Wang and Chris Toumey on the same topic here. (Sorry...you or your institution need a subscription to see these, or if you would like a reprint of mine, drop me an email.)

December 29, 2011

Don't drink the water


"Don't drink the water from the sink!” read a sign taped to the mirror. As I was in rather desperate need of a glass of water before rehearsing the piece I would sing solo at Christmas, I was glad to find someone had left a gallon jug of distilled water and a stack of paper cups. Rehearsing the next day, as I went to grab a cup of water, a colleague pointed out that yesterday someone had mistakenly put out distilled water, which he had swapped for spring water. “Hopefully no one drank it!” he said.

“Why not?” I inquired.

“You’re not supposed to drink distilled water.”

Ah. Yes and no.

Distilled water is water that has been boiled, trapped as steam and condensed, leaving behind the non-volatile impurities (the stuff that doesn’t easily turn into a gas, like metal salts). Other components, like alcohols can still be carried along into the distillate.

Distilled water lacks most of the ions that tap water has, and thus, much of its flavor. Some of the ions (such as fluoride) in regular tap water may have health benefits, so a steady diet of distilled water may deprive you of certain useful trace elements. Conversely, drink water that is too hard (has a lot of ions in it) is correlated with kidney stones. It’s unlikely that the ionic content of your drinking water has a huge impact on your health (despite claims found here and there). All of the trace elements (including fluoride) can be found in other food sources. And distilled water’s osmotic pressure isn’t so different from that of plain water, therefore drinking it will not cause the cells in your body to suck up water until they burst and you begin to bleed internally (yes, this theory is out there, for both distilled water and deionized water). Bottom line, yes, you can drink distilled water.

That said, you probably shouldn’t drink the distilled water in most labs, as it is not tested to be free of bacterial contamination (which it can pick up in storage tanks) or volatile organic compounds. The same goes for bottled distilled water that hasn’t been tested to be certain it’s potable.


And while we're on urban myths about water, it's impossible to completely remove all the ions from water. Water is always in equilibrium with hydronium ions (H3O+) and hydroxide (OH-).



Image Copyright Filipe B. Varela, 2011. Used under license from Shutterstock.com

September 02, 2011

Changing exams


I just handed out a math assessment in my physical chemistry class, the same one I’ve used for the last several years. I generally don’t re-use exams (though I know colleagues who do), though I do re-use questions. By now I’ve been creating exams for more than a quarter of a century, and I wonder what the drift has been like over that time. How are the questions I ask now different (or not!) from what I asked 25 years ago? Or have the questions remained the same, and just the answers changed?

Fueling my introspection are the selections from the University of London’s 19th century bachelor’s degree exams. (H/T to a tweet from Nature Chemistry and the RSC). The chemistry question is one I could envision asking my students on an exam: “Explain the nature, from a chemical point of view, of the chief operations involved in the production of a photograph.”

The only catch, of course, is that the answer I’m expecting could be quite different than what the examiners in 1892 expected. In 1892, production of a photographic print necessarily involved silver, developers and fixing agents — and a darkroom. In 2011, production of a print could involve silicon and germanium, and a clean room. The theoretical underpinnings are less about pH and solution chemistry and more about semi-conductors and quantum mechanics.

What other reasonable exam questions might I ask, where the answers have changed so dramatically?

(And you have to love the example English question - just how important were werewolves in the 19th century?)


Photo of 39/365 Kodak Vigilant Six-20 Antique Camera, by M.Christian on Flickr.

August 23, 2011

Can gender gaps impede scientific progress?


My commentary on Marie Curie and the paucity of women chemistry Nobel laureates ends wondering

"...if what underlies the inability to fully acknowledge the social biases that obscure and downplay women’s scientific achievements, and the ways in which our spaces silently speak to us about who belongs and who doesn’t, who appears capable and who does not, is the assumption that if a Marie doesn’t make a critical breakthrough, of course, a Pierre somewhere will. Will chemistry make all the critical leaps it could, without the contribution of half of its finest minds?"

Last week, the president of Bryn Mawr College (where I teach) had an opinion piece in Inside Higher Ed about closing the gap for women in science and engineering. She, too, worries that progress in science and technology is impeded by lack of participation by women (and I would add the lack of recognition for women's work in these fields) President McAuliffe writes "As long as there is a gender gap in these fields, there will be an innovation gap."

Some readers of McAuliffe's essay had a hard time imagining that scientific progress could be impeded when women are underrepresented or sidelined in science and said so in the comments. Sam Kean's delightful Disappearing Spoon includes a clear counterexample: In 1934, Ida Noddak suggested the possibility of atomic fission. Her work was dismissed as "ill conceived and unfounded" by Emilio Segre (who won the Nobel prize in physics for the discovery of the anti-proton); Irene Joliet-Curie similarly thought it possible; Lise Meitner definitely discovered fission in 1939 (and Otto Hahn won the Nobel for the discovery).

Another example on the same theme: Lise Meitner also discovered the Auger effect, in 1922, a year before it was discovered by Pierre Auger (for whom it is named).

I realize these are historical examples, but they do prove the point. A blanket disregard (for whatever reason, be it gender, country of origin, venue for publication) for the contributions of a subset of scientists can impede the progress of science. As Matt

Sex in the citadel of science


"The problem was to give birth to a boy
and not a girl," said the fathers of the atom bomb.
Marie Curie did not give birth to any joy.
Tenderly she leans toward jars of glowing radium,
as she had earlier at the bed
of her sleeping daughter Irene. (And then she bore Eve!)
Four years clothed in bitter smoke, in a shed,
stirring a mass in ebullition, nothing secretive,

an iron cauldron, iron rod nearly as big as herself,
a shed no one wanted, not fit for cadavers.
Science is the primordial interest of my life,
nor do I know whether I could live
without the laboratory. Her problem—to give breath,
to let there be light, out of slag, abandoned earth.

— from "Her Crucible: A Poem of Marie Curie" by Margaret Almon


In the latest issue of Nature Chemistry, I have a commentary speculating on why women, despite their increasing presence in the field, win the Nobel in chemistry less frequently than 100 years ago. The essay is framed around Marie Curie, the first woman to win the Nobel prize in chemistry. This year marks the 100th anniversary of Prof. Curie's Nobel (her second).

It's not about mathematical ability (sorry Larry Summers, there's hard data that punctures your theory) or lack of inherent interest. Instead, I wonder if it has to do with the built environment: the size, color, shape of the laboratory and its equipment:
Built space is not neutral, as Winston Churchill noted, “we shape our buildings, and afterwards our buildings shape us.” As much as scientists use labs to create science, labs themselves create scientists. (Read the rest here....)

July 21, 2011

Psychrometry - or how to tell when it's crazy hot out


The heat index is 107 oF (42oC) at the moment. It's hot, and I'm procrastinating going outside by blogging.

My youngest son is doing summer theater, and their rehearsal space is not all air conditioned. So I bought him a cooling towel to help him stay comfortable. When he asked how it worked, I said it was like having a portable swamp cooler — a familiar item as my dad used one for years to cool his house.

The basic principle at work is that it takes energy to make water evaporate. Unless the relative humidity is 100% (in other words, the air has all the water it can hold), water will evaporate. If you keep running air past a wet surface (think a fan blowing past a damp towel, or the breeze blowing over your sweaty face), water will continue to evaporate as drier air is constantly being replenished. The energy to turn the water from a liquid into a gas has to come from somewhere, in this case, the surrounding air and the water itself. The air gets cooler. Whew!

The towel works similarly, there is a very large damp surface area (why the fancy $15 towel really does works better than a damp cotton lawn handkerchief, a much higher surface area than the smooth cotton weave) and as you move around, air moves past. The water evaporates, pulling energy from the water in the towel and makes it colder.

To get a sense of how much energy that is, it takes about 34,000 J to evaporate 15 grams of water (about a tablespoon). 34,000 J is roughly 8 nutritional calories. If you pulled all that energy out of a cup of water, the cup of water would cool off to about 41o F. (In practice, you don't get things this cool!)

This whole endeavor depends on the air being able to soak up some water, so if the humidity is too high, you are going to be crazy hot towel or no. Swamp coolers work great in desert areas (where my dad lives, for example), and are pretty much useless in New Orleans.

So how cool can you get? To figure it out you need the dry bulb temperature and the wet bulb temperature of the air. The dry bulb temp is just the temperature of the air measured in the usual way (being careful to keep the thermometer out of the sun). The web bulb temperature is obtained by blowing air over a thermometer whose bulb is fitted with a tiny damp sock. For that you can use a sling psychrometer (see the video).

Too hot to be slinging thermometers around? Look up the dew point (your favorite weather app will likely have it) and you can estimate the wet bulb temp this way:

1. Subtract the dew point from the ambient temperature (what your regular thermometer reads)
2. Divide what you get in step 1 by 3.
3. Subtract the result in step 2 from the ambient temperature.

Right now the thermometer outside my window reads 100o F, the National Weather Service says the dew point is 70o F, so I take 100-70=30; 30/3 = 10; so the approximate wet bulb temperature is 100-10 or 90o F.

Once you've got the wet bulb temp you can figure out just how much cooling you can get with a fan and a damp towel!

1. Subtract the wet bulb temp from the ambient temp (the dry bulb temperature)
2. Multiply the difference by 0.8 (assuming the process is about 80% efficient, which is a pretty reasonable estimate)

My calculations suggest that the best I could do to produce cool air in my study this afternoon would be 80% of *100-90) or 8 degrees of cooling. 100o F or 92o F? Both are way too hot...I think it's time to stop writing for the day and head for the pool!!


There are more sophisticated ways to do this, talk to the meteorologists if you want to know more.

Psychrometry comes from the Greek for cold ("psuchron") and should not be confused with anything psychiatric (unless you are talking about mad dogs and Englishmen...)

July 11, 2011

Writing (in) blocks


I'm writing this summer on a wide range of projects, which means writing for a substantial period every day. That said, I recently took a bit more than a full week away from the keyboard, doing no writing at all (not even email) except for few (handwritten) sentences each day. In their delightful piece in Nature on turbocharging your writing (free), Maria Gardiner and Hugh Kearns point out that "binge writing" — writing on the rare occasions when you have huge blocks of time — is generally not as effective as "snack writing" writing often (nearly every day) for shorter periods. (In my life it can be a challenge in some weeks to find an uninterupted 45 minutes or hour each day.)

Gardiner and Kearns note the barrier to writing again when it's been a long time since you last sat down to write can be huge. I won't argue with that. As I sat down this weekend to work on a 500-600 word column due this morning (at the latest!) after my week off, I could feel the creaks and groans. Really, 500 publishable words? How about I warm up with a blog post or write a couple of emails? Fortunately, deadlines are great motivators, especially those that are hard and fast as this one is (the paper goes to bed on Tuesdays, with or without my column). The piece went off this morning, and I'm ready to really dig into a couple of project tomorrow morning.

I would add to Gardiner and Kearns good advice that interruptions — those that knock at your door and your own desktop temptations — are a real hazard. Silence the phone, close the email browser, barricade the door (necessary in my house, the cat opens it otherwise), tell students/colleagues/kids that you cannot be disturbed for anything short of (fill in your favorite catastrophe here). Some research suggests that each interruption costs 5 to 10 minutes of time to refocus on the task at hand (plus whatever time it took to deal with the situation that led to the interruption). If you only have 45 minutes to write, and are interrupted twice, you may have lost nearly half your writing time.

If you want more advice about writing for the professional science journal, join me on Thursday, July 14 for a one hour conversation I'm moderating for the American Chemical Soceity with Dr. Cynthia Burrows (senior editor at Journal of Organic Chemistry) and Dr. George Schatz (editor in chief of Journal of Physical Chemistry.) More details are here. They are taking questions live, so sign up (it's free, but you need to register) and ask away.



Photo
is by Brandi Korte. Used under Creative Commons license.

June 06, 2011

Upping the anti

Science fiction is fast approaching science fact as scientists are progressing rapidly toward "bottling" antimatter. In a paper published online today by the journal Nature Physics, the ALPHA experiment at CERN, including key Canadian contributors, reports that it has succeeded in storing antimatter atoms for over 16 minutes. While carrying around bottled antimatter like in the movie Angels and Demons remains fundamentally far-fetched, storing antimatter for long periods of time opens up new vistas for researchers struggling to understand this elusive substance. ALPHA managed to store twice the antihydrogen (the antimatter partner to normal hydrogen) 5,000 times longer than the prior best, setting the stage, for example, to test whether antihydrogen and normal hydrogen fall the same way due to gravity........

Seeing hidden building blocks of life

Researchers from Finland and France have developed a new synchrotron X-ray technique that may revolutionize the chemical analysis of rare materials like meteoric rock samples or fossils. The results have been published on 29 May 2011 in Nature Materials as an advance online publication. Life, as we know it, is based on the chemistry of carbon and oxygen. The three-dimensional distribution of their abundance and chemical bonds has been difficult to study up to now in samples where these elements were embedded deep inside other materials. Examples are tiny inclusions of possible water or other chemicals inside martian rock samples, fossils buried inside a lava rock, or minerals and chemical compounds within meteorites........

April 27, 2011

Two thousand mockingbirds

I'm writing final exams for two intro chem courses. I try for a light touch brush of humor on at least a couple of the questions, it's stressful enough without every question probing deeply important things. (Stage notes: reverb last line)

Some useful (in this context) unit conversions:

2000 mockingbirds = 2 kilomockingbirds
10-6 fish = 1 microfiche
454 graham crackers = 1 pound cake
10 millipedes = 1 centipede
10 monologs = 5 dialogues
2 monograms = 1 diagram
8 nickels = 2 paradigms
10-2 mental = 1 centimental

Have more to suggest?

March 31, 2011

Bunsen and quantum mechanics



Today's Google doodle honors the 200th birthday of Robert Bunsen, the inventor (or not?)of the eponymous burner. The doodle is great, click on it and it bubbles and whirs.

"It is known that several substances have the property of producing certain bright lines when brought into the flame. A method of qualitative analysis can be based on these lines, whereby the field of chemical reactions is greatly widened and hitherto inaccessible problems are solved. We limit ourselves here to developing the method for alkali and earth-alkali metals and demonstrating its value by some examples.

The lines show up the more distinctly the higher the temperature and the lower the luminescence of the flame itself. The gas burner described by one of us (Bunsen, these Ann. 100, p. 85) has a flame of very high temperature and little luminescence and is, therefore, particularly suitable for experiments on the bright lines that are characteristic for these substances." Opening to Gustav Kirchhoff and Robert Bunsen, Annalen der Physik und der Chemie 110 (1860), 161-189.

Bunsen is not a name typically associated with the development of quantum mechanics, yet I might argue he is one of the key figures. The observation of line spectra and the realization that the lines are characteristic of particular elements is a significant step toward the development of quantum mechanics. It's one of the observations that Bohr was trying to explain in his model of the atom. General chemistry texts boast figures of line spectra to demonstrate the point - I showed several in my lecture last week. This apparatus developed by Kirchoff and Bunsen made possible the routine observation of such lines. I have a beautiful brass example in my office.

This paper goes on to note that sodium, even at very low concentrations produces quite bright lines. It reminds me of the many happy hours I spent playing with my mom's gas stove and making flame tests on anything I could scrounge up (most of which contained sodium). Is this the formative experience that impelled me toward quantum mechanics? Who knows! I do still think of sodium and line spectra every time the pasta boils over and the flame on my stove flares that characteristic sodium yellow-orange.

Happy birthday, Bunsen, I might not have a job without you!


There is more on Bunsen beyond the burner at The Sceptical Chymist.


March 24, 2011

Writing Science: The End






My quarter long science writing course came to a close last Friday. We test-drove one of the methods sections students wrote early on (how to make the perfect cup of hot chocolate, rather than coffee), ate pastries from the wonderful shop down the street and read from favorite works we'd written or read as part of the course. It was a lovely way to bring things to an end.

The final "writing" prompt
Bring a selection (roughly 200 to 300 words in length) from a piece you wrote that you'd like to read or a piece you read during the course that you'd like to share.

Thanks, too, to everyone who followed along, and especially those who shared, here (in the comments) and there.

Reading
I had more on my list of things to read than we could possibly get to -- if anyone would like the full reading list, send me a note and I'd be happy to share.

Final writing assignment
Write an 'In Your Element'-style essay for Nature Chemistry's science writing contest on any one of the following elements — helium, nitrogen, sodium, copper, bromine, indium or plutonium. 700-800 -words. All the details are here. Deadline is August 1, 2011.

Illustration is from Wikimedia commons.

March 23, 2011

ACS On Campus Rides into Houston Next Month

ACS On Campus heads to Houston, TX, on April 15, for ACS on Campus: Rice University. Sessions will range from a discussion of what the "Journal of the Future" will look like to a SciFinder Solutions Session demo with our partners at Chemical Abstracts Service. For a complete list of events and speakers at Rice University, as well as an opportunity to RSVP, visit pubs.acs.org/page/4librarians/acsoc/rice.html. You can also find video, PowerPoint presentations, and other content from previous ACS On Campus events at pubs.acs.org/r/acsoc. We look forward to seeing you on campus!

March 10, 2011

Lab Notes: Walking the walk


Some days you have to be willing to walk the walk as well as talk the talk. My primary care physician keeps copious, real time notes on her encounters with her patients. She starts every visit with her pad in her lap - writing notes to herself (and best, yet, notes to me on what I need to follow-up on, complete with phone numbers and details) as the visit proceeds. So when she inquired about my immunization status during my physical yesterday, and she asked about tetanus, I thought I recalled getting a booster in 2008. Nothing in her notes on that.

Do we trust my memory or her notes? We'd chatted about my science writing, and given my expressed thoughts about (good) field notes - it was no contest. I have a sore arm, but no regrets.

The book I really want to read about field notes is not yet out (but I've ordered a copy) - Field Notes on Science and Nature edited by Michael Canfield of Notes from the field. The cover is beautiful and the contents look intriguing.


Image is from Wikimedia commons. A 1964 poster boosting boosters.

March 03, 2011

Writing Science: Punch Lines

"When a thing is funny, search it carefully for a hidden truth." George Bernard Shaw

How seriously should we take science? Is science inherently funny - are those odd spots where truth is hidden? Can science be humorous without being a caricature? Do you have to be a scientist to get the joke? What role might humor play in teaching science? And for that matter, why are words with a hard c sound (like cryogenic) funny?



Readings


Brian Malow - superb stand up science comedy
The Big Blog Theory - the science behind the humor on The Big Bang Theory

Periodic table humor.

XKCD a comic strip which carries the warning: "this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors)." And apparently unsuitable for high school students, it's blocked as "adult content" where I'm on the web. I'm in the high school nominally supervising the theater tech crew as they construct a set. Don't ask about the decibel level!)

Men of Mystery (subscription only) Taking on the stereotypes of science: why are scientists drawn as guys in white coats with bad hair? M.M Francl, Nature Chemistry, 2, 68-70 (2010).

February 25, 2011

Writing Science: Poetic Movements

Paul Dirac (Nobel Prize in physics, 1933) once said: "In science one tries to tell people, in such a way as to be understood by everyone, something that no one ever knew before. But in poetry, it's the exact opposite."

Is it? Can or should poetry and science mix? Should we teach scientists how to write poetry as a matter of course?




Writing Prompt

Using 2 to 5 words from the list write a poem. Stuck for form? Try haiku.
(5 syllables, 7 syllables, 5 syllables)

protein, atom, diffuse, drosophila, phylum, differential, set, scalar, momentum, graphite, ionized, equilibrium, eutrophic, entropy, catalyst, precipitate

Reading
When Science and Poetry Were Friends, an essay by Freeman Dyson
The Future of Science is Art, Jonah Lehrer, Seed Magazine
Roald Hoffman (Bio here) Individual poems here.
Sabrina Vourvoulais Fata Morgana
Karl Kirchewey, Propofol
J.C. Todd, Instant of Turbulence and Endless Caverns, in What Space This Body
Photo is from surrealmuse, used under a Creative Commons license.

Writing Science: Fact in Fiction

Can you communicate science via fiction? What are the risks? the benefits? Are there signals in a fiction piece that mixes fact and fiction that help you sort? Should there be?

Writing Prompt
Write a (very) short story using the following three words: planet, curry, madman. Don't like these words? Generate a set using a random word generator.

Reading
  • "A Little Heart" Baruch, Jay. Fourteen Stories: Doctors, Patients, and Other Strangers. Kent State University Press, 2007.
  • "Dissections" Baruch, Jay. Fourteen Stories: Doctors, Patients, and Other Strangers. Kent State University Press, 2007.
  • Rothman, Claire Holden. The Heart Specialist. Cormorant Books, 2009. Ch. 13
  • "Carbon: Part One" by Justina Robson and Andrew Bleloch in Ryman, Geoff. When It Changed: 'Real Science' Science Fiction. Comma Press, 2010
  • "Moss Witch" by Sara Maitland and Jennifer Rowntree in Ryman, Geoff. When It Changed: 'Real Science' Science Fiction. Comma Press, 2010
  • "Without a Shell" by Adam Marek and Vinod Dhanak in Ryman, Geoff. When It Changed: 'Real Science' Science Fiction. Comma Press, 2010
  • “A History Lesson” Robert Scherrer, Nature, 469, 574 (2011).
  • “A Question of Breeding” Jeff Hecht, Nature, 453, 562 (2008).
  • “All of Me” Ed Rybicki, Nature, 454, 1028 (2008).
  • “The Last Laboratory” John Gilbey, Nature, 469, 126 (2011).

Photo is from Wikimedia.

February 21, 2011

Scientists should blog about their pets

My latest Thesis column is out in March's Nature Chemisty: Blogging on the sidelines (subscription needed). In part a response to Royce Murray's editorial in Analytical Chemistry last fall, the column considers what the role of blogging critically about the primary literature might be. Does blogging by scientists about science help researches? My short answer is yes, it's an effective post-publication filter, a niche that has been filled at other times in other ways.

But I also think that scientists writing about life in the lab or their pets or commute has a role to play in making better science. That wouldn't fit in the column, so the delightful editors at Nature Chem have posted it on their blog.

December 03, 2009

Nitrogen Dioxide, Ozone & Lead Partner to Increase Pollution Dangers to Urban Children

Scientists from the University of California, Irvine have found that Nitrogen Dioxide (NO2) and Ozone (O3) react with surfaces painted with lead based paint to increase the release of lead from said paint posing an even greater risk for children. By Roberta Barbalace

October 29, 2009

The final step in evolution is extinction


Dear Gentle Readers,

For a long time I have been an author and outlet for many in the chemistry community and the run was, to say the least, more than I could have ever expected.  It was through this blog that I found a cathartic release of frustration, anger and, most importantly, the insatiable curiosity I have always had for science.

Some time ago, a reader named Bethany Halford asked me a question about why I blog and I framed my answer in as quotable of a context as I could – because I wanted to see how far I could push this thing.  I think I have pushed it far enough and I have reached the end of my intellectual interest and now wish to divest myself from blogging so that I may completely free myself for the pursuit of other things.  No doubt you have noticed that the frequency of posting has diminished as my other projects have begun to take off and my fullest efforts are required there.

Now that blogging appears to be an activity which is regulated by the FTC, I think it’s safe to say that it has finally arrived.  I now know (or at least I think I know) what it takes for someone to develop a successful web presence and what sort of innovations are needed to build on that presence.  My programming skills are also none the worse for the endeavor.

In any regard, this is the end.  The lights will be shut off next month, the gmail account will no longer be answered and the chemblog store with its catchy EJ cup and functional group poster will be deleted.

Good bye, world.

Yours,

Kyle Finchsigmate

October 23, 2009

I would like a fish in my hood


Today I constructed a brand new shelf in my hood.  I love hood shelves.  You can put chemicals on them, solvents, glassware… all kinds of things that would ordinarily go somewhere else more… public.   After I was done constructing my masterpiece I began to admire my handiwork and populate it with things (mostly chemicals) but, while I was standing there talking with my hood neighbor, the consensus was reached that the new shelf begged a novel hood design:  it needed hood Feng Shui.

While I have no idea what Feng Shui actually is, I’m 99% certain it has something to do with colorful fish or those lucky bamboo things they sell at Target and since 99% is basically 100% I figured my hood needs a fish inside of it.

Of course, I’m a realist.  I can’t put a whole aquarium in my hood – that would be chest slappingly short bus retarded.  Since I don’t want to run an air pump through my hood I need a labyrinth fish.  The king of such fish is the betta fish or the Siamese fighting fish.  And  because I’m 99% sure Feng Shi also means making sure your shit matches, it needs to be in a round bottom flask.  (That useless 29/42 ground glass is suddenly less useless!)

So, I’m thinking about something like this:

fishinaflask

I would put the fish in a flask on my shelf, where I would feed it and it could watch my reactions for me at night (and tell me who the fuck keeps turning my hood’s airflow alarm back on).

Alternatively, I could set up an ant farm and run the ant tubes all over my hood.  That would prolly kick ass, too.

October 16, 2009

Initial Energy Audit for 70s House Eco Renovation

This energy audit was conducted on our house as part of our 70s house eco renovation project to help us prioritize weatherization and energy efficiency projects. This is one in a series of articles documenting the eco renovation of our house. By Erik North, Free Energy Maine LLC.