Chemistry on Holiday: Science Cookies

'tis the season for baking on the home front. It's been mostly biologically based leavening (yeast) at my house, but some strictly chemical rising has been going on as well. For an interesting mix of chemistry and biology in the kitchen check out Not So Humble Pie's science cookies: zebrafish, drosophila, gel electrophoresis and atoms are on the menu. Something to keep in mind for the next snow day around here...

Unfortunate Acronyms: PUS

When I was lecturing on lasers this week, I was surprised to discover how many of my students were unaware that laser was an acronym (Light Amplification by Stimulated Emission of Radiation). Science is replete with acronyms - Ira Levine once essayed that if you knew enough acronyms you could pretend you knew computational chemistry - good, bad, really funny and occasionally unfortunate.

On my desk is a paper which refers (with as near as I can tell with a straight face) to "PUS research." Public Understanding of Science. I swear this is true.

If you've got a favorite one - funny, famous or truly unfortunate - leave it in the comments for all of us to enjoy...

---

Related Posts
Science in the kitchen: Jello lasers
Romancing the stone (steampunk lit and lasers)

Sex and the scientist

(Cross posted at my other blog.)

I am in the midst of writing an essay for Nature Chemistry - about why people are so curious about stereotypes of scientists, but seem less so about other fields. There is the DAST (draw a scientist test), but not as far as I can discover similar instruments to assess the images of other professions. Where are the DATTs (draw a teacher test) and DACTs (draw a chef test)? On the other end of the cultural spectrum there is the Big Bang Theory.

The earliest anthropological study I can find dates to the late 1950s and is by Margaret Mead (yes, that Margaret Mead) and Rhoda Metraux under the auspices of the AAAS. They analyzed thousands of essays, drawn from a set of 35,000 written by US high school students. The 1 page essays were written in response to one of three prompts. Prompt I read "When I think about a scientist, I think of..."

What took my breath away was Prompt II (italics are not mine, but as given in Mead's original paper - Science 126, 384-390 (1957)):

If you are a boy, complete the following statement in your own words.
If I were going to be a scientist, I should like to be the kind of scientist who...

If you are a girl, you may complete either the sentence above or this one:
If I were going to marry a scientist, I should like to marry the kind of scientist who..."

Math Man points out that I did both.

UPDATE: So there is a draw-a-teacher test (DATt) (H/T to Neil who commented on drawing God - another area that has been explored by educators and psychologists)

---

Images are from K.D. Finson, J.B. Beaver, B.L. Cramond, "Development and Field Test of a Checklist for the Draw-A-Scientist Test" School Science and Mathematics 95, p. 195 (1995).

Feeling quizical?

Pew tracks American's familiarity with the news of the day - my kids took the latest quiz (and each scored in the top quartile for adults and so were quite pleased with themselves). I played with something similar for science...it's definitely NOT rocket science, so if you've any science background at all -- you should score 100%.

If you're looking for the answers - they are here.

Nobel quote

After I won a Nobel Prize I suddenly turned into an omniscient sage, whereas formerly I was simply a workaholic.

Richard Ernst, Chemistry 1991

(H/T to Nature Chemistry's October editorial)









Photo of Dirac's Nobel Medal is from: rubberpaw at Flickr

Quantum Mechanics on the Silver Screen: Science of Watchmen

I drive my kids crazy when I critique dramas based on their science content. Listen to the science consultant for Watchmen (Physicist James Kakalio of University of Minnesota) talk about the quantum mechanical underpinnings of Dr. Manhattan's powers.

The pressure to preserve

Stephen Davey, associate editor for Nature Chemistry, blogged at the Sceptical Chymist about visiting the National Archives and seeing the Declaration of Independence, the Constitution and the Bill of Rights. He was surprised to find that the documents were stored under helium as opposed to argon - and wondered why. That started me wondering as well, particularly since the inert gases are not interchangeable in all circumstances (you can use helium to dilute the air mixture for diving, but not argon, for example.)

Helium is both more expensive (not an issue in this context, the cost of the gas inside the cases has got to be the least expensive piece!) and difficult to work with than argon. It can leak out through materials that seem air and water "tight". That's why those latex balloons that looked so cheery on the day of the party are withered and droopy by the morning. They're waterproof, but not helium proof.

In the 1950s the US National Bureau of Standards (now NIST) was charged with deciding on the best way to preserve the Charters of Freedom (the three founding documents of the United States of America). (You can read the full report here.) Helium was chosen, despite its propensity to leak through many materials, partly because a high purity, local source was readily available but most because of its thermal conductivity.

The designers of the encasements wanted a way to measure the pressure of the helium within the cases without having to open them, or remove a sample. Since the thermal conductivity of helium is very different than that of air, changes in the thermal conductivity (how heat moves between the panes) could be used to detect leaks. Argon's thermal conductivity is similar to air, so if argon leaked out and air in, the change would be hard to detect.

New casements were designed about ten years ago, with argon as the gas of choice this time. Sapphire ports are embedded to allow the atmosphere inside the cases to be monitored spectroscopically - by passing a beam of light through the port. Since the new methods of monitoring don't require the inert atmosphere to have a different thermal conductivity, it allows argon - which can't wiggle its way out the way helium can - to be used.

---

The photo is from The Science News-Letter, vol. 62 (Dec. 6 1952), p. 359.

Word Wraps: From the ACS meeting

I am at the ACS meeting in Washington DC, here as "press" rather than chemist. It's a very different way to see the meeting. I went to a press briefing this morning - on the first phases of development of aresol vaccines for measles (Robert Sievers). The press center is tucked away next to the registration, and has everything a writer might want: food, wireless access and a steady stream of caffeine and conversation.

The briefings are being streamed live on the web and journalists watching can send their questions in to be asked. Miss something the first time round? Watch the replay here.

Listening as a scientist to a talk, and as a writer to the briefing turn out to be slightly different experiences. Both require critical listening, but listening as a writer prompts me to think far more about the words the science is coming wrapped in. The shorthand scientists use sounds almost staccato in this context. "Measles naive" instead of "never exposed to the measles virus" or "no evidence of viremia" instead of "no measurable virus in the bloodstream".

We try to be both precise and concise, but I wonder how often the combination in giving a talk, or even reading a paper in the literature leads to attentional processing deficits? An interesting experiment in attentional processing is to present subjects with a rapidly changing sequences of letter, interspersed with numbers. If two numbers are placed too close together, subjects can "miss" the second letter while their brain is busy processing the first. Pack too much into a sentence, and your "subjects" might miss bits.

---

My Thesis column in Nature Chemistry this month, Stretching Toplogy, takes a slightly different tack in thinking about the ways words wrap around science.

Chocolate Math Mystery

My youngest and I are heading into Philadelphia tonight for a chocolate dessert feast, so it seems apt that a friend sent me this bit of mathematical magic this morning - with a plea to explain how it works.

Chocolate Calculator:

This is pretty neat. Don’t say your age; you will probably lie anyway!

DON’T CHEAT BY SCROLLING DOWN FIRST

It takes less than a minute. Work this out as you read.

Be sure you don’t read the bottom until you’ve worked it out!

1. First of all, pick the number of times a week that you would like to have chocolate (more than once but less than 10)
2. Multiply this number by 2 (just to be bold)
3. Add 5
4. Multiply it by 50 — I’ll wait while you get the calculator
5. If you have already had your birthday this year add 1759. If you haven’t, add 1758.
6. Now subtract the four digit year that you were born.

You should have a three digit number

The first digit of this was your original number (i.e., how many times you want to have chocolate each week).

The next two numbers are YOUR AGE! (Oh YES, it is!!!!!)

THIS IS THE ONLY YEAR (2009) IT WILL EVER WORK, SO SPREAD IT AROUND WHILE IT LASTS!

So how does it work?
Expressed algebraically, the procedure if you have had your birthday can be written as:
50 (2n +5) + 1759 - y
where n is the number you chose and y the year you were born

The author asserts that this will produce a number where the digit in the 100's place is n and the remaining digits are your age or 100*n + age. If you have had your birthday this year, your age in 2009 can be written in terms of your birth year, y, as
age = 2009 - y
So the formula should produce 100*n + (2009 - y).

It is trivial (I love saying that) to show that

50 (2n +5) + 1759 - y = 100*n + (2009 - y)

This will not work if your age is greater than 99, but as long as you are younger than that, the last two digits will always be your age even if the number of times you want to eat chocolate in a week is greater than 10 -- so in either case eat all the chocolate you want!

Weird Words of Science: Azote

I was playing Scrabble online the other day and when a z materialized on my rack near the end of the game was desperate enough to try "azo". Good news, what I thought was chemist's shorthand, the dictionary thinks is a word. "Azo" has been part of my vocabulary since I was very young. My dad's graduate work was on azides - molecules that contain three linked nitrogen atoms (N₃) tagged at the end and that are notoriously unstable (a fancy chemistry term for "could explode at any time" - at a dinner for his PhD adviser some 25 years later the number of people around the table lacking fingers was astounding). Azo compounds are molecular relatives of the azides - molecules that have an two linked nitrogens in the middle (R-N=N-R). Some azo compounds are brightly colored and generally they are more stable than azides.

As a rule of thumb, if you see "azo" in a compound's name, it's likely to have nitrogen in it somewhere. Why? French chemist Lavoisier dubbed the fraction of air that cannot support life "azote" from the Greek azotos: without + life. We now know that roughly 80% of the air we breathe is nitrogen gas - hence the connection between azo and nitrogen.

Lavoisier's alternate terms was "mephitic air" -- another Greek import, this time from the name of the goddess who prevented noxious smells from arising from sewers: Mephitis. Ironically, while many nitrogen compounds smell awful (dead fish anyone?), nitrogen gas, Lavoisier's mephitic air, is odorless. That goddess has lent her name to smellier pursuits though - the striped skunk's Latin name is Mephitis mephitis. I can personally attest to the smell.

---

Photo used under Creative Commons license. Credit to Kevin Bowman.