Chemistry
retrospectacle | September 25, 2007
One of the more, uh, interesting culinary experiences I have had in Asia was ordering fugu (pufferfish) sushi at a Japanese restaurant in China. A few moments after my order, a plate was sat in front of me that contained lots of fresh, white sushi slices...positioned just below the still-gasping decapitated fugu head. My dad was so disturbed that he asked the waitress to take the fugu head away while I happily chomped away at the delicious sushi. Well, at least I knew it was fresh!
The fugu, or pufferfish, is a delicacy in Asia (and particularly Japan) due to the dangers inherent in…
jstemwedel | September 4, 2007Since scientist-on-scientist communication is a longstanding topic of interest in these parts, I wanted to point out a recent (August 13, 2007) article in Chemical & Engineering News (behind a paywall, but definitely worth locating a library with a subscription) that offers tips for writing journal articles. It's quite a substantial article, drawing on advice from "dozens of scientists and engineers around the world in academia, industry, and government" -- which is to say, the people who read and write journal articles as part of their jobs.
It goes without saying that this crowd has…
jstemwedel | August 16, 2007On the basis of this article about emissions from laser printers, our department administrator came by this week to take my HP 1200 series LaserJet away.
I said I wanted to keep it.
The worry is that the particles of toner emitted when printing with a laser printer may be just as bad for human health as secondhand cigarette smoke.
But ... I like my laser printer! It yields a higher quality printout than the inkjet printers I've used. And it's still working really well. And it's not like I'm printing stuff on it all day, every day. There are some days when I don't print anything at all.…
jstemwedel | August 15, 2007As I mentioned in my last post, I was sucked out of the blogosphere for much of last week by the International Society for the Philosophy of Chemistry (ISPC) 2007 Summer Symposium .
I did not live-blog the conference. I did use overheads. Why, other than being a tremendous Luddite, would I use overheads?
One big issue that has me using overheads rather than PowerPoint presentations is time. As many conferences are, this one was scheduled within an inch of its life. Each speaker had 20 minutes to talk and 5 minutes at the end for questions and answers. Indeed, if the previous speaker…
retrospectacle | August 9, 2007Cone snail shells are beautiful, but their venom is a potent cocktail used to paralyze passing fish. The venom is a witch's brew of hundreds of novel compounds, many more than are found in snake venom (which has been used by science extensively as well). One compound in particular is a pain killer many times more effective than morphine.
The venom apparatus consists of a muscular venom bulb which pushes venom from a gland down a long duct to a chitinous tooth (the pink thing). The tooth is like a little barbed harpoon, which becomes soaked in venom and jabs into prey. Venom is quickly…
jstemwedel | July 27, 2007Chad and Rob have already noted this piece of news about soon-to-be-published research indicating that the order in which high school students are taught physics, chemistry, and biology makes very little difference to their performance in science classes at the college level, while a rigorous math curriculum in high school gives their college science performance a significant boost.
I have a few things to say about this.
Good math instruction is good for students.
As Chad points out, it helps you build problem solving skills and think systematically. To the extent that these skills are…
jstemwedel | July 27, 2007
During one of our recent visits to The Tech Museum, we ran across a fun hands-on activity. The pretty purplish circle pictured here is what the younger Free-Ride offspring produced in this activity.
The kids thought they were just doing an art project. But there's science in that art.
The art project works using the same principles as a time-honored separation technique called paper chromatography. In this post, I'll lay out some ways you can play with paper chromatography at home, and I'll point you toward the scientific principles at work underlying the behavior of the materials you'll…
jstemwedel | July 23, 2007My last post for the basic concepts series involved phases of matter and transformations from one phase to another. This post will look at how a phase change can be put to practical use in a common household appliance -- the freezer. My aim here is to give you a good thermodynamic feel for how a freezer works. As a bonus, I'll explain why leaving the freezer door open is a futile strategy for cooling down a hot kitchen.
If you're constructing a freezer (or a refrigerator -- the same basic set up, but with a different temperature range), the goal is to keep the temperature in your cold…
jstemwedel | July 20, 2007Since Sandra has posted links to sites with brainy games for kids*, and Karmen is working on her list of science education web sites for children, I thought I'd mention one of my favorite online destinations for kid-strength chemistry. Luddite that I am, what I like best is that the site isn't hypnotizing your child with a virtual chemistry experiment, but actually gives you activities to do with the child in the three-dimensional world.
The site is chemistry.org/kids, a portal of the American Chemical Society website aimed specifically at kids, parents, and teachers.
For summer (here in…
retrospectacle | July 19, 2007 On my way over to a friend's house last night, an unusual thing happened: a firefly which was in the process of lighting up got squashed against my windshield at that exact moment. While there wasn't much resembling an insect left, smeared across the glass was a streak of glowing green goo which continued to fluoresce for 5 or 6 seconds before fading into black. In fact, in the last few moments the guts glowed brighter than the bug did.
Which got me thinking about 2 things. One, how do fireflies bioluminesce? And two, does science use this glowing protein in a similar way as GFP (green…
jstemwedel | July 17, 2007The July 9 issue of Chemical & Engineering News (alas, behind a paywall -- but worth checking to see if your library has an institutional subscription) has an interesting piece [1] on the recently-settled trial in which the makers of Equal (an artificial sweetener based on aspartame) sued the makers of Splenda (an artificial sweetener based on sucralose) over their claim in advertisements, "Splenda is made from sugar, so it tastes like sugar." The makers of Equal (a company called Merisant) asserted that this claim was deceptive.
Most of the C&E News piece focuses on the ways the two…
jstemwedel | July 11, 2007
People sometimes worry that throwing ethics coursework at scientists-in-training is not such a great strategy for training them to be ethical scientists. (I've explored worries of this sort myself.)
For one thing, at many schools the existing coursework may be a fairly broad "moral issues" course aimed at understanding what it means to be a good person rather than a good scientist.* Or the ethics course on the books may have more to do with meta-ethics (the examination of various theoretical frameworks grounding claims about what is good and what is bad) rather than practical ethics. And…
jstemwedel | July 9, 2007Some months ago I made a (seemingly idle) threat to follow up my basic concepts posts on polar and non-polar molecules and intermolecular forces with a post on phase changes. Finally it's here!
Since the discussion here will be leaning on a number of the concepts discusses in the earlier posts, don't be afraid to click back to them to re-read any of the parts that seem rusty.
First, in this post I'll only be discussing the three phases of matter taken for granted in intro chemistry classes, namely, solids, liquids, and gases. I won't be getting into more exotic things like plasmas; there…
jstemwedel | July 4, 2007It's the 4th of July, and here in the U.S., that usually means fireworks.*
What could be better than explosions in pretty colors? Maybe a few details of how firework makers get those colors into the fireworks.
If you've taken a chemistry course with a lab, you may remember having done "flame tests" of compounds. You dipped you little wire loop in the compound you were characterizing, stuck it in the Bunsen burner flame, and watched what color the flame turned. (You had to pay attention; if you missed the color your compound burned, you were left looking at the plain old Bunsen burner flame…
jstemwedel | June 29, 2007The June 25th issue of Chemical & Engineering News has two pieces that talk about ways people are using features of the "new internet" (or Web 2.0) to disseminate and explore chemistry online.
Celia Henry Arnaud's article "A New Science Channel" looks at efforts scientists and scientific organizations have made to harness YouTube as a tool of outreach. Organizations like the Museum of Science, Boston and AAAS have taken videos created for museum kiosks and meetings and posted them on YouTube in the hopes that they "go viral" and reach a broader audience. (As AAAS discovered, this can be…
jstemwedel | June 25, 2007There's an article in today's Inside Higher Ed on the building momentum in college chemistry courses to make the labs greener -- that is, to reduce the amount of hazardous materials necessary in the required student experiments. What grabbed me about the article is that it looks like the greening of the chem labs may not just be good for the environment -- it could be better for student learning, too.
First, consider a chemist's description of how to revamp laboratory experiments to make them greener. The article quotes Ken Doxsee, a chemistry professor at University of Oregon:
"We look at…
jstemwedel | June 7, 2007In the June 4, 2007 issue of Chemical & Engineering News (which is behind a paywall accessible only to ACS members and those with institutional subscriptions, I'm afraid) there's an article on how college and university labs may be impacted by the interim final regulation on chemical security issued recently by the Department of Homeland Security.
In a nutshell, that impact looks like it could involve thousands of hours and hundreds of thousands of dollars for a single university to comply with the rules, even if the chemicals they use fall into those specified by DHS as being at the…
jstemwedel | June 4, 2007Via a press release from Consumers Union, the July 2007 issue of Consumer Reports will include a call for more testing and regulation of nanotechnology:
[T]he risks of nanotechnology have been largely unexplored, and government and industry monitoring has been minimal. Moreover, consumers have been left in the dark, since manufacturers are not required to disclose the presence of nanomaterials in their labeling.
Your first question may be, what the heck is nanotechnology? From the press release,
Nanotechnology involves creating new materials or reducing the particles in standard materials…
worldsfair | May 24, 2007"Food chemistry includes not only food analysis to find out what is in the food, but also about how and why food changes during processing and storage, how different ingredients interact, how changes in pH and chemical make-up can be used to preserve food and prevent micro-organisms from growing or in the case of bread, cheese, beer or wine encourage the right organisims to grow."
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worldsfair | May 24, 2007"Food science and food technology are used interchangeably as there is rarely any distinction between them. While it is more likely that a food technologist would be working in industry rather than at research, all food scientists & technologists are concerned with the science required to understand and improve our food supply."
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