Cell Phone Spectrometer

(or, A Guided Inquiry Approach to Teaching How to Think About Analytical Instrumentation.Wired has a great article about a scientist at the University of Illinois / Urbana-Champaign who published software and plans for turning a cell phone camera into a simple DIY spectrometer.

The camera simply takes a photo, and the resulting JPEG is analyzed by a Windows program. The software and source are available under Creative Commons on the project’s website.

“Science is basically about using your senses to see things – it’s just that we’ve got so much technology that now it’s all hidden,” Scheeline said. “The student gets the impression that a measurement is something that goes on inside a box and it’s completely inaccessible, not understandable – the purview of expert engineers.”

“In order to get across the idea, ‘I can do it, and I can see it, and I can understand it,’ they’ve got to build the instrument themselves,” he added.

This is a fantastic example of how to encourage people to learn by taking a complex idea and breaking it into simple (and fun!) to reproduce steps.

Scoring a dewar from the U.W.

My buddy yoyojedi got quite the score at the last U.W. public auction: a 35 liter dewar, for only $150! The folks at Central Welding (our preferred purveyors of liquid nitrogen) had never seen one so big. But that didn’t stop them from filling it for us. Just halfway, thanks.

Fill 'er up!

Handling LN2 is a somewhat tricky business. First there is the obvious threat of burns and frostbite when handling a substance at -321 °F. Since it has an expansion ratio of nearly 1:700, there’s also the possibility of explosion if it is stored improperly (hence the use of a proper dewar rather than, say, a thermos). Then there’s the threat of asphyxiation, should enough of the liquid turn to gas in a closed space (for example, an automobile). But none of this deterred us as we happily purchased about 12 liters of the stuff.


(Yes, we rode just a short distance with the windows down.) Fortunately, all went well and many fun freezing adventures were had by all. I was so happy with the day that I got myself a pony keg of argon to celebrate. I gotta say it was a GOOD DAY.