Monday, 20 January 2014

09:03 – Costco run and dinner with Mary and Paul yesterday. They were telling us about their experiences judging elementary school science fair projects. Ordinarily, they’re volunteer judges for middle- and high-school science fair projects, but this time their schedules didn’t allow that so they ended up judging the elementary school projects. They said the projects ran the usual gamut. Some were good science but mediocre presentation, some the reverse and a couple were both good science and good presentation. They and the other judges had to rank the top five projects, which will go on to the next level. Apparently, the top three or four were pretty easy to rank, with numbers four and five less so. Of course, all the kids got a certificate for participating.

While I was making up the Kastle-Meyer reagent over the weekend, I thought about Albert Einstein’s famous definition of insanity as doing the same thing over and over and expecting different results. Einstein was obviously a physicist, not a chemist.

Any working chemist who does the same thing over and over expects different results, at least occasionally. You might do the same synthesis nine times in a row with perfect results each time, high yield and a nice pure product. Then, the tenth time you do the synthesis—nothing different, you understand; the same chemicals, the same equipment, the same working environment, the same everything—you might get a pathetic yield or a tarry mess in the reaction vessel. Or both.

In fact, there’s an entire discipline devoted to dealing with this problem. It’s called chemical engineering. Getting unexpected results in a lab-scale synthesis is one thing. You’ve wasted some time and (usually) anything from a few dollars’ to a few hundred dollars’ worth of chemicals. But when you scale things up from 1-liter flasks to 100,000-liter reaction vessels in a factory, you can’t afford surprises. Ultimately, that’s what chemical engineering is about. Scaling things up while making sure that things work predictably and properly.