Colored-flame tricks that make use of methanol and various metal ions are old hat--and a source of in-class accidents---but one does not often see the use of zinc oxide, which is the main ingredient of Ihle's paste, some foot powders and many diaper rash ointments. The electron transitions of zinc ion are very sensitive to different flame temperatures, and the emissions are beautiful.

ZnO is red between 568 to 704 degrees Celsius

ZnO is green between 704 to 948 degrees Celsius.

Fifteen years ago I was lucky enough to teach chemistry for a year at a private school on the slopes of Diamond Head in Honolulu. I even managed to convince the girls' choir to sing this spoof of "My Favorite Things". Warning: if you have good hearing, you will need a hearing aid to listen to what was originally recorded on a cheap tape recorder.

Recently The Economist lamented the fact that in Britain a typical university spends 65% of its budget on academic journals.

Scientists are looking for recognition through publication in such media, and so most of them willingly write for free. Even reviewers and editors work for just a few more peanuts.

In this convenient arrangement, the publishers naturally rake in gargantuan profits: 1.1 billion dollars for one publisher alone(Elsevier), in a recession year to boot! Maybe I'm naive, but wouldn't it make more sense if scientists published their work right here on Science 2.0 in a special column?

Most of the time, we are not who we think we are. With our own existence at stake, we normally evaluate ourselves through a filter designed to let mostly self-advantageous material trickle through. On the other hand, we are not the sum of people’s perceptions either. Assume it was possible to get a thousand different opinions of a person through all the people one has ever come in contact with. Pretend that each interpretation could be represented as a vector in space. Some vectors would clearly reinforce each other; others cancel; the rest would combine to give resultant opinions, which in turn would recombine into one single vector.

As most baseball fans know, batting average is simply the ratio of the number of hits to the number at bats. That makes it a linear relationship: for any given number of at bats, a .400 hitter (hypothetically, since there has not been one since Red Sox slugger Ted Williams did it about sixty years ago)will have obtained twice the number of hits as a .200 hitter. But consider a similar statistic known as the batting average of a pitcher's opponents. Strange as it may seem, if you plot the number of hits given up by the pitcher per game versus the opponents' average, you will notice a non-linear relationship!

Here's why:

Let A = batting average for opposing hitters