We Accidentally Discovered A RARE Scientific Phenomenon (10,000fps Collisions)

Most of this video - as is typical of videos from these ridiculous Aussies - can be skipped. It's primarily just repeated, slow motion footage of two giant air cannons firing random things (plastic dinosaurs, basketballs, cola cans, pumpkins, rubber band balls, spray paint cans, and such) at each other and ridiculous mugging for the camera.

But then - at 16:30 - they fire two glass balls at each other and something really interesting happens.

Well, at 16:30 they load the two glass balls and mug around for two and a half minutes before showing us the scientifically interesting slow motion video. Go ahead and skip to 19:00 to see the science.

I'll wait for you...

At 19:24 we get a flash of light when the two highly accelerated glass balls hit each other.

The flash of light certainly wasn't something that I expected to see and seems to be an example of triboluminescence (light produced from force or movement).

The initial science explanation (at 20:00 about IMFs being broken) seems a bit dodgy, and I'm really happy that they come back around 21:00 with something that sounds more correct to me.

I've never heard of glass causing triboluminescence (nor fractoluminescence which is a subset of triboluminescence, I guess), but I'd like to see somebody with way more science knowledge than I have explain what's happening here.

Thanks, by the way, to reddit for the gif.

Boxed cake vs scratch cake — Why bakers can't beat SCIENCE

A few years back - when we were still in the previous iteration of Princeton High School - I had my AP chemistry students make cupcakes with three separate leavening methods: baking soda, baking powder & soda, and mechanical leavening (whipping egg whites). The three methods are fascinatingly different and produce very different results.

In this video Adam and his baker friend look at the differences between box cake mix and from-scratch cakes. They're not quite looking at just the leavenings, but the science behind the differences are fascinating.

I'm sometimes sad that we went with material science rather than food science as one of our science electives at Princeton. I wish I had a good curriculum for high school students to explore food science, but that would also require a cooking classroom - something that our principal at the time of the building of new Princeton High School wasn't interested in building anything that practical.

Aluminum and mercury

I'm thinking that the dangers of mercury thermometers on aluminum-skinned airplanes has mostly passed us by - both because home mercury thermometers are all but outlawed and have been replaced by digital thermometers and because so little of a commercial airplane is being made out of aluminum at this point.

But the demonstration of the formation of mercury-aluminum amalgam is still really cool to watch.