As they say, "Diamonds are forever."
That's what they say, anyway, but chemically it's not remotely true.
Diamonds are just a covalent network of carbon atoms and occasional impurities. Those covalent bonds are fairly easily broken in a combustion reaction at a high enough temperature.
That's why I tried to convince my wife that cubic zirconia was the fare more durable, stable, long-lasting choice to show the permanence of our love.
She wanted a diamond, though.
It wasn't something I was familiar with, but I had a decent guess that green on the hand was a reaction with something copper-based...and brass is certainly copper based.
With a little looking up and finding the various brass compositions used in brass instrumentation - 67-89% copper in the brass used, I feel pretty certain that it's the copper corroding and creating that green residue - on the instrument and on the hand.
My student - MK of the Eastman School nowadays - said that she tried one of the suggested solutions - lacquer on the horn - and didn't care for how it changed the tone of the instrument. If anybody has a better suggestion, I'll pass it along to MK.
Simple enough, eh?
I remember my dad saying that he used to play around with toy carbide cannons when he was growing up. By the time I was a kid, however, carbide cannons as children's toys had gone well by the wayside because of the danger involved.
The Rose Hulman Fighting Engineers (seriously), however, still fired one off in their quonset hut of a gym (since replaced) back when I was a student at Wabash College and occasionally travelling to watch the basketball team. I can't remember exactly why they were firing off the cannon. Maybe it was for their football team and I'm misremembering things. I can't find proof on the internet either way.
Check out some more carbide toys after the jump - including a far safer way to demonstrate this reaction thanks to Steve Spangler and Bob Becker.
Yes...sort of...
The video above explains that aerated water in sewage treatment plants - the ones with warning signs saying 'non-buoyant water' - might not be as deadly and non-buoyant as advertised.
From a 1985 study in Indiana, a Mythbusters episode (see below), and a Facebook/LinkedIn post, it looks like aerated water isn't quite as deadly as the signs say.
People do drown in aeration tanks from time to time, and I'm sure it's a very unpleasant way to die, but it appears that the drop in buoyancy - while very real - is apparently counteracted by the upward flow of the bubbles in those tanks. There is also a current caused by the upwelling that can create a circulation pushing any object toward the pool's walls and then downward (sort of like the bubbles in a pint of Guinness).
So, should you ignore the non-buoyant water signs? Not at all.
But is the risk not quite as risky as it's been made out to be? Probably.
