Fireworks economics

Training

I promised, so here it is.
6/23. 7 miles in 55, working the downhills.
6/24. 9 in 81, plus one walked. Dead quads.
6/25. 9 in 66, 1 cool-down, 2 walked. Sore left tensor fasciae latae muscle.
6/26. 3 in 27.
6/27. 4 in 34.
[6/28. Plan repeats of Afton campground hill]
[6/29. Plan repeats of Hyland hill]

Pyrotechonomics

When you see fireworks on Independence day, check to see how many blue ones there are. Each year I see fewer and this year I expect none. White flashes are done with magnesium or aluminum and are cheap. Yellow is sodium and very cheap (but rare, because tricky to make). Red is strontium, which is surprisingly cheap. The best greens are made of copper, but due to the expense of copper, they're now usually phosphates with sulphuric acid, which are harder to make, but cheaper. Violet is potassium, which is dirt cheap.

Dark blue is copper chloride and it's very expensive. Copper bromide makes blue which turns into green (even more expensive). Light blues can be made with lead, arsenic or selenium and I expect they'll be substituted in many places this year.