Jul 7, 2016 03:32 AM
http://nautil.us/blog/fireworks-displays...e-and-blue
EXCERPT: Mother Nature can be a handful when she wants to be,” says John Conkling, the former technical director of the American Pyrotechnics Association and a professor emeritus of chemistry at Washington College. Except he used a stronger, more colorful word than “handful.” When it comes to fireworks, “she just doesn’t want to give you that perfect red color or that perfect green color. You have to work for it.” But she especially doesn’t want to give away her secret recipe for blue. To this day, a deep, vibrant blue is still beyond our reach, despite the fact that fireworks were invented more than a millennium ago. It’s the holy grail for pyrotechnic experts.
[...] First the Italians incorporated trace amounts of metals to produce different hues. For each new metal, electrons would jump up into different excited states, and therefore emit photons with different amounts of energy—that is, different colors—when they fell back down. Strontium and lithium both produce deep reds; calcium creates an orange color; sodium generates yellow; barium burns green; copper creates blues; and finally titanium and magnesium burn silver or white. Combining chlorine with barium produces neon green flames and combining it with copper produces turquoise flames. But finding those perfect combinations didn’t come easily, and the effects of various combinations are surprisingly unpredictable. Even today you can’t simply input a certain color into a computer, run a model, and wait for it to output the required combination of chemical elements. Instead you have to zero in on that sweet spot through trial and error, says Conkling. It’s still an art...
EXCERPT: Mother Nature can be a handful when she wants to be,” says John Conkling, the former technical director of the American Pyrotechnics Association and a professor emeritus of chemistry at Washington College. Except he used a stronger, more colorful word than “handful.” When it comes to fireworks, “she just doesn’t want to give you that perfect red color or that perfect green color. You have to work for it.” But she especially doesn’t want to give away her secret recipe for blue. To this day, a deep, vibrant blue is still beyond our reach, despite the fact that fireworks were invented more than a millennium ago. It’s the holy grail for pyrotechnic experts.
[...] First the Italians incorporated trace amounts of metals to produce different hues. For each new metal, electrons would jump up into different excited states, and therefore emit photons with different amounts of energy—that is, different colors—when they fell back down. Strontium and lithium both produce deep reds; calcium creates an orange color; sodium generates yellow; barium burns green; copper creates blues; and finally titanium and magnesium burn silver or white. Combining chlorine with barium produces neon green flames and combining it with copper produces turquoise flames. But finding those perfect combinations didn’t come easily, and the effects of various combinations are surprisingly unpredictable. Even today you can’t simply input a certain color into a computer, run a model, and wait for it to output the required combination of chemical elements. Instead you have to zero in on that sweet spot through trial and error, says Conkling. It’s still an art...
