Alternative explanation for particles on the tie
Maybe DBC liked fireworks! Recent article in the NY Times talks about the use of barium, strontium and other rare minerals to produce the colors in fireworks. See below:
Tryggvi Adalbjornsson@tryggvia
“Mom, are they going to turn off fireworks because of you?”
Kimberly Prather remembers her kids asking her that when they learned that she had written a scientific study of fireworks pollution. Professor Prather is a chemist at University of California San Diego who spends most of her time studying cloud formation. But she has a side interest — fireworks.
Her work around the July 4, 1995, holiday measured particles in the air in Riverside County, Calif., and found a spike in chemicals like barium, which isn’t a particularly common element in the atmosphere, but is vital to fireworks. It’s what helps create vivid greens.
The goal of fireworks is to be big, loud and colorful. To achieve that, a range of chemicals is needed, often including charcoal-based fuel along with various metal compounds to make the colors. For instance, copper has a role in blue bursts, and strontium in red ones.
And at least when Professor Prather did her original research, there was also a small amount of lead. Since then, she expects that lead content has been reduced. But this year she will be bringing out the test equipment to see. “I’m curious as heck if the lead’s really gone,” she said.
How worried should we be? “I definitely try to avoid breathing that air,” she said.
But at least it’s not as bad on the Fourth of July as it sometimes gets in India, where the annual Diwali “Festival of Lights” is celebrated with so many fireworks that in 2016, some schools were closed because of thick pollution. Last year, India’s Supreme Court temporarily banned fireworks in the capital.
There’s a chance for “green” fireworks in the future, though — and not the barium kind. Another pyrotechnic-minded professor, Thomas M. Klapötke of Ludwig Maximilian University of Munich in Germany, has been looking for ways to make fireworks better for the environment. His research focuses on military-grade products (flares, for instance), but the chemistry is similar.
In 2014, his team introduced a new way to make blue fireworks. Traditionally, chlorine was involved, but “Our new chlorine-free coloring agent could revolutionize the manufacture of fireworks and blue-emitting signal flares for the U.S. Army and Navy,” he said at the time.
Coming soon, in other words: Maybe more fireworks that don’t take your breath away?
Poll