July 4th Evening Open Thread

Good Evening

Hope everyone is doing well, the open thread will be short tonight.

Here in Banjoville the rain has been falling for days, so that puts the kibosh on any fireworks show down over the lake…but that doesn’t mean the country boys won’t be out there shooting their favorite 2nd Amendment brand of firework.

Ever wonder, How do fireworks get their colors?

Thousands of people across the United States will be celebrating Independence Day on July 4 by attending a fireworks display. The red, orange, yellow, green, blue and purple colors exploding in the night sky during a pyrotechnic festival are created by the use of metal salts.

In chemistry, a salt is defined as an ionic compound that is formed from the reaction of an acid and a base. Salts are electrically neutral compounds that are composed of both positively charged ions and negatively charged ions. For example, familiar table salt consists of both positive sodium ions (Na⁺) and negative chloride ions (Cl^–).

Metal salts that are commonly used in firework displays include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks). Purple fireworks are typically produced by use of a mixture of strontium (red) and copper (blue) compounds.

These salts are packed into little balls called “stars” that are then placed with in the firework package that includes the fuse.  The gunpowder charge is what gets the firework up into the sky while the fuse burns down to the stars within the firework package.

When metal salts ignite, they emit light. The heat from the ignition causes an influx of energy into the metal atoms. As heat gets absorbed by the metal atoms, electrons that are circling around the lower orbitals of the atomic nucleus excite and jump to a higher energy level. As the heat dissipates, the electrons fall back to their lower energy level or ground state and release the extra energy in the form of light.

Light travels in waves. Different metal atoms produce different colors of light when excited because the light that they emit is traveling at different wavelengths. The wavelengths of light produced by metals vary in accordance with the amount of energy that is released by the unique arrangement of electrons in the atom as it falls from an excited state back to a ground state.

When metal salts emit short wavelengths of visible light in the range of 400 to 500 nanometers, they produce violet and blue colors. When metal salts emit longer wavelengths of visible light in the range of 600 to 700 nanometers, they produce orange and red colors. Yellow and green colors are produced by metal salts that emit visible light at intermediate wavelengths (500 to 600 nanometers) along the electromagnetic spectrum.

Bottom line: The red, orange, yellow, green, blue and purple colors exploding in the night sky during a pyrotechnic festival are created by the use of metal salts. When metal salts are ignited, they release energy in the form of light. Shorter wavelengths of light (400 to 500 nanometers) produce violet and blue colors while longer wavelengths of light (600 to 700 nanometers) produce orange and red colors. Yellow and greens are produced by intermediate wavelengths (500 to 600 nanometers) along the electromagnetic spectrum.

Now a couple of cartoons, one gives an update on a case in California that we have been following:

Rall: Yo, BofA, it’s just chalk – latimes.com

San Diego graffiti protester who wrote anti-bank messages in chalk on the sidewalk outside branches of Bank of America was acquitted this week. (Ted Rall / For The Times / July 4, 2013)

Jeff Olson, 40, charged with vandalism after he wrote protest slogans in chalk outside Bank of America branches, was found not guilty by a San Diego jury.

Statue of Liberty – Truthdig

And finally a series of vintage photos:

18 Vintage Photos of People Celebrating Independence Day | Mental Floss

You’ll spend today grilling, drinking, and watching fireworks. Here’s how people celebrated in years gone by.

10. 1906: A little boy holding three large firecrackers and an American flag. Photo courtesy of the Library of Congress.

Hope you enjoy those pictures…this is an open thread.