Lighting Up Our Lives
Fireworks Over the Harbour
Police arrested two kids yesterday, one was drinking battery acid, the other was eating fireworks. They charged one and let the other one off.
- Tommy Cooper
I guess I kinda lost control, because in the middle of the play I ran up and lit the evil puppet villain on fire. No, I didn't. Just kidding. I just said that to illustrate one of the human emotions, which is freaking out. Another emotion is greed, as when you kill someone for money, or something like that. Another emotion is generosity, as when you pay someone double what he paid for his stupid puppet.
- Deep Thoughts by Jack Handey
Source: The Dominion Monday 6 November 2000 photo is by Craig Round
Click to begin
It All Starts with Some Excited Electrons
by Seth Borenstein
Washington - The excitement of a huge fireworks display starts with the excitement of the tiny part of the itsy-bitsy atom: the electron. Without some excited electrons, there are no blazing reds and brilliant blues, no ear-splitting bangs. The electrons, goosed by exploding gunpowder and desperate to return to their usual state, release their excess energy by emitting light. That light is what produces the "oohs and aahs" of a fireworks show.
About a century ago, scientists first figured out how atoms are structured by studying the wavelengths of the light - the colours - given off by fireworks and other burning metals. Now, science continues to find new twists in the ancient Chinese art of fireworks.
A California company will debut some high-tech pyrotechnics at the Macy's fireworks display in New York on the Fourth of July. Each shell contains a computer chip that coordinates the burst of colour and sound within one one-thousandth of a second to the famous opening of German composer Richard Strauss' Also Sprach Zarathustra, the theme from the 1968 movie 2001: A Space Odyssey.
"I'm fusing together the ancient art of fireworks with modem technology," said Jim Souza, the president of Pyro Spectaculars by Souza of Rialto, California, which is co-producing the Macy's show. "Music is now digital - the same with fireworks."
Installing a computer chip in a shell triples the cost, but it's worth it for big displays, Souza said. The chip-in-a-shell "is going to revolutionise the industry," said Philip Butler, a producer at the rival Fireworks By Grucci, a Brookhaven, New York, firm that staged fireworks for the last six presidential inaugurations. Fireworks are not rocket science, because "we don't use rockets," Butler said. Instead, fireworks are shot out of fiberglass guns, although some have rocket motors in them to make them squirm around in the sky.
A fireworks show is "20% science, 80% artistry," said John Conkling, a professor of chemistry at Washington College in Chestertown, Maryland, and the technical director of the American Pyrotechnics Association. "The chemist makes the paint and the fireworks artists create the picture."
Mostly, though, fireworks are just chemistry in action - at the subatomic level in superheated metals.
Using recipes handed down for generations, fireworks makers use different metals - each of which produces a different colour (strontium yields deep reds, copper produces blue, sodium yields yellow, and iron filings and charcoal pieces produce gold sparks; bright flashes and loud bangs come from aluminium powder) that are mushed, baked into paste and dried into 2-foot-by-2-foot cakes. The cakes are cut into pieces the size of sugar cubes with something akin to a bread knife and coated with gunpowder to help them explode, Butler said. These cubes, called "stars," are then dried for a week. Hundreds if not thousands of these stars are packed, with more gunpowder, into shells that can be as big as a foot in diameter. The shells are fired into the air, where they explode. And that's where, in millionths of a second, the action takes place.
The gunpowder explodes, producing temperatures as high as 2,700°, Conkling said. This transfers energy into the atoms, especially the electrons (the negatively charged particles that orbit the center of the atom), and changes their paths. The electrons are supercharged with electricity, but nature dictates that they prefer to return to their usual more leisurely state. To rid themselves of that excess energy, the excited electrons must release either heat or light. The metals used in fireworks emit light, providing brilliant colours.
"In the fireworks rainbow, there are five primary colors: red, white, blue, green and gold," Butler said. Fireworks makers use sodium to produce yellow or gold, barium to make green, strontium to make red and magnesium to make white. Blue is the toughest color to make, and thus the rarest. It's created from copper arsenic, a dangerous chemical. To get smiley faces, Saturn rings, hearts and other trendy designer bursts, fireworks makers arrange the stars and gunpowder in specific patterns.
They say they continue to find new chemicals and techniques to improve their ancient art. "As with anything," Souza said, "the sky is always the limit."
Source: The Sunday Star-Ledger 1 July 2001 from Knight Ridder Newspapers
by Elizabeth Wilson
More than 1,000 years ago, most likely in China, someone made the serendipitous discovery that a mixture of sulfur, charcoal, and saltpeter (potassium nitrate) burned with startling speed and flash. The mixture, which eventually came to be known as gunpowder, was a Chinese mainstay for centuries, used in ceremonies to scare off evil spirits and even in military rockets. Gunpowder made its way to Europe, probably during the early 1200s. During the Middle Ages, gunpowder-based creations - the precursor to modern fireworks - were limited to booms and a few sparkles, aided by a few iron filings or some copper or zinc. The repertoire of colours was that found in most campfires: oranges, yellows, and the occasional white-hot. It wasn't until the 1800s that chemists began to use then-recently synthesised compounds that, in the right mixtures, burned in reds, greens, even blues and purples, and that the colors we traditionally ascribe to fireworks began to show up in night skies. But with the exception of minor formula improvements, your fireworks colours have been the fireworks colors of your great-grandparents - until recently. Connoisseurs of Fourth of July displays may have noticed that over the past two decades, colors have gotten markedly more vivid. Even blue, the most difficult color of all to produce, has evolved from an anemic bluish white to something approximating an honest-to-goodness blue.
"People may think colours look brighter - well, they're correct," says John A Conkling, technical director of the American Pyrotechnics Association and adjunct chemistry professor at Washington College in Chestertown, Maryland. The new breeds of fireworks colours operate by the same principles as fireworks colours in general. Certainly, one would never suspect that dazzling colours can spew forth when the dull gray pellets of mixtures are set aflame. So what is that stuff, anyway?
The orangish hues of ancient fireworks are largely produced by black- or gray-body radiation - the glow of very hot solid particles. By contrast, the striking greensand reds in modern fireworks are the spectral emissions of excited gas-phase molecules. A few metal chlorides, which fluoresce strongly in the visible wavelengths, are the basis for almost all the colours in modern fireworks. Barium chloride produces green; strontium chloride produces red; copper chloride produces blue. The problem is, these compounds are so hygroscopic that they render any mixture damp, unburnable, and even unstable. The solution to this problem has been to bring metal and chlorine together in a vapour during the burning process, where the energy from the burning can then excite the molecules' electrons, producing the colorful emissions.
A typical fireworks color burning mixture consists of, in addition to the requisite fuel and oxidizer, a compound containing one of the metals and a chlorine-donating compound. The mixture is wetted down to bind it together, then cut into flammable chunks known as stars - the colored dots that burst from a fireworks shell into the sky. Old books on pyrotechnics are chock-full of recipes for stars, formulas that enthusiasts have been continually refining over the decades. In fact, Conkling says, little professional research is devoted to fireworks: Most developments in fireworks formulas stem from experiments by amateurs.
During the early days of fireworks colours, stars were made with potassium chlorate, KClO3, which serves as both an oxidizer and a chlorine donor. But KClO3's unfortunate propensity for forming friction-sensitive compounds when it comes in contact with sulfur, metal powders, ammonium salts, or moisture has caused more than a few deadly explosions. Consequently, it's rarely used in display fireworks anymore. Nowadays, most star formulas use potassium perchlorate (KClO4). Such stars are harder to ignite but are not nearly as unstable. Potassium chlorate wasn't the only hazard fireworks makers used to face. Numerous chemicals were quite useful and had picturesque names but were also deadly poisons: Paris green (copper acetoarsenite), calomel (mercurous chloride), and realgar (arsenic sulfide). Barium chlorate - which has its metal, chlorine donor, and oxidizer built into one compound - produces a brilliant deep green that many fireworks experts believe is unparalleled. But again, the compound suffers from chlorate's notorious instability. Now, fireworks makers rely on compounds such as barium nitrate, strontium carbonate or nitrate, sodium oxalate, and copper carbonate.
Blue has always presented a special problem for fireworks designers, because copper chloride doesn't survive well in a hot flame. But a big advance in fireworks colours has come in recent decades, with the use of a magnesium-aluminum alloy known as magnalium. Stars made with magnalium burn electric, almost fluorescent, green, red, yellow, and comparatively decent blue and purple. By themselves, magnesium and aluminum make silvers and sparkles and act as a fuel. The high heat generated by metal fuels can also increase the intensity of the coloured molecular emissions. But the incandescence from the metal particles is usually so brilliant that it overwhelms the colour. Magnalium, however, still gets the flame hot without washing the colour out. How this happens isn't exactly known, Conkling says. But one possibility is that the metal somehow forms vaporous species in the gas phase, and so doesn't incandesce. Even with magnalium, though, a great blue continues to be fireworks makers' dream, one that they'll keep chasing. "Blue is still the weakest link in the whole fireworks picture," Conkling says.
In addition to being Chemical & Engineering News's West Coast associate editor, Wilson is a pyrotechnician, licensed in the state of California.
Source: pubs.acs.org 2 July 2001
When we lived aboard Lady Fair, if the wind picked up at all during the fireworks displays, we sometimes had to run around on deck stomping out embers.
Source: wellington.govt.nz Wellington City Council
Why not have everyone sing the national anthem? (At least until someone writes a "Wellington City Song".) For those of you who don't know the words to the anthem:
God Defend New Zealand
Honour the Anthem
...I would suggest the All Blacks be instructed to learn and honour our National Anthem. Compare the enthusiasm with which others perform theirs before a game.
It's embarrassing to see half the All Black team not even mouth the words, let alone sing the anthem. But then I suppose they are preoccupied...
Source: The Evening Post Tuesday 30 January 2001 Letters to the Editor
Hear Our Voices We Entreat
New Zealanders are being encouraged to take more pride in the national anthem - learning the Maori and English verses and belting it out with fervour. The campaign got a boost when Ministry of Maori Development and Maori Language Commission staff handed out cards printed with the words of the anthem to passengers flying out for the Bledisloe Cup rugby test in Sydney tonight.
Maori Language Commission chief executive Haami Piripi said the anthem was about pride in being a New Zealander and in being bilingual. However, he was reluctant to criticise those too shy or self-conscious to sing. "It's not a compliance issue ... people have to want to do it."
Te Puni Kokiri chief executive Leith Comer said he dreamed of the day when television cameras panned down the All Black lineup and showed them all putting their hearts into it. Unlike the haka, singing the anthem is optional for the All Blacks and they do not practise it.
Source: Stuff 26 July 2003
For satellite photos and pictures of Wellington from several different angles and for articles about earthquakes, history, business, the Ohariu Valley, statistics, fireworks, the
national anthem, the kiwi icon and more click the "Up" button below to take you to the Table of Contents for this Wellington section.