h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

When rocket type fireworks are ignited, a gunpowder-like substance explodes, creating gasses
that shoot the firework into the air. Another charge takes a certain amount of time to reach a
certain altitude. Then another charge causes it to blow up, releasing fine metal powders into the
air. The electrons in these metal particles become hot and excited, giving off light, called
photons.

This is incorrect.
1. When rockets are ignited, the rocket engine combusts, not explodes. As the engine burns, it emits gasses very rapidly downward, causing an upward reaction in the rocket. No explosion takes place until later.
2. The rocket engine is usually made out of tightly pressed black powder, although other compounds are often used. Modern gunpowder is not used in fireworks.
3. A break charge is placed at the top of the engine. Once the fire has reached the top of the engine, the engine has been burned out and the break charge has been lit.
4. The break charge ignites and scatters the small bits of metal surrounding it, creating the "flower" effect of a fireworks burst.
5. Light is not called photons. Light is made up of small packets of energy called photons. While light is always made of photons, photons are not always light.

As this entry is marked edited, could it Please Be Edited,
so as to be correct?
(I'll do so, if advised as to process....)

Notably, there is one statement that is Lethally False.

Darth's comments, are, in general, well taken.

Background:
I am a trained display assistant, working 10-15 shows/
yewar in the states. Additionally, I have some
training and experience at licensed manufacturers

> Fireworks
...snip....

>Over the course of time, fireworks have become a traditional way to >memorialize distinguished as well as whimsical occasions across the >planet. Events throughout the world are celebrated with fiery >flowers and monumental reports1 in the sky. Examples of such events >are Bonfire Night in England, 4 July Independence celebrations in >America, and New Years festivities.
Might add Bastille day (14 July) in France, and Canada's
national day, the correct designator i forget.

>When rocket type fireworks are ignited, a gunpowder-like substance >explodes, creating gasses that shoot the firework into the air. >Another charge takes a certain amount of time to reach a certain >altitude. Then another charge causes it to blow up, releasing fine >metal powders into the air.
Technically, the metal salts, and oxidizers are preformed
into pellets called stars. THOSE are dispersed.
Suggest saying: ...disperses the burning stars...

> The electrons in these metal particles become hot and excited,
> giving off light, called photons.

>Magnesium is the compound that gives off the bright white light in >fireworks. This happens when the magnesium is suddenly exposed to >oxygen, to which it is very sensitive, and that exposure causes the >compound to burn. Other metals or transition elements that have >electrons can also be used. When their particles get hot, they give >off photons in the visible spectrum, which is how the colors in >fireworks are created.
Not exact: all require IGNITION by the BURST charge.
Magnesium dos not self ignote except under VERY special
circumstances. Can be reworded.
...snip...

>Some of the different types of fireworks3:

>Rocket type: Rockets are actually powered by an internal engine.
>The rocket type of firework has more in common with a mortar
>shell than it does with a true rocket.
What, pray tell, in this context is a 'true rocket'?
I suggest that the original, and 'true' rockets
are/were fireworks rockets.

> These fly through the air when ignited. They sometimes carry
>parachutes, stars4,
stars4?

>or big bangs
which go off

>when they reach the peak of their flight.

>Roman candles: These long tubes shoot compact balls of chemicals >from one end, creating a series of flaming stars. Inside the tubes, >the chemical balls are packed one on top of the other, with layers >of sawdust between them.
close enough...

>Fountains: These are cone-shaped and sit on the ground. A hole in
>the top allows gasses
and stars and sparks
> to escape, shooting coloured sparks into the air.

>Arial shells:
_Aerial_

> These are the kings of fireworks. The most spectacular visually,
> and usually the loudest. These are the ones the professionals
> use.
[small ones may be available as 'home use' in some
jurisdictions.]

> These are launched the same way mortar shells are launched.
[They ARE mortar shells...]

> An external fuse is lit before
NO NO NO NO NO!
THIS WILL GET SOMEONE KILLED or hurt..
Fuse (leader) is long enough to reach OUT of the
tube, and be lit AFTER the shell is in the tube.

> placing the shell into a skyward facing tube. The explosion
>of the lift carriage inside the tube then launches the shell.
_charge_

>Use of fireworks
>Safety is very important and cannot be stressed enough when
>using fireworks. Most precautions are obvious, but it is
>important to keep the not-so-obvious tips in mind as well.

>Observe laws in your jurisdiction.
>Read the warning label on the firework.
>Wear safety glasses. Yeah, they look silly, but they may
> save your eyesight.
Professionals wear them. They will stop a small caliber
bullet.

>Wear somewhat tight-fitting clothing. Loose clothing, like
> long floppy sleeves and such, will more easily catch fire.
Some fabrics, generally artifical, burn more easily.

>Light fireworks in an open area on a flat hard surface.

>Keep a fire extinguishing device handy just in case. A
>bucket of water, a pail of sand, or a fire extinguisher
>all work nicely.
...and refil, if used, before continuing...

...snip...

>Pets hate loud noises and big flashes. So as not to
>traumatize them, keep them away from the fireworks.
[MOST pets. The occaisonal dog enjoys them....]

>Store your fireworks in a safe place, preferably not in a
>common room.

---------------------------------------------------------------------
>1 The loud bang or boom produced by the firework or other
> pyrotechnic device.
>2 If you don't know what you are doing, the only spectacular
>result that you're likely to create is to blow yourself up.
...or major burns...
[overstating a risk can get that risk ignored...]

>3 Laws in your local jurisdiction will determine if these are
> consumer or display fireworks.
>4 Stars are small metal powders that create the effect of stars.
'stars' are _mixtures_ of oxidizers and fuels, to get various
effects. [Most, in fact, do NOT use metal powders: some do.]
=========================================================
To Darth's poins:
>>When rocket type fireworks are ignited, a gunpowder-like
It's gunpowder, properly defined.

>substance explodes,
burns. If it explaodes, its a failure.

> creating gasses that shoot the firework into the air.
> Another charge takes a certain amount of time to reach a
> certain altitude. Then another charge causes it to blow
> up, releasing fine metal
cf above on stars.

> powders into the air. The electrons in these metal
> particles become hot and excited, giving off light,
> called photons.
[overmuch detail....]

>This is incorrect.
>1. When rockets are ignited, the rocket engine combusts,
>not explodes.
Agreed.

> As the engine burns, it emits gasses very rapidly downward,
> causing an upward reaction in the rocket. No explosion
> takes place until later.
...hopefully...

>2. The rocket engine is usually made out of tightly pressed
>black powder, although other compounds are often used. Modern
> gunpowder is not used in fireworks.
gunpowder == black powder, properly used.
The reference to 'modern gunpowder' is presumably to
_SMOKELESS Powder, whichis what is used in modern
arms. cf any technical dictionary. (The usage of
gunpowder is commonly confusing, tho straightforward,
once understood.)

> 3. A break charge is placed at the top of the engine. Once
>the fire has reached the top of the engine, the engine has
>been burned out and the break charge has been lit.
agreed.

>4. The break charge ignites and scatters the small bits of
>metal
STARS (cf above) are what is scattered. These are variously
compounded, to get desired effect. 'metal' as such
is never used, tho SOME (white/silver) stars MAY use
'raw' metals, together with oxidzers, in their makeup.

> surrounding it, creating the "flower" effect of a fireworks burst.

>5. Light is not called photons. Light is made up of small packets
>of energy called photons. While light is always made of photons,
> photons are not always light
True, but one level of detal further than needed. neither
RF nor X-Rays are produced in fireworks...

best
dwp

I think Jimster's taken care of these in another forum. If not, let me know, and I'll draw his attention over here.

Re the use of safety specs:
Good idea, should always be used. But while professional ones might "stop a small calibre bullet", I doubt those from local DIY store are that good. Best to remove the phrase, just in case.

I appreciate whomever taking time to follow up on my
screed from yesterday. A few points:

1)I forgot to add, and this is IMPORTANT:
If shooting: USE HEARING PROTECTION. Professionals do.
Arguably do so if watching. Hearing loss is cumulative,
subtle and progressive. (and: the 'tinies' ears are
_different_.

2) Check the ISO standards on the safety glasses. At least
in the US, standard, DIY, glasses WILL do so. (OK: I've
not tested them....) I mention it as many may think they
are 'too light' and 'not worth the effort'. They are
worth the effort. If other method than bullet analogy
be preferred to urge their use, fine.

3) The comment about rocket fuel 'exploding' is WRONG.
It does not explode. cf any _text_ on fireworks.
(This misconception is widespread, may be in some non
professional references (encyclopedia articles, etc)
(The reference to 'professional' is to _fireworks_
professional.)). cf Shimizu, Pyrotechnics, the Art
Science and Technique, any of Rev. Lancaster's books
(or himself.)

4) Same comment on 'metal powders'. No need to go into
details, when an ACCURATE, simple version is available:
_stars_ are spread, rather than 'metal powders'.
cf any reference as above. Or any of several
Fireworks _Professional's_ sites. Two that come to hand:
www.atlaspyro.com/howaretheymade.asp
and
www.japan-fireworks.com/eindex.html

Again: Thanks for the chance to contribute...
3 and 4 are fine points, can easily be made correct.

best
dwp