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The Science of 4th of July Fireworks

Posted by samzenpus on from the go-boom dept.

StartsWithABang writes: There are few things as closely associated with American independence as our willingness and eagerness to celebrate with fiery explosions. I refer, of course, to the unique spectacle of fireworks, first developed nearly a millennium ago halfway across the world. But these displays don't happen by themselves; there's an intricate art and science required to deliver the shows we all expect. So what's the science behind fireworks? Here's the physics (and a little chemistry) behind their height, size, shape, color and sound, just in time for July 4th!

40 comments

  1. Americans setting off fireworks... snicker by Rei · · Score: 3, Informative

    New York City for example usually sets off 20-25 tonnes of fireworks on the 4th of July. Meanwhile, little Reykjavík sets off about 300 tonnes on New Years' Eve. Americans average shooting off about 200 grams of Fireworks each over the course of the entire year, combining fireworks shows, personal usage, etc. Icelanders average about a kilogram per person just on New Years'.

    And I know it's not just Iceland. I had a friend from Peru who moved to America and was terribly disappointed by what passed for a fireworks display there versus in her home country. Seriously, aren't you guys supposed to be the ones who enjoy blowing everything up? ;) Or do you get it out of your systems in the Middle East? ;)

    (Note: not meant as an insult :) )

    --
    Dear Lord: One of your creatures may be hurt tonight. Please let it be the other creature.
    1. Re:Americans setting off fireworks... snicker by sycodon · · Score: 4, Funny

      Our Federal Government is invested with tens of thousands of people who's job is to suck the fun out of everything.

      --
      When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
    2. Re:Americans setting off fireworks... snicker by Anonymous Coward · · Score: 0

      It's okay. We own guns and that makes up for it.

    3. Re:Americans setting off fireworks... snicker by pahles · · Score: 1

      In the Netherlands some 60-70 million kilogram of fireworks are sold to the public for New Years' Eve. That's 4-5 kilogram per person on average... Last New Years' Eve some 574 people ended up in the hospital, some of which lost complete eyesight, or lost one or more fingers.

      --
      Sig?
    4. Re:Americans setting off fireworks... snicker by Rei · · Score: 2

      Oh come on, what's New Years without an ER visit? ;) But yeah, I know some of your places have fireworks bans due to drought and the like.

      In case you're curious, here's what New Years looks like here. It goes on at that intensity for at least half an hour, half intensity for maybe an additional hour or so, quarter intensity for another hour, etc. All this comes after the "brennur", which is about a dozen house-sized bonfires scattered all over town.

      Basically, if one can make it burn or explode and there's nobody who objects, we'll set it on fire. Often while drinking heavily ;)

      --
      Dear Lord: One of your creatures may be hurt tonight. Please let it be the other creature.
    5. Re:Americans setting off fireworks... snicker by Rei · · Score: 1

      Whoops, I was wrong - it's nearly 2 kilograms per person here, not 1. But you've still got us beat :) (Also, it looks like America is up to 207 million pounds of fireworks per year, a big increase... so 285 grams per capita per year).

      I just think it's really weird how Americans see themselves as a major-fireworks nation when they set off so few.

      --
      Dear Lord: One of your creatures may be hurt tonight. Please let it be the other creature.
    6. Re:Americans setting off fireworks... snicker by Anonymous Coward · · Score: 0

      Caveat Emptor.

    7. Re:Americans setting off fireworks... snicker by Wrath0fb0b · · Score: 1

      There are not large parts of Iceland that are a spark away from burning to a crisp.

    8. Re:Americans setting off fireworks... snicker by Anonymous Coward · · Score: 0

      Yep, the shows get shorter and less interesting every year, it seems.

      Around here the best show is actually illegal! There's a park along the river through town that sees a very large number of people show up to set off their own fireworks. They aren't just buying the very wimpy basic stuff available locally, and they buy an amazing quantity of it. They start setting theirs off even before sunset and continue well after. While the city's official show - held just a mile or so away at the ballpark - might last 30-45 minutes, this one will go on for 3-4 hours of non-stop insanity.

      Others will line the nearby bridges over the river to watch, and some of us get on the river in kayaks and watch from the water.

      Fireworks are illegal in the city limits. It's funny to watch, you can tell when the occasional police bike patrol rides through as you'll see this dark gap in the show slowly move down the length of the park. They start launching again almost as soon as the cops turn their backs! It's a great show.

    9. Re:Americans setting off fireworks... snicker by penguinoid · · Score: 1

      Other countries don't have to worry about their own citizens blowing them up.

      --
      Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
    10. Re:Americans setting off fireworks... snicker by rvw14 · · Score: 1

      Unfortunately fireworks are largely illegal on the west coast of the US due to the high possibility of a wildfire being sparked.

    11. Re:Americans setting off fireworks... snicker by Anonymous Coward · · Score: 0

      It has nothing to do with taking away fun and everything to do with not burning my fucking house down. Every holiday I always have to call the fire or police department and have them come out to bust negligent people firing off illegal fireworks around here.

    12. Re: Americans setting off fireworks... snicker by Anonymous Coward · · Score: 0

      200 grams seems a little low. I have individual fireworks bigger than that. Hell, I'll probably smoke that much weed tomorrow. Besides, it's not about celebrating our independence anymore. It's about having fun, making noise, and sticking it to the facist regime that is trying to take away our independence.

    13. Re:Americans setting off fireworks... snicker by sjames · · Score: 1

      Sure it does. You for some reason ASSuME that the fireworks will inevitably set your house on fire (apparently it has yet to happen), so you kill the fun for everyone else. Water your lawn that afternoon and hose down the roof, it'll be fine.

    14. Re:Americans setting off fireworks... snicker by Anonymous Coward · · Score: 0

      Considering those holidays are the busiest for our local fire department, yes, houses do get burned down very often. Fuck you for being a self-centred sack of shit who places their "fun" above the lives of the people who live nearby.

      If I were to water down my roof in the afternoon, it would be dry within ten minutes. I live in SoCal, where the temperatures are high and humidity is low. The roof isn't my only concern, what happens when someone's misfired skyrocket flies in through the window of a house? What happens when someone happens to be walking by a location where someone has just planted an M1000?

      Just earlier today I was walking down the street and someone had planted a small bomb in the fucking median on a busy road and ran away before it went off. That would be enough to startle a driver into crashing into someone else. That really could be construed as an act of terrorism.

      It's dangerous, it's obnoxious (especially when they start setting them off at 2 AM), it's illegal and I do not hesitate to report it to the cops when I see it happen.

    15. Re:Americans setting off fireworks... snicker by sjames · · Score: 1

      OMG you must tremble for hours every time a car backfires! A skyrocket through a window? I have NEVER heard of such a thing happening. Unless you mean an open and unscreened window.

      Many people in my neighborhood shoot fireworks every year on the 4th and there has never been a fire.

      Your description of a firecracker as a "small bomb" tells me you are permanently set to "overreact".

    16. Re:Americans setting off fireworks... snicker by Anonymous Coward · · Score: 0

      You must be some sheltered idiot who lives in Nowheresville then. Let me lay it out for you:

      For every holiday such as New Year's, Cinco de Mayo and Fourth of July, we get people setting off illegal fireworks a full month before and after the actual holiday. Sometimes it's in the middle of the day and sometimes it's in the middle of the night. Because of their proximity, we basically get no peace from the beginning of April through the end of July. People setting off a sequence of ten to twenty high powered (as in commercial grade) skyrockets, which can easily break or set alight a screen or bust through a window, and people setting off M-1000s. You try living here for a while see if it doesn't concern you.

      Many people in my neighborhood shoot fireworks every year on the 4th and there has never been a fire.

      I bet they also aren't setting off nearly as many or nearly as high powered. You also convenient skirted around the fact that our fire department has to deal with the most fires during times when people are setting off illegal fireworks and the cause? Illegal fireworks. It doesn't help that we are in a drought and that there is a lot of dry brush around tightly populated areas with no rain and high heat.

      Your description of a firecracker as a "small bomb" tells me you are permanently set to "overreact".

      You've never seen an M-1000 then. This is the kind of shit people blow up around here and exactly the type of bomb I saw go off in the median of a busy street yesterday. If that can't be classified as a small bomb, then I don't know what qualifies in your limited mind.

      Face it, you don't know what you're talking about and you're only arguing because you're an ignorant rube. Try looking beyond your little bubble.

    17. Re:Americans setting off fireworks... snicker by sjames · · Score: 1

      That was not a normal M1000. It was clearly (badly) hand made or modified. I know this because I used to make fireworks as a hobby until the ATF started hiking it's skirt up and doing the mousey dance every time someone sneezed.

      This is an actual M-1000.The message is clear, don't set off fireworks on the patio furniture.

      Some of the ones I made might BARELY qualify as a small bomb but those involved 4 oz. of black powder and a well reinforced tube.

      You should note that commercial fireworks are mortar shells, not skyrockets.

      Now, how many times has your house burned down in all of that? How many skyrockets in your windows?

      I can understand you not wanting it daily for months, but surely on the actual holidays it might be nice to not get all bunched up over it.

    18. Re:Americans setting off fireworks... snicker by Anonymous Coward · · Score: 0

      Those are what they call M-1000s around here. They bring them over the border from Mexico. There was a recent bust in this city where they found a stockpile of those things in someone's house. Any kind of firework that shoots into the air and explodes is classed a skyrocket by the fire department and is a no-no. The ones they set off around here are the same as you would see at a professional fireworks show.

      And yes, I would care a lot less about it about it they could confine their fireworks to just the evening of the holiday and stop before 9 or 10 PM. Still, it is very dangerous in this area due to the already existing fire hazards caused by the heat, dryness and drought. The least these people could do is go to the beach and shoot them out over the ocean, but they have no consideration for anyone's safety, which is why I have to call the police on them.

  2. More carp from StartsWithABang by Anonymous Coward · · Score: 1

    From TFA (really SEAN's medium.com blog):

    Potassium nitrate is found in sources like bird droppings or bat guano. Take a mortar and pestle, mix them together, and what youâ(TM)ll get is a fine, black powder.

    I tried this and my homemade firework only made a little farting sound.

    1. Re:More carp from StartsWithABang by Anonymous Coward · · Score: 0

      What comes from the Fart, remains just a Fart.

    2. Re:More carp from StartsWithABang by Anonymous Coward · · Score: 0

      Black powder needs to be confined in order to go bang. That's what makes it useful in everything from rockets and lift charges to firecrackers and burst charges.
      Real black powder is milled in a ball mill or similar for several hours, slightly moistened, compressed into pucks by tons of force, left to dry, crushed and screened into different grain sizes. You won't get a good powder using a mortar and pestle; it's mostly useful as a demonstration.

      There are much more recent advances in fireworks colors than what the article mentions, though they're not available to us amateurs yet. They're mostly based on nitrocellulose or other nitrated compounds, that burn emmitting much less smoke than traditional organic- or metal-fueled compounds.

  3. Yay linkspam by Anonymous Coward · · Score: 0

    I'm sure it's of linkspammer's usual factual correctness and accurate wording, so no need to actually read it.

  4. Re: More (crap) from StartsWithABang by Anonymous Coward · · Score: 0

    Dang carpy joke-ruining autocorrect!

  5. Should be the Chemistry of Fireworks by Anonymous Coward · · Score: 0

    There is a bit of physics involved but the complexity and understanding is on the chemistry side.

    It is also a bit depressing that the fun aspects of the science of fireworks is out of reach of our STEM push. Having dabbled in this in my youth and done it safely I hope that our next crop of scientists and engineers get a little more hands one earlier and are not limited to computer simulations. At least you can still get Estes rockets although finding a place to launch them is getting harder and harder. I learned a lot about safety and science because the process was overseen by adults and it was fun.

  6. What about non-4th-of-July fireworks by Anonymous Coward · · Score: 0

    Same physics and chemistry? Or are your fireworks also "exceptional"?

  7. americans don't use a lot of fireworks by Anonymous Coward · · Score: 0

    Just about every country in the world uses more fireworks than the US.

    Maybe that's why fireworks and 4th of July are so tightly coupled in US minds? That's really the only time when people *expect* to see fireworks, and here in California, the shows are pretty lame (financial pressure on local municipalities, augmented by fears of wildfire, etc... although I think that's to a certain extent made up - "let's use fire danger as the reason why we're cancelling this year".)

    Other places in the US have a lot more fireworks than California.

    But even so, fireworks are something that is fairly unusual. Disneyland does fireworks. Fancy weddings might do a little bit of fireworks. There's small scale fireworks (ground display type stuff, gerbs and the like) at summer music concerts.

    1. Re:americans don't use a lot of fireworks by Anonymous Coward · · Score: 0

      Laws and liability significantly limit availability.

  8. What has happened that slashdot has to explain fir by Anonymous Coward · · Score: 0

    I mean, come on! Isn't this sort of thing common knowledge, and something every 'nerd' experimented with in childhood? I did...

    It's just basic chemistry and physics.

  9. Re: More (crap) from StartsWithABang by Anonymous Coward · · Score: 0

    I hate when carps ruin jokes! Get back in that water where we can't hear you anymore!

  10. Ouch by DerekLyons · · Score: 2

    I actually lost IQ points reading that mess...

    I should have stopped at the third paragraph,

    Charcoal, in this case, is not the briquettes you use on your grill, which often contain no actual charcoal, but is the carbon residue left behind by organic matter (like wood) once it has been charred (or pyrolyzed)

    Um, who is this moron? Yes, charcoal briquettes contain actual charcoal. They most certainly do contain (among other things) "the carbon residue left behind [etc...]". The rest of the article, breathless clickbait written at the kindergarten level, just goes downhill from there.

    Looking at his submission history, he has a record of submitting equally moronic content all from the same site. (And one comment, over a year ago.) Pure slashvertisement.

    1. Re:Ouch by Anonymous Coward · · Score: 0

      Anything from this submitter, which always submits a link to Medium.com, is automatically skipped by me. I have no idea what type of relationship exists between Medium.com and Dice, but these submissions obviously do not make it to the front page based on their merits.

    2. Re:Ouch by Anonymous Coward · · Score: 0

      If you automatically skip it then how did you make this comment?

    3. Re:Ouch by Anonymous Coward · · Score: 0

      If you automatically skip it then how did you make this comment?

      He didn't make your comment; you did.

  11. Boston! by Anonymous Coward · · Score: 0

    The 4th in Boston is special. Start with the 1812 Overture at the Hatch Shell (complete with canon barages), followup with a Blue Angel fly-over, and finish with an amazing firework display from a bunch of barges on the Charles River! Of course, once in awhile the barges blow up unexpectedly, but what is the 4th for! :-)

  12. Headline stolen from Newspaper Sunday suplement' by BlindRobin · · Score: 1

    Now I want to know how the science of 4th of July fireworks differs from the science of say New Years fireworks. I mean that is what I was expecting from the headline Exceptionally American 4th of July Fireworks Sciency Stuff please.

  13. A little bit late... by Anonymous Coward · · Score: 0

    "Just in time"? Actually a bit late. Up here, we did our fireworks on Wednesday. ;)

  14. Happy 4th by ArylAkamov · · Score: 1

    There are a number of inaccuracies here, especially that bit about charcoal.

    I dearly miss the days of celebrating the 4th in my own way, with my own chemistry. But now that I'm older, I don't want to be mistaken for a terrorist so I usually stick to consumer fireworks.

    Oh, and flamethrowers. Those are legal is almost every U.S. state and are a great way to light up fire pits.

  15. Science by cdxta · · Score: 1

    Fireworks 101:
          What ever goes up, must blow up!

  16. Despite the rockets red glare by Anonymous Coward · · Score: 0

    you'r still all perfidious traitors!