Hacking Candle Extinguishing

Anyone can put out a candle by blowing on it. According to [Physics Girl], that method is old hat. She made an educational video that shows five different ways to put out a candle using–what else–physics.

You might not need alternate ways to put out a candle, but if you are looking to engage students in STEM (Science, Technology, Engineering, and Math), this video along with others from [Physics Girl] might spark interest.

The video shows entertaining demonstrations that cover thermodynamics, fluid dynamics, and other science topics. Spoiler alert: the final method is to quench the flame with liquid nitrogen. But keep watching after that for a little mini-blooper reel, where she makes a bit of a mess and nearly burns down her studio.

Once you’ve started doing science with a candle, you might move on to thermoelectric generators, or you could do some more advanced studies.

42 thoughts on “Hacking Candle Extinguishing

    1. I agree, not a hack. Yet I submit a tip 2 weeks ago on how to hack a common eBay bench power supply to increase it from 3 to 5 amp output, and they never posted it. Trying to figure out what is post worthy on Had is like trying to figure out the chicken vs egg paradox lately.

  1. “makes a mess and nearly burns down her studio” No not really, knocked a candle on its side spilling a blob of wax on the table. Yes.
    Colin Furze has probably come much closer to setting himself and his studio\ workshop on fire in much much more spectacular fashions.

  2. Blowing round a curved surface works due to the Coanda effect. https://en.wikipedia.org/wiki/Coand%C4%83_effect Not really a science video as there are not citations or links to text so although you can repeat her experiments you won’t be able to learn further without doing your own literature review. To quote mythbusters the difference between science and messing around is writing it down. Ok this is supposed to be “fun” but there’s no reason they couldn’t put further info in the video description or a click through for a write up.

      1. Wow. What do you think science is?

        From wikipedia “Science is a systematic enterprise that creates, builds and organizes knowledge in the form of testable explanations and predictions about the universe.”

        If you don’t document it, you’re just messing around.

        1. Nothing in the quote you supplied says anything about writing anything down.

          Simply phrasing a hypothesis and testing it is enough for science. Amazing a child with ‘magic’ and explaining the science behind the magic does not require writing findings down, simply stoking the need for knowledge is enough for science.

          …elitist troll…

          1. I’m actually concerned that our current efforts to show children how cool science and engineering is through STEM/STEAM outreach is slightly hypocritical. On a daily basis the solid engineering (and science) work is writing reports, safety cases, business cases, and painstaking planning and checking. The science bit in experiments is always thinking about what a result means in the world. You don’t do experiments at all until you have written up what you are testing for and how you will assess success or failure. Thinking about the long term plan here. Ok children enjoy the video. What next… How will adults find instructions or worksheets to take that initial interest and help the child to build on it to discover the fascinating world around them and equip them with the discipline to explore without becoming disheartened when an experimental result isn’t as expected? How will this help move the child on in their development towards a career in engineering, science, or maths? Things don’t work in this world “because science” The scientific method is purely us trying to understand and use the physical underpinnings of our universe. It’s also been wrong a fantastically huge number of times. Only carefully planned experimentation has demonstrated misunderstandings in the way the world works. Only through being able to accurately repeat those experiments can we be confident in their results. The scientific method is literally the writing it down bit.

          2. “The scientific method is literally the writing it down bit.”

            Exactly. Furthermore, the scientific method is the application of certain philosophies to the interpretation of what data you’ve got. It doesn’t have to be literally written down – it can be video taped or sound recorded – but the important bit is that you don’t go “This happened, that means god did it” without damn good reasoning behind your statement.

            That’s why even “writing it down” isn’t quite yet science. Adam Savage who’s famously quoted for saying it is ironically often so much in error with his statistical methods and other interpretation of the data, that he could be called a pseudoscientist.

            The misunderstanding that science is just documenthing shit has lead many people down the cranky woo side of things.

          3. “Simply phrasing a hypothesis and testing it is enough for science.”

            That’s like saying “simply cutting wood and nailing it together is enough for carpentry”.

            Yeeess… but how you do it is kinda important as well.

          4. Actually, let me illustrate it to you.

            Let’s forget all that we demand of the philosophy of science, the scientific method, ontology and other things, and concentrate on just presenting a hypothesis and testing it. After all, that alone should be sufficient for science according to the claim.

            I have a coin in my hand. I present a hypothesis: “If the coin lands heads up, there is God up in heaven”. I toss the coin, and it lands heads up. Hypothesis, test – science. Or is it?

            The word “science” means roughly the state of knowing : knowledge as distinguished from ignorance or misunderstanding. If you don’t apply intellectual rigour to your science, even if you write it down, it’s still just messing around just like a child would do hammering nails to a piece of wood to play a carpenter. You may become very good at hammering nails or flipping coins, but you haven’t actually produced any useful furniture or science.

            That’s the reason why nearly all of “Science” in entertainment like this is not science but simply a cargo cult version thereof – a mockery. It’s the same sort of misunderstanding as thinking that calculating 1 + 1 means you’re doing mathematics. There is a confusion because we use the word mathematics when we actually mean arithmetics, and so people get the idea that all a mathematician does is calculation and computation.

          5. It’s true that “science” as entertainment is often not much more than magic tricks with a loose explanation of how it works but as much as it has little value as science per se, it is an important part of public outreach and recruiting. It’s PR and like all PR is more style than substance.

          6. Of course, but calling it “science” instead of showmanship is giving the opposition of science (cranks, conmen, religious, fools etc.) more ammunition because of the low standards you set.

            If that is what you pass as science to the public, you’re doing them a disservice because they can’t tell the difference between a common huckster and someone presenting real scientific evidence. The television entertainment Science with a capital S is the reason why the average person has trouble understanding why things like small samples sizes in studies mean you shouldn’t go running down the street yelling how vaccines cause cancer.

            But if Mythbursters can do science throwing a football 12 times and discern a 5% difference between helium and air filled balls, it must be true! There’s no need for such concepts as normal distribution or R^2 values – just take the average and write it down – “Science” bitches!

    1. It’s actually better to have flip flops than shoes that will absorb and partially contain the LN2. The Leydenfrost effect will boil the LN2 right off your skin and onto the ground with flip flops. However, if you were to accidentally pour it inside your leather shoe…

  3. wow it worked with the cashew nuts inside the jar as well?
    pretty cool guys!

    the copper trick sounds great but very poorly executed, the whole point should be to show that removing (only) heat (and not oxygen or fuel) extinguishes a flame to prove the fire triangle. using a tightly wound copper coil and exclaiming that it removes oxygen too defeats the purpose of the demonstration. add to that you can see the flame still burning blue at the bottom of the wick before it ‘comes back to life’ when the coil is removed.

    we shouldn’t encourage anyone to into stem especially with pandering drivel that has nothing to do with even basic science never mind actual science that you end up doing in later life as a scientist which is often boring and tedious.
    if you want to do it you want to do it, that’s great you should do what you enjoy
    there are enough people being pressured and bribed (the only people i know who took grants/bursaries to study in further education were women (it’s not me being sexist, they were only available to women) who ended up dropping out or leaving to do some other course because they weren’t interested in the first place) into doing things they don’t want to do and wasting everyone’s time.

  4. 1. Peeing it out (might work with other body fluids, too)
    2. Throwing dog poop at it
    3. Use a camel’s foamy saliva to extinguish it
    4. use your LHC to create a small black hole to suck up the flame
    5. teabag it.

    What? You said “weird” but none of my suggestions are in the video? Oh, what a shame :(

  5. Well, there’s a crapton of negative comments here, but I gotta say, the pouring CO2 between glasses thing was pretty cool; I had no idea that was possible, I assumed the CO2 would be blown away by air currents from movements in the room much faster than that.

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