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General Science / Questions about 'Sparklers'
« on: 04/09/2007 02:19:15 »
I don't know why no one else has answered this, and I also don't know the details of how they are made. But I'm quite sure that the reason they don't burn your hand is this:
Temperature is different than heat. Temperature is the average molecular energy; heat is total energy. Two red hot horseshoes have twice as much heat as one red hot horseshoe. A spark can be white hot, but it's so small that it doesn't have enough heat energy to burn you. As it transfers its heat to your skin it cools off before any damage is done.
Another way to look at is, that the heat something "contains" is the amount of energy that's needed to get it up to a certain temperature. Of course the same amount of energy is released when it cools. Obviously, two red hot horseshoes tossed in a pail of water will will warm the water twice as much as one horseshoe. And a cup of boiling water can put you in the hospital, while a teeny bit of white hot metal won't.
Temperature is different than heat. Temperature is the average molecular energy; heat is total energy. Two red hot horseshoes have twice as much heat as one red hot horseshoe. A spark can be white hot, but it's so small that it doesn't have enough heat energy to burn you. As it transfers its heat to your skin it cools off before any damage is done.
Another way to look at is, that the heat something "contains" is the amount of energy that's needed to get it up to a certain temperature. Of course the same amount of energy is released when it cools. Obviously, two red hot horseshoes tossed in a pail of water will will warm the water twice as much as one horseshoe. And a cup of boiling water can put you in the hospital, while a teeny bit of white hot metal won't.