WEBVTT - BrainStuff Classics: Why Can It Be Painful To Bite Aluminum Foil?

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<v Speaker 1>Welcome to Brainstuff, a production of I Heart Radio. Hey

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<v Speaker 1>brain Stuff, I'm Lauren Vogelbaum, and today's episode is a

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<v Speaker 1>classic from our former host, Christian Sagar. This one concerns

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<v Speaker 1>a strange bit of everyday science. Why can it be

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<v Speaker 1>strangely painful to bite down on a piece of aluminum foil? Hey, everybody,

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<v Speaker 1>it's me Christian Sager. Now today's question is why is

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<v Speaker 1>it so painful to bite into aluminum foil? And if

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<v Speaker 1>you're from across the pond, you may be wondering right now,

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<v Speaker 1>why is he saying aluminum instead of aluminium? Well, I'm American,

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<v Speaker 1>That's how I've pronounced it all my life. I apologize,

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<v Speaker 1>we're gonna go forward with aluminum. But it's a good question, right.

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<v Speaker 1>So first things first, it's actually not painful for everybody

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<v Speaker 1>to bite into this foil. It's painful for people who

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<v Speaker 1>have fillings or crowns made of metal. You probably already

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<v Speaker 1>knew that part, So let's fast forward. What is actually

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<v Speaker 1>happening here. It's sort of like making a battery. So

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<v Speaker 1>how does this happen exactly? Well, first, it's two different metals,

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<v Speaker 1>the aluminum foil and the metal in your filling or crown.

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<v Speaker 1>They have what's called an electrochemical potential difference, and they

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<v Speaker 1>create the sort of voltage in the environment in your mouth,

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<v Speaker 1>which is moist and salty. It's produced by your saliva.

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<v Speaker 1>It's perfect for these two things to come into contact

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<v Speaker 1>this way and to transmit energy. The electrical stimulation from

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<v Speaker 1>this bootleg battery you have created is hitting the nerve

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<v Speaker 1>in your tooth, and that is producing that weird unique pain.

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<v Speaker 1>The production of this current between the contact of two

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<v Speaker 1>dissimilar metals. It's actually a pretty old concept. It's called

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<v Speaker 1>the voltaic effect. It's named after a guy named Alessandro Volta,

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<v Speaker 1>who most people credit with discovering this. In fact, if

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<v Speaker 1>you want to learn more about this, on my other podcast,

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<v Speaker 1>Stuff to Blow Your Mind, we went really far into

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<v Speaker 1>voltaic batteries in an episode we did on Frankenstein. Now

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<v Speaker 1>Volta he was making extra batteries a long time ago,

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<v Speaker 1>and what he did was he stacked these dissimilar metals

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<v Speaker 1>together and in between them he would put water paper

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<v Speaker 1>soaked with salt water. And he found that by doing

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<v Speaker 1>this he could create a very low power battery. So

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<v Speaker 1>that's essentially it. That's what's happening when you open a

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<v Speaker 1>candy bar and you bite down on a piece of

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<v Speaker 1>chocolate that still has a little bit of foil in it,

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<v Speaker 1>and you freak out because it's painful. You're essentially creating

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<v Speaker 1>a battery in your mouth. Today's soote was written by

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<v Speaker 1>Ben Bollen and produced by Tyler Clang. For more on

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<v Speaker 1>this and lots of other topics, visit how stuffworks dot com.

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<v Speaker 1>Brain Stuff is a production of I Heart Radio. For

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