WEBVTT - How Vacuums Work

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<v Speaker 1>Welcome to brain Stuff from how stuff works dot com

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<v Speaker 1>where smart Happens. Hi, I'm Marshall Brain with today's question,

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<v Speaker 1>what a balloon filled with vacuum instead of helium float?

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<v Speaker 1>At sea level? Air weighs about one point to five

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<v Speaker 1>grams per leader. A leader of helium, on the other hand,

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<v Speaker 1>weighs about point one eight grams. If you weigh a

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<v Speaker 1>one leader bottle filled with air and then weigh the

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<v Speaker 1>same bottle filled with helium, it will weigh about one

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<v Speaker 1>gram less. If the bottle itself weighed less than a gram,

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<v Speaker 1>you couldn't weigh it at all because it would float.

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<v Speaker 1>You would have to turn the scale upside down and

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<v Speaker 1>put it above the floating bottle to check its negative weight. Generally,

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<v Speaker 1>a balloon has to be several leaders in size before

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<v Speaker 1>that one gram per leader weight difference of helium versus

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<v Speaker 1>air is enough to overcome the weight of the balloon

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<v Speaker 1>itself and float. If you could somehow fill a one

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<v Speaker 1>leader bottle with a vacuum, it would float even better.

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<v Speaker 1>A perfect vacuum ways zero grams, so a leader of

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<v Speaker 1>perfect vacuum ways zero grams, and that's point one eight

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<v Speaker 1>grams less than a leader of helium. The problem, of course,

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<v Speaker 1>is that building a lightweight container that can hold a

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<v Speaker 1>vacuum is not nearly as easy as building a container

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<v Speaker 1>that can hold helium. The phrase nature of horrors of

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<v Speaker 1>vacuum sums it up nicely. If you could figure out

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<v Speaker 1>a way to do it, however, you could be set

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<v Speaker 1>your vacuum balloon would float even better than a helium balloon.

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<v Speaker 1>Not that you don't need to have a perfect vacuum

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<v Speaker 1>for this to work. Any air that you take out

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<v Speaker 1>of the container helps a vacuum balloon to float. Do

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<v Speaker 1>you have any ideas or suggestions for this podcast? If so,

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<v Speaker 1>please send me an email at podcast at how stuff

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<v Speaker 1>works dot com. For more on this and thousands of

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<v Speaker 1>other topics, go to how stuff works dot com.