BrainStuff

Circular saws are much noisier than table saws partly because of the type of motor they possess. Learn more about universal and induction motors in BrainStuff, a podcast from HowStuffWorks.com.

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Airplane toilets serve the same function as regular ones, but because they exist in a moving environment, they rely on slightly different technology to get the job done. Find out how they work in this podcast from HowStuffWorks.com.

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Cats tend to purr when they're happy, but pleasure isn't the only reason for this behavior. And they aren't the only animals who purr. Find out why and how cats and other animals purr in this episode of BrainStuff.

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Learn about the causes of gas -- and not the kind you put in your car -- in this podcast from Marshall Brain.

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Milk is often touted as a "miracle drink," full of restorative, nutritional properties. And there's some truth to this claim. Find out why mammal milk is called "the perfect food" in this podcast from HowStuffWorks.com.

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As far as weight goes, Earth is a pretty hefty celestial body. But exactly how heavy? And how does one measure something so massive? Find out in this podcast from HowStuffWorks.com.

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Batteries are a common way to store energy, but there are many others. Discover more energy storage techniques, from falling weights to fuel cells, in this podcast from HowStuffWorks.com.

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We've all had a cold at one point or another; it entails an uncomfortable cocktail of symptoms like sneezing, coughing and a runny nose. But why do we get colds? How do they work? Find out in this podcast from HowStuffWorks.com.

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Three elements create a fire. Discover what they are and how dry chemical fire extinguishers combat them in this podcast from HowStuffWorks.com.

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Aluminum is both lightweight and strong, so it's no wonder that space stations, airplanes and thousands of other products use this metal. But where does it come from, and what makes it so special? Tune in to learn more.

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