BrainStuff

An electric toothbrush gets power from its base without the help of metal contacts. Find out how this sealed system works in the following podcast from HowStuffWorks.com. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

When you put a fresh piece of wood on a hot fire, volatile organic carbons in the wood evaporate, creating smoke. Learn more about smoke in this Brainstuff podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

An X-ray machine is essentially a camera that uses x-rays to expose the film, instead of visible light. Learn more about x-ray machines in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Mucous contains mostly water and mucin -- a branched polysaccharide. When polysaccharides such as mucin or cornstarch are mixed with water, the result is a sticky substance. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

A new company is claiming that, next year, the problems of carbon emissions, foreign oil dependence, oil spills, fuel shortages, etc. will all end due to a breakthrough in biotechnology. Is it true? Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Can you buy a good, long-lasting toy helicopter for under $30? Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Eyebrows are prominent human features, but what purpose do they serve? Scientists think they help keep stuff out of our eyes and aid in nonverbal communication, among other things. Learn more about eyebrows in this episode. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Salad dressings like Ranch and Thousand Island are traditional favorites, but have you ever wondered how they got their names? Marshall Brain reveals what salad dressings are made of -- and where their famous names came from -- in this episode. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Botulism bacteria creates a type of poisoning and paralysis -- but how does it actually work? Check out this HowStuffWorks podcast to learn more about the effects and spread of botulism. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Most disposable diapers contain a crystalline, absorbent substance called sodium polyacrylate. Learn how this polymer helps contain messes -- and some of the controversy surrounding this substance -- in this podcast from HowStuffWorks. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

As of 1999, all TV sets sold in the Untied States are required to contain a viewer-control chip, also known as a v-chip. Check out this HowStuffWorks podcast to learn more about v-chips and television ratings Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Aircraft carriers contain some of the most advanced technology in the world. Learn more about aircraft and aircraft carriers in this podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Airplanes rely on gravity to disperse fuel to the engine, but what happens when the plane is flying upside down? Tune in to this podcast from HowStuffWorks.com to discover ways that acrobatic planes fly upside down without crashing. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

The decibel unit is used to measure the intensity of a sounds. Check out our HowStuffWorks article to learn more about the decibel scale. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

When you look at a normal 120-volt outlet in the United States, there are two vertical slots and then a round hole centered below. Take a look at this HowStuffWorks article to learn why appliance cords are shaped this way. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Sodium acetate heat pads start out as a pouch of liquid and crystallize into a warm solid. Explore the fascinating chemistry that makes these heat pads work in this podcast from HowStuffWorks.com. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Groundskeepers at baseball fields create patterns using a process called lawn striping. Tune in to find out how this process works -- and how you can duplicate it to create designs in your own yard. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

In this episode of BrainStuff, Marshall Brain explains the chemistry behind rust, or iron oxide, and the rusting process. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Like cheese, pastrami is a good example of old-fashioned food preservation techniques. Find out how corned beef becomes pastrami in this podcast from HowStuffWorks.com. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Instant cameras makes it possible to see a photograph almost immediately after you take it. But how? In this episode, Marshall explains the chemical processes behind regular and instant photographic film. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

What causes stinky, smelly feet? Sweat and bacteria. Find out exactly how bacteria turn sweat into malodorous feet in this episode. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

If you've ever looked carefully at a U.S. one-dollar bill, you've probably noticed some mysterious symbols and Latin phrases. What do these symbols stand for? Why are they on there? Marshall Brain breaks it down for you in this episode. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

The amount of calories a person needs to consume on a daily basis varies by individual. Discover the three factors that can help you determine your daily caloric needs in this episode of BrainStuff. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Today's pencils are manufactured very differently than the original versions; but they still use a material called graphite, which isn't lead at all. How does the graphite get in the pencil? Find out in this episode. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Once relegated to high-end restaurants and clubs, valets are increasingly common across the United States. But how can you trust your valet -- and how will you know if the valet is scamming you? Tune in and find out. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.