BrainStuff

If you look on the label of a water filter, you'll often see the filter contains activated charcoal -- but what exactly is this stuff? Tune in as Marshall Brain explains the nature of activated charcoal in this podcast from HowStuffWorks.com. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

SETI -- the Search for Extraterrestrial Intelligence -- is an enormous, global undertaking meant to detect signs of life beyond our solar system. Learn how you can help from home in this podcast from HowStuffWorks. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Everyone's familiar with those little packets of silicate gel, found in thousands of products -- but what exactly do they do? Check out this HowStuffWorks podcast and learn more about silica gel. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

It's often said that "nature abhores a vacuum." If that's true, then why doesn't the vacuum of space suck away our atmosphere? Tune in as Marshall Brain explains the science behind vacuums in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

If a balloon was filled by a vacuum -- rather than helium or air -- would it float? Check out this HowStuffWorks podcast to learn the science behind balloons and vacuum. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

An MRE -- or meal ready to eat -- contains precooked, sterilized food originally made to nourish soldiers. Check out this HowStuffWorks podcast to learn more about the retort packaging that makes MREs possible. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Also known as 'lie detectors,' polygraphs are used to record an individual's vital signs, such as breathing rate, pulse, and so forth. Check out this podcast from HowStuffWorks to learn more about polygraphs and the art of lie detection. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

A Boeing 747 uses approximately one galloon of fuel per second -- over the course of a ten hour flight, it might burn 36,00 galloons of fuel. How does this compare to a car? Check out this HowStuffWorks podcast to learn more about airplane mileage. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

CDs store music using 44,100 16-bit digital samples per second, adding up to about 10 megabytes per minute -- and that's too large to move easily move across the internet. Check out this HowStuffWorks podcast to learn how MP3 files solve this problem. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

All cells contains thousands of enzymes, and each of these enzymes is necessary for the cell. Check out this HowStuffWorks podcast to learn which enzymes cause apples and potatoes to turn brown upon exposure to oxygen. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

In houses with a built-in sprinkler system, anti-siphon valves prevent pesticides, pet waste, and other contaminants from polluting the home's water source. Check out this HowStuffWorks podcast to learn more about anti-siphon valves. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

A normal 120 volt outlet in the US has two vertical slots and a role hole centered below the slots -- the outlets with a pair of red and black 'test' and 'reset' buttons are known as GCFI outlets. Check out this HowStuffWorks podcast to learn more. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

By using a computer to monitor the rotation of the car's wheels, an anti-lock braking system helps drivers avoid skids. Could this computer also monitor flat tires? Check out this HowStuffWorks podcast to learn more about brake systems. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

The sound of gunfire is incredibly loud, and it is amazing that anything is able to silence a firearm. However, the principle behind a gun silencer is surprisingly simple. Check out our HowStuffWorks article to learn more about silencers. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Since the heart is a muscle, it relies on the oxygen and nutrients contained in blood. This blood is supplied by arteries on the exterior of the heart -- when these arteries are blocked, a heart attack results. Take a look at our HowStuffWorks article to Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Jam, jelly, and preserves are all made from fruit mixed with sugar and pectin. Jell-O, on the other hand, is completely different. Take a look at our HowStuffWorks article to learn more. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Every person has a set of chromosomes, or coiled strands of DNA. Check out this HowStuffWorks podcast to learn how chromosomes combine to promote variation from one generation to the next. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

There are three different technologies that fall into the catapult category: the ballista, the trebuchet and the catapult. Check out this HowStuffWorks podcast to learn more about the differences between catapult technologies. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

All cars manufactured today contain at least one computer -- but what does it do? Check out this HowStuffWorks podcast to learn more about car computers. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

The idea behind a water softener is simple: the calcium and magnesium ions in hard water are replaced with sodium ions. Learn more about the harmful effects of hard water -- and the benefits of soft water -- in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Learn how the length of hydrocarbon atom chains have different properties, producing substances such as kerosene, methane and other forms of fossil fuel. Check out this HowStuffWorks podcast to learn more about fossil fuels. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

The camel's hump is a giant deposit of fat that lets the camel survive up to 2 weeks without food. Learn more about camels in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

The fizzing you see when you drop an Alka-Seltzer tablet in water is the same sort of fizzing that you see from baking powder. This reaction is caused by an acid reacting with a base. Check out this HowStuffWorks podcast to learn more. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

The problem of pipes banging on a wall is often called "water hammer." Check out this HowStuffWorks podcast to learn more about this phenomenon. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Catalytic convertors convert hydrocarbons, carbon monoxide, and nitrogen oxides into three harmless chemicals, making the exhaust of a vehicle much cleaner. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

A 3-way bulb contains two filaments, and these filaments have differing wattages. Depending on the setting, the filaments operate separately or together to create the appropriate amount of light. Learn more about 3-way bulbs in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

For air in a submarine to remain usable, three things must happen: The oxygen must be replenished as it is consumed, the carbon dioxide must be removed from the air, and the moisture in human breath must also be removed. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

In this podcast, learn what causes a fever and what actually happens to the body when a fever occurs. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Built before the invention of electric pumps, fountains in Rome were powered through an ingenious system of gravity, cisterns, and aqueducts. Learn more about fountains in Rome in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

One minute of arc on planet earth is equal to one nautical mile. Listen to this HowStuffWorks podcast and learn more about the measurement of nautical miles. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Today, most answering machines are digital, and use the same technology as a CD or MP3 player. Learn more about digital answering machines in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

The clear, thin sap of Maple trees must be boiled down to create maple syrup -- it takes about 30 to 40 gallons of sap to create one gallon of syrup. Check out this HowStuffWorks podcast to learn more about Maple syrup. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

In many watches, phosphor is mixed with a radioactive element that continously charges the phosphor, powering glowing watch hands. Learn more about glowing watch hands in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

An uninterruptible power supply protects computers against surges, spikes, sags, and total power failure. Check out this HowStuffWorks podcast to learn more about uninterruptible power supplies. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

The 2009 Corvette ZR1 combines several technical innovations to produce a turbo-charged, eight-cylinder engine. Learn more about the Corvette ZR1 in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Next time you're filling up your tank at a gas station, ask yourself this: how does the nozzle know when the tank is full? Learn more about gas pumps in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

As sunlight passes through the atmosphere, particles in the air scatter blue light more efficiently than any other color in the light spectrum, creating a blue sky. Learn more about the sky and light in this Brainstuff podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Although most people are frightened by radiation, the truth is we are irradiated every day, both from cosmic rays in the sky, and radioactive elements in the ground. Learn more about radiation in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Carats are used for diamonds, while karats are used for gold. Learn more about the difference between carats and karats in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Is there any way that people could know the world is sphere while standing on the earth? Learn more about perceiving earth as a sphere in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Learn about the causes of gas (flatulence) in this podcast from Marshall Brain. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

A normal calendar years is 365 days long, but the earth actually takes 365.2422 days to completely orbit the sun. Learn more about leap years in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

The flash of a camera is bright enough to cause a reflection off the human retina -- the red we see in these photos comes from the blood vessels in the eye. Learn more about red eyes and cameras in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Although the speed of computers is growing exponentially, the human brain may handle roughly ten quadrillion instructions per second. Learn more about the world's fastest computer in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

A vitamin is a small molecule the body needs but cannot manufacture on its own. Learn more about vitamins in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

A company named Nanosolar is shaking up the alternative energy industry by offering solar technology at the lowest prices in history -- even cheaper than energy derived from coal. Learn more about Nanosolar in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

A standard HD screen has roughly 2 million pixels per frame -- but an ultra HD has four times that resolution. Learn more about ultra hi-definition in this HowStuffWorks podcast. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

Shaping an airplane a certain way -- or using materials that absorb radar waves -- causes a stealth aircraft to have the signature of a small bird, rather than an airplane. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.