BrainStuff

Virtual first down lines are used to indicate where play resumes in football -- but how do they work? Listen in as Marshall Brain explains how the technology superimposes a virtual line in this podcast on HowStuffWorks.com. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

Dioxin is an organic chemical that consists of benzene, oxygen and chlorine. This chemical is also toxic. Tune in to learn more about dioxin and Agent Orange in this podcast from HowStuffWorks.com. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com See omnystudio.com/listener for privacy information.

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.com See 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.com See 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.com See 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.com See 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.com See 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An MRE -- or meal ready to eat -- contains precooked, sterilized food originally made to nourish soldiers.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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See 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.com See omnystudio.com/listener for privacy information.