How Stuff Works   |   Podcast, ±3 min episodes every 2 days
Join Marshall Brain in the BrainStuff Podcast and learn answers to life's everyday questions. Improve your knowledge with the BrainStuff Podcast.

How do scratch-and-sniff stickers work?

Scratch-and-sniff stickers are novelties that delight both children and adults. Sniff out the ingenious technology that makes them work in this podcast from

Why is carbon monoxide so poisonous?

The structure of hemoglobin causes oxygen to bind loosely to iron -- however, carbon monoxide binds very tightly to the blood's iron, reducing your ability to breathe. Check out this podcast from HowStuffWorks to learn more.

How do I know if my catalytic converter has failed?

An automobile's catalytic converter uses a catalyst to convert harmful exhaust fumes into harmless ones. Find out what happens when your catalytic converter stops working properly -- and how you can tell -- in this episode.

What is the worst invasive public species?

From kudzu to cane toads, invasive species are changing the world. But which of these transplants is the worst for the local landscape? Tune in as Marshall Brain tackles invasive species across the world -- and ultimately concludes which one is the worst.

How many people work at a Formula 1 pit stop?

If you've ever seen a Formula 1 race, then you know the race isn't just between cars -- it's also between pit stop crews. In seven seconds these crews perform an entire pit stop. But how does it work, and how many people does it take? Tune in to find out.

What is the battery light on your car's dashboard for?

Cars rely on batteries to keep their electrical parts running and alternators to keep their batteries alive. Battery lights come into play when there's a charging problem. Find out more about battery lights in this podcast from

When I pay by check, where does that check go?

When you write a check to purchase goods and services, it passes through the hands of several banks before the process is complete. Marshall explains how checks are processed through intermediary banks in this episode.

How does a credit card's magnetic stripe work?

The magnetic stripe on the back of the card plays a key role in transactions made by credit card. Learn more about how these "mag stripes" work in this episode of BrainStuff.

Why do Wint-O-Green Life Savers spark in the dark?

If you've ever bitten into a Wint-O-Green Life Saver candy in the dark, you've probably noticed an accompanying spark of light. Marshall Brain explains the chemistry behind the phenomenon known as triboluminescence in this episode.

How can we eliminate fossil fuels?

It's no secret that fossil fuels have a detrimental effect on the environment, but do feasible alternatives exist? In this episode, Marshall takes a look at the possibilities of DIY biofuel.

What does "not guilty by reason of insanity" mean?

Claiming the "insanity defense" in fictional courts of law is common and seems pretty straightforward; in real life, it's much more rare and complex. Discover the legal definition of "insanity" -- and how it relates to mental illness -- in this episode.

How do kosher foods work?

In this episode of BrainStuff, Marshall Brain gives a detailed explanation of the Jewish dietary laws and preparations that make foods "kosher" and "pareve."