Don't do lead, kids! Nowadays everyone knows the dangers this substance poses to humans -- especially children in their formative years -- but back in the day, lead was everywhere. Ancient Rome was riddled with the stuff, using lead in everything from pipes, to smelting, to cutlery, pottery and wine. It's tough to know just how much lead the average person encountered, but breathing the lead-filled air alone may have dropped children's IQs by up to three points. In today's episode, Ben, Noel and Max discover a fascinating, controversial theory: that Rome didn't fall due to war and economic troubles... but instead, the empire toppled because everyone slowly became dumber and dumber.See omnystudio.com/listener for privacy information.

In this week's Classic episode: In 1918, as the planet was consumed by World War I, the government of California found itself combating an unexpected and catastrophic enemy: Ground squirrels. The rodents were wreaking havoc across the countryside, consuming crops left and right. State horticulture commissioner George H. Hecke proposed an unorthodox solution -- enlist schoolchildren in a statewide massacre of all ground squirrels. Oddly enough, it worked.See omnystudio.com/listener for privacy information.

Most people think of yo-yos as a fun, old-school toy for kids: a pretty simple, clever device leveraging physics with a string and a weight. Yet as Ben, Noel and Max discover in today's episode, the story of the humble dates back into antiquity -- and the story of its evolution is riddled with ridiculous ups and downs.See omnystudio.com/listener for privacy information.

The results are in: pretty much everyone loves pizza... but what doth a pizza make varies from place to place. Obsessed with a game-changing message from a former pizzaiolo on the inside, Ben, Noel and Max dive into the delicious (and arguably disturbing) conspiracy of what makes a pizza "supreme".See omnystudio.com/listener for privacy information.

In this week's Classic episode: Were it not for the coal mine, the town of Vulcan, West Virginia may well have never existed. As a rural and geographically isolated community, Vulcan relied on a single, small bridge for its connection to the larger world. When the bridge failed, the town repeatedly tried to get financial assistance from the local and state government -- with no success. In a state of increasing desperation, the Mayor of Vulcan wrote the Soviet Union for help... during the Cold War. Tune in and learn what happened next.See omnystudio.com/listener for privacy information.

Espionage takes many forms. As Ben, Noel and Max learned in the first part of this two-part series, one of those forms was knitting. In today's episode, the guys explore the stories of phenomenal spies who used knitting as a form of top-secret communication.See omnystudio.com/listener for privacy information.

For a lot of folks in the modern day, knitting is more a relaxing hobby than a household necessity. However, not too long ago, this needlecraft was a genuine -- and effective! -- tool for spies. In the first part of this two-part series, Ben, Noel and Max dive into the fascinating history of knitting as espionage.See omnystudio.com/listener for privacy information.

Language is beautiful and, in many cases, continually evolving. As a result, we end up with hundreds of strange idioms and figures of speech that we use on a daily basis, with little to no understanding of what they originally meant. Join Ben and Noel with special guests Frank Mulherin and Rowan Newbie, the creator of the Pitches podcast, as they explore the bizarre origins of your favorite turns of phrase in this Classic episode.See omnystudio.com/listener for privacy information.

We all know pi, right? It's one of the most famous 'irrational numbers' in history, and mathematicians are still trying to figure it out in the modern day. While this may seem arcane to some of us non-mathheads, in today's episode, Ben, Noel and Max learn these numbers were3 once such a big deal that legends say folks got murdered for discovering them. Tune in to learn the harrowing tale of Hippasus, a Pythagorean cultist who discovered irrational numbers -- and, in doing so, pissed off the Gods so much that they drowned him.See omnystudio.com/listener for privacy information.

As the Fox sisters became global superstars for their purported ability to speak with the dead, the Spiritualism movement became both a social phenomena and a booming business. Yet along with the rise of true believers and performing psychics, an army of skeptics and investigators rose as well... and the questions they asked eventually brought the entirety of the movement down. Join Ben, Noel, Max and returning special guest Jonathan Strickland (aka The Quizster) for the second part of this special two-part episode.See omnystudio.com/listener for privacy information.