Some people love the feeling of cracking their knuckles, while others cringe at the sound. But what causes that trademark pop? And is it dangerous? Eleanor Nelsen gives the facts behind joint popping. [Directed by Steve Belfer Creative, narrated by Addison Anderson].

Nearly 350 species of fish have specialized anatomical structures that generate and detect electrical signals. Underwater, where light is scarce, electrical signals offer ways to communicate, navigate, find, and sometimes stun prey. But how do these fish produce electricity? And why? Eleanor Nelsen illuminates the science behind electric fish. [...

Imagine you're watching a runaway trolley barreling down the tracks, straight towards five workers. You happen to be standing next to a switch that will divert the trolley onto a second track. Here's the problem: that track has a worker on it, too — but just one. What do you do? Do you sacrifice one person to save five? Eleanor Nelsen details th...

It's so obvious that it's practically proverbial: you can't unboil an egg. But actually, it turns out that you can -- sort of. Eleanor Nelsen explains the process by which mechanical energy can undo what thermal energy has done. [Directed by Província Studio, narrated by Addison Anderson].

Imagine a neuroscientist who has only ever seen black and white things, but she is an expert in color vision and knows everything about its physics and biology. If, one day, she sees color, does she learn anything new? Is there anything about perceiving color that wasn't captured in her knowledge? Eleanor Nelsen explains what this thought experi...

Ah, spring. Grass growing, flowers blooming, trees budding. For those with allergies, though, this explosion of new life probably inspires more dread than joy. So what's behind this annual onslaught of mucus? Eleanor Nelsen explains what happens when your immune system goes rogue. [Directed by Lisa LaBracio, narrated by Addison Anderson, music b...