Nature has handed out some wildly uneven perks. While certain animals can regrow entire limbs, humans are limited to patch jobs. Julian and Trace dig into what it would actually take to rebuild an arm or leg from scratch, from the cellular machinery needed to kick-start regeneration to the staggering calorie bill your body would have to pay along the way. Building a replacement limb would mean your body would have to manufacture bones, muscles, nerves, blood vessels, and skin on an industrial scale—all while somehow keeping the rest of you running at the same time.

If you’ve ever been sick and wondered how a seemingly endless supply of mucus can fit inside your face, you’re not alone. This week, Trace and Julian investigate where all that snot actually comes from, explore the surprisingly strange evolutionary history of mucus, and discover how your sinuses can produce so much crud despite being smaller than you’d think. Naturally, Trace uncovers one of the most delightfully bizarre studies we’ve ever discussed on the show that may or may not involve human and goat cadavers, sinus drainage, and a question that apparently required researchers to discover positions neither species was ever meant to be in… and somehow, that’s still only part of the story.

This week, Julian and Trace imagine a world where gravity vanishes for ten seconds every day. There, they discover that humanity would have a lot more to worry about than a few floating tchotchkes. True weightlessness means the slightest movement could send you drifting across a room trapped in mid-air only to crash back down again when gravity returns. The guys think about how society and nature might adapt to this daily gravity outage and (of course) detour into the surprisingly persistent rumor that solar eclipses affect gravity, proving that even a completely absurd scenario can lead to some very real physics.

🎶 Game of Thrones theme 🎶

DRA-GONS. WHAT ARE DRAG-ONS? LET US KNOWWWWWW

OR MER-MAIDS. FRICKIN’ MER-MAIDS… HOW THEY GOOOOO?

PLUS JUUUU-LIAN WANTS TO CHECK ON MIRROR TRAAAACE

HE THINKS, THIS MIRROR TRACE MIGHT BE EVIL TRAAAAAACE!

👏👏👏👏👏👏

Today in Pod 48 Ellen Weatherford from “Just The Zoo of Us” (family friendly) and “Spellbound and Gagged” (NSFW) joins us to talk out about dragons, scientifically correct mermaids and a possible Mirror-Universe Trace! 🤫

This week, Trace and Julian investigate a deceptively simple mystery: why do things look darker when they’re wet? Although the question sounds almost too obvious to ask, Trace takes us on a fascinating exploration of light, color, optics, and the strange ways our brains make sense of the world around us. It’s one of those everyday phenomena that feels totally obvious—right up until you try to explain it. Kind of like how Trace keeps winning all those wet T-shirt contests… and how Julian’s always the judge.

This week, Julian and Trace imagine a world where humanity never got around to inventing ships and discovers that the consequences run a WHOLE lot deeper than a disappointing cruise industry. Without boats, trade slows down, migration patterns change dramatically, and some parts of the world might never have been settled at all. Along the way, Julian uncovers just how much nautical history is hiding in our everyday language, from common phrases to metaphors that only exist because somebody, somewhere, looked at a vast expanse of definitely-not-scary open water and thought, “Yeah, I can probably cross that.”

In this TAPE classic, Trace tackles a transportation problem of his own creation by figuring out just how many chihuahuas it would take to complete the Iditarod, the legendary dogsled race across hundreds of miles of Alaskan wilderness, forcing him to confront the limits of canine endurance, logistics, and plain old common sense. Meanwhile, Julian investigates whether AI can help cook an egg, only to discover that turning a simple breakfast into a prompt-driven exercise may be far more complicated than cracking a shell.

This week, Trace and Julian embark on a surprisingly existential mission: finding the most boring day in history. Easy, right? Just pick a day where nothing happened. Unfortunately—or fortunately, depending on how you look at it—the universe refuses to sit still. From the way our brains define boredom to the impossible task of measuring excitement across an entire planet (and beyond), Trace discovers that "nothing happened" may be one of the hardest things to prove. After all, if trees are growing, species are evolving, galaxies are colliding, and someone somewhere is having the weirdest day of their life, can any day really be boring?

This week, Trace dives into the eerie blue glow of Cherenkov radiation—the phenomenon that makes nuclear reactors look suspiciously like sci-fi props—and asks the obvious next question: is blue really the best color? Meanwhile, Julian heads beneath the waves to investigate one of nature's most famous "friendships," only to discover that when it comes to biological partnerships, the documentary 'Finding Nemo' might have glossed over a few crucial details. Turns out, even the natural world has its fair share of freeloaders, bad roommates, and complicated relationship dynamics.

This week, Julian launches an investigation into “Big Sun” and its wild claim that humans can somehow absorb vitamins from a giant nuclear fireball 93 million miles away. Unfortunately for conspiracy theorists, that actually does somehow happen. Later, Trace ventures into the unexplored corners of the human mind to ask whether there are any feelings that nobody has ever experienced before—and whether humanity might still be hiding entirely new emotions somewhere beyond the edge of our emotional vocabulary.

In this TAPE Classic episode, Trace explores the science of stasis, diving into hyper-sleep, cryogenic freezing, and whether humanity might one day be able to snooze our way through long journeys. Meanwhile, Julian applies rocket science to one of humanity’s least celebrated forms of propulsion, uncovering just how much thrust it would take to achieve the dream of self-powered flight. As a bonus, an unexpected detour reveals that the 1993 classic film “Demolition Man" may have been far more prophetic than anyone intended.

If our magic button killed every microbe on Earth — all bacteria, all viruses, gone — what would be left standing? Spoiler: You'd be missing something powerful. Julian goes full overachiever and zooms in on FOUR questions all on this devastating topic. Then, Trace, somewhere else in the solar system, is singing in the rain. But does it even rain elsewhere? Is rain weird? Find out this week!

This week, Trace and Julian accidentally stumble into what may be the most in-depth discussion of a certain food-based weather movie ever recorded. To determine whether giant pancakes, spaghetti tornadoes, and burger-based weather systems would actually be fun or the beginning of humanity’s downfall, Trace recruits our associate producer, Sabrina Capello. Longtime listeners may know her as the person who bullies us on social media, but today she joins the show in her true role: professional opinion haver and alarmingly dedicated Cloudy with a Chance of Meatballs expert. What begins as a whimsical thought experiment quickly turns into a shocking investigation into a world far more horrifying than the movie ever suggests.

This week, Julian explores whether animals can be allergic to humans, digging into all things histamine to find out if nature has ever collectively decided that people are, medically speaking, just too annoying to be around. Later, Trace investigates a deeply cursed question: how many holes do humans really have? Oh, and he also tackles the ACTUAL question of what it would be like if humans were born full of holes—think a walking, talking monstera plant, but flesh. Horrifying… and also quite unsanitary.

If we had a nickel for every time Julian answered a question involving pigeons, we’d have two nickels. Not that many, but weird that it’s happened twice. This week, he investigates pigeon logistics, excreta coverage, and everything about the Great Wall of China, all fueled by the power of basic research and—horrifyingly—firsthand investigation. Meanwhile, Trace attempts to outsmart the cruel economics of holiday birthdays using special and general relativity, which was definitely the simplest and most reasonable way possible to solve this problem.

Is that a slogan for hair shampoo or fizzy drinks? Well, kick back, relax, and crack open a can—or, you know, be like us and choose from one of the many flat ones you forgot on your desk. Either way, if you’re serious about your bubbles, Julian has a proposition for you: skip the middleman and suckle straight from the teat of the soda fountain. On the flip side, Trace embarks on a trek to the follicular frontier to discover how much hair you’d have to grow to actually lose weight. It’s a hairy situation, but we’re all about life hacks on this show!

This week, Trace digs into whether life could’ve ever gotten its start somewhere else—say, Mars, for example—quickly pointing out that our lovely planet's existence is already pretty insane on its own. Meanwhile, Julian takes a simple “why hot things glow red” question and follows it straight through Max Planck to the idea of whether the universe itself has a maximum possible temperature. Naturally, we end up circling the origin of everything like that isn’t wildly overkill, and we somehow accidentally relive the Big Bang along the way.