Getting a firm hold on the truth is never as simple as nailing down the facts of a situation. This hour, we go after a series of seemingly simple facts -- facts that offer surprising insight, facts that inspire deeply different stories, and facts that, in the end, might not matter at all.

Stories of nature and nurture slamming into each other, & shaping our biological blueprints.

Stories of striving, grasping, tripping, and falling for happiness, perfection, and Bliss.

The inhumanly fast world of high-speed trading, an excruciatingly slow experiment, and a physicist plays Zeus.

This hour, we walk the tightrope between doubt and certainty, and wonder if there's a way to make yourself at home on that razor's edge between definitely...and not so sure.

When Kelley Benham and her husband Tom French finally got pregnant, after many attempts and a good deal of technological help, everything was perfect. Until it wasn't. Their story raises questions that, until recently, no parent had to face… and that are still nearly impossible to answer.

What can machines tell us about being human?

Winners, losers, underdogs--what can games tell us about who we really are?

The surprising ways that loops steer…and sometimes derail…our lives.

Radiolab hunts for Patient Zeroes from all over the map.

We wrestle with the dark side of human nature, and ask whether it's something we can ever really understand, or fully escape.

Stories about traps and getaways ... about getting stuck, and breaking free.

A look at the messy mystery in our middles, and what the rumblings deep in our bellies can tell us about ourselves.

Strange stories of brains that lead their owners astray, knock them off balance, and, sometimes, propel them to do amazing things.

In this episode, real-life people try to pin down, and make peace with, mysterious figures that haunt them, prod them, and fade out of existence.

Radiolab rips the rainbow a new one.

In this episode, a question that haunted Charles Darwin: if natural selection boils down to survival of the fittest, how do you explain why one creature might stick its neck out for another?

Stories about getting lost, and how our brains, and our hearts, help us find our way back home.

What do you do when your own worst enemy is...you?

Stories of unlikely (and surprisingly simple) answers to seemingly unsolvable problems.

From hair parts to the origin of the universe, how symmetry shapes our existence.

Oops. In this hour of Radiolab, stories of unintended consequences--from a psychologist whose zeal to safeguard national security may have backfired, to a toxic lake that spawned new life.

It’s almost impossible to imagine a world without words. But in this hour, we try to do just that.

We plunge into a black hole, take a trip over Niagara Falls, and upend some myths about falling cats.

One tidy mathematical formula may hold the key to how cities work. We take to the streets to test the numbers, & ask what really makes cities tick.

Stories about the tug of war between force of will and fate.

This hour of Radiolab: communicating across species. We get the story of a rescued whale that may have found a way to say thanks, ask whether dogs feel guilt, and wonder if a successful predator may have fallen in love with a photographer.

Chimps. Bonobos. Humans. We're all great apes, but that doesn’t mean we’re one happy family.

A journey to the edge of human limits -- from a bike race that makes the Tour de France look like child’s play, to a mind-stretching memory competition.

Say hello to the growth that killed Ulysses S. Grant, & get to know the woman whose cancer cells changed modern medicine.

How well can you ever really know the people around you?

How stochasticity -- a wonderfully smarty-pants word for randomness -- drives our lives, and the patterns we see around us.

Eleven meditations on how, when, and even if we die.

Tales of lethargic farmers, zombie cockroaches, and even mind-controlled humans (kinda, maybe).

Peacenik baboons, a man in a dress, and cuddly tame foxes. Stories of adaptation, and reframing ideas about normalcy.

Love 'em or hate 'em, you rely on numbers every day. We ask how they confuse us, connect us, & even reveal secrets about us.

We turn up the volume on the voices in our heads, and try to get to the bottom of what really steers our decisions.

We examine our beginnings, take a tour of the animal kingdom, and ponder a world where frozen sperm can last for all eternity.

Radiolab asks what race is, and whether it's fixed or fluid, genes or culture?

Humans love to solve problems. This hour, Diagnosis -- our attempt to find out what's wrong, and give it a label.

Stories of love and loss in the name of science.

We all laugh. This hour of Radiolab asks why.

Lies, liars, and lie catchers. And the strange power of lying to yourself.

Martians, mass media, and hysteria – how one of the most controversial broadcasts ever sparked panic in the 1930s, & fooled audiences, again and again, for decades.

The uneasy marriage of biology and engineering raises big questions about the nature of life.

Nightmarish stories of musical hallucinations, songs with the power to transcend language, & the triumphant return of the Elvis of Afghanistan.

From the symbolic power of the doctor coat, to the very real stash of opium in your brain, this hour of Radiolab explores the healing powers of belief and imagination.

Birds do it, bees do it...yet science still can't answer the basic question: why do we sleep?

Blood-thirsty Romans, frozen carcasses, wild jaguars, and a question: how do you build a better cage?

Remembering is a tricky, unstable business. This hour: a look behind the curtain of how memories are made...and forgotten.

The modern search for the fountain of youth, and personal stories of witnessing death.

Digging up the past leads to some very unexpected finds. This hour, Radiolab plays detective and goes sleuthing in some rather unusual places: an ancient trash dump, the side of the highway, and in the blood of millions of Asians.

We explore the line between music and language, and turn to physics and biochemistry to ask how sound becomes feeling.

For thousands of years philosophers have debated the essence of morality. Now, neuroscientists may have answers.

Radiolab examines the connection between your brain and your body -- and what happens when it breaks.

We ponder our insignificant place in the universe, and boldly go after stories of romance & cynicism in Outer Space.

The "mind" and "self" were formerly the domain of philosophers and priests. But in this hour of Radiolab, neurologists lead the charge. We  reflect on the illusion of selfhood, contemplate the evolution of consciousness, and meet a woman who one day woke up as a completely different person.

Stories of stress -- from a singer who loses her voice, to an author caught in a body that never grew up.

What happens when there is no leader? We look at the bottom-up logic of cities, Google, and even our brains.

The strange, subjective nature of time -- from a sped-up spin through childhood, to a really, really slowed-down Beethoven symphony. 

Fighting the inevitable march of time -- or at least the common sense view of it.