Life by the Numbers
AdultsAnimalsBiologyNature...There are now more than 7 billion human beings on Earth, and that got me wondering: How successful are we compared to other species? I take a look at out how our numbers stack up to some other domains of life. It turns out that biomass, or what things weigh, can be more important than how many of something there are. Find out how our numbers stack up against everything from bugs to bacteria, and get ready for some mind-blowing numbers!
Why Are Some People Left-Handed?
AdultsData ScienceScienceSociety...We've got two perfectly good hands attached to two perfectly good arms, so why do most people prefer to use one over the other for common tasks?
Can You Erase Bad Memories?
AdultsBiologyHumanNeuroscience...What if you could delete specific memories?
Watch The World's Most Polite Birds Wait In Line To Greet A Potential Mate
AdultsAnimalsNatureBiologyInstead of fighting it out with one another for a mate's affection, Blue manakins give each other a fair shot and let the lady decided. When a female manakin is feeling amorous, males will form an orderly little line in front of her, taking turns to introduce themselves and to put their colorful foliage on display.
Inside the ant colony
AdultsAnimalsNatureSociety...Ants have one of the most complex social organizations in the animal kingdom; they live in structured colonies that contain different types of members who perform specific roles. Sound familiar? Deborah M. Gordon explains the way these incredible creatures mate, communicate and source food, shedding light on how their actions can mimic and inform our own behavior.
How do we smell?
AdultsHumanNeuroscienceScience...An adult human can distinguish up to 10,000 odors. You use your nose to figure out what to eat, what to buy and even when it's time to take a shower. But how do the molecules in the air get translated into smells in your brain? Rose Eveleth charts the smelly journey through your olfactory epithelium and explains why scent can be so subjective.
The loathsome, lethal mosquito
AdultsAnimalsScienceEnvironment...Everyone hates mosquitos. Besides the annoying buzzing and biting, mosquito-borne diseases like malaria kill over a million people each year (plus horses, dogs and cats). And over the past 100 million years, they've gotten good at their job -- sucking up to three times their weight in blood, totally undetected. So shouldn't we just get rid of them? Rose Eveleth shares why scientists aren't sure.
The Most Amazing Thing About Trees
AdultsEcologyNatureScience...Trees create immense negative pressures of 10's of atmospheres by evaporating water from nanoscale pores, sucking water up 100m in a state where it should be boiling but can't because the perfect xylem tubes contain no air bubbles, just so that most of it can evaporate in the process of absorbing a couple molecules of carbon dioxide. Now I didn't mention the cohesion of water (that it sticks to itself well) but this is implicit in the description of negative pressure, strong surface tension etc.
Why do we cry? The three types of tears
AdultsBiologyHumanScience...Whether we cry during a sad movie, while chopping onions, or completely involuntarily, our eyes are constantly producing tears. Alex Gendler tracks a particularly watery day in the life of Iris (the iris) as she cycles through basal, reflex and emotional tears.
Dead stuff: The secret ingredient in our food chain
AdultsEcologyFoodScience...When you picture the lowest levels of the food chain, you might imagine herbivores happily munching on lush, living green plants. But this idyllic image leaves out a huge (and slightly less appetizing) source of nourishment: dead stuff. John C. Moore details the "brown food chain," explaining how such unlikely delicacies as pond scum and animal poop contribute enormous amounts of energy to our ecosystems.
How Wolves Change Rivers
AdultsAnimalsEnvironmentNature...When wolves were reintroduced to Yellowstone National Park in the United States after being absent nearly 70 years, the most remarkable "trophic cascade" occurred. What is a trophic cascade and how exactly do wolves change rivers? George Monbiot explains in this movie remix.
The mystery of motion sickness
AdultsHealthScienceBiologyAlthough one third of the population suffers from motion sickness, scientists aren't exactly sure what causes it. Like the common cold, it's a seemingly simple problem that's still without a cure. And if you think it's bad on a long family car ride, imagine being a motion sick astronaut! Rose Eveleth explains what's happening in our bodies when we get the car sick blues.
How sugar affects the brain
AdultsBiologyHealthHuman...When you eat something loaded with sugar, your taste buds, your gut and your brain all take notice. This activation of your reward system is not unlike how bodies process addictive substances such as alcohol or nicotine -- an overload of sugar spikes dopamine levels and leaves you craving more. Nicole Avena explains why sweets and treats should be enjoyed in moderation.
The Invisible Universe Of The Human Microbiome
AdultsBiologyHumanScience...The next time you look in a mirror, think about this: In many ways you're more microbe than human. There are 10 times more cells from microorganisms like bacteria and fungi in and on our bodies than there are human cells. But these tiny compatriots are invisible to the naked eye. So we asked artist Ben Arthur to give us a guided tour of the rich universe of the human microbiome.
How we found the giant squid
AdultsAnimalsWorldEnvironment...Humankind has been looking for the giant squid (Architeuthis) since we first started taking pictures underwater. But the elusive deep-sea predator could never be caught on film. Oceanographer and inventor Edith Widder shares the key insight that helped to capture the squid on camera for the first time.
Sleeping hummingbird "snores" in Peru
AdultsAnimalsEnvironmentNature...A female Amethyst-throated Sunangel (Heliangelus amethysticollis) sleeps in Peru.
Explore the Galapagos' biodiversity with Street View
AdultsTravelWorldNature...This week marks the 178th anniversary of Darwin's first exploration of the Galapagos Islands. This volcanic archipelago is one of the most biodiverse and unique places on the planet, with species that have remarkably adapted to their environment. Through observing the animals, Darwin made key insights that informed his theory of evolution. Here's a short documentary that captures the 10-day expedition: More info
Giant Ant Hill Excavated
AdultsAnimalsEnvironmentNature...A giant ant colony is pumped full of concrete, then excavated to reveal the complexity of its inner structure.