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.
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.
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.
Fish With Transparent Head Filmed
AdultsAnimalsNatureBiology...For the first time, a large Pacific barreleye fish - complete with transparent head - has been caught on film by scientists using remotely operated vehicles at the Monterey Bay Aquarium Research Institute. The deep-sea fish's tubular eyes pivot under a clear dome.
What is fat? - George Zaidan
AdultsBiologyHealthScience...As the narrative goes, fat is bad. Well, it's actually more nuanced than that. The type of fat you eat is more impactful on your health than the quantity. George Zaidan examines triglycerides, the varied molecules that make up fat, and how to identify which types of fat you are consuming.
Amazing Avian Evolution
AdultsAnimalsNaturePhotography...All 39 species of New Guinea's spectacular birds of paradise have now been captured on film by renowned photographer Tim Laman and ornithologist Ed Scholes.