When is water safe to drink? - Mia Nacamulli
AdultsEcologyHealthScience...Water is refreshing, hydrating, and invaluable to your survival. But clean water remains a precious and often scarce commodity - there are nearly 800 million people who still don't have regular access to it. Why is that? And how can you tell whether the water you have access to - whether from a tap or otherwise - is drinkable? Mia Nacamulli examines water contamination and treatment.
Why wildfires are necessary - Jim Schulz
AdultsEcologyNatureEnvironment...Our early ancestors relied on lightning to cause forest fires, from which they could collect coals and burning sticks to help them cook food and clear land. Yet, it wasn't just humans who benefited from these natural phenomena. Even as they destroyed trees, fires also helped the forests themselves. Jim Schulz outlines the benefits of wildfire.
When a River Goes Missing, It's Kind of a Big Deal...
AdultsEcologyGlobal WarmingNature...How does a river suddenly disappear? It gets stolen! How do you steal a river? With climate change!
Indigenous Panamanians protect their forests with drones
AdultsEcologyNatureTechnology...Settlers are illegally clearing trees on their land. So indigenous people are employing modern technology to stop them.
How Did The Deepest Part Of The Ocean Get So Polluted?
AdultsEcologyGlobal WarmingNature...Scientists have found trash in the deepest parts of the ocean, the Mariana Trench. What does this mean for us and the organisms living there?
How much of human history is on the bottom of the ocean?
AdultsEcologyHistoryNature...Sunken relics, ghostly shipwrecks, and lost cities aren't just wonders found in fictional adventures. Beneath the ocean's surface, there are ruins where people once roamed and shipwrecks loaded with artifacts from another time.
Deep ocean mysteries and wonders
AdultsEcologyEnvironmentNature...In the deepest, darkest parts of the oceans are ecosystems with more diversity than a tropical rainforest. Taking us on a voyage into the ocean -- from the deepest trenches to the remains of the Titanic -- marine biologist David Gallo explores the wonder and beauty of marine life.
How big is the ocean?
AdultsEcologyNatureEnvironment...While the Earth's oceans are known as five separate entities, there is really only one ocean. So, how big is it? As of 2013, it takes up 71% of the Earth, houses 99% of the biosphere, and contains some of Earth's grandest geological features. Scott Gass reminds us of the influence humans have on the ocean and the influence it has on us.
Where Do Birds Go In Winter?
AdultsAnimalsEcologyEnvironment...As winter approaches, V-shaped flocks glide overhead as the world's birds begin their long treks to warmer climates. Humans used to have some pretty crazy theories about where birds went for winter, like the moon, or to the bottom of the ocean.
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.
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.
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