In this video Paul Andersen explains how Kirchhoff's Junction Rule can be applied to series and parallel circuits. Kirchhoff's Junction Rule is an application of the conservation of charge. The current into a junction will always equal...

When he learned of the threat that rising sea levels posed to his coastal hometown of Miami, Florida, eco-artist Xavier Cortada founded a movement around beautifully designed elevation markers highlighting the risk of flood damage. The...

In this video Paul Andersen explains how the continuity equation is an application of conservation of matter in a fluid. The continuity equation may apply to either mass or volumetric flow. Example problem and examples are included.

Research suggests that more diverse ecosystems are better for the bottom line.

We know how to clone animals, so why aren't we saving endangered species by cloning their populations?

In this video Paul Andersen explains how biodiversity measures the variety of genes, species, and ecosystems on the planet. Biodiversity provides resources and ecosystem services for humans on the planet. He also explains how...

Conservationist and TED Fellow Moreangels Mbizah studied the famous Cecil the lion until he was shot by a trophy hunter in 2015. She wonders how things could've gone differently, asking: "What if the community that lived next to Cecil...

In this video Paul Andersen compares and contrasts elastic and inelastic collisions. In all collisions the linear momentum will be conserved. In an elastic collision the kinetic energy of the objects will also be maintained. Several...

In this video Paul Andersen explains how the energy in a closed system can be converted from kinetic to potential to kinetic energy. Sample problems and a simulation is contained.

In this captivating talk, journey into the surprisingly colorful nights of the Amazon Rainforest, as artistic entomologist Leo Lanna and designer Lvcas Fiat introduce us to the shapeshifting wonder of a creature they've fallen in love...

In this video Paul Andersen explains how matter and energy flow and cycle through systems. He starts by explaining how energy and matter input and output will always be conserved. He addresses the many misconceptions surround energy and...

Hank wraps up the Crash Course on ecology by taking a look at the growing fields of conservation biology and restoration ecology, which use all the kung fu moves we've learned about in the past eleven weeks and apply them to protecting...

Well, it wouldn't be too long after we started developing Ecology that we would try to control the environment. In some ways this was helpful and likely prevented a lot of people from starving. But, there have been a few downsides.

We’ve explored the origins of modern biology, the earth sciences, and even the sciences of outer space. Now it’s time to put these disciplines together. It's Ecology time!!!

Today, we continue our exploration of fluids and fluid dynamics. How do fluids act when they're in motion? How does pressure in different places change water flow? And what is one of the motion annoying things about filming outside on a...

In this video Paul Andersen explains how chemical reactions progress as bonds are broken and reformed reformed. He explains the difference between changes in state and changes in molecules. He discussed collision theory and explains why...

From a special black-footed ferret to coral that can withstand warming waters, genetic rescue efforts that use genomics and synthetic biology are helping nature thrive. But despite the huge successes of this kind of intervention,...

In this video Paul Andersen explains how water is unequally distributed around the globe through the hydrologic cycles. Seawater is everywhere but is not useful without costly desalination. Freshwater is divided between surface water and...

We need a radically new approach to ocean conservation, says marine biologist and TED Fellow Alasdair Harris. In a visionary talk, he lays out a surprising solution to the problem of overfishing that could both revive marine life and...

The Hindu Kush Himalaya region is the world's third-largest repository of ice, after the North and South Poles -- and if current melting rates continue, two-thirds of its glaciers could be gone by the end of this century. What will...

How do coral reef conservationists balance the environmental needs of the reefs with locals who need the reefs to survive? Joshua Drew draws on the islands of Fiji and their exemplary system of protection, called "connectivity", which...

Everything in our universe has mass - from the smallest atom to the largest star. But the amount of mass has remained constant throughout existence even during the birth and death of stars, planets and you. How can the universe grow...

The gharial and king cobra are two of India's most iconic reptiles, and they're endangered because of polluted waterways. Conservationist Romulus Whitaker shows rare footage of these magnificent animals and urges us to save the rivers...

Island and coastal nations need to protect their waters to keep the oceans healthy. But they often have lots of debt and aren't able to prioritize ocean conservation over other needs. Mark Tercek and his team at The Nature Conservancy...