What is the difference between mass and weight?

An introduction to matter.

An introduction to rocks and the rock cycle.

Using simple tests such as luster, hardness, and cleavage/fracture, you can identify most common minerals.

Forget "animal, vegetable, or mineral?" The scientific definiton of a mineral is much more specific.

75% of the Earth’s surface is water., but that only scratches the surface, as Robert dives into this deep subject.

From the beaches of Florida to the mountains of California, learn how wind, water, ice and gravity can erode big rocks into smaller rocks, eventually turning them into soil.

Have you ever really thought about the water cycle, about how old that glass of water really is, and all the places it has been?

Just as we change as we age, the Earth changes too, wearing away in some places and building back up in others.

From earthquakes that last seconds to continental drift that takes millions of years, the Earth changes in many ways.

With Americans producing 600,000 tons of garbage a day, it is important to look at what we throw away.