US Department of Agriculture
The Science of Color in Autumn Leaves
Coupled with a beautiful photo gallery, the National Arboretum sets out to explain the science behind why leaves of deciduous trees change their color in the autumn months. While temperature effects the colors, learn here what happens in...
Exploratorium
Exploratorium: Science Snacks: Avalanche
In this activity, pour a salt-sand mixture into a CD case to notice how the particles separate themselves. Observe the effect known as granular convection as the smaller sand particles fall beneath the larger particles leaving a layered...