January 18, 2019

Why do toilets north and south of the equator flush in different directions?

It’s a fact confirmed by cartoons and travel shows: Flush a toilet in England and the water swirls counterclockwise; flush one in Australia and it empties […]
January 18, 2019

What conditions on Earth make it so favorable for life?

Earth’s atmosphere not only provides the right mix of breathable air for animals and plants, but it – combined with an oxygen-rich ozone layer and the […]
January 19, 2019

Why do leaves change color in the fall?

Leaves are colored by molecules called pigments. The pigment that causes leaves to be green is chlorophyll. Chlorophyll is important for plants to make food using […]
January 19, 2019

Why do tumbleweeds tumble?

To set the mood for shootouts at high noon in old cowboy movies, of course. Actually, tumbleweeds tumble to create future generations of tumbling tumbleweeds. The […]