Sparticl

While it looks like skaters defy the principles of physics, in reality they're using momentum, gravity, friction, and centripetal force to perform amazing tricks.

And physics isn't the only science involved in this extreme sport. New technologies and designs are being applied to skateboarding all the time.

Most people now understand the need to protect their skin from too much sun. But what did people do before the invention of sunscreen? And do you know the difference between sunscreen and sun block?

Discover the history of sunscreen and sun block, learn about natural products to protect your skin and about modern innovations for skin protection.

Magnificent and beautiful to behold, a rainbow forms when, under just the right conditions, sunlight hits water droplets and breaks into the seven colors of the visible spectrum. At a place like Victoria Falls in Zambia, they're nearly a permanent feature.

For more than 400 million years, the chambered nautilus has propelled itself through ocean depths in search of prey. Like its squid and octopus relatives, it also has tentacles, but its shell makes it unique.

Investigate what else (besides the animal) is inside its many-chambered shell and how this very active predator uses it.

These insects provide summer background music using body parts as instruments. Individual species play distinctive songs, which you can use to identify them even if you can’t see them.

They belong to the same order, Orthoptera — along with locusts and katydids — but differ in physical features and behavior.