A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high frequency alternating-current electricity. Tesla's original circuits, as well as most modern coils use a simple spark gap to excite oscillations in the tuned transformer

Excavations in El Salvador recently unearthed the remains of some of the region's oldest societies.

The marine iguana is a species of iguana found only on the Galápagos Islands. This very unique lizard can dive as deep as 98 feet and spend up to one hour underwater. When diving to 23 feet or deeper, they regularly remain submerged for approximately 30 minutes.

A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle.