Gliders are mostly made out of

Glider wing design can be described as

Glide ratio is

The space shuttle is a glider. What is its glide ratio?

How do most gliders/sailplanes take off?

The variometer in a glider indicates

The variometer has an audible tone that

When does the tow plane release the glider?

The inner layer of a thermal (the hole) is ascending air.

Thermals are created when the moon is above the horizon.

Shadowed areas create really strong thermals.

Cloud layers inhibit thermal creation.

Dry land masses are more likely to create thermals than damp ones.

Ridge lift is air that has been lifted as it moves over rolling sand dunes.

Ridge lift is when the prevailing wind strikes a mountain that is large and steep enough to deflect wind upward.

A long mountain range can provide enough lifting force for a glider to stay airborne for a long time and travel a great distance.