Tide Tables. Tide tables list the high and low water heights and times for each day.
Buoyancy. Buoyancy is an upward force exerted by a fluid that pushes against an object's weight.
Seismograph. The Richter Scale assigns a number to quantify the amount of seismic energy.
Karst. Karst topography is a landscape shaped by the dissolution of a layer or layers of soluble bedrock.
Spiral. Edwin Hubble first described a spiral galaxy in "The Realm", his 1936 work.
Electromagnet. An electromagnet loses its magnetic force when the current ceases.
Calving. The calving of glaciers in Greenland creates 12,000 to 15,000 icebergs annually.
0.447. 1 mile per hour = 5280 feet per hour.
Leaf. In the fall, leaves stop producing chlorophyll, which allows the other colors in the leaf to show through.
Elevons. Elevons are aircraft control surfaces.
Venus. Venus rotates once on its axis every 243 earth days.
Pond. "Succession" is the term for the transformation of a pond to a type of landform.
English Channel. The English Channel joins the North Sea to the Atlantic Ocean.
Brown Eyes. Brown is the most common eye color in the world.
Airplane Radar. The National Hurricane Center tracks hurricane activity with radar.
5 Billion Kilometers. Mars Observer was launched by the U.S. in September 1992.
Tropical Depression. A tropical depression is an organized group of thunderstorms.
Seamounts. A seamount never reaches the surface of the ocean, thus never becoming an island.
Uranus. Uranus is theorized to have been hit by something large millions of years ago, causing its odd rotation.
Jupiter. Jupiter is the fifth planet from the Sun.