What causes gravity remains a mystery. Einstein’s general theory of relativity states a massive object curves space-time, causing other bodies to move toward it. This theory helps explain why gravity can act at a distanc... More »

There are varying theories on how the moon was created. Some scientists believe that it was created when a Mars-sized planet named Theia crashed into the Earth during the early years of the formation of the solar system. More »

www.reference.com Science Astronomy Our Moon

Scientists have two main theories that explain how the world was created. Most believe in the core accretion theory, though a few believe in the disk instability theory. The core accretion theory makes more sense when it... More »

Wind energy is created when moving air causes a wind turbine to rotate, powering a motor that generates electricity. The energy of the wind itself derives from differential heating of the air by the sun and the rotation ... More »

Mass movement refers to the relocation of surface material resulting from gravity. The most common types of mass movement are landslides and rockfalls; these types of movements are very sudden. Other forms of mass moveme... More »

If the Earth were to suddenly stop spinning, it would be the high winds, rather than gravity, that would immediately remove all traces of life from the Earth's surface. Thankfully, there is virtually no chance of the Ear... More »

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Ocean currents can be formed by wind, gravity, earthquakes and temperature and salinity variations that cause density differences in the water mass, according to the National Oceanic and Atmospheric Administration. Some ... More »