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'''Gravitation''' is a phenomenon which attracts all objects within the [[universe]] to each other <ref>New Oxford American Dictionary, 2nd Edition</ref>. In modern [[physics]], it is explained by the [[Theory of relativity|General Theory of relativity]]. Before general relativity, gravitation was described by [[Sir Isaac Newton|Isaac Newton's]] law of universal gravitation, which is still useful in most situations.

'''Gravitation''' is a [[phenomenon]] which attracts all objects within the [[universe]] to each other <ref>New Oxford American Dictionary, 2nd Edition</ref>. In modern [[physics]], it is explained by the [[Theory of relativity|General Theory of relativity]]. Before general relativity, gravitation was described by [[Sir Isaac Newton|Isaac Newton's]] law of universal gravitation, which is still useful in most situations.

Everything in the universe that has mass attracts every other thing that has mass. How much depends on the size of the masses and the distance between them. For normal objects, this pull is minute, but you can measure the pull between a very large object like the [[Earth]] and another object like you by standing on the scales. Your weight is the measure of the pull of gravity between you and the planet you are standing on. This force depends on your mass and the mass of that planet, but it also depends on your distance from the center of the planet. The further you are from the planet's center, the weaker the pull between it and your body. If you double your distance, the force is one quarter. At ten times the distance, the force is one hundredth. It drops off with the square of the distance. This is called the [[Inverse Square Law.]] <ref>http://hyperphysics.phy-astr.gsu.edu/hbase/forces/isq.html</ref>The force never becomes zero, no matter how far you travel.

Everything in the universe that has mass attracts every other thing that has mass. How much depends on the size of the masses and the distance between them. For normal objects, this pull is minute, but you can measure the pull between a very large object like the [[Earth]] and another object like you by standing on the scales. Your weight is the measure of the pull of gravity between you and the planet you are standing on. This force depends on your mass and the mass of that planet, but it also depends on your distance from the center of the planet. The further you are from the planet's center, the weaker the pull between it and your body. If you double your distance, the force is one quarter. At ten times the distance, the force is one hundredth. It drops off with the square of the distance. This is called the [[Inverse Square Law.]] <ref>http://hyperphysics.phy-astr.gsu.edu/hbase/forces/isq.html</ref>The force never becomes zero, no matter how far you travel.