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An instrument for measuring the direction, intensity, and duration of quakes on earth or another body by measuring the actual movement of the ground
A discrease in a property, as energy, per unit area of a wave or a beam of particles, occuring as the distance from the source increases as a result of absorption, scattering, spreading in three dimensions
Corner Cube Reflector
Reflective devices placed on the surface of the moon allow laser beams to be redirected back to earth
1 a change or difference in condition, amount, or level, typically with certain limits 2 a different or distinct form or version of something
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