A definition of “cold” or “coldness” is “a relative absence of heat” (Chambers, 1941). Basically the word cold indicates a lack of heat energy; it does not represent an entity but a relative absence of something real, namely energy.  Similarly “vacuum” represents a relative absence of pressure, a real force. Since “vacuum” is not an entity, a vacuum pump cannot “pump” it. A vacuum pump is a device that removes air and/or gases from a vessel thus reducing the pressure inside it.  A vacuum can therefore be considered a as an air pressure lower than atmospheric pressure.  The term “vacuum… Login to continue

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