Suction

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Suction is the day-to-day term for forces experienced by objects that are exposed to the movement of gases or liquids moving along a pressure gradient. Contrary to popular belief, however, the forces acting in this case do not originate from the lower pressure side (the vacuum), but from the side of the higher pressure.

When the pressure in one part of a physical system is reduced relative to another, the fluid or gas in the higher pressure region will exert a force relative to the region of lowered pressure, referred to as pressure-gradient force. If all gas or fluid is removed the result is a perfect vacuum in which the pressure is zero. Hence, no negative pressure forces can be generated. Accordingly, from a physics point of view, the objects are not sucked but pushed.