Vaakumid

Vaakumid refer to regions or states in which the pressure is far below atmospheric pressure, or in which matter is largely absent. In physics, a vacuum is not absolute emptiness but a state in which particle density is extremely low. Practical vacuums are described by the absolute pressure, measured in units such as pascals (Pa) or torr; atmospheric pressure is about 101,325 Pa or 760 torr.

Vacuum technology relies on pumps, gauges, and chamber systems to create and maintain low-pressure environments. Common pump types include mechanical piston and rotary vane pumps for rough vacuum, and diffusion, turbomolecular, and ion pumps for higher levels of vacuum. Vacuum systems are often baked and degassed to remove volatile contaminants and improve stability. Pressure is monitored with gauges calibrated to the vacuum range being used.

Vacuum levels are typically categorized as rough or low vacuum, high vacuum, and ultrahigh vacuum, with the boundaries defined by achievable pressures and measurement standards. The choice of category depends on the application, as different processes require different environmental conditions.

Historically, attempts to study vacuums date to early barometers and experiments by Torricelli and Evangelista Torricelli in the 17th century, followed by Otto von Guericke’s air-pressure demonstrations. The development of specialized pumps and instrumentation in the 19th and 20th centuries enabled modern science and industry to exploit vacuums in manufacturing, research, and space simulation.

Beyond classical vacuums, the quantum vacuum in physics denotes the lowest-energy state of a field, which exhibits fluctuations and non-classical effects. Practical applications of vacuums include electron microscopy, semiconductor fabrication, thin-film coating, vacuum distillation, and vacuum packaging.