vakum

A vacuum is a region or space in which the density of matter is extremely low, approaching emptiness. In physics, a perfect vacuum would contain no particles, but real vacuums still have trace gases, dust, and background radiation. Vacuums are characterized by their pressure: rough vacuum (near atmospheric pressure down to about 1 Torr), high vacuum (below 1 Torr, typically down to 10^-9 to 10^-7 Torr), and ultrahigh vacuum (below about 10^-9 Torr). Pressures are commonly expressed in Torr or pascals; 1 Torr equals 133.322 Pa, and 1 atmosphere equals 760 Torr.

Vacuum can occur naturally in outer space, which is considered a very large-scale vacuum, though still not perfectly empty. On Earth, vacuums are engineered using pumps and sealed chambers. Common devices include piston or rotary vane pumps for rough vacuum, and diffusion pumps, turbomolecular pumps, ion pumps, and cryopumps for higher vacuums. Vacuum systems require tight seals and low outgassing materials. Vacuum levels are measured with gauges such as Pirani, cold cathode, and ionization gauges.

Applications of vacuum technology span science and industry. They enable surface science experiments, vacuum deposition and thin-film coatings, electron microscopy, and semiconductor fabrication. They are also used in vacuum packaging, food preservation, and insulation systems (for example, vacuum-insulated panels). In everyday life, vacuums power household vacuum cleaners and various packaging and preservation processes.

Historical notes: early demonstrations of vacuum concepts arose in the 17th century with Evangelista Torricelli and Otto von Guericke, followed by developments in pump technology and vacuum physics that underpinned modern instrumentation and industrial processes.