Definition of the word vacuum flask

The term "vacuum flask" initially derived from the two essential components that it encompasses—a vacuum and a flask. In the 19th century, researchers discovered that gases could be extracted from a container by subjecting it to ultrahigh vacuum conditions. This phenomenon, known as vacuum pumping, led to the invention of vacuum flasks. A vacuum flask is a closed container designed to retain the contents' temperature by minimizing heat transfer. It functions based on the fundamental physics concept of heat transfer; heat always moves from a higher temperature body to a lower temperature body unless transferred by an external source. By removing all the air and molecules from the space between the flask's walls, the vacuum flask nullifies the conduction and convection of heat, preventing it from entering or leaving the flask. Therefore, vacuum flasks are also called "thermos bottles" for retaining heat during thermal insulation. The vacuum space prevents heat transfer by both conduction and convection. Since conduction involves heat moving between two solid objects in contact, eliminating the medium means there's nothing for heat to move through. Convection is heat transfer resulting from the movement of fluids, and eliminating fluids removes the avenue for convection currents. In summary, vacuum flasks revolutionized food preservation, scientific experimentation, and energy conservation by retaining hot or cold temperatures efficiently. Called as such owing to their vacuum interiors and unique insulating functionality, vacuum flasks continue being a vital technology over a century and a half since their invention.