Void in scientific terminology refers to a volume of space that does not have matter in it and is empty. Science further determines that in a vacuum the gaseous pressure is zero or less than atmospheric pressure. Quantum theory does not take into account the complete total vacuum but does specify the near perfect situation that can exist.
History records that the two great scientists, Plato and Aristotle, did not believe that emptiness was possible and did not imagine a reality in which there is nothing. The first successful vacuum test was performed by Evangelista Torricelli in 1643 and the experiment was henceforth referred to as the torricellian vacuum.
With rapid industrialization and scientific advancement, the vacuum concept has started to be adopted for common daily applications with great success.
Today we use a variety of devices and equipment that operate on the basis of the theory and principles of vacuum. The most commonly used devices are vacuum cleaners and vacuum pumps. All vacuum-based applications use the suction created by a vacuum to perform their functions.
Vacuum-based applications abound in the industrial sector. The automotive industry used this principle to make vacuum brakes on trains and other vehicles which were later replaced by air brakes. Even car windshield wipers operated on the basis of vacuum pumps long before better technology took over.
Vacuum sealing is widely used in the packaging process especially in food and other items. The vacuum seal neutralizes the chemical action. Lots of processes such as vacuum frying, cold welding, dry etching, etc. are found based on this principle.
Vacuum technology is also widely used to make gaskets and seals for various field applications. Medical and surgical field use is also being explored in different laboratories.
The most interesting aspect of vacuum can be found in the study of outer space which has very less atmospheric pressure and is settled into a near perfect vacuum state. Scientists conduct a lot of experiments to understand the vacuum in space that enables different stars and planets to travel freely on their own gravitational trajectories. Space travel, placing satellites in outer space, etc. involves a detailed understanding of atmospheric conditions in outer space.
Humans and living things if exposed to a vacuum would instantly lose consciousness and could die from hypoxia. Astronauts wear a space protective suit called the Crew Altitude Protection Suit to prevent embolism from low pressure. Conversely, astronauts cannot immediately take off their suits and expose themselves to the atmosphere when they come from the void of a vacuum and they need time for the body to adjust to normal atmospheric pressure and acclimate.