When a volume has no matter within it, it’s considered a true vacuum.
To create one, matter needs to be pumped out of a space, which in
turn lowers its atmospheric pressure. This is something vacuum cleaners are constantly trying to achieve. For a vacuum cleaner to function, a high-speed fan spins to push air out of the machine. This creates a difference in air pressure between the inside of the vacuum cleaner and the air surrounding it. The air pressure within a typical working vacuum cleaner is around 20 per cent lower than the air outside. Creating a low air pressure environment within the vacuum cleaner forces the air outside the machine to rush inside, balancing out the pressure and creating suction. If the nozzle of a vacuum cleaner were to be blocked and the fans continued to spin, it would pump out the majority of the gas molecules within until it created a vacuum. Since vacuum cleaners carry air from the nozzle through to an exhaust, a proper vacuum doesn’t form.
DID YOU KNOW?
Evangelista Torricelli, a student of Galileo, proved the existence of a vacuum in 1644