A vacuum (Latin: empty space, emptiness) is a region in space devoid of all types of matter, such as atoms and molecules. Such a region does not transmit sound waves or conduct heat, although heat can travel through it via radiation. Vacuums have important uses for science and technology.
While a perfect vacuum is theoretically possible, it has never been replicated in the lab. Pascal was the first person to prove the existence of a vacuum.
In the 17th century air pumps were developed and used by travelling scientists who commonly demonstrated formation of vacuum by withdrawing air from flask (glass bell jar) containing an animal such as bird which then deprived of oxygen started to suffocate as reflected in famous painting by J.Wright of Derby.[1] Later the air pumps were used to demonstrate that sound does not travel in an airless space. The first molecular pump to be used for creating a vacuum in experimental chambers based on Knudsen's investigation on flow of gases through long and narrow tubes was introduced by Gaede in 1912 at the meeting of German Physical Society.[2]
According to K.Jousten et al., there is no doubt that there are macroscopic areas between galaxies where there is no single molecule. For such volume contemporary physics introduced a term absolute vacuum. However, even such absolute vacuum is expected not to be void in terms of energy if it should be in accordance with natural laws. The energy of vacuum with still unknown nature is believed to be possibly related to cosmological constant introduced by Einstein and permitting particles to be generated spontaneously by fluctuating quantum fields for short time intervals, even in absolute vacuum. From this perspective, there is supposed to be no place in the world that is truly empty.[2] According to 2011 Nobel Laureate in Physics, Brian P. Schmidt, it is a big mystery why space should have energy at all, "people around the world are scratching their heads to figure out but as of today there has not been lot progress yet".[3] YEC creationist physicist J.Hartnett however declares that in the new theory introduced by M.Carmeli the physics of the cosmos including the energy of the vacuum is defined by correct choice of metric that is a solution to Einstein's field equations.[4]
The New American Desk Encyclopedia, Penguin Group, 1989
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