Asked by: Talhah Loonat, Handforth
A vacuum is defined as a space devoid of all matter. In the Solar System, space contains on average five atoms per 1cm3. Interstellar space, between stars, contains around one atom per 1cm3, while intergalactic space, between galaxies, contains 100 times less. Ultimately, a perfect vacuum isn’t possible because quantum theory dictates that energy fluctuations known as ‘virtual particles’ are constantly popping in and out of existence, even in ‘empty’ space.
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