Space is an almost perfect vacuum, full of cosmic voids. And in short, gravity is to blame. But to really understand the vacuum of our universe, we have to take a moment to understand what a vacuum really is — and what it’s not.
So, what is a vacuum, and why isn’t space a true vacuum?
First, forget the vacuum cleaner as an analogy to the vacuum of space, Jackie Faherty, a senior scientist in the Department of Astrophysics at the American Museum of Natural History in New York City, told Live Science. The household cleaning machine effectively fills itself with dirt and dust sucked out of your carpet. (That is, the vacuum cleaner uses differential pressure to create suction. Suction cleaner might be a better name than vacuum cleaner). But the vacuum of space is the opposite. By definition, a vacuum is devoid of matter. Space is almost an absolute vacuum, not because of suction but because it’s nearly empty.
That emptiness results in an extremely low pressure. And while it’s impossible to emulate the emptiness of space on Earth, scientists can create extremely low pressure environments called partial vacuums.
Even with the vacuum cleaner analogy out, “understanding the concept of the […]
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