Why is space vacuumed?

Space is an almost a perfect vacuum, full of holes in the universe. Simply speaking, it is because of gravity. But to better understand the vacuum of our universe, it takes some time to understand what a vacuum is -- and what is not vacuum.

So, what is a vacuum? Why isn't space completely empty?

Jackie Faherty who is a senior scientist in the Astrophysics department at the American Museum of Natural History told Live Science that firstly you cannot compare a vacuum cleaner to the vacuum of space. A household vacuum cleaner will effectively remove dust and dirt from your carpet. But the vacuum of space is just the opposite. A vacuum is, by definition, completely devoid of matter. Space is almost completely empty, not because of suction, but because it is almost empty.

This void leads to extreme low pressure. Although we cannot imitate the emptiness of space on Earth, scientists can create extremely low pressure environments known as “partial vacuums”.

Even without vacuuming analogy, "understanding a vacuum is almost unknow because it contradicts the way we exist,” Faherty says. Our experience as human beings is completely confined to a very dense, crowded and dynamic corner of the universe. So it's hard to really understand nothingness or emptiness. But in fact, what seems normal to us on Earth is uncommon in the whole universe, because most of it over there is almost nothing.