When people run around and around in circles we say they are crazy. When planets do it we say they are orbiting. Most books now say our sun is a star. But it still knows how to change back into a sun in the daytime. Many dead animals of the past changed to fossils, others preferred to be oil.
Vacuums are nothings.
We only mention them to let them know we know they're there. Some people can tell what time it is by looking at the sun. But I have never been able to make out the numbers. We say the cause of perfume disappearing is evaporation. Evaporation gets blamed for a lot of things people forget to put the top on.