difference between galaxy and vaccum
Answers
A vacuum is defined as a space devoid of all matter. In the Solar System, space contains on average five atoms per cc. Interstellar space, between stars, contains around one atom per cc, while intergalactic space, between galaxies, contains 100 times less.
What is the difference between a vacuum inside a galaxy and a vacuum outside a galaxy?
This question gives me a perfect excuse to go into my vacuum rant. Let's reword that question. What is the difference between a void inside a galaxy and a void outside a galaxy?
Now we all have a tendency to look upon a void as an absolute. If I take a glass tube and start sucking the air out and stop, it is not a vacuum. Most would agree the pressure inside the tube is less then it is outside. If I suck all the air out and then discharge a thing called a getter, all the air is gone and I have a true vacuum.
Kindly explain to me how I get a true vacuum in space? If in fact there was a vacuum in space there would be no difference between a vacuum in a galaxy and outside a galaxy.