BTW, the average density of the universe is roughly 5.9 protons per cubic meter.
Where was that measurement taken ?
The mass of the universe is not increasing. How would we know whether it was or not ? We don't even know how 'big' it is, or if it is infinite.
It's not expanding "into" anything.
To help clarify, you are using 'space' and 'universe' interchangeably, correct ?
The mass of the universe is not increasing.
How would we know whether it was or not ? We don't even know how 'big' it is, or if it is infinite.