Does nature really abhor a vacuum as the popular saying goes?

 

I mean is there really something called a "true vacuum?"

 

Now with the concept of dark matter and our knowledge of Cosmic Background radiation (which translates into mass if we read einsteins equation backward) there is nothing where matter (or energy) is truly absent?

 

How do we explain this?

 

How do we explain this?

 

It is explained by "vacuum" having multiple definitions. A volume completely devoid of energy and matter might be called a perfect or ideal vacuum, and this does not exist. But a volume that has a much lower concentration of matter than the surroundings is also called a vacuum, and that is the condition to which the phrase "nature abhors a vacuum" applies.

 

It is explained by "vacuum" having multiple definitions. A volume completely devoid of energy and matter might be called a perfect or ideal vacuum, and this does not exist. But a volume that has a much lower concentration of matter than the surroundings is also called a vacuum, and that is the condition to which the phrase "nature abhors a vacuum" applies.

Given that the greater volume of space is a vacuum by your second definition it would be more accurate to say, surely, that nature abhors a vacuum when it is within a setting where substantial quantities of gas are present.