The null hypothesis is a term used in science to help weed out parts of theories that can be shaved by Ockam's Razor. When performing a scientific test, the null hypothesis refers to a specific variable that you can assume is not necessary to the success of the test. If it was removed, the test would work as well as it does when it is present. So when it comes to describing the test and its method, you needn't even mention the variable, because it has no effect whatsoever.
This is how atheists feel about the universe and God. They see atheism as the null hypothesis, with God as the useless variable, because they see that the universe runs just fine without him.
But isn't that quite clearly concluding atheism based on the presupposition of atheism? Yes. Yes it is.
