Proof.
First you need a hypothesis.
Second, you must prove your hypothesis by performing an experiment that proves your hypothesis.
Third, the experiment must be repeatable.
Fourth, Other people must be able to repeat the same experiment and come up with the same results.
Then you have a theory.
When I talk about peer review, it relates to the fourth requirement. Anyone can come up with a theory, but it must rigorously tested before it can in fact be proven.
In my opinion the only people to really look towards for peer reviewing is the actual scientific community.
If a theory can't be proved false, like gravity or thermodynamics, then it is a law.
Many universities are working on ways to disprove the existing laws. Thermodynamics hasn't.