#### Re: WIMPs are just a hypothesis

"But theoretical physics is based on Mathematics, not observation."

(see "the unreasonable effectiveness of mathematics in physics".)

Mathematics is based on axioms and derivation rules. The content of mathematics is just what can be derived from the axioms using the derivation rules. The axioms are absolutely arbitrary (but some axiom sets are more interesting than others). A good mathematician doesn't believe in reality.

Physicists believe that there is an objective world and that events are explainable. The content of physics is a map between this objective world and a set of mathematics. One can take an experiment, map it into the corresponding mathematics, do some calculations, and map back the result to make predictions - this is the content of physics. There is no claim that this is the only mapping - just that a mapping seems to be relevant (and hopefully accurate).

The Ptolemaic model of the solar system was quite accurate and had the advantage of using "perfect" circles in its construction. The Copernican model used fewer circles so was deemed better. Newton derived everything from the inverse square law. Einstein got rid of action at a distance and derived everything by (roughly) setting the energy-momentum tensor equal to the Riemann curvature tensor.

Each new theory produced a more accurate correspondence between the mathematics and observable reality. None of the earlier theories were wrong - just not as "simple" or illuminating as succeeding theories.

But you cannot do physics without observation and the best observation is the one that is at variance with current theories because that is how we learn.