Irrational Atheism

I have never seen evidence of irrational numbers, therefore, irrational numbers do not exist.

Prove me wrong.

So called "proofs of the existence of irrational numbers" will be swiftly labeled as what they are, proofs of complicated artifacts arising naturally from the existence of certain relations and processes within the standard rational number system.  They are COMPLETELY EXPECTED and DO NOT CONFLICT AT ALL WITH OBSERVATION.  GB2 Aljabr.

That's only true in a flat world, which we are assuming.  Can you actually prove that we live in 3d flat space (even if you do measurements, remember that there are limitations to how accurate the measurements are)?  If we use mathematics to construct a circle, and find its area/circumference, then we are dealing with an invented construct (which we assume to be a good model of reality).