the burden of proof lies with the person making the claim

To assume a claim is true because it hasn been proven false ignores many other possibilities:that it hasn been proven false yet, that it can be proven true or false,or that it isn completely true or completely false, to name a few.This leads to a handy rule of thumb:the burden of proof lies with the person making the claim.In other words, you make the claim,you supply the proof.If someone told you aliens exist,would you head off to find proof that they don exist?Of course not.