Well for starters there is no scientific fact. There are several levels of how sure a hypothesis is There is hypothesis- this is the lowest, it is just a thought with little or no experimentation The highest is THEORY- it is the highes, it is a hypothesis that has been tested thousands of times and has always turned out true. Keep in mind make believe tests, ie star trek ships going warp infinity or something are not actual tests they are make believe. There is no fact. Everything around us that we think of as a fact is a theory. Theory's can only be disproven when there is a well documented test where it has been proven false. THERE IS NO SCIENTIFIC FACT.